MAX V, 50MHz, Low-Offset, Low-Power, Rail-to-Rail I/O Op Amp

Transcription

1 EVALUATION KIT AVAILABLE MAX V, 5MHz, Low-Offset, General Description The MAX4428 offers a unique combination of high speed, precision, low noise, and low-voltage operation making it ideally suited for a large number of signal processing functions such as filtering and amplification of signals in portable and industrial equipment. The amplifier features an input offset of less than 5FV and a high-gain bandwidth product of 5MHz while maintaining a low 1.8V supply rail. The device is internally compensated for gains of 5V/V or greater. The device s rail-to-rail input/outputs and low noise guarantee maximum dynamic range in demanding applications such as 12- to 16-bit SAR ADC drivers. Unlike traditional rail-to-rail input structures, input crossover distortion is absent due to an optimized input stage with an ultra-quiet charge pump. The MAX4428 includes a fast-power-on shutdown mode for further power savings. The MAX4428 operates from a supply range of 1.8V to 5.5V over the -4NC to +125NC temperature range and can operate down to 1.7V over the NC to +7NC temperature range. The MAX4428 is available in a small, 6-pin SC7 package and is also available in a 1mm x 1.5mm thin µdfn (ultra-thin LGA) package. Ordering Information appears at end of data sheet. Features S Low 1.8V Supply Rail Over the -4 C to +125 C Range S 1.7V Supply Rail Over the C to +7 C Range S 5MHz Bandwidth S Low 12.7nV/ Hz Input Voltage-Noise Density S Low 1.2fA/ Hz Input Current-Noise Density S Low 5µV (max) VOS at +25 C S 5fA Low Input Bias Current S 75µA Quiescent Current per Amplifier S < 1µA Supply Current in Shutdown S Small, 2mm x 2mm SC7 and 1mm x 1.5mm Thin µdfn Packages S Low -11dB Total Harmonic Distortion S 5V/V Minimum Stable Gain Notebooks 3G/4G Handsets Portable Media Players Portable Medical Instruments Battery-Operated Devices Analog-to-Digital Converter Buffers Transimpedance Amplifiers General-Purpose Signal Processing Applications Typical Application Circuit +3.3V V SIG 2.4kI MAX4428 1kI 3.3nF ADC MAX kI For related parts and recommended products to use with this part, refer to: For pricing, delivery, and ordering information, please contact Maxim Direct at , or visit s website at ; Rev 2; 8/12

2 MAX V, 5MHz, Low-Offset, ABSOLUTE MAXIMUM RATINGS IN+, IN-, OUT...(V SS -.3V) to (V DD +.3V) V DD to V SS...-.3V to +6V SHDN...-.3V to +6V Output to Short-Circuit Ground Duration... 1s Continuous Input Current into Any Pin... Q2mA Continuous Power Dissipation (T A = +7NC) SC7 (derate 3.1mW/NC above +7NC)...245mW Thin µdfn (Ultra-Thin LGA) (derate 2.1mW/NC above +7NC) mW Operating Temperature Range... -4NC to +125NC Junction Temperature...+15NC Lead Temperature (soldering, 1s)...+3NC Soldering Temperature (reflow)...+26nc Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. PACKAGE THERMAL CHARACTERISTICS (Note 1) SC7 Junction-to-Ambient Thermal Resistance (B JA ) NC/W Junction-to-Case Thermal Resistance (B JC )...115NC/W Thin µdfn (Ultra-Thin LGA) Junction-to-Ambient Thermal Resistance (B JA )... 47NC/W Junction-to-Case Thermal Resistance (B JC )... 12NC/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to ELECTRICAL CHARACTERISTICS (V DD = 3.3V, V SS = V, V IN+ = V IN- = V DD /2, RL = 1kI to V DD /2, V SHDN = V DD, T A = -4NC to +125NC. Typical values are at T A = +25NC, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC CHARACTERISTICS Input Voltage Range V IN+ V IN- Guaranteed by CMRR test -.1 V DD +.1 V Input Offset Voltage V OS T A = -4 C to +125 C after calibration 1 FV T A = +25NC 1 5 T A = -4 C to +125 C 5 Input Offset Voltage Drift V OS - TC.8 5 FV/NC Input Bias Current (Note 3) I B T A = -4NC to +85NC 1 pa T A = +25NC.1.5 T A = -4NC to +125NC 1 Input Capacitance C IN.4 pf Common-Mode Rejection Ratio CMRR V CM = -.1V to (V DD +.1V) 75 9 db Open-Loop Gain A OL.4V P V OUT P V DD -.4V, R OUT = 6I 91 1 db.4v P V OUT P V DD -.4V, R OUT = 1kI V P V OUT P V DD -.4V, R OUT = 32I 8 Output Short-Circuit Current I SC To V DD or V SS 85 ma 2

