LT6230/LT / LT6231/LT MHz, Rail-to-Rail Output, 1.1nV/ Hz, 3.5mA Op Amp Family DESCRIPTIO FEATURES APPLICATIO S TYPICAL APPLICATIO

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1 FEATURES Low Noise Voltage:.nV/ Hz Low Supply Current: 3.mA/Amp Max Low Offset Voltage: 3µV Max Gain Bandwidth Product: LT623: 2MHz; A V LT623-: 4MHz; A V Wide Supply Range: 3V to 2.6V Output Swings Rail-to-Rail Common Mode Rejection Ratio db Typ Output Current: 3mA Operating Temperature Range 4 C to 8 C LT623 Shutdown to µa Maximum LT623/LT623- in SOT-23 Package Dual LT623 in 8-Pin SO and Tiny DFN Packages LT6232 in 6-Pin SSOP Package APPLICATIO S U Ultrasound Amplifiers Low Noise, Low Power Signal Processing Active Filters Driving A/D Converters Rail-to-Rail Buffer Amplifiers, LTC and LT are registered trademarks of Linear Technology Corporation. LT623/LT623-/ 2MHz, Rail-to-Rail Output,.nV/ Hz, 3.mA Op Amp Family DESCRIPTIO U The LT 623/ are single/dual/quad low noise, rail-to-rail output unity gain stable op amps that feature.nv/ Hz noise voltage and draw only 3.mA of supply current per amplifier. These amplifiers combine very low noise and supply current with a 2MHz gain bandwidth product, a 7V/µs slew rate and are optimized for low supply voltage signal conditioning systems. The LT623- is a single amplifier optimized for higher gain applications resulting in higher gain bandwidth and slew rate. The LT623 and LT623- include an enable pin that can be used to reduce the supply current to less than µa. The amplifier family has an output that swings within mv of either supply rail to maximize the signal dynamic range in low supply applications and is specified on 3.3V, V and ±V supplies. The e n I SUPPLY product of.9 per amplifier is among the most noise efficient of any op amp. The LT623/LT623- is available in the 6-lead SOT-23 package and the LT623 dual is available in the 8-pin SO package with standard pinouts. For compact layouts, the dual is also available in a tiny dual fine pitch leadless package (DFN). The LT6232 is available in the 6-pin SSOP package. TYPICAL APPLICATIO IN IN V S /2 LT623 R Ω /2 LT623 V S R2 96Ω R3 96Ω R4 499Ω R 499Ω A V = 4 BW =.MHz V S = ±.V to ±V U Low Noise Low Power Instrumentation Amplifier V S LT622 V S R6 499Ω R7 499Ω V OUT I S = ma E N =.8µV RMS INPUT REFERRED, MEASUREMENT BW = 8MHz 6232 TAa NOISE VOLTAGE (nv/ Hz) Noise Voltage and Unbalanced Noise Current vs Frequency V S = ±2.V V CM = V NOISE CURRENT NOISE VOLTAGE k k k 6232 TAb UNBALANCED NOISE CURRENT (pa/ Hz) 6232fa

2 LT623/LT623-/ ABSOLUTE AXI U RATI GS W W W Total Supply Voltage (V to V ) V Input Current (Note 2)... ±4mA Output Short-Circuit Duration (Note 3)... Indefinite Operating Temperature Range (Note 4)...4 C to 8 C Specified Temperature Range (Note )...4 C to 8 C U (Note ) Junction Temperature... C Junction Temperature (DD Package)... 2 C Storage Temperature Range...6 C to C Storage Temperature Range (DD Package)... 6 C to 2 C Lead Temperature (Soldering, sec)... 3 C U PACKAGE/ORDER I FOR ATIO W U OUT V 2 IN 3 OUT A IN A 2 IN A 3 V 4 TOP VIEW 6 V S6 PACKAGE 6-LEAD PLASTIC TSOT-23 T JMAX = C, θ JA = 2 C/W TOP VIEW S8 PACKAGE 8-LEAD PLASTIC SO ENABLE 4 IN V OUT B IN B IN B ORDER PART NUMBER LT623CS6 LT623IS6 LT623CS6- LT623IS6- S6 PART MARKING* LTAFJ LTAFK ORDER PART NUMBER LT623CS8 LT623IS8 S8 PART MARKING T JMAX = C, θ JA = 2 C/W I OUT A IN A IN A V TOP VIEW DD PACKAGE 8-LEAD (3mm 3mm) PLASTIC DFN T JMAX = 2 C, θ JA = 6 C/W UNDERSIDE METAL CONNECTED TO V (PCB CONNECTION OPTIONAL) OUT A IN A 2 IN A 3 V 4 IN B IN B 6 OUT B 7 NC 8 A B TOP VIEW GN PACKAGE 6-LEAD NARROW PLASTIC SSOP T JMAX = C, θ JA = 3 C/W V OUT B IN B IN B D C OUT D IN D IN D V IN C IN C OUT C NC ORDER PART NUMBER LT623CDD LT623IDD DD PART MARKING* LAEU ORDER PART NUMBER LT6232CGN LT6232IGN GN PART MARKING I *The temperature grade is identified by a label on the shipping container.consult LTC Marketing for parts specified with wider operating temperature ranges fa

