LT1784 2.5MHz, Over-The-Top Low Power, Rail-to-Rail Input and Output Op Amp in SOT-23 DESCRIPTIO U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Operates with Inputs Above V + Rail-to-Rail Input and Output Low Profile (1mm) ThinSOTTM Package Gain Bandwidth Product: 2.5MHz Slew Rate: 2.1V/µs Low Input Offset Voltage: 3.5mV Max High Voltage Gain: 1000V/mV Single Supply Input Range: 0V to 18V Specified on 3V, 5V and ±5V Supplies Reverse Battery Protection to 18V Low Power: 750µA Supply Current Max Output Shutdown on 6-Lead Version High Output Current: 15mA Min Operating Temperature Range: – 40°C to 85°C U APPLICATIO S ■ ■ ■ ■ ■ The input range of the LT1784 includes ground, and a unique feature of this device is its Over-The-TopTM operation capabilitity with either or both of its inputs above the positive rail. The inputs handle 18V both differential and common mode, independent of supply voltage. The input stage incorporates phase reversal protection to prevent false outputs from occurring even when the inputs are 9V below the negative supply. The LT1784 can drive loads up to 15mA and still maintain rail-to-rail capability. A shutdown feature on the 6-lead version can disable the part, making the output high impedance and reducing quiescent current to 5µA. The LT1784 op amp is available in the 5- and 6-lead SOT-23 packages. For applications requiring lower power, refer to the LT1782 and LT1783 data sheets. Portable Instrumentation Battery-Powered Systems Sensor Conditioning Supply Current Sensing MUX Amplifiers 4mA to 20mA Transmitters , LTC and LT are registered trademarks of Linear Technology Corporation. Over-The-Top and ThinSOT are trademarks of Linear Technology Corporation. U ■ The LT®1784 is a 2.5MHz op amp available in the small SOT-23 package that operates on all single and split supplies with a total voltage of 2.5V to 18V. The amplifier draws less than 750µA of quiescent current and has reverse battery protection, drawing negligible current for reverse supply voltages up to 18V. TYPICAL APPLICATIO Programmable Gain, AV = 2, AV = 20, 100kHz Amplifier Programmable Gain Amplifier Frequency Response VCC AV = 20 30 AV = 2 25 SHDN 15 OUT LT1784 SHDN VCC – + VEE VEE R2 9.09k R1 10k AV = 1+ OR 1+ ( ( R1 + R2 R3 R1 R2 + R3 10 5 AV = 2 0 –5 LT1782 – GAIN (dB) + IN AV = 20 20 VCC –10 ) ) –15 –20 1k 10k 100k 1M FREQUENCY (Hz) 10M 1784 TA01a R3 1k 1784 TA01 1 LT1784 U W W W ABSOLUTE MAXIMUM RATINGS (Note 1) Total Supply Voltage (V + to V –) .............................. 18V Input Differential Voltage ........................................ 18V Input Pin Voltage to V – ............................... + 24V/– 10V Shutdown Pin Voltage Above V – ............................ 