3 MAX V, 5MHz, Low-Offset, ELECTRICAL CHARACTERISTICS (continued) (V DD = 3.3V, V SS = V, V IN+ = V IN- = V DD /2, RL = 1kI to V DD /2, V SHDN = V DD, T A = -4NC to +125NC. Typical values are at T A = +25NC, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Output Voltage Swing V OL - V SS V DD - V OH R OUT = 1kI 2 R OUT = 6I 5 R OUT = 32I 4 7 R OUT = 1kI 1 R OUT = 6I 4 R OUT = 32I 4 8 AC CHARACTERISTICS Input Voltage-Noise Density e n f = 1kHz 12.7 nv/ Hz Input Current-Noise Density i n f = 1kHz 1.2 fa/ Hz Gain-Bandwidth Product GBWP 5 MHz Minimum Stable Gain A MIN 5 V/V Slew Rate SR 3 V/Fs Settling Time V OUT = 2V P-P, V DD = 3.3V, A V = 5V/V, C L = 3pF (load), settle to.1%.6 µs No sustained oscillation, 5V/V 8 Capacitive Load C LOAD No sustained oscillation, 1V/V 5 pf Total Harmonic Distortion THD f = 1kHz, V O = 2V P-P, A V = 5V/V, R OUT = 1kI -11 db Output Transient Recovery Time DV OUT =.2V, V DD = 3.3V, A V = 5V/V; R S = 2Ω, C L = 1nF (load) 1 µs POWER-SUPPLY CHARACTERISTICS Guaranteed by PSRR Power-Supply Range V DD T A = NC to +7NC V Power-Supply Rejection Ratio PSRR V CM = V DD / db Quiescent Current I DD µa Shutdown Supply Current I SHDN 1 µa Shutdown Input Low V IL.7 V Shutdown Input High V IH 1.3 V Output Leakage Current in Shutdown I SHDN 1 pa Shutdown Input Bias Current I IL /I IH 1 µa Shutdown Turn-On Time t SHDN 15 µs Turn-On Time t ON 1 ms Note 2: All devices are 1% production tested at T A = +25NC. Temperature limits are guaranteed by design. Note 3: Guaranteed by design. mv 3

4 MAX V, 5MHz, Low-Offset, Typical Operating Characteristics (V DD = 3.3V, V SS = V, V IN+ = V IN- = V DD /2, R L = 1kI to V DD /2, V SHDN = V DD, T A = -4NC to +125NC. Typical values are at T A = +25NC, unless otherwise noted. All devices are 1% production tested at T A = +25NC. Temperature limits are guaranteed by design.) INPUT OFFSET VOLTAGE (µv) INPUT OFFSET VOLTAGE vs. COMMON-MODE VOLTAGE T A = -4 C COMMON-MODE VOLTAGE (V) MAX4428 toc1 INPUT OFFSET VOLTAGE (µv) INPUT OFFSET VOLTAGE vs. SUPPLY VOLTAGE T A = -4 C SUPPLY VOLTAGE (V) MAX4428 toc2 PERCENT OCCURRENCE (%) INPUT V OS HISTOGRAM INPUT OFFSET VOLTAGE (µv) MAX4428 toc3 PERCENT OCCURRENCE (%) INPUT OFFSET DRIFT HISTOGRAM MAX4428 toc4 INPUT BIAS CURRENT (pa) INPUT BIAS CURRENT vs. COMMON-MODE VOLTAGE T A = -4 C T A = +85 C MAX4428 toc5 OUTPUT VOLTAGE LOW (mv) OUTPUT VOLTAGE LOW vs. OUTPUT SINK CURRENT (V OL - V EE, V CC = 1.8V) T A = -4 C MAX4428 toc INPUT OFFSET DRIFT (µv/ C) COMMON-MODE VOLTAGE (V) OUTPUT SINK CURRENT (ma) 4