3 LT623/LT623-/ ELECTRICAL CHARACTERISTICS, V S = V, V; V S = 3.3V, V; V CM = V OUT = half supply, ENABLE = V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V OS Input Offset Voltage LT623S6, LT623S6- µv LT623S8, LT6232GN 3 µv LT623DD 7 4 µv Input Offset Voltage Match 6 µv (Channel-to-Channel) (Note 6) I B Input Bias Current µa I B Match (Channel-to-Channel) (Note 6)..9 µa I OS Input Offset Current..6 µa Input Noise Voltage.Hz to Hz 8 nv P-P e n Input Noise Voltage Density f = khz, V S = V..7 nv/ Hz i n Input Noise Current Density, Balanced Source f = khz, V S = V, R S = k pa/ Hz Unbalanced Source f = khz, V S = V, R S = k 2.4 pa/ Hz Input Resistance Common Mode 6. MΩ Differential Mode 7. kω C IN Input Capacitance Common Mode 2.9 pf Differential Mode 7.7 pf A VOL Large-Signal Gain V S = V, V O =.V to 4.V, R L = k to V S /2 2 V/mV R L = k to V S /2 2 4 V/mV V O = V to 4V, R L = Ω to V S /2.4 9 V/mV V S = 3.3V, V O =.6V to 2.6V, R L = k to V S /2 9 7 V/mV R L = k to V S / V/mV V CM Input Voltage Range Guaranteed by CMRR, V S = V, V. 4 V V S = 3.3V, V. 2.6 V CMRR Common Mode Rejection Ratio V S = V, V CM =.V to 4V 9 db V S = 3.3V, V CM =.V to 2.6V 9 db CMRR Match (Channel-to-Channel) (Note 6) V S = V, V CM =.V to 4V 84 2 db PSRR Power Supply Rejection Ratio V S = 3V to V 9 db PSRR Match (Channel-to-Channel) (Note 6) V S = 3V to V 84 db Minimum Supply Voltage (Note 7) 3 V V OL Output Voltage Swing LOW (Note 8) No Load 4 4 mv I SINK = ma 8 9 mv V S = V, I SINK = 2mA mv V S = 3.3V, I SINK = ma 8 3 mv V OH Output Voltage Swing HIGH (Note 8) No Load mv I SOURCE = ma 9 2 mv V S = V, I SOURCE = 2mA 32 6 mv V S = 3.3V, I SOURCE = ma 2 4 mv I SC Short-Circuit Current V S = V ±3 ±4 ma V S = 3.3V ±2 ±4 ma I S Supply Current per Amplifier ma Disabled Supply Current per Amplifier ENABLE = V.3V.2 µa 6232fa 3

4 LT623/LT623-/ ELECTRICAL CHARACTERISTICS ENABLE = V, unless otherwise noted., V S = V, V; V S = 3.3V, V; V CM = V OUT = half supply, SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS I ENABLE ENABLE Pin Current ENABLE =.3V 2 7 µa V L ENABLE Pin Input Voltage LOW.3 V V H ENABLE Pin Input Voltage HIGH V.3V V Output Leakage Current ENABLE = V.3V, V O =.V to 3.V.2 µa t ON Turn-On Time ENABLE = V to V, R L = k, V S = V 3 ns t OFF Turn-Off Time ENABLE = V to V, R L = k, V S = V 4 µs GBW Gain Bandwidth Product Frequency = MHz, V S = V 2 MHz LT623-3 MHz SR Slew Rate V S = V, A V =, R L = k, V O =.V to 4.V 42 6 V/µs LT623-, V S = V, A V =, R L = k, 2 V/µs V O =.V to 4.V FPBW Full Power Bandwidth V S = V, V OUT = 3V P-P (Note 9) MHz LT623-, HD 2 = HD 3 = % MHz t S Settling Time (LT623, LT623, LT6232).%, V S = V, V STEP = 2V, A V =, R L = k ns The denotes the specifications which apply over C < T A < 7 C temperature range. V S = V, V; V S = 3.3V, V; V CM = V OUT = half supply, ENABLE = V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V OS Input Offset Voltage LT623S6, LT623S6-6 µv LT623S8, LT6232GN 4 µv LT623DD µv Input Offset Voltage Match 8 µv (Channel-to-Channel) (Note 6) V OS TC Input Offset Voltage Drift (Note ) V CM = Half Supply. 3 µv/ C I B Input Bias Current µa I B Match (Channel-to-Channel) (Note 6) µa I OS Input Offset Current.7 µa A VOL Large-Signal Gain V S = V, V O =.V to 4.V, R L = k to V S /2 78 V/mV R L = k to V S /2 7 V/mV V O = V to 4V, R L = Ω to V S /2 4. V/mV V S = 3.3V, V O =.6V to 2.6V, R L = k to V S /2 66 V/mV R L = k to V S /2 3 V/mV V CM Input Voltage Range Guaranteed by CMRR, V S = V, V. 4 V V S = 3.3V, V. 2.6 V CMRR Common Mode Rejection Ratio V S = V, V CM =.V to 4V 9 db V S = 3.3V, V CM =.V to 2.6V 8 db CMRR Match (Channel-to-Channel) (Note 6) V S = V, V CM =.V to 4V 84 db PSRR Power Supply Rejection Ratio V S = 3V to V 8 db PSRR Match (Channel-to-Channel) (Note 6) V S = 3V to V 79 db Minimum Supply Voltage (Note 7) 3 V V OL Output Voltage Swing LOW (Note 8) No Load mv I SINK = ma 2 mv V S = V, I SINK = 2mA mv V S = 3.3V, I SINK = ma 38 mv fa

