LT1637 1.1MHz, 0.4V/µs Over-The-Top Micropower, Rail-To-Rail Input and Output Op Amp DESCRIPTIO U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Operates with Inputs Above V + Rail-to-Rail Input and Output Micropower: 250µA Supply Current Max Gain-Bandwidth Product: 1.1MHz Slew Rate: 0.4V/µs Low Input Offset Voltage: 350µV Max Single Supply Input Range: – 0.4V to 44V High Output Current: 25mA Min Specified on 3V, 5V and ±15V Supplies Output Shutdown Output Drives 4700pF with Output Compensation Reverse Battery Protection to 25V High Voltage Gain: 800V/mV High CMRR: 110dB The LT1637 has a unique input stage that operates and remains high impedance when above the positive supply. The inputs take 44V both differential and common mode, even when operating on a 3V supply. Built-in resistors protect the inputs for faults below the negative supply up to 22V. There is no phase reversal of the output for inputs 5V below VEE or 44V above VEE, independent of VCC. U APPLICATIO S ■ ■ ■ ■ Battery or Solar Powered Systems: Portable Instrumentation Sensor Conditioning Supply Current Sensing Battery Monitoring MUX Amplifiers 4mA to 25mA Transmitters The LT1637 op amp is available in the 8-pin MSOP, PDIP and SO packages. , LTC and LT are registered trademarks of Linear Technology Corporation. Over-The-Top is a trademark of Linear Technology Corporation. U ■ The LT®1637 is a rugged op amp that operates on all single and split supplies with a total voltage of 2.7V to 44V. The LT1637 has a gain-bandwidth product of 1.1MHz while drawing less than 250µA of quiescent current. The LT1637 can be shut down, making the output high impedance and reducing the quiescent current to only 3µA. The LT1637 is reverse supply protected: it draws virtually no current for reverse supply up to 25V. The input range of the LT1637 includes both supplies and the output swings to both supplies. Unlike most micropower op amps, the LT1637 can drive heavy loads; its rail-to-rail output drives 25mA. The LT1637 is unity-gain stable into all capacitive loads up to 4700pF when optional 0.22µF and 150Ω compensation is used. TYPICAL APPLICATIO Over-The-TopTM Current Source with Shutdown Switchable Precision Current Source 4V TO 44V + 4.7µF 6V LT1004-1.2 2k Current Source Timing 4V R VSHDN R* 2V + LT1637 – IOUT SHDN 0V TP0610 IOUT = 1.2 R e.g., 10mA = 120Ω *OPTIONAL FOR LOW OUTPUT CURRENTS, R* = R 1637 TA01 10mA IOUT 5mA 0mA 100µs/DIV 1637 TA01b 1 LT1637 U W W W ABSOLUTE AXI U RATI GS (Note 1) Total Supply Voltage (V + to V –) .............................. 44V Input Differential Voltage ......................................... 44V Input Current ...................................................... ±25mA Shutdown Pin Voltage Above V – ..................................... 32V Shutdown Pin Current ........................................ ±10mA Output Short-Circuit Duration (Note 2) ......... Continuous Operating Temperature Range (Note 3) .. – 40°C to 85°C Specified Temperature Range (Note 4) ... – 40°C to 85°C Junction Temperature ........................................... 