GT755 50kHz, 7μA, CMOS, RailtoRail Operational Amplifier Advanced. Features SingleSupply Operation from. ~ 5.5 Low Offset oltage: 5.5m (Max.) RailtoRail Input / Output Quiescent Current: 7μA per Amplifier (Typ.) GainBandwidth Product: 50kHz (Typ.) Operating Temperature: 40 C ~ 5 C Low Input Bias Current: 0pA (Typ.) Available in SOT35 and SOP8 Packages. General Description The GT755 is a single supply, low power CMOS operational amplifier; these amplifiers offer bandwidth of 50kHz, railtorail inputs and outputs, and singlesupply operation from. to 5.5. Typical low quiescent supply current of 7μA in single operational amplifiers within one chip and very low input bias current of 0pA make the devices an ideal choice for low offset, low power consumption and high impedance applications. The GT755 is available in SOT35 and SOP8 packages.. The extended temperature range of 40 o C to 5 o C over all supply voltages offers additional design flexibility. 3. Applications Portable Equipment Medical Instrumentation Mobile Communications BatteryPowered Instruments Smoke Detector Handheld Test Equipment Sensor Interface 4. Pin Configuration 4. GT755 SOT35 and SOP8 (Top iew) OUT 5 DD NC 8 NC SS MARKING IN IN 3 MARKING 7 6 DD OUT IN 3 4 IN SS 4 5 NC Figure. Pin Assignment Diagram (SOP35 and SOP8 Package) Note: Please see section Part Markings for detailed Marking Information. Copyright 00 Giantec Semiconductor Inc. (Giantec). All rights reserved. Giantec reserves the right to make changes to this specification and its products at any time without notice. Giantec products are not designed, intended, authorized or warranted for use as components in systems or equipment intended for critical medical or surgical equipment, aerospace or military, or other applications planned to support or sustain life. It is the customer's obligation to optimize the design in their own products for the best performance and optimization on the functionality and etc. Giantec assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and prior placing orders for products. A0 /6
GT755 5. Application Information 5. Size GT755 series op amps are unitygain stable and suitable for a wide range of generalpurpose applications. The small footprints of the GT755 series packages save space on printed circuit boards and enable the design of smaller electronic products. 5. Power Supply Bypassing and Board Layout GT755 series operates from a single. to 5.5 supply or dual ±. to ±.75 supplies. For best performance, a 0.μF ceramic capacitor should be placed close to the DD pin in single supply operation. For dual supply operation, both DD and SS supplies should be bypassed to ground with separate 0.μF ceramic capacitors. 5.3 Low Supply Current The low supply current (typical 7μA) of GT755 series will help to maximize battery life. They are ideal for battery powered systems 5.4 Operating oltage GT755 series operate under wide input supply voltage (. to 5.5). In addition, all temperature specifications apply from 40 o C to 5 o C. Most behavior remains unchanged throughout the full operating voltage range. These guarantees ensure operation throughout the single LiIon battery lifetime 5.5 RailtoRail Input The input commonmode range of GT755 series extends 00m beyond the supply rails ( SS0. to DD0.). This is achieved by using complementary input stage. For normal operation, inputs should be limited to this range. 5.6 RailtoRail Output RailtoRail output swing provides maximum possible dynamic range at the output. This is particularly important when operating in low supply voltages. The output voltage of GT755 series can typically swing to less than 0m from supply rail in light resistive loads (>00kΩ), and 60m of supply rail in moderate resistive loads (0kΩ). 