5 ELECTRICAL CHARACTERISTICS LT623/LT623-/ The denotes the specifications which apply over C < T A < 7 C temperature range. V S = V, V; V S = 3.3V, V; V CM = V OUT = half supply, ENABLE = V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V OH Output Voltage Swing HIGH (Note 8) No Load 6 mv I SOURCE = ma 2 mv V S = V, I SOURCE = 2mA 6 mv V S = 3.3V, I SOURCE = ma 43 mv I SC Short-Circuit Current V S = V ±2 ma V S = 3.3V ±2 ma I S Supply Current per Amplifier 4.2 ma Disabled Supply Current per Amplifier ENABLE = V.2V µa I ENABLE ENABLE Pin Current ENABLE =.3V 8 µa V L ENABLE Pin Input Voltage LOW.3 V V H ENABLE Pin Input Voltage HIGH V.2V V Output Leakage Current ENABLE = V.2V, V O =.V to 3.V µa t ON Turn-On Time ENABLE = V to V, R L = k, V S = V 3 ns t OFF Turn-Off Time ENABLE = V to V, R L = k, V S = V 6 µs SR Slew Rate V S = V, A V =, R L = k, V O =.V to 4.V 3 V/µs LT623-, A V =, R L = k, 22 V/µs V O =.V to 4.V FPBW Full Power Bandwidth (Note 9) V S = V, V OUT = 3V P-P 3.7 MHz LT623, LT623, LT6232 The denotes the specifications which apply over 4 C < T A < 8 C temperature range. V S = V, V; V S = 3.3V, V; V CM = V OUT = half supply, ENABLE = V, unless otherwise noted. (Note ) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V OS Input Offset Voltage LT623S6, LT623S6-7 µv LT623S8, LT6232GN µv LT623DD 6 µv Input Offset Voltage Match µv (Channel-to-Channel) (Note 6) V OS TC Input Offset Voltage Drift (Note ) V CM = Half Supply. 3 µv/ C I B Input Bias Current 2 µa I B Match (Channel-to-Channel) (Note 6). µa I OS Input Offset Current.8 µa A VOL Large-Signal Gain V S = V, V O =.V to 4.V, R L = k to V S /2 72 V/mV R L = k to V S /2 6 V/mV V O = V to 4V, R L = Ω to V S /2 3.6 V/mV V S = 3.3V, V O =.6V to 2.6V,R L = k to V S /2 6 V/mV R L = k to V S /2 2 V/mV V CM Input Voltage Range Guaranteed by CMRR, V S = V, V. 4 V V S = 3.3V, V. 2.6 V CMRR Common Mode Rejection Ratio V S = V, V CM =.V to 4V 9 db V S = 3.3V, V CM =.V to 2.6V 8 db CMRR Match (Channel-to-Channel) (Note 6) V S = V, V CM =.V to 4V 84 db PSRR Power Supply Rejection Ratio V S = 3V to V 8 db 6232fa

6 LT623/LT623-/ ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over 4 C < TA < 8 C temperature range. V S = V, V; V S = 3.3V, V; V CM = V OUT = half supply, ENABLE = V, unless otherwise noted. (Note ) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS PSRR Match (Channel-to-Channel) (Note 6) V S = 3V to V 79 db Minimum Supply Voltage (Note 7) 3 V V OL Output Voltage Swing LOW (Note 8) No Load 6 mv I SINK = ma 2 mv V S = V, I SINK = ma mv V S = 3.3V, I SINK = ma 39 mv V OH Output Voltage Swing HIGH (Note 6) No Load 7 mv I SOURCE = ma 22 mv V S = V, I SOURCE = 2mA 67 mv V S = 3.3V, I SOURCE = ma 44 mv I SC Short-Circuit Current V S = V ± ma V S = 3.3V ± ma I S Supply Current per Amplifier 4.4 ma Disabled Supply Current per Amplifier ENABLE = V.2V µa I ENABLE ENABLE Pin Current ENABLE =.3V µa V L ENABLE Pin Input Voltage LOW.3 V V H ENABLE Pin Input Voltage HIGH V.2V V Output Leakage Current ENABLE = V.2V, V O =.V to 3.V µa t ON Turn-On Time ENABLE = V to V, R L = k, V S = V 3 ns t OFF Turn-Off Time ENABLE = V to V, R L = k, V S = V 72 µs SR Slew Rate V S = V, A V =, R L = k, V O =.V to 4.V 3 V/µs LT623-, A V =, R L = k, 8 V/µs V O =.V to 4.V FPBW Full Power Bandwidth (Note 9) V S = V, V OUT = 3V P-P 3.3 MHz LT623, LT623, LT6232,, V CM = V OUT = V, ENABLE = V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V OS Input Offset Voltage LT623, LT623- µv LT623S8, LT6232GN 3 µv LT623DD 7 4 µv Input Offset Voltage Match 6 µv (Channel-to-Channel) (Note 6) I B Input Bias Current µa I B Match (Channel-to-Channel) (Note 6)..9 µa I OS Input Offset Current..6 µa Input Noise Voltage.Hz to Hz 8 nv P-P e n Input Noise Voltage Density f = khz..7 nv/ Hz i n Input Noise Current Density, Balanced Source f = khz, R S = k pa/ Hz Unbalanced Source f = khz, R S = k 2.4 pa/ Hz fa

7 LT623/LT623-/ ELECTRICAL CHARACTERISTICS,, V CM = V OUT = V, ENABLE = V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Input Resistance Common Mode 6. MΩ Differential Mode 7. kω C IN Input Capacitance Common Mode 2.4 pf Differential Mode 6. pf A VOL Large-Signal Gain V O = ±4.V, R L = k 4 26 V/mV R L = k 3 6 V/mV V O = ±2V, R L = Ω 8. 6 V/mV V CM Input Voltage Range Guaranteed by CMRR 3 4 V CMRR Common Mode Rejection Ratio V CM = 3V to 4V 9 2 db CMRR Match (Channel-to-Channel) (Note 6) V CM = 3V to 4V 89 2 db PSRR Power Supply Rejection Ratio V S = ±.V to ±V 9 db PSRR Match (Channel-to-Channel) (Note 6) V S = ±.V to ±V 84 db V OL Output Voltage Swing LOW (Note 8) No Load 4 4 mv I SINK = ma 8 9 mv I SINK = 2mA mv V OH Output Voltage Swing HIGH (Note 8) No Load mv I SOURCE = ma 9 2 mv I SOURCE = 2mA 32 6 mv I SC Short-Circuit Current ±3 ma I S Supply Current per Amplifier ma Disabled Supply Current per Amplifier ENABLE = 4.6V.2 µa I ENABLE ENABLE Pin Current ENABLE =.3V 3 8 µa V L ENABLE Pin Input Voltage LOW.3 V V H ENABLE Pin Input Voltage HIGH 4.6 V Output Leakage Current ENABLE = V 4.6V, V O = ±V.2 µa t ON Turn-On Time ENABLE = V to V, R L = k 3 ns t OFF Turn-Off Time ENABLE = V to V, R L = k 62 µs GBW Gain Bandwidth Product Frequency = MHz 2 MHz LT623-4 MHz SR Slew Rate A V =, R L = k, V O = 2V to 2V 7 V/µs LT623-, A V =, R L = k, V O = 2V to 2V 32 V/µs FPBW Full Power Bandwidth V OUT = 3V P-P (Note 9) MHz LT623-, HD2 = HD3 % MHz t S Settling Time (LT623, LT623, LT6232).%, V STEP = 2V, A V =, R L = k ns 6232fa 7