150°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U W U PACKAGE/ORDER I FOR ATIO TOP VIEW NULL – IN + IN V– 1 2 3 4 8 7 6 5 NULL V+ OUT SHDN ORDER PART NUMBER LT1637CMS8 MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 150°C, θJA = 250°C/W NULL 1 8 NULL 2 7 V+ 3 6 OUT V– 4 5 SHDN – IN + IN N8 PACKAGE 8-LEAD PDIP MS8 PART MARKING ORDER PART NUMBER TOP VIEW LT1637CN8 LT1637CS8 LT1637IN8 LT1637IS8 S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 130°C/W (N8) TJMAX = 150°C, θJA = 190°C/W (S8) S8 PART MARKING LTIE 1637 1637I Consult factory for Military grade parts. U 3V A D 5V ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VSHDN = V –,VCM = VOUT = Half Supply unless otherwise specified. (Note 4) SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage N8, S8 Packages 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● MS8 Package 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● N8, S8 Packages, – 40°C ≤ TA ≤ 85°C MS8 Package, – 40°C ≤ TA ≤ 85°C VCM = 44V (Note 5) Input Offset Voltage Drift (Note 9) IOS IB Input Offset Current Input Bias Current VCM = 44V (Note 5) VS = 0V MIN TYP MAX UNITS 100 350 550 700 µV µV µV 100 350 750 900 µV µV µV ● ● 1 2 3 6 ● ● 0.4 6.0 2.5 nA µA ● ● 20 23 0.1 50 60 nA µA nA µV/°C µV/°C Input Noise Voltage 0.1Hz to 10Hz 0.6 µVP-P en Input Noise Voltage Density f = 1kHz 27 nV/√Hz in Input Noise Current Density f = 1kHz 0.08 pA/√Hz 2 LT1637 U 3V A D 5V ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VSHDN = V –, VCM = VOUT = Half Supply unless otherwise specified. (Note 4) SYMBOL PARAMETER CONDITIONS MIN TYP RIN Input Resistance Differential Common Mode, VCM = 0V to 44V 1 0.7 2.6 1.4 MΩ MΩ CIN Input Capacitance 4 pF Input Voltage Range MAX 44 UNITS ● 0 CMRR Common Mode Rejection Ratio (Note 5) VCM = 0V to (VCC – 1V) VCM = 0V to 44V (Note 8) ● ● 88 80 110 98 dB dB AVOL Large-Signal Voltage Gain VS = 3V, VO = 500mV to 2.5V, RL = 10k VS = 3V, 0°C ≤ TA ≤ 70°C VS = 3V, – 40°C ≤ TA ≤ 85°C 150 100 75 400 ● ● V/mV V/mV V/mV VS = 5V, VO = 500mV to 4.5V, RL = 10k VS = 5V, 0°C ≤ TA ≤ 70°C VS = 5V, – 40°C ≤ TA ≤ 85°C 300 200 150 800 ● ● V/mV V/mV V/mV VOL Output Voltage Swing LOW No Load ISINK = 5mA VS = 5V, ISINK = 10mA ● ● ● VOH Output Voltage Swing HIGH VS = 3V, No Load VS = 3V, ISOURCE = 5mA ● ● 2.94 2.25 2.975 2.67 V V VS = 5V, No Load VS = 5V, ISOURCE = 10mA ● ● 4.94 3.80 4.975 4.45 V V VS = 3V, Short Output to Ground VS = 3V, Short Output to VCC 10 15 14 45 mA mA VS = 5V, Short Output to Ground VS = 5V, Short Output to VCC 15 15 22 60 mA mA 90 98 dB 25 40 ISC PSRR Short-Circuit Current (Note 2) Power Supply Rejection Ratio VS = 3V to 12.5V, VCM = VO = 1V Minimum Supply Voltage Reverse Supply Voltage IS ISHDN ● 3 325 580 2.7 ● IS = – 100µA Supply Current (Note 6) ● 8 700 1300 V mV mV mV V V 190 250 295 µA µA ● Supply Current, SHDN VPIN5 = 2V, No Load (Note 6) ● 3 12 µA Shutdown Pin Current VPIN5 = 0.3V, No Load (Note 6) VPIN5 = 2V, No Load (Note 5) VPIN5 = 3.3V VPIN5 = 5V ● ● 0.2 1.0 2.5 4.3 15 5 nA µA µA µA Output Leakage Current VPIN5 = 2V, No Load (Note 6) ● 