18V Shutdown Pin Current ....................................... ±10mA Output Short-Circuit Duration (Note 2) ........... Indefinite Operating Temperature Range (Note 10) – 40°C to 85°C Specified Temperature Range (Note 11) – 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 INFORMATION ORDER PART NUMBER TOP VIEW 5 V+ OUT 1 V– 2 + – +IN 3 4 –IN + 6 V OUT 1 LT1784CS5 LT1784IS5 ORDER PART NUMBER TOP VIEW V– 2 +IN 3 + – LT1784CS6 LT1784IS6 5 SHDN 4 –IN S5 PACKAGE 5-LEAD PLASTIC SOT-23 S5 PART MARKING S6 PACKAGE 6-LEAD PLASTIC SOT-23 S6 PART MARKING TJMAX = 150°C, θJA = 250°C/ W LTJD LTSN TJMAX = 150°C, θJA = 230°C/ W LTIW LTIX Consult LTC marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the specified temperature range, otherwise specifications are TA = 25°C. VS = 3V, 0V; VS = 5V, 0V, VCM = VOUT = half supply, for the 6-lead part VPIN5 = 0V, pulse power tested unless otherwise specified. SYMBOL PARAMETER CONDITIONS VOS TA = 25°C 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● – 40°C ≤ TA ≤ 85°C VCM = 18V (Note 3) Input Offset Voltage ∆VOS/∆T Input Offset Voltage Drift (Note 7) IOS IB Input Offset Current Input Bias Current VCM = 18V (Note 3) SHDN or VS = 0V, VCM = 0V to 18V ∆IB/∆T Input Bias Current Drift – 40°C ≤ TA ≤ 85°C MIN TYP MAX UNITS 1.5 3.5 4.2 4.5 mV mV mV ● 5 15 µV/°C ● ● 25 50 50 nA µA ● ● 250 225 0.1 500 400 nA µA nA ● 0.4 nA/°C Input Noise Voltage 0.1Hz to 10Hz 1.5 µVP-P en Input Noise Voltage Density f = 10kHz 25 nV/√Hz in Input Noise Current Density f = 10kHz 0.3 pA/√Hz RIN Input Resistance Differential Common Mode, VCM = 0V to (VCC – 1.2V) Common Mode, VCM = 0V to 18V 200 150 80 kΩ MΩ kΩ 5 pF CIN Input Capacitance VCM Input Voltage Range 2 100 45 ● 0 18 V LT1784 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the specified temperature range, otherwise specifications are TA = 25°C. VS = 3V, 0V; VS = 5V, 0V, VCM = VOUT = half supply, for the 6-lead part VPIN5 = 0V, pulse power tested unless otherwise specified. SYMBOL PARAMETER CONDITIONS CMRR VCM = 0V to VCC – 1.2V VCM = 0V to 18V (Note 6) ● ● Common Mode Rejection Ratio (Note 3) MIN TYP 84 60 95 70 MAX UNITS dB dB PSRR Power Supply Rejection Ratio VS = 3V to 12.5V, VCM = VO = 1V ● 90 100 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 1000 ● ● 133 90 60 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 266 180 120 1000 ● ● 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 = 3mA ● ● 2.885 2.600 2.93 2.8 V V VS = 5V, No Load VS = 5V, ISOURCE = 10mA ● ● 4.885 4.400 4.93 4.7 V V VS = 3V, Short to GND VS = 3V, Short to VCC 4 15 7.5 30 mA mA VS = 5V, Short to GND VS = 5V, Short to VCC 12.5 20.0 22 40 mA mA ISC Short-Circuit Current (Note 2) Minimum Supply Voltage Reverse Supply Voltage IS ISHDN 4 200 350 2.5 ● IS = –100µA Supply Current (Note 4) ● 10 400 600 2.7 18 mV mV mV V V 500 750 900 µA µA ● Supply Current, Shutdown VPIN5 = 2V, No Load (Note 8) ● 7 18 µA SHDN Pin Current VPIN5 = 0.3V (On), No load (Note 8) VPIN5 = 2V (Shutdown), No Load (Note 8) VPIN5 = 5V (Shutdown), No Load (Note 8) ● ● 0.5 2.0 5.0 8 nA µA µA VPIN5 = 2V, No Load (Note 8) ● 0.05 1 µA 10 30 µA 0.3 V Output Leakage Current, Shutdown Maximum SHDN Pin Current VPIN5 = 18V, No Load (Note 8) ● VIL SHDN Pin Input Low Voltage (Note 8) ● VIH SHDN Pin Input High Voltage (Note 8) ● tON Turn-On Time VPIN5 = 5V to 0V, RL = 10k (Note 8) 18 µs tOFF Turn-Off Time VPIN5 = 0V to 5V, RL = 10k (Note 8) 2.2 µs GBW Gain Bandwidth Product (Note 4) f = 5kHz 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C 1.5 1.2 1.1 2.5 ● ● MHz MHz MHz Slew Rate (Note 5) AV = –1, RL = ∞ 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C 