8 LT623/LT623-/ ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over C < T A < 7 C temperature range., V CM = V OUT = V, ENABLE = V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V OS Input Offset Voltage LT623S6, LT623S6-6 µv LT623S8, LT6232GN 4 µv LT623DD µv Input Offset Voltage Match 8 µv (Channel-to-Channel) (Note 6) V OS TC Input Offset Voltage Drift (Note ). 3 µv/ C I B Input Bias Current µa I B Match (Channel-to-Channel) (Note 6) µa I OS Input Offset Current.7 µa A VOL Large-Signal Gain V O = ±4.V, R L = k V/mV R L = k 27 V/mV V O = ±2V, R L = Ω 6 V/mV V CM Input Voltage Range Guaranteed by CMRR 3 4 V CMRR Common Mode Rejection Ratio V CM = 3V to 4V 9 db CMRR Match (Channel-to-Channel) (Note 6) V CM = 3V to 4V 89 db PSRR Power Supply Rejection Ratio V S = ±.V to ±V 8 db PSRR Match (Channel-to-Channel) (Note 6) V S = ±.V to ±V 79 db V OL Output Voltage Swing LOW (Note 8) No Load mv I SINK = ma 2 mv I SINK = 2mA mv V OH Output Voltage Swing HIGH (Note 8) No Load 6 mv I SOURCE = ma 2 mv I SOURCE = 2mA 6 mv I SC Short-Circuit Current ±2 ma I S Supply Current per Amplifier 4.6 ma Disabled Supply Current per Amplifier ENABLE = 4.7V µa I ENABLE ENABLE Pin Current ENABLE =.3V 9 µa V L ENABLE Pin Input Voltage LOW.3 V V H ENABLE Pin Input Voltage HIGH 4.7 V Output Leakage Current ENABLE = 4.7V, V O = ±V µa t ON Turn-On Time ENABLE = V to V, R L = k 3 ns t OFF Turn-Off Time ENABLE = V to V, R L = k 8 µs SR Slew Rate A V =, R L = k, V O = 2V to 2V 44 V/µs LT623-, A V =, R L = k, V O = 2V to 2V 3 V/µs FPBW Full Power Bandwidth V OUT = 3V P-P (Note 9) 4.66 MHz LT623, LT623, LT fa

9 LT623/LT623-/ ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over 4 C < T A < 8 C temperature range., V CM = V OUT = V, ENABLE = V, unless otherwise noted. (Note ) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V OS Input Offset Voltage LT623, LT623-7 µv LT623S8, LT6232GN µv LT623DD 6 µv Input Offset Voltage Match µv (Channel-to-Channel) (Note 6) V OS TC Input Offset Voltage Drift (Note ). 3 µv/ C I B Input Bias Current 2 µa I B Match (Channel-to-Channel) (Note 6). µa I OS Input Offset Current.8 µa A VOL Large-Signal Gain V O = ±4.V, R L = k 93 V/mV R L = k 2 V/mV V O = ±.V, R L = Ω 4.8 V/mV V CM Input Voltage Range Guaranteed by CMRR 3 4 V CMRR Common Mode Rejection Ratio V CM = 3V to 4V 9 db CMRR Match (Channel-to-Channel) (Note 6) V CM = 3V to 4V 89 db PSRR Power Supply Rejection Ratio V S = ±.V to ±V 8 db PSRR Match (Channel-to-Channel) (Note 6) V S = ±.V to ±V 79 db V OL Output Voltage Swing LOW (Note 8) No Load 6 mv I SINK = ma 2 mv I SINK = ma mv V OH Output Voltage Swing HIGH (Note 8) No Load 7 mv I SOURCE = ma 22 mv I SOURCE = 2mA 67 mv I SC Short-Circuit Current ± ma I S Supply Current per Amplifier 4.8 ma Disabled Supply Current per Amplifier ENABLE = 4.8V µa I ENABLE ENABLE Pin Current ENABLE =.3V µa V L ENABLE Pin Input Voltage LOW.3 V V H ENABLE Pin Input Voltage HIGH 4.8 V Output Leakage Current ENABLE = 4.8V, V O = ±V µa t ON Turn-On Time ENABLE = V to V, R L = k 3 ns t OFF Turn-Off Time ENABLE = V to V, R L = k 72 µs SR Slew Rate A V =, R L = k, V O = 2V to 2V 37 V/µs LT623-, A V =, R L = k, V O = 2V to 2V 26 V/µs FPBW Full Power Bandwidth (Note 9) V OUT = 3V P-P 3.9 MHz LT623, LT623, LT fa 9