0.02 1 µA ● 20 150 µA Maximum Shutdown Pin Current VPIN5 = 32V, No Load (Note 5) tON Turn-On Time VPIN5 = 5V to 0V, RL = 10k 45 µs tOFF Turn-Off Time VPIN5 = 0V to 5V, RL = 10k 3 µs tSETTLING Settling Time 0.1% AV = 1, ∆VO = 2V GBW Gain-Bandwidth Product (Note 5) f = 10kHz 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C Slew Rate (Note 7) AV = – 1, RL = ∞ 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C SR 9 µs 1000 ● ● 650 550 500 kHz kHz kHz 0.210 0.185 0.170 0.35 ● ● V/µs V/µs V/µs 3 LT1637 ±15V ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, VOUT = 0V, VSHDN = V – unless otherwise specified. (Note 4) SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage N8, S8 Packages 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● MS8 Package 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● N8, S8 Packages, – 40°C ≤ TA ≤ 85°C MS8 Package, – 40°C ≤ TA ≤ 85°C ● ● Input Offset Voltage Drift (Note 9) MIN TYP MAX UNITS 100 450 650 800 µV µV µV 100 450 800 950 µV µV µV 1 2 3 6 µV/°C µV/°C IOS Input Offset Current ● 1 6 nA IB Input Bias Current ● 17 50 nA Input Noise Voltage 0.1Hz to 10Hz µVP-P 0.6 en Input Noise Voltage Density f = 1kHz 27 nV/√Hz in Input Noise Current Density f = 1kHz 0.08 pA/√Hz RIN Input Resistance Differential Common Mode, VCM = – 15V to 14V 3 2200 MΩ MΩ CIN Input Capacitance 4 pF Input Voltage Range 1 ● – 15 29 V CMRR Common Mode Rejection Ratio VCM = – 15V to 29V ● 80 110 dB AVOL Large-Signal Voltage Gain VO = ±14V, RL = 10k 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C 400 ● ● 100 75 50 V/mV V/mV V/mV VOL Output Voltage Swing LOW No Load ISINK = 5mA ISINK = 10mA ● ● ● VOH Output Voltage Swing HIGH No Load ISOURCE = 5mA ISOURCE = 10mA ● ● ● 14.9 14.2 13.7 14.967 14.667 14.440 V V V ISC Short-Circuit Current (Note 2) Short Output to GND 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ±25 ±20 ±15 ±31.7 ● ● mA mA mA VS = ±1.5V to ±22V ● 90 115 dB PSRR Power Supply Rejection Ratio Minimum Supply Voltage IS – 14.997 – 14.680 – 14.420 V V V ±1.35 V 230 300 370 µA µA ● Supply Current – 14.95 – 14.25 – 13.65 ● Positive Supply Current, SHDN VPIN5 = – 20V, VS = ±22V, No Load ● 6 40 µA Shutdown Pin Current VPIN5 = – 21.7V, VS = ±22V, No Load VPIN5 = – 20V, VS = ±22V, No Load ● ● 0.3 0.9 15 8 nA µA Maximum Shutdown Pin Current VPIN5 = 32V, VS = ±22V ● 20 150 µA Output Leakage Current VPIN5 = – 20V, VS = ±22V, No Load ● 0.02 2 µA VL Shutdown Pin Input Low Voltage VS = ±22V ● VH Shutdown Pin Input High Voltage VS = ±22V ● tON Turn-On Time VPIN5 = – 10V to – 15V, RL = 10k 35 µs tOFF Turn-Off Time VPIN5 = – 15V to – 10V, RL = 10k 3 µs ISHDN 4 – 21.7 – 21.6 – 20.8 V –20.0 V LT1637 ±15V ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, VOUT = 0V, VSHDN = V – unless otherwise specified. (Note 4) SYMBOL PARAMETER CONDITIONS GBW Gain-Bandwidth Product f = 10kHz 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C AV = – 1, RL = ∞, VO = ±10V, Measure at VO = ±5V 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C SR Slew Rate Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: A heat sink may be required to keep the junction temperature below absolute maximum. Note 3: The LT1637 is guaranteed functional over the operating temperature range of – 40°C to 85°C. Note 4: The LT1637C is guaranteed to meet specified performance from 0°C to 70°C. The LT1637C is designed, characterized and expected to meet specified performance from – 40°C to 85°C but is not tested or QA sampled at these temperatures. The LT1637I is guaranteed to meet specified performance from – 40°C to 85°C. MIN TYP MAX UNITS 750 650 600 1100 ● ● kHz kHz kHz 0.225 0.200 0.180 0.4 ● ● V/µs V/µs V/µs Note 5: VS = 5V limits are guaranteed by correlation to VS = 3V and VS = ±15V or VS = ±22V tests. Note 6: VS = 3V limits are guaranteed by correlation to VS = 5V and VS = ±15V or VS = ±22V tests. Note 7: Guaranteed by correlation to slew rate at VS = ±15V and GBW at VS = 3V and VS = ±15V tests. Note 8: This specification implies a typical input offset voltage of 650µV at VCM = 44V and a maximum input offset voltage of 5.4mV at VCM = 44V. Note 9: This parameter is not 100% tested. U W TYPICAL PERFOR A CE CHARACTERISTICS Supply Current vs Supply Voltage SUPPLY CURRENT (µA) 300 TA = 125°C 250 200 TA = 25°C 150 TA = –55°C 100 50 0 400 40 300 30 INPUT BIAS CURRENT (µA) CHANGE IN INPUT OFFSET VOLTAGE (µV) 400 350 Input Bias Current vs Common Mode Voltage Minimum Supply Voltage 200 100 0 TA = 125°C –100 TA = –55°C –200 –300 TA = 25°C 10 20 30 40 TOTAL SUPPLY VOLTAGE (V) 1637 G01 20 10 TA = –55°C 0.12 0.08 TA = 125°C 0.04 TA = 25°C 0 0.04 –400 0 VS = 5V, 0V 0.08 0 1 2 3 4 TOTAL SUPPLY VOLTAGE (V) 5 1637 G02 4 4.2 4.4 4.6 4.8 5 10 20 30 40 50 COMMON MODE VOLTAGE (V) 1637 G03 5 LT1637 U W TYPICAL PERFOR A CE CHARACTERISTICS Output Saturation Voltage vs Load Current (Output Low) Output Saturation Voltage vs Load Current (Output High) 10 0.1 TA = 125°C TA = 25°C TA = – 55°C 0.01 0.1 1 10 0.0001 0.001 0.01 SOURCING LOAD CURRENT (mA) 100 VS = 5V, 0V VOD = 30mV 1 0.1 TA = 125°C TA = 25°C 0.01 TA = – 55°C 0.001 0.1 1 10 0.0001 0.001 0.01 SINKING LOAD CURRENT (mA) 100 OUTPUT SATURATION VOLTAGE (mV) VS = 5V, 0V VOD = 30mV OUTPUT SATURATION VOLTAGE (V) OUTPUT SATURATION VOLTAGE (V) 1 Output Saturation Voltage vs Input Overdrive 1637 G04 VS = ±15V 60 50 40 30 8 9 1 10 10 100 FREQUENCY (Hz) Open-Loop Gain and Phase Shift vs Frequency 80 PHASE 40 60 30 40 GAIN 20 20 0 10 0 –10 –20 –30 1k 10k 100k FREQUENCY (Hz) 1M 1637 G10 6 PHASE SHIFT (DEG) GAIN (dB) 50 100 GAIN-BANDWIDTH PRODUCT (kHz) VS = ±2.5V OUTPUT LOW 0 10 20 30 40 50 60 70 80 90 100 INPUT OVERDRIVE (mV) VS = ±15V 1.2 1.0 0.8 0.6 0.4 0.2 10 100 FREQUENCY (Hz) 1 Slew Rate vs Temperature 1300 0.7 1200 0.6 1100 1000 VS = ±15V VS = ±1.5V 900 800 700 – 50 –25 1000 1637 G09 Gain-Bandwidth Product vs Temperature 120 60 10 1637 G08 1637 G07 70 OUTPUT HIGH 20 0 1000 SLEW RATE (V/µs) 7 30 Input Noise Current vs Frequency INPUT NOISE CURRENT DENSITY (pA/√Hz) INPUT NOISE VOLTAGE DENSITY (nV/√Hz) NOISE VOLTAGE (200nV/DIV) 4 5 6 TIME (s) 40 1.4 20 3 50 Noise Voltage Density vs Frequency VS = ± 2.5V 2 60 1637 G06 