1.2 1.1 1.0 2.1 ● ● V/µs V/µs V/µs FPBW Full-Power Bandwidth (Note 9) VOUT = 2VP-P 350 kHz tS Settling Time VS = 5V, ∆VOUT = 2V to 0.1%, AV = –1 3.7 µs THD Distortion VS = 3V, VO = 1.8VP-P, AV = 1, RL = 10k, f = 1kHz 0.001 % SR 2 V 3 LT1784 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the specified temperature range, otherwise specifications are TA = 25°C. VS = ±5V, VCM = 0V,VOUT = 0V, for the 6-lead part VPIN5 = V –, pulse power tested unless otherwise specified. SYMBOL PARAMETER CONDITIONS VOS TA = 25°C 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● –40°C ≤ TA ≤ 85°C Input Offset Voltage ∆VOS/∆T Input Offset Voltage Drift (Note 7) MIN TYP MAX UNITS 1.6 3.75 4.50 4.80 mV mV mV ● 5 15 µV/°C ● 25 50 nA ● 250 500 ● 0.4 nA/°C 1.5 µVP-P IOS Input Offset Current IB Input Bias Current ∆IB/∆T Input Bias Current Drift 0°C ≤ TA ≤ 70°C Input Noise Voltage 0.1Hz to 10Hz en Input Noise Voltage Density f = 1kHz 25 nV/√Hz in Input Noise Current Density f = 1kHz 0.3 pA/√Hz RIN Input Resistance Differential Common Mode, VCM = –5V to 13V 200 80 kΩ kΩ CIN Input Capacitance 5 pF VCM Input Voltage Range ● ● 100 45 ● –5 13 nA V CMRR Common Mode Rejection Ratio VCM = –5V to 13V ● 60 70 dB AVOL Large-Signal Voltage Gain VO = ±4V, RL= 10k 0°C ≤ TA ≤ 70°C 100 ● 50 35 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 ● ● ● 4.885 4.550 4.400 4.92 4.75 4.65 ISC Short-Circuit Current (Note 2) Short to GND 0°C ≤ TA ≤ 70°C 15 10 27 ● mA mA VS = ±1.5V to ±9V ● 90 100 dB PSRR Power Supply Rejection Ratio IS Supply Current – 4.996 – 4.800 – 4.650 – 4.99 – 4.60 – 4.40 V V V V V V 540 800 975 µA µA ● Supply Current, Shutdown VPIN5 = –3V, VS = ±5V, No Load (Note 8) ● 8 20 µA SHDN Pin Current VPIN5 = –4.7V (On), VS = ±5V, No load (Note 8) VPIN5 = –3V (Shutdown), VS = ±5V, No Load (Note 8) ● ● 0.5 2.0 8 nA µA Maximum SHDN Pin Current VPIN5 = 9V, VS = ±9V (Note 8) ● 10 30 µA Output Leakage Current, Shutdown VPIN5 = –7V, VS = ±9V, No Load (Note 8) ● 0.05 1 µA VIL SHDN Pin Input Low Voltage VS = ±5V (Note 8) ● – 4.7 V VIH SHDN Pin Input High Voltage VS = ±5V (Note 8) ● tON Turn-On Time VPIN5 = 0V to –5V, RL = 10k (Note 8) ● 18 µs tOFF Turn-Off Time VPIN5 = –5V to 0V, RL = 10k (Note 8) ● 2.2 µs GBW Gain Bandwidth Product f = 5kHz 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C 2.6 ● ● MHz MHz MHz ISHDN 4 –3 1.55 1.30 1.20 V LT1784 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the specified temperature range, otherwise specifications are TA = 25°C. VS = ±5V, VCM = 0V,VOUT = 0V, for the 6-lead part VPIN5 = V –, pulse power tested unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP SR AV = –1, RL = ∞, VO = ±4V, Measured at VO = ±2V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C 1.3 1.2 1.1 2.2 V/µs V/µs V/µs Slew Rate ● ● MAX UNITS FPBW Full-Power Bandwidth (Note 9) VOUT = 8VP-P 94 kHz tS Settling Time VS = 5V, ∆VOUT = 4V to 0.1%, AV = 1 3.4 µs 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: VS = 5V limits are guaranteed by correlation to VS = 3V and VS = ±5V or VS = ±9V tests. Note 4: VS = 3V limits are guaranteed by correlation to VS = 5V and VS = ±5V or VS = ±9V tests. Note 5: Guaranteed by