10 LT623/LT623-/ ELECTRICAL CHARACTERISTICS Note : Absolute maximum ratings are those values beyond which the life of the device may be impaired. Note 2: Inputs are protected by back-to-back diodes. If the differential input voltage exceeds.7v, the input current must be limited to less than 4mA. Note 3: A heat sink may be required to keep the junction temperature below the absolute maximum rating when the output is shorted indefinitely. Note 4: The LT623C/LT623I the LT623C/LT623I, and LT6232C/ LT6232I are guaranteed functional over the temperature range of 4 C and 8 C. Note : The LT623C/LT623C/LT6232C are guaranteed to meet specified performance from C to 7 C. The LT623C/LT623C/LT6232C are designed, characterized and expected to meet specified performance from 4 C to 8 C, but are not tested or QA sampled at these temperatures. The LT623I/LT623I/LT6232I are guaranteed to meet specified performance from 4 C to 8 C. Note 6: Matching parameters are the difference between the two amplifiers A and D and between B and C of the LT6232; between the two amplifiers of the LT623. CMRR and PSRR match are defined as follows: CMRR and PSRR are measured in µv/v on the matched amplifiers. The difference is calculated between the matching sides in µv/v. The result is converted to db. Note 7: Minimum supply voltage is guaranteed by power supply rejection ratio test. Note 8: Output voltage swings are measured between the output and power supply rails. Note 9: Full-power bandwidth is calculated from the slew rate: FPBW = SR/2πV P Note : This parameter is not % tested. TYPICAL PERFOR A CE CHARACTERISTICS (LT623/) NUMBER OF UNITS V OS Distribution 2 V S = V, V V CM = V /2 S8 U W 2 INPUT OFFSET VOLTAGE (µv) SUPPLY CURRENT (ma) Supply Current vs Supply Voltage (Per Amplifier) T A = 2 C T A = C TOTAL SUPPLY VOLTAGE (V) OFFSET VOLTAGE (mv) Offset Voltage vs Input Common Mode Voltage V S = V, V T A = C T A = 2 C INPUT COMMON MODE VOLTAGE (V) 6232 GO 6232 GO GO3 4 Input Bias Current vs Common Mode Voltage V S = V, V Input Bias Current vs Temperature V S = V, V Output Saturation Voltage vs Load Current (Output Low) V S = V, V INPUT BIAS CURRENT (µa) T A = C T A = 2 C INPUT BIAS CURRENT (µa) V CM = 4V V CM =.V OUTPUT SATURATION VOLTAGE (V).. T A = 2 C T A = C COMMON MODE VOLTAGE (V) TEMPERATURE ( C)... LOAD CURRENT (ma) 6232 GO GO 6232 GO6 6232fa

11 LT623/LT623-/ TYPICAL PERFOR A CE CHARACTERISTICS (LT623/) OUTPUT SATURATION VOLTAGE (V).. Output Saturation Voltage vs Load Current (Output High) V S = V, V T A = 2 C U W T A = C... LOAD CURRENT (ma) 6232 G7 OFFSET VOLTAGE (mv). Minimum Supply Voltage. V CM = V S / T A = 2 C T A = C TOTAL SUPPLY VOLTAGE (V) 6232 G8 OUTPUT SHORT-CIRCUIT CURRENT (ma) Output Short Circuit Current vs Power Supply Voltage SINKING SOURCING T A = 2 C POWER SUPPLY VOLTAGE (±V) T A = 2 C T A = C T A = C GO9 INPUT VOLTAGE (mv) Open Loop Gain Open Loop Gain Open Loop Gain R L = k R L = Ω.. 2 OUTPUT VOLTAGE (V) V S = 3V, V 2. 3 INPUT VOLTAGE (mv) R L = k R L = Ω OUTPUT VOLTAGE (V) V S = V, V INPUT VOLTAGE (mv) R L = k R L = Ω OUTPUT VOLTAGE (V) 6232 G 6232 G 6232 G2 Offset Voltage vs Output Current Warm-Up Drift vs Time Total Noise vs Total Source Resistance OFFSET VOLTAGE (mv) T A = C T A = 2 C CHANGE IN OFFSET VOLTAGE (µv) V S = ±2.V V S = ±.V TOTAL NOISE (nv/ Hz) VS = ±2.V V CM = V f = khz UNBALANCED SOURCE RESISTORS TOTAL NOISE RESISTOR NOISE AMPLIFIER NOISE VOLTAGE OUTPUT CURRENT (ma) TIME AFTER POWER-UP (s). k k k SOURCE RESISTANCE (Ω) 6232 G G G 6232fa

12 LT623/LT623-/ TYPICAL PERFOR A CE CHARACTERISTICS (LT623/) NOISE VOLTAGE (nv/ Hz) Noise Voltage and Unbalanced Noise Current vs Frequency U W V S = ±2.V V CM = V NOISE CURRENT NOISE VOLTAGE UNBALANCED NOISE CURRENT (pa/ Hz) nv/div nv nv.hz to Hz Output Voltage Noise V S = ±2.V GAIN BANDWIDTH (MHz) Gain Bandwidth and Phase Margin vs Temperature C L = pf R L = k V CM = V S /2 V S = 3V, V V S = 3V, V PHASE MARGIN GAIN BANDWIDTH PHASE MARGIN (DEG) k k k s/div TEMPERATURE ( C) 6232 G G G8 GAIN (db) Open Loop Gain vs Frequency GAIN PHASE V S = 3V, V V S = 3V, V C L = pf R L = k V CM = V S /2 2 2 k M M M 8 G 6232 G PHASE (db) GAIN BANDWIDTH (MHz) Gain Bandwidth and Phase Margin vs Supply Voltage C L = pf R L = k PHASE MARGIN GAIN BANDWIDTH TOTAL SUPPLY VOLTAGE (V) G PHASE MARGIN (DEG) SLEW RATE (V/µs) Slew Rate vs Temperature A V = R F = R G = k RISING V S = ±2.V RISING FALLING V S = ±2.V FALLING TEMPERATURE ( C) 6232 G2 OUTPUT IMPEDANCE (Ω) 2 Output Impedance vs Frequency k V S = V, V A V = A V = 2 A V =.. k M M M 6232 G22 COMMON MODE REJECTION RATIO (db) Common Mode Rejection Ratio vs Frequency 2 V S = V, V V CM = V S /2 k k M M M 6232 G23 G CHANNEL SEPARATION (db) k Channel Separation vs Frequency A V = M M M 6232 G fa