5 MAX V, 5MHz, Low-Offset, Typical Operating Characteristics (continued) (V DD = 3.3V, V SS = V, V IN+ = V IN- = V DD /2, R L = 1kI to V DD /2, V SHDN = V DD, T A = -4NC to +125NC. Typical values are at T A = +25NC, unless otherwise noted. All devices are 1% production tested at T A = +25NC. Temperature limits are guaranteed by design.) OUTPUT VOLTAGE LOW (mv) OUTPUT VOLTAGE LOW vs. OUTPUT SINK CURRENT (V OL - V EE, V CC = 3.3V) T A = -4 C OUTPUT SINK CURRENT (ma) MAX4428 toc7 OUTPUT VOLTAGE LOW (mv) OUTPUT VOLTAGE LOW vs. OUTPUT SINK CURRENT (V OL - V EE, V CC = 5V) T A = -4 C OUTPUT SINK CURRENT (ma) MAX4428 toc8 OUTPUT VOLTAGE HIGH (mv) OUTPUT VOLTAGE HIGH vs. OUTPUT SOURCE CURRENT (V CC - V OH, V CC = 1.8V) T A = -4 C OUTPUT SOURCE CURRENT (ma) MAX4428 toc9 OUTPUT VOLTAGE HIGH (mv) OUTPUT VOLTAGE HIGH vs. OUTPUT SOURCE CURRENT (V CC - V OH, V CC = 3.3V) T A = -4 C MAX4428 toc1 OUTPUT VOLTAGE HIGH (mv) OUTPUT VOLTAGE HIGH vs. OUTPUT SOURCE CURRENT (V CC - V OH, V CC = 5V) T A = -4 C MAX4428 toc11 SUPPLY CURRENT (µa) SUPPLY CURRENT vs. SUPPLY VOLTAGE T A = -4 C MAX4428 toc OUTPUT SOURCE CURRENT (ma) OUTPUT SOURCE CURRENT (ma) SUPPLY VOLTAGE (V) 5

6 MAX V, 5MHz, Low-Offset, Typical Operating Characteristics (continued) (V DD = 3.3V, V SS = V, V IN+ = V IN- = V DD /2, R L = 1kI to V DD /2, V SHDN = V DD, T A = -4NC to +125NC. Typical values are at T A = +25NC, unless otherwise noted. All devices are 1% production tested at T A = +25NC. Temperature limits are guaranteed by design.) SHUTDOWN SUPPLY CURRENT (µa) SHUTDOWN SUPPLY CURRENT vs. SUPPLY VOLTAGE (V SHDN = V EE ) T A = -4 C MAX4428 toc13 OPEN-LOOP GAIN (db) OPEN-LOOP GAIN vs. FREQUENCY MAX4428 toc14 CMRR (db) COMMON-MODE REJECTION RATIO vs. FREQUENCY MAX4428 toc SUPPLY VOLTAGE (V) k 1k 1k FREQUENCY (khz) k 1k 1k FREQUENCY (khz) PSRR (db) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY k 1k 1k FREQUENCY (khz) MAX4428 toc16 REJECTION RATIO (db) DC CMRR DC CMRR AND PSRR vs. TEMPERATURE DC PSRR TEMPERATURE ( C) MAX4428 toc17 INPUT-VOLTAGE NOISE DENSITY (nv/ Hz) INPUT VOLTAGE-NOISE DENSITY vs. FREQUENCY k 1k FREQUENCY (khz) MAX4428 toc18 6

7 MAX V, 5MHz, Low-Offset, Typical Operating Characteristics (continued) (V DD = 3.3V, V SS = V, V IN+ = V IN- = V DD /2, R L = 1kI to V DD /2, V SHDN = V DD, T A = -4NC to +125NC. Typical values are at T A = +25NC, unless otherwise noted. All devices are 1% production tested at T A = +25NC. Temperature limits are guaranteed by design.).5µv/div.1hz TO 1Hz OUTPUT-VOLTAGE NOISE MAX4428 toc19 INPUT-CURRENT NOISE DENSITY (fa/ Hz) INPUT CURRENT-NOISE DENSITY vs. FREQUENCY MAX4428 toc2 TOTAL HARMONIC DISTORTION vs. INPUT AMPLITUDE (f = 1kHz, V CC = 5.5V, AV = 5V/V) -8 THD (db) MAX4428 toc21 4s/div k 1k FREQUENCY (Hz) OUTPUT AMPLITUDE (V) TOTAL HARMONIC DISTORTION (db) TOTAL HARMONIC DISTORTION vs. FREQUENCY (V OUT = 2V P-P ) V CC = 3.3V V CC = 5.5V MAX4428 toc22 INPUT 2mV/div V CC /2 OUTPUT 5mV/div V CC /2 SMALL-SIGNAL TRANSIENT RESPONSE (A V = 5V/V, R F = 4kI, R G = 1kI) MAX4428 toc23 INPUT 1mV/div OUTPUT 5mV/div LARGE-SIGNAL TRANSIENT RESPONSE (A V = 5V/V, R F = 4kI, R G = 1kI) MAX4428 toc k 1k 1k 1G FREQUENCY (Hz) 1ns/div 1ns/div 7