70 1 70 1637 G05 0.1Hz to 10Hz Noise Voltage 0 80 0 100 VS = 5V, 0V NO LOAD 90 RISING, VS = ±15V 0.5 RISING, VS = ±1.5V 0.4 FALLING, VS = ±15V 0.3 FALLING, VS = ±1.5V 0.2 50 25 75 0 TEMPERATURE (°C) 100 125 1637 G11 0.1 – 50 – 25 0 50 75 25 TEMPERATURE (°C) 100 125 1637 G12 LT1637 U W TYPICAL PERFOR A CE CHARACTERISTICS CMRR vs Frequency 1250 50 PHASE MARGIN 1200 45 1150 40 GAIN BANDWIDTH 1100 35 1050 30 1000 0 5 10 15 20 25 30 35 40 TOTAL SUPPLY VOLTAGE (V) 45 PSRR vs Frequency 100 90 90 80 VS = ±15V 70 60 VS = ±1.5V 50 40 30 20 10 0 25 1k 10k 100k FREQUENCY (Hz) 30 GAIN BANDWIDTH 900 25 800 20 700 100 AV = 100 10 AV = 10 1 AV = 1 0.1 100 10 100k 1k 15 10 10k 100k FREQUENCY (Hz) 0 100 1M –4 AV = – 1 Total Harmonic Distortion + Noise vs Frequency AV = 1 60 AV = 5 50 AV = 10 40 VS = 3V, 0V VOUT = 1.8VP-P VCM = 1.2V RL =10k 1 AV = 2 70 30 20 –8 0.1 0.01 AV = –1 0.001 AV = 1 10 –10 0 10 30 20 SETTLING TIME (µs) 0 40 1637 G19 100k 1637 G18 THD + NOISE (%) –2 1k 10k FREQUENCY (Hz) 10 80 AV = – 1 0 Vs = ± 2.5V VS = ±2.5V NO OUTPUT COMPENSATION 90 OVERSHOOT (%) OUTPUT STEP (V) 20 5 100 2 –6 DISTORTION ≤ 1% AV = 1 Vs = ±15V 25 Capacitive Load Handling, Overshoot vs Capacitive Load VS = ±15V AV = 1 1M Undistorted Output Swing vs Frequency 1637 G17 Settling Time to 0.1% vs Output Step AV = 1 10k 100k FREQUENCY (Hz) 35 1637 G16 4 0 1637 G15 15 6 10 1k OUTPUT SWING (VP-P) 1000 OUTPUT IMPEDANCE (Ω) GAIN-BANDWIDTH PRODUCT (kHz) 35 8 NEGATIVE SUPPLY 20 30 PHASE MARGIN (DEG) 1100 10 30 1k 40 10k LOAD RESISTANCE (Ω) 40 VS = ± 2.5V PHASE MARGIN 1k POSITIVE SUPPLY 50 1M 10k 45 1200 600 60 Output Impedance vs Frequency 50 1300 70 1637 G14 Gain-Bandwidth Product and Phase Margin vs Load Resistance VS = ± 2.5V VS = ± 2.5V 80 –10 1637 G13 1400 POWER SUPPLY REJECTION RATIO (dB) 55 COMMON MODE REJECTION RATIO (dB) 1300 PHASE MARGIN (DEG) GAIN-BANDWIDTH PRODUCT (kHz) Gain-Bandwidth Product and Phase Margin vs Supply Voltage 0.0001 10 100 1000 CAPACITIVE LOAD (pF) 10000 1637 G20 10 100 1k 10k FREQUENCY (Hz) 100k 1637 G21 7 LT1637 U W TYPICAL PERFOR A CE CHARACTERISTICS Total Harmonic Distortion + Noise vs Load Resistance 10 1 THD + NOISE (%) 1 VS = 3V, 0V VIN = 0.6V TO 2.4V 0.01 RL = 10k VCM = HALF SUPPLY f = 1kHz FOR AV = –1, RG = 100k VS = 3V TOTAL AV = 1 VIN = 1.8VP-P AT 1kHz VS = ±1.5V VIN = ±0.9V 0.1 THD + NOISE (%) Total Harmonic Distortion + Noise vs Output Voltage 0.001 AV = 1 VS = 3V, 0V AV = –1 VS = ±1.5V AV = 1 VS = ±1.5V 0.1 AV = 1 VS = 3V, 0V 0.01 VS = 3V, 0V VIN = 0.3V TO 2.1V AV = –1, VS = 3V, 0V 0.001 0.0001 100 1k 10k LOAD RESISTANCE TO GROUND (Ω) 0 100k 1 2 OUTPUT VOLTAGE (VP-P) 1637 G23 1637 G22 Large-Signal Response Small-Signal Response VS = ±15V AV = – 1 VS = ±15V VS = ±15V AV = 1 10V A A B 50mV B C C – 50mV A: RL = 2k B: RL = 10k C: RL = 50k – 10V 1637 G24 1637 G25 W –10V 0V 10V OUTPUT VOLTAGE (5V/DIV) 1637 G26 U CHANGE IN INPUT OFFSET VOLTAGE (50µV/DIV) Open-Loop Gain 3 U U APPLICATIO S I FOR ATIO Supply Voltage Inputs The positive supply pin of the LT1637 should be bypassed with a small capacitor (about 0.01µF) within an