13 LT623/LT623-/ TYPICAL PERFOR A CE CHARACTERISTICS (LT623/) POWER SUPPLY REJECTION RATIO (db) U W Power Supply Rejection Ratio vs Frequency NEGATIVE SUPPLY V S = V, V V CM = V S /2 POSITIVE SUPPLY k k k M M M 6232 G2 OVERSHOOT (%) Series Output Resistance and Overshoot vs Capacitive Load V S = V, V A V = R S = Ω R L = Ω R S = Ω R S = 2Ω CAPACITIVE LOAD (pf) 6232 G26 OVERSHOOT (%) Series Output Resistance and Overshoot vs Capacitive Load V S = V, V A V = 2 R S = Ω R L = Ω R S = Ω R S = 2Ω CAPACITIVE LOAD (pf) 6232 G27 SETTLING TIME (ns) 2 Settling Time vs Output Step (Non-Inverting) 4 A V = mv V IN mv mv Ω V OUT mv OUTPUT STEP (V) 6232 G28 SETTLING TIME (ns) 2 Settling Time vs Output Step (Inverting) 4 V IN mv Ω mv Ω mv 3 2 OUTPUT STEP (V) A V = V OUT mv G29 OUTPUT VOLTAGE SWING (V PP ) Maximum Undistorted Output Signal vs Frequency 2 k A V = HD 2, HD 3 < 4dBc A V = 2 k M M 6232 G3 DISTORTION (dbc) Distortion vs Frequency Distortion vs Frequency Distortion vs Frequency V S = ±2.V A V = V OUT = 2V (PP) R L = Ω, 2ND R L = k, 2ND R L = Ω, 3RD DISTORTION (dbc) A V = V OUT = 2V (PP) R L = Ω, 2ND R L = k, 2ND R L = Ω, 3RD DISTORTION (dbc) V S = ±2.V A V = 2 V OUT = 2V (PP) R L = Ω, 2ND R L = Ω, 3RD 9 k R L = k, 3RD k M M 9 k R L = k, 3RD k M M 9 k R L = k, 2ND R L = k, 3RD k M M 6232 G G G fa 3

14 LT623/LT623-/ TYPICAL PERFOR A CE CHARACTERISTICS (LT623/) U W 4 Distortion vs Frequency A V = 2 V OUT = 2V (PP) R L = Ω, 3RD 2V Large Signal Response Small Signal Response DISTORTION (dbc) R L = k, 3RD R L = Ω, 2ND V/DIV V 2V mv/div V 9 k R L = k, 2ND k M M V S = ±2.V A V = R L = k 2ns/DIV G3 V S = ±2.V A V = R L = k 2ns/DIV G G34 Large Signal Response Output Overdrive Recovery V V IN (V/DIV) V 2V/DIV V V V OUT (2V/DIV) V A V = R L = k 2ns/DIV G37 V S = ±2.V A V = 3 2ns/DIV G38 (LT623) ENABLE Characteristics SUPPLY CURRENT (ma) Supply Current vs ENABLE Pin Voltage V S = ±2.V T A = C T A = 2 C PIN VOLTAGE (V) ENABLE PIN CURRENT (µa) ENABLE Pin Current vs ENABLE Pin Voltage T A = C T A = 2 C PIN VOLTAGE (V) V S = ±2.V A V = V OUT ENABLE PIN V V.V V ENABLE Pin Response Time V S = ±2.V V IN =.V A V = R L = k µs/div G G G fa

15 LT623/LT623-/ TYPICAL PERFOR A CE CHARACTERISTICS (LT623-) GAIN BANDWIDTH (MHz) U W Gain Bandwidth and Phase Margin vs Temperature A V = V S = 3V, V V S = 3V, V GAIN BANDWIDTH PHASE MARGIN TEMPERATURE ( C) 6232 G PHASE MARGIN (DEG) SLEW RATE (V/µs) Slew Rate vs Temperature A V = R F = k R G = Ω V S = ±2.V FALLING FALLING RISING V S = ±2.V RISING TEMPERATURE ( C) 6232 G43 OVERSHOOT (%) Series Output Resistor and Overshoot vs Capacitive Load V S = V, V A V = R S = 2Ω R S = Ω R S = Ω CAPACITIVE LOAD (pf) 6232 G44 GAIN (db) Open Loop Gain and Phase vs Frequency GAIN PHASE V S = 3V, V 2 8 V S = 3V, V A V = C L = pf 4 R L = k 6 V CM = V S /2 8 k M M M G 6232 G4 PHASE (DEG) GAIN BANDWIDTH (MHz) Gain Bandwidth and Phase Margin vs Supply Voltage A V = C L = pf R L = k GAIN BANDWIDTH PHASE MARGIN TOTAL SUPPLY VOLTAGE (V) G46 PHASE MARGIN (DEG) GAIN BANDWIDTH (MHz) Gain Bandwidth vs Resistor Load AV V S = ±V R F = k R G = TOTAL RESISTOR LOAD (Ω) (INCLUDES FEEDBACK R) 6232 G47 COMMON MODE REJECTION RATIO (db) Common Mode Rejection Ratio vs Frequency k k M M V S = V, V V CM = V S /2 M 6232 G48 G OUTPUT VOLTAGE SWING (V PP ) Maximum Undistorted Output Signal vs Frequency k A V = HD 2 = HD 3 4dBc k M M M 6232 G49 DISTORTION (dbc) k 2 nd and 3 rd Harmonic Distortion vs Frequency V S = ±2.V A V = V OUT = 2V (PP) R L = Ω, 3RD R L = Ω, 2ND R L = k, 3RD R L = k, 2ND k M M 6232 G 6232fa