5.7 Capacitive Load Tolerance The GT755 series can directly drive 50pF capacitive load in unitygain without oscillation. Increasing the gain enhances the amplifier s ability to drive greater capacitive loads. In unitygain configurations, the capacitive load drive can be improved by inserting an isolation resistor R ISO in series with the capacitive load, as shown in Figure. R ISO OUT IN C L Figure. Indirectly Driving a Capacitive Load Using Isolation Resistor The bigger the R ISO resistor value, the more stable OUT will be. However, if there is a resistive load R L in parallel with the capacitive load, a voltage divider (proportional to R ISO/R L) is formed, this will result in a gain error. The circuit in Figure 3 is an improvement to the one in Figure. R F provides the DC accuracy by feedforward the IN to R L. C F and R ISO serve to counteract the loss of phase margin by feeding the high frequency component of the output signal back to the amplifier s inverting input, thereby preserving the phase margin in the overall feedback loop. Capacitive drive can be increased A0 /6
GT755 by increasing the value of C F. This in turn will slow down the pulse response. C F R F R ISO OUT IN C L R L Figure 3. Indirectly Driving a Capacitive Load with DC Accuracy 5.8 Differential amplifier The differential amplifier allows the subtraction of two input voltages or cancellation of a signal common the two inputs. It is useful as a computational amplifier in making a differential to singleend conversion or in rejecting a common mode signal. Figure 4. shown the differential amplifier using GT755. R R IN R 3 OUT IP OUT ( RR R3R 4 ) R R 4 IN R R ( IP RR R3R R 4 REF Figure 4. Differential Amplifier 4 ) R R 3 REF If the resistor ratios are equal (i.e. R =R 3 and R =R 4), then OUT R R ( IP IN) REF 5.9 Instrumentation Amplifier The input impedance of the previous differential amplifier is set by the resistors R, R, R3, and R4. To maintain the high input impedance, one can use a voltage follower in front of each input as shown in the following two instrumentation amplifiers. 5.0 ThreeOpAmp Instrumentation Amplifier The dual GT755 can be used to build a threeopamp instrumentation amplifier as shown in Figure 5. A0 3/6
GT755 R R IM IP R 3 OUT R 4 REF Figure 5. ThreeOpAmp Instrumentation Amplifier The amplifier in Figure 5 is a high input impedance differential amplifier with gain of R /R. The two differential voltage followers assure the high input impedance of the amplifier. o R R 4 ( )( IP IN ) 3 5. TwoOpAmp Instrumentation Amplifier GT755 can also be used to make a high input impedance twoopamp instrumentation amplifier as shown in Figure 6. R R 4 R R 3 IM IP OUT Figure 6. TwoOpAmp Instrumentation Amplifier Where R =R 3 and R =R 4. If all resistors are equal, then o =( IP IN ) A0 4/6
GT755 5. SingleSupply Inverting Amplifier The inverting amplifier is shown in Figure 6. The capacitor C is used to block the DC signal going into the AC signal source IN. The value of R and C set the cutoff frequency to ƒ C=/(πR C ). The DC gain is defined by OUT=(R /R ) IN R IP C R IN R 3 OUT R 4 Figure 7. Single Supply Inverting Amplifier 5.3 Low Pass Active Filter The low pass active filter is shown in Figure 8. The DC gain is defined by R /R. The filter has a 0dB/decade rolloff after its corner frequency ƒ C=/(πR 3C ). C R IN R OUT R 3 Figure 8. Low Pass Active Filter 5.4 SallenKey nd Order Active LowPass Filter GT755 can be used to form a nd order SallenKey active lowpass filter as shown in Figure 9. The transfer function from IN to OUT is given by OUT CC RR LP ( S) ALP IN S S( ) CR CR CR CR A CC RR Where the DC gain is defined by A LP=R 3/R 4, and the corner frequency is given by C C C R R The pole quality factor is given by A0 5/6