8 MAX V, 5MHz, Low-Offset, Typical Operating Characteristics (continued) (V DD = 3.3V, V SS = V, V IN+ = V IN- = V DD /2, R L = 1kI to V DD /2, V SHDN = V DD, T A = -4NC to +125NC. Typical values are at T A = +25NC, unless otherwise noted. All devices are 1% production tested at T A = +25NC. Temperature limits are guaranteed by design.) OVERSHOOT (%) PERCENT OVERSHOOT vs. RESISTIVE LOAD (V IN = 1mV P-P ) MAX4428 toc25 ISOLATION RESISTANCE (Ω) STABILITY vs. CAPACITIVE LOAD AND ISOLATION RESISTANCE (R LOAD IN SERIES C LOAD ) STABLE UNSTABLE STABLE UNSTABLE GAIN = 5V/V GAIN = 1V/V MAX4428 toc26 1, 1, RESISTIVE LOAD (Ω) STABILITY vs. CAPACITIVE AND RESISTIVE LOAD (R LOAD CLOAD) STABLE UNSTABLE GAIN = 5V/V GAIN = 1V/V STABLE UNSTABLE MAX4428 toc27 1 1k 1k 1k RESISTANCE (I) CAPACITIVE LOAD (pf) , CAPACITIVE LOAD (pf) POWER-UP TIME MAX4428 toc28 TURN-ON TIME FROM SHUTDOWN MAX4428 toc29 V CC 2V/div GND SHDN 2V/div V SS OUTPUT 5mV/div OUTPUT 5mV/div GND V SS 4ms/div 1µs/div 8

9 MAX V, 5MHz, Low-Offset, Pin Configurations TOP VIEW V DD SHDN OUT IN+ 1 + MAX V DD V SS 2 5 SHDN MAX4428 IN- 3 SC7 4 OUT IN+ V SS IN- THIN µdfn (Ultra-Thin LGA) Pin Description PIN NAME FUNCTION 1 IN+ Positive Input 2 V SS Negative Power Supply. Bypass with a.1ff capacitor to ground. 3 IN- Negative Input 4 OUT Output 5 SHDN Active-Low Shutdown 6 V DD Positive Power Supply. Bypass with a.1ff capacitor to ground. 9

10 MAX V, 5MHz, Low-Offset, Detailed Description The MAX4428 is a high-speed low-power op amp ideal for signal processing applications due to the device s high precision and low-noise CMOS inputs. The device self-calibrates on power-up to eliminate effects of temperature and power-supply variation. The MAX4428 also features a low-power shutdown mode that greatly reduces quiescent current while the device is not operational and recovers in 3µs. Crossover Distortion This op amp features a low-noise integrated charge pump that creates an internal voltage rail 1V above V DD, which is used to power the input differential pair of pmos transistors as shown in Figure 1. Such a unique architecture eliminates crossover distortion common in traditional CMOS input architecture (Figure 2), especially when used in a noninverting configuration, such as for Sallen-Key filters. The charge pump s operating frequency lies well above the unity-gain frequency of the amplifier. Thanks to its highfrequency operation and ultra-quiet circuitry, the charge pump generates little noise, does not require external components, and is entirely transparent to the user. INTERNAL CHARGE PUMP STANDARD INPUT STRUCTURE MAX4428 INPUTS STRUCTURE Figure 1. Comparing the Input Structure of the MAX4428 to Standard Op-Amp Inputs CROSSOVER DISTORTION AMPLIFIER OUTPUT MAX4428 TIME Figure 2. Crossover Distortion of Typical Amplifiers 1