16 LT623/LT623-/ TYPICAL PERFOR A CE CHARACTERISTICS U W (LT623-) 2 nd and 3 rd Harmonic Distortion vs Frequency Large Signal Response Output-Overload Recovery DISTORTION (dbc) A V = V OUT = 2V (PP) R L = Ω, 3RD R L = Ω, 2ND R L = k, 3RD V OUT (2V/DIV) V V OUT (2V/DIV) V IN (.V/DIV) V V 9 k R L = k, 2ND k M M ns/div A V = R F = 9Ω, R G = Ω G2 V S = V, V ns/div A V = R F = 9Ω, R G = Ω G G Small Signal Response Input Referred High Frequency Noise Spectrum V OUT (mv/div) 2.V nv/ Hz/DIV V S = V, V ns/div A V = R F = 9Ω, R G = Ω G4 khz MHz/DIV MHz G fa

17 LT623/LT623-/ APPLICATIO S I FOR Amplifier Characteristics ATIO U W U U Figure is a simplified schematic of the LT623/LT623/ LT6232, which has a pair of low noise input transistors Q and Q2. A simple current mirror Q3/Q4 converts the differential signal to a single-ended output, and these transistors are degenerated to reduce their contribution to the overall noise. Capacitor C reduces the unity cross frequency and improves the frequency stability without degrading the gain bandwidth of the amplifier. Capacitor C M sets the overall amplifier gain bandwidth. The differential drive generator supplies current to transistors Q and Q6 that swing the output from rail-to-rail. Q V C M Q3 Q4 DESD V V V OUT C DIFFERENTIAL DESD6 DESD DESD2 V DRIVE GENERATOR V V IN Q Q2 V D D2 Q6 V IN DESD3 V V DESD4 I Figure. Simplified Schematic 6232 F ENABLE Input Protection There are back-to-back diodes, D and D2 across the and inputs of these amplifiers to limit the differential input voltage to ±.7V. The inputs of the LT623/LT623/ LT6232 do not have internal resistors in series with the input transistors. This technique is often used to protect the input devices from over voltage that causes excessive current to flow. The addition of these resistors would significantly degrade the low noise voltage of these amplifiers. For instance, a Ω resistor in series with each input would generate.8nv/ Hz of noise, and the total amplifier noise voltage would rise from.nv/ Hz to 2.nV/ Hz. Once the input differential voltage exceeds ±.7V, steady state current conducted through the protection diodes should be limited to ±4mA. This implies 2Ω of protection resistance is necessary per volt of overdrive beyond ±.7V. These input diodes are rugged enough to BIAS V V V/DIV 2.V V 2.V µs/div 6232 F2 Figure 2. V S = ±2.V, A V = with Large Overdrive handle transient currents due to amplifier slew rate overdrive and clipping without protection resistors. The photo of Figure 2 shows the output response to an input overdrive with the amplifier connected as a voltage follower. With the input signal low, current source I saturates and the differential drive generator drives Q6 into saturation so the output voltage swings all the way to V. The input can swing positive until transistor Q2 saturates into current mirror Q3/Q4. When saturation occurs, the output tries to phase invert, but diode D2 conducts current from the signal source to the output through the feedback connection. The output is clamped a diode drop below the input. In this photo, the input signal generator is limiting at about 2mA. With the amplifier connected in a gain of A V 2, the output can invert with very heavy overdrive. To avoid this inversion, limit the input overdrive to.v beyond the power supply rails. ESD The LT623/ have reverse-biased ESD protection diodes on all inputs and outputs as shown in Figure. If these pins are forced beyond either supply, unlimited current will flow through these diodes. If the current is transient and limited to one hundred milliamps or less, no damage to the device will occur. Noise The noise voltage of the LT623/ is equivalent to that of a 7Ω resistor, and for the lowest possible noise it is desirable to keep the source and feedback resistance at or below this value, i.e. R S R G R FB 7Ω. 6232fa 7

18 LT623/LT623-/ APPLICATIO S I FOR ATIO U W U U With R S R G R FB = 7Ω the total noise of the amplifier is: e N = (.nv) 2 (.nv) 2 =.nv/ Hz Below this resistance value, the amplifier dominates the noise, but in the region between 7Ω and about 3k, the noise is dominated by the resistor thermal noise. As the total resistance is further increased beyond 3k, the amplifier noise current multiplied by the total resistance eventually dominates the noise. The product of e N I SUPPLY is an interesting way to gauge low noise amplifiers. Most low noise amplifiers with low e N have high I SUPPLY current. In applications that require low noise voltage with the lowest possible supply current, this product can prove to be enlightening. The LT623/ have an e N I SUPPLY product of only.9 per amplifier, yet it is common to see amplifiers with similar noise specifications to have e N I SUPPLY as high as 3.. For a complete discussion of amplifier noise, see the LT28 data sheet. Enable Pin The LT623 includes an ENABLE pin that shuts down the amplifier to µa maximum supply current. The ENABLE pin must be driven high to within.3v of V to shut down the supply current. This can be accomplished with simple gate logic; however care must be taken if the logic and the LT623 operate from different supplies. If this is the case, then open drain logic can be used with a pull-up resistor to ensure that the amplifier remains off. See Typical Characteristic Curves. The output leakage current when disabled is very low; however, current can flow into the input protection diodes D and D2 if the output voltage exceeds the input voltage by a diode drop fa

19 LT623/LT623-/ APPLICATIO S I FOR ATIO U W U U Single Supply, Low Noise, Low Power, Bandpass Filter with Gain = Frequency Response Plot of Bandpass Filter R 732Ω C2 47pF 23 V IN C pf R2 732Ω C3.µF R3 k R4 k V LT623 EN.µF 6232 F3 V OUT f = = MHz 2πRC C = C C 2, R = R = R2 f = ( 732Ω ) MHz, MAXIMUM f = MHz R f 3dB = f 2. A V = 2dB at f E N = 4µV RMS INPUT REFERRED I S = 3.7mA FOR V = V GAIN (db) 3 7 k M M 6232 F4 Low Noise, Low Power, Single Supply, Instrumentation Amplifier with Gain = V IN C2 22pF C µf R6 Ω R 3.9Ω R3 3.9Ω V U LT623- V R2 Ω EN R4 Ω R6 88.7Ω R 88.7Ω R3 2k R2 Ω C8 68pF R Ω C9 68pF V U3 LT623 EN V OUT V IN2 C3 µf R Ω U2 LT623- EN R4 2k C4 µf V OUT = (V IN2 V IN ) GAIN = ( R2 ) ( R ) R R INPUT RESISTANCE = R = R6 f 3dB = 3Hz TO MHz E N = 2µV RMS INPUT REFERRED I S =.ma FOR V S = V, V R = R3 R2 = R4 R = R2 R = R F 6232fa 9