GT755 C Q C R C R C R ALP C R Let R=R=R and C=C=C, the corner frequency and the pole quality factor can be simplified as below C CR And Q=R 3/ R 4 C IN R R C R 3 OUT R 4 Figure 9. SanllenKey nd Order Active LowPass Filter 5.5 SallenKey nd Order highpass Active Filter The nd order Sallenkey highpass filter can be built by simply interchanging those frequency selective components R, R, C, and C as shown in Figure 0. R C C IN OUT R R 3 R 4 Figure 0. SanllenKey nd Order Active HighPass Filter OUT IN ( S) S S ( CR S AHP A CR CR HP ) CC R R Where A HP =R 3 /R 4 A0 6/6
GT755 6. Electrical Characteristics 6. Absolute Maximum Ratings Condition Min Max Power Supply oltage ( DD to ss) 0.5 7 Analog Input oltage (IN or IN) ss0.5 DD0.5 PDB Input oltage ss0.5 7 Operating Temperature Range 40 C 5 C Junction Temperature 50 C Storage Temperature Range 65 C 50 C Lead Temperature (soldering, 0sec) 300 C Package Thermal Resistance (T A=5 ) SOP8, θ JA 30 C MSOP8, θ JA 0 C Note: Stress greater than those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions outside those indicated in the operational sections of this specification are not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability. A0 7/6
GT755 6. Electrical Characteristics ( DD = 5, ss = 0, CM = 0, OUT = DD /, R L =00K tied to DD /, SHDNB = DD, T A = 40 C to 5 C, unless otherwise noted. Typical values are at T A =5 C.) (Notes ) Parameter Symbol Conditions Min. Typ. Max. Units Supplyoltage Range Quiescent Supply Current (per Amplifier) DD Guaranteed by the PSRR test. 5.5 DD = 5 7 0 μa Input Offset oltage OS 5.5 m Input Offset oltage Tempco Δ OS/ΔT 3 μ/ C Input Bias Current I B (Note ) 0 pa Input Offset Current I OS (Note ) 0 pa Input CommonMode oltage Range CM 0. DD0. CommonMode Rejection Ratio CMRR DD=5.5 ss0. CM DD0. 55 65 db ss CM 5 60 70 db PowerSupply Rejection Ratio PSRR DD =. to 5.5 60 70 db OpenLoop oltage Gain A DD=5, R L=00k, 0.05 O 4.95 DD=5, R L=5k, 0.05 O 4.95 85 9 db 75 8 db Output oltage Swing OUT IN IN 0m DD OH 0 m R L = 00k to DD/ OL SS 0 m IN IN 0m DD OH 00 m R L = 5k to DD/ OL SS 00 m Output ShortCircuit Current I SC Sinking or Sourcing 5 0 ma Gain Bandwidth Product GBW A = / 50 khz Slew Rate SR A = / 0.5 /μs Settling Time t S To 0.%, OUT = step A = / 5 μs Over Load Recovery Time IN Gain= S 6 μs Input oltage Noise Density e n ƒ = khz 0 n/hz Note : All devices are 00% production tested at T A = 5 C ; all specifications over the automotive temperature range is guaranteed by design, not production tested. Note : Parameter is guaranteed by design. A0 8/6
GT755 6.3 Typical characteristics At T A =5 C, R L =00 kω connected to S / and OUT = S /, unless otherwise noted. A0 9/6
GT755 At T A =5 C, R L =00 kω connected to S / and OUT = S /, unless otherwise noted. Sourcing Current IQ Sinking Current ISC Phase Gain Falling Edge Rising Edge A0 0/6
GT755 7. Ordering Information GT XXXX XX X X Temperature Range I Industrial: 40 C ~5 C Pb Status G GREEN Package Type: TF G SOT35 SOP8 Part Number Giantec Prefix GT Giantec Order Number Package Description Package Option GT755TFGITR SOT35 Tape and Reel 3000 GT755GGITR SOP8 Tape and Reel 4000 A0 /6
GT755 8. Part Markings 8. GT755TFGI (Top iew) 5 5 Y W 55 GT755TFGI Pin Indicator Y Seal Year W Seal Week 00 (st half year) A Week 0 A 00 (nd half year) B Week 0 B 0 (st half year) C 0 (nd half year) D Week 6 Z 0 (st half year) E Week 7 A 0 (nd half year) F Week 8 B 0 (nd half year) Z Week 5 Z A0 /6
GT755 8. GT755GGI (Top iew) G T 7 5 5 G G I Lot Number Y Y W W S GT755GGI Lot Number States the last 9 characters of the wafer lot information Pin Indicator YY Seal Year 00 = 000 0 = 00 99 = 099 WW Seal Week 0 = Week 0 = Week... 5 = Week 5 5 = Week 5 S Subcon Code J = ASESH L = ASEKS Die ersion A0 3/6
GT755 9. Package Information 9. SOP35 A0 4/6
GT755 9. SOP8 A0 5/6
GT755 0. Revision History Revision Date Descriptions A0 Sept.,0 Initial ersion A0 6/6