11 MAX V, 5MHz, Low-Offset, Applications Information Power-Up Autotrim The IC features an automatic trim that self-calibrates the V OS of this device to less than 5FV of input offset voltage on power-up. This self-calibration feature allows the device to eliminate input offset voltage effects due to power supply and operating temperature variation simply by cycling its power. The autotrim sequence takes approximately 1ms to complete and is triggered by an internal power-on-reset (POR) circuitry. During this time, the inputs and outputs are put into high impedance and left unconnected. Shutdown Operation The MAX4428 features an active-low shutdown mode that puts both inputs and outputs into high impedance and substantially lowers the quiescent current to less than 1FA. Putting the output into high impedance allows multiple outputs to be multiplexed onto a single output line without the additional external buffers. The device does not self-calibrate when exiting shutdown mode and retains its power-up trim settings. The device also recovers from shutdown in under 3Fs. The shutdown logic levels of the device is independent of supply, allowing the shutdown feature of the device to operate off of a 1.8V or 3.3V microcontroller, regardless of supply voltage. Rail-to-Rail Input/Output The input voltage range of the IC extends 1mV above V DD and below V SS. The wide input common-mode voltage range allows the op amp to be used as a buffer and as a differential amplifier in a wide-variety of signal processing applications. Output voltage high/low is designed to be only 5mV above V SS and below V DD allowing maximum dynamic range in single-supply applications. The high output current and capacitance drive capability of the device make it ideal as an ADC driver and a line driver. Input Bias Current The IC features a high-impedance CMOS input stage and a specialized ESD structure that allows low-input bias current operation at low-input, common-mode voltages. Low-input bias current is useful when interfacing with high-ohmic sensors. It is also beneficial for designing transimpedance amplifiers for photodiode sensors. This makes the device ideal for ground-referenced medical and industrial sensor applications. Active Filters The MAX4428 is ideal for a wide variety of active filter circuits that makes use of the wide bandwidth, rail-to-rail input/output stages and high-impedance CMOS inputs. Driver for Interfacing with the MAX11645 ADC The IC s tiny size and low noise make it a good fit for driving 12- to 16-bit resolution ADCs in space-constrained applications. The Typical Application Circuit shows the MAX4428 amplifier output connected to a lowpass filter driving the MAX11645 ADC. The MAX11645 is part of a family of 3V and 5V, 12-bit and 1-bit, 2-channel ADCs. The MAX11645 offers sample rates up to 94ksps and measures two single-ended inputs or one differential input. These ADCs dissipate 67FA at the maximum sampling rate, but just 6FA at 1ksps and.5fa in shutdown. Offered in the ultra-tiny, 1.9mm x 2.2mm WLP and FMAX- 8 packages, the MAX11645 ADCs are an ideal fit to pair with the MAX4428 amplifier in portable applications. Where higher resolution is required, refer to the MAX169 (14-bit) and MAX1169 (16-bit) ADC families. 11

12 MAX V, 5MHz, Low-Offset, Chip Information Ordering Information PROCESS: BiCMOS PART TEMP RANGE PIN-PACKAGE +Denotes a lead(pb)-free/rohs-compliant package. TOP MARK MAX4428AXT+ -4NC to +125NC 6 SC7 +AED MAX4428AYT+ -4NC to +125NC 6 Thin FDFN (Ultra-Thin LGA) +AZ 12

13 MAX V, 5MHz, Low-Offset, Package Information For the latest package outline information and land patterns (footprints), go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 6 SC7 X6SN Thin FDFN (Ultra-Thin LGA) Y61A

14 MAX V, 5MHz, Low-Offset, Package Information (continued) For the latest package outline information and land patterns (footprints), go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 14

15 MAX V, 5MHz, Low-Offset, Package Information (continued) For the latest package outline information and land patterns (footprints), go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 15

16 MAX V, 5MHz, Low-Offset, Revision History REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 12/11 Initial release 1 4/12 Updated Package Thermal Characteristics, Electrical Characteristics, and Ordering Information. 2, 3, /12 Added Note 3 to Electrical Characteristics. 2, 3 cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a product. No circuit patent licenses are implied. reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. 16 Rio Robles, San Jose, CA USA Products, Inc. and the logo are trademarks of Products, Inc.