20 LT623/LT623-/ PACKAGE DESCRIPTIO U S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # ).62 MAX.9 REF 2.9 BSC (NOTE 4).22 REF 3.8 MAX 2.62 REF.4 MIN 2.8 BSC..7 (NOTE 4) PIN ONE ID RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR.9 BSC PLCS (NOTE 3) BSC DATUM A. MAX...3. REF BSC (NOTE 3) S6 TSOT NOTE:. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR. MOLD FLASH SHALL NOT EXCEED.24mm 6. JEDEC PACKAGE REFERENCE IS MO fa

21 LT623/LT623-/ PACKAGE DESCRIPTIO U DD Package 8-Lead Plastic DFN (3mm 3mm) (Reference LTC DWG # ).67 ±. 3. ±. 2. ±..6 ±. (2 SIDES) PACKAGE OUTLINE.2 ±.. BSC 2.38 ±. (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS R =. TYP 8.38 ±. PIN TOP MARK (NOTE 6).2 REF 3. ±. (4 SIDES).7 ±....6 ±. (2 SIDES) 4.2 ± ±. (2 SIDES) BOTTOM VIEW EXPOSED PAD NOTE:. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M-229 VARIATION OF (WEED-) 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED.mm ON ANY SIDE. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN LOCATION ON TOP AND BOTTOM OF PACKAGE. BSC (DD8) DFN fa 2

22 LT623/LT623-/ PACKAGE DESCRIPTIO U S8 Package 8-Lead Plastic Small Outline (Narrow. Inch) (Reference LTC DWG # -8-6). BSC.4 ± (4.8.4) NOTE MIN.6 ± ( )..7 ( ) NOTE 3.3 ±. TYP RECOMMENDED SOLDER PAD LAYOUT (.23.24)..2 (.24.8) 4 8 TYP.3.69 ( ).4. (..24).6. (.46.27) NOTE: INCHES. DIMENSIONS IN (MILLIMETERS).4.9 (.3.483) TYP 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED.6" (.mm). (.27) BSC SO fa

23 LT623/LT623-/ PACKAGE DESCRIPTIO U GN Package 6-Lead Plastic SSOP (Narrow. Inch) (Reference LTC DWG # -8-64).4 ± * ( ) (.229) REF.24 MIN ( )..7** ( ).6 ±. RECOMMENDED SOLDER PAD LAYOUT.2 BSC ( ). ±.4 (.38 ±.) 4 8 TYP (.3.7).4.98 (.2.249).6. (.46.27) NOTE:. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) 3. DRAWING NOT TO SCALE *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED.6" (.2mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED." (.24mm) PER SIDE.8.2 (.23.3) TYP.2 (.63) BSC GN6 (SSOP) 24 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 6232fa 23

24 LT623/LT623-/ TYPICAL APPLICATIO S The LT623 is applied as a transimpedance amplifier with an I-to-V conversion gain of.kω set by R. The LT623 is ideally suited to this application because of its low input offset voltage and current, and its low noise. This is because the.k resistor has an inherent thermal noise of nv/ Hz or 3.4pA/ Hz at room temperature, while the LT623 contributes only.nv and 2.4pA / Hz. So, with respect to both voltage and current noises, the LT623 is actually quieter than the gain resistor. The circuit uses an avalanche photodiode with the cathode biased to approximately 2V. When light is incident on U the photodiode, it induces a current I PD which flows into the amplifier circuit. The amplifier output falls negative to maintain balance at its inputs. The transfer function is therefore V OUT = I PD.k. C ensures stability and good settling characteristics. Output offset was measured at 28µV, so low in part because R2 serves to cancel the DC effects of bias current. Output noise was measured at.mv PP on a MHz measurement bandwidth, with C2 shunting R2 s thermal noise. As shown in the scope photo, the rise time is 7ns, indicating a signal bandwidth of 2MHz. Low Power Avalanche Photodiode Transimpedance Amplifier I S = 3.3mA Photodiode Amplifier Time Domain Response ADVANCED PHOTONIX V BIAS C 4.7pF R.k 3mV/DIV R2.k C2.µF LT623 V V ENABLE 6232 TA2a ns/div 6232 TA2b OUTPUT OFFSET = µv TYPICAL BANDWIDTH = 2MHz OUTPUT NOISE =.mv PP (MHz MEASUREMENT BW) RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT28 Single, Ultra Low Noise MHz Op Amp.8nV/ Hz LT677 Single, Low Noise Rail-to-Rail Amplifier 3V Operation, 2.mA, 4.nV/ Hz, 6µV Max V OS LT86/LT87 Single/Dual, Low Noise 32MHz Rail-to-Rail Amplifier 2.V Operation, µv Max V OS, 3.nV/ Hz LT62/LT62 Single/Dual, Low Noise 6MHz.9nV Hz, Rail-to-Rail Input and Output LT622/LT623/LT624 Single/Dual/Quad, Low Noise, Rail-to-Rail Amplifier.9nV/ Hz, 3mA Max, MHz Gain Bandwidth fa LT/TP 34 K REV A PRINTED IN USA Linear Technology Corporation 63 McCarthy Blvd., Milpitas, CA (48) FAX: (48) LINEAR TECHNOLOGY CORPORATION 23