inch of the pin. When driving heavy loads an additional 4.7µF electrolytic capacitor should be used. When using split supplies, the same is true for the negative supply pin. The LT1637 has two input stages, NPN and PNP (see the Simplified Schematic), resulting in three distinct operating regions as shown in the Input Bias Current vs Common Mode typical performance curve. The LT1637 is protected against reverse battery voltages up to 25V. In the event a reverse battery condition occurs, the supply current is typically less than 1nA. When operating the LT1637 on total supplies of 30V or more, the supply must not be brought up faster than 1µs. This is especially true if low ESR bypass capacitors are used. A series RLC circuit is formed from the supply lead inductance and the bypass capacitor. 5Ω of resistance in the supply or the bypass capacitor will dampen the tuned circuit enough to limit the rise time. 8 For input voltages about 0.9V or more below V +, the PNP input stage is active and the input bias current is typically – 20nA. When the input voltage is about 0.5V or less from V +, the NPN input stage is operating and the input bias current is typically 80nA. Increases in temperature will cause the voltage at which operation switches from the PNP stage to the NPN stage to move towards V +. The input offset voltage of the NPN stage is untrimmed and is typically 600µV. LT1637 U W U U APPLICATIO S I FOR ATIO A Schottky diode in the collector of each NPN transistor of the NPN input stage allows the LT1637 to operate with either or both of its inputs above V +. At about 0.3V above V + the NPN input transistor is fully saturated and the input bias current is typically 23µA at room temperature. The input offset voltage is typically 600µV when operating above V +. The LT1637 will operate with its input 44V above V – regardless of V +. The inputs are protected against excursions as much as 22V below V – by an internal 1.3k resistor in series with each input and a diode from the input to the negative supply. There is no output phase reversal for inputs up to 5V below V –. There are no clamping diodes between the inputs and the maximum differential input voltage is 44V. Lower load resistance increases the output crossover distortion, but has no effect on the input stage transition distortion. For lowest distortion the LT1637 should be operated single supply, with the output always sourcing current and with the input voltage swing between ground and (V + – 0.9V). See the Typical Performance Characteristics curves. Gain The open-loop gain is less sensitive to load resistance when the output is sourcing current. This optimizes performance in single supply applications where the load is returned to ground. The typical performance photo of Open-Loop Gain for various loads shows the details. Output Shutdown The output voltage swing of the LT1637 is affected by input overdrive as shown in the typical performance curves. When monitoring input voltages within 100mV of V +, gain should be taken to keep the output from clipping. The LT1637 can be shut down two ways: using the shutdown pin or bringing V + to within 0.5V of V –. When V + is brought to within 0.5V of V – both the supply current and output leakage current drop to less than 10nA. When the shutdown pin is brought 1.2V above V –, the supply current drops to about 3µA and the output leakage current is less than 1µA, independent of V +. In either case the input bias current is less than 0.1nA (even if the inputs are 44V above the negative supply). The output of the LT1637 can be pulled up to 25V beyond V + with less than 1nA of leakage current, provided that V + is less than 0.5V. The normally reverse biased substrate diode from the output to V – will cause unlimited currents to flow when the output is forced below V –. If the current is transient and limited to 100mA, no damage will occur. The LT1637 is internally compensated to drive at least 200pF of capacitance under any output loading conditions. A 0.22µF capacitor in series with a 150Ω resistor between the output and ground will compensate these amplifiers for larger capacitive loads, up to 4700pF, at all output currents. The shutdown pin can be taken up to 32V above V –. The shutdown pin can be driven below V –, however the pin current through the substrate diode should be limited with an external resistor to less than 10mA. Input Offset Nulling The input offset voltage can be nulled by placing a 10k potentiometer between Pins 1 and 8 with its wiper to V – (see Figure 1). The null range will be at least ±3mV. Distortion There are two main contributors of distortion in op amps: output crossover distortion as the output transitions from sourcing to sinking current and distortion caused by nonlinear common mode rejection. Of course, if the op amp is operating inverting there is no common mode induced distortion. When the LT1637 switches between input stages there is significant nonlinearity in the CMRR. LT1637 8 1 10k V– 1637 F01 Figure 1. Input Offset Nulling 9 LT1637 W W SI PLIFIED SCHE ATIC 7 V+ Q1 Q13 D1 – IN SHDN Q23 R1 1M D3 2 Q24 Q21 Q2 10µA Q25 R3 1.3k R2 6k 5 Q19 D2 R4 1.3k Q9 Q10 Q14 Q15 Q18 Q20 6 OUT Q22 3 + IN Q11 Q12 Q17 Q16 Q26 Q3 Q4 Q6 Q7 Q5 Q8 D4 D5 NULL R5 7k R6 7k R7 400Ω R8 400Ω 1 8 NULL 4 V– 1637 SS U TYPICAL APPLICATIO S Optional Output Compensation for Capacitive Loads Greater Than 200pF Positive Supply Rail Current Sense Lamp Outage Detector 3V 5V TO 44V V+ 1M 200Ω + VIN 0.2Ω LOAD 100k 5k CL ≤ 4700pF – + 0.5Ω Q1 2N3904 LT1637 200Ω LAMP ON/OFF LT1637 5V – 2k ILOAD OUT 150Ω 1637 TA02 VOUT = (2Ω)(ILOAD) LT1637 + 0.22µF 0V TO 4.3V – OUT = 0V FOR GOOD BULB 3V FOR OPEN BULB 1637 TA03 1637 TA05 Over-The-Top Comparator with Hysteresis Over-The-Top Current Sense 0.1V TO 44V R1 200Ω 1M 3V TO 44V IN1 (0V TO 44V) 10k 5V + VOUT LT1637 – RS 0.2Ω + LT1637 1M – 1M 2N5087 IN2 (0V TO 44V) 10k 1M LOAD V HYSTERESIS = CC 100 10 ILOAD 2N5210 1637 TA04 ILOAD = VOUT (RS)(R2/R1) Q1 2N3904 VOUT (0V TO 4.3V) R2 2k 1637 TA06 LT1637 U PACKAGE DESCRIPTIO Dimensions in inches (millimeters) unless otherwise noted. MS8 Package 8-Lead Plastic MSOP (LTC DWG # 05-08-1660) 0.040 ± 0.006 (1.02 ± 0.15) 0.007 (0.18) 0.118 ± 0.004* (3.00 ± 0.102) 0.034 ± 0.004 (0.86 ± 0.102) 8 7 6 5 0° – 6° TYP SEATING PLANE 0.012 (0.30) 0.0256 REF (0.65) BSC 0.021 ± 0.006 (0.53 ± 0.015) 0.006 ± 0.004 (0.15 ± 0.102) 0.118 ± 0.004** (3.00 ± 0.102) 0.193 ± 0.006 (4.90 ± 0.15) MSOP (MS8) 1098 1 * DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE 4 2 3 N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.300 – 0.325 (7.620 – 8.255) 0.009 – 0.015 (0.229 – 0.381) ( 0.045 – 0.065 (1.143 – 1.651) 0.130 ± 0.005 (3.302 ± 0.127) 0.065 (1.651) TYP +0.035 0.325 –0.015 +0.889 8.255 –0.381 0.400* (10.160) MAX ) 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 ± 0.003 0.100 (2.54) BSC (0.457 ± 0.076) N8 1098 *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 0°– 8° TYP 0.016 – 0.050 (0.406 – 1.270) 0.014 – 0.019 (0.355 – 0.483) TYP *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 8 7 6 5 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) BSC 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 1 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. 2 3 4 SO8 1298 11 LT1637 U TYPICAL APPLICATIO S Sample-and-Hold 3V VIN 3V + + LT1637 – 0.22µF SHDN VSAMPLE LT1636 150Ω VOUT – 3V 1637 TA07 0V DROOP (LT1636 BUFFER): 200mV/s DROOP INTO HIGH IMPEDANCE : LESS THAN 0.625mV/s MUX Amplifier MUX Amplifier Waveforms 5V VIN1 5kHz AT 4VP-P + VOUT LT1637 – VOUT 2V/DIV SHDN 5V – INPUT SELECT 5V/DIV LT1637 VIN2 10kHz AT 2VP–P + 0.2ms/DIV SHDN 1637 TA08 INPUT SELECT 1kHz AT 5VP–P 74HC04 1637 TA09 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1078/LT1079 LT2078/LT2079 Dual/Quad 55µA Max, Single Supply, Precision Op Amps Input/Output Common Mode Includes Ground, 70µV VOS(MAX) and 2.5µV/°C Drift (Max), 200kHz GBW, 0.07V/µs Slew Rate LT1178/LT1179 LT2178/LT2179 Dual/Quad 17µA Max, Single Supply, Precison Op Amps Input/Output Common Mode Includes Ground, 70µV VOS(MAX) and 4µV/°C Drift (Max), 85kHz GBW, 0.04V/µs Slew Rate LT1366/LT1367 Dual/Quad Precision, Rail-to-Rail Input and Output Op Amps 475µV VOS(MAX), 500V/mV AVOL(MIN), 400kHz GBW LT1490/LT1491 Dual/Quad Over-The-Top Micropower, Rail-to-Rail Input and Output Op Amps Single Supply Input Range: – 0.4V to 44V, Micropower 50µA per Amplifier, Rail-to-Rail Input and Output, 200kHz GBW LT1636 Single Over-The-Top Micropower Rail-to-Rail Input and Output Op Amp 55µA Supply Current, VCM Extends 44V above VEE, Independent of VCC; MSOP Package, Shutdown Function LT1638/LT1639 Dual/Quad 1.2MHz Over-The-Top Micropower, Rail-to-Rail Input and Output Op Amps 0.4V/µs Slew Rate, 230µA Supply Current per Amplifier LT1782 Micropower, Over-The-Top, SOT-23, Rail-to-Rail Input and Output Op Amp SOT-23, 800µV VOS(MAX), IS =55µA (Max), Gain-Bandwidth = 200kHz, Shutdown Pin LT1783 1.2MHz, Over-The-Top, Micropower, Rail-to-Rail Input and Output Op Amp SOT-23, 800µV VOS(MAX), IS =300µA (Max), Gain-Bandwidth = 1.2MHz, Shutdown Pin 12 Linear Technology Corporation 1637f LT/TP 0100 4K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com LINEAR TECHNOLOGY CORPORATION 1999