correlation to slew rate at VS = ±5V, and GBW at VS = 5V and VS = ±5V tests. Note 6: This specification implies a typical input offset voltage of 5.7mV at VCM = 18V and a maximum input offset voltage of 18mV at VCM = 18V. Note 7: This parameter is not 100% tested. Note 8: Specifications apply to 6-lead SOT-23 with shutdown. Note 9: Full-power bandwidth is calculated from the slew rate. FPBW = SR/2πVP. Note 10: The LT1784C is guaranteed functional over the operating temperature range – 40°C to 85°C. Note 11: The LT1784C is guaranteed to meet specified performance from 0°C to 70°C. The LT1784C 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. LT1784I is guaranteed to meet specified performance from – 40°C to 85°C. U W TYPICAL PERFOR A CE CHARACTERISTICS Supply Current vs Supply Voltage 700 5 TA = 125°C 600 TA = 25°C 550 500 TA = –55°C 450 400 350 300 VS = 5V, 0V 300 4 200 100 TA = 125°C 0 TA = –55°C VOUT (V) INPUT OFFSET VOLTAGE CHANGE (µV) 400 650 SUPPLY CURRENT (µA) Output Voltage vs Large Input Voltage Minimum Supply Voltage TA = 25°C –100 4 8 10 12 14 6 SUPPLY VOLTAGE (V) 16 18 1784 G01 2 5V VIN –200 1 + – –300 –400 2 3 1 3 2 4 TOTAL SUPPLY VOLTAGE (V) 5 1784 G02 0 –10 –6 –2 6 2 VIN (V) 10 14 18 1784 G03 5 LT1784 U W TYPICAL PERFOR A CE CHARACTERISTICS Input Bias Current vs Common Mode Voltage 1 OUTPUT SATURATION VOLTAGE (V) VS = 5V, 0V INPUT BIAS CURRENT (nA) 200,000 150,000 100,000 TA = 25°C 800 TA = –55°C 600 400 TA = 125°C 200 0 1 VS = ±2.5V VOD = 30mV 0.1 OUTPUT SATURATION VOLTAGE (V) 300,000 250,000 Output Saturation Voltage vs Load Current (Output Low) Output Saturation Voltage vs Load Current (Output High) TA = 125°C TA = 25°C TA = –55°C –200 –400 3.5 0.01 4.5 5 5.5 14 16 18 4 COMMON MODE VOLTAGE (V) 1 100 10 1000 SOURCING LOAD CURRENT (µA) 10000 Output Saturation Voltage vs Input Overdrive 0.01 TA = –55°C 0.001 1 OUTPUT LOW 0.1Hz to 10Hz Noise Voltage VS = ±2.5V VS = ±5V 40 SINKING 35 30 VS = ±2.5V NO LOAD SOURCING 20 30 40 50 INPUT OVERDRIVE (mV) 25 –50 –25 60 50 75 0 25 TEMPERATURE (°C) 1784 G07 1.6 60 50 40 30 20 10 0 100 1k FREQUENCY (Hz) 10k 100k 1784 G10 6 2 3 4 5 6 TIME (sec) 7 8 10 9 1784 G09 Gain and Phase Shift vs Frequency 70 VS = ±2.5V VS = ±2.5V 60 1.4 50 1.2 1.0 GAIN (dB) 70 1 0.8 0.6 0.4 120 100 80 PHASE 40 60 30 40 20 20 GAIN 10 0 PHASE (DEG) INPUT NOISE CURRENT DENSITY (pA/√Hz) 80 10 0 125 Input Noise Current vs Frequency VS = ±2.5V 1 100 DC194 G02 Noise Voltage Density vs Frequency 90 10000 NOISE VOLTAGE (400nV/DIV) 10 100 10 100 1000 SINKING LOAD CURRENT (µA) 1784 G06 45 OUTPUT CURRENT (mA) OUTPUT SATURATION VOLTAGE (mV) 50 OUTPUT HIGH 1 INPUT NOISE VOLTAGE DENSITY (nV/√Hz) TA = 25°C Output Short-Circuit Current vs Temperature 100 10 TA = 125°C 0.1 1784 G05 1784 G04 0 VS = ±2.5V VOD = 30mV 0 –20 –10 –40 0.2 –20 –60 0 –30 1 10 100 1k FREQUENCY (Hz) 10k 100k 1784 G11 1k 10k 100k 1M FREQUENCY (Hz) –80 10M 1784 G12 LT1784 U W TYPICAL PERFOR A CE CHARACTERISTICS Gain Bandwidth Product vs Temperature 3.0 VS = ±5V GAIN BANDWIDTH PRODUCT (MHz) VS = ±2.5V f = 5kHz 2.7 SLEW RATE (V/µs) RISING 2.6 2.5 2.4 2.5 FALLING 2.0 2.3 50 25 75 0 TEMPERATURE (°C) 100 1.5 –50 –25 125 50 25 75 0 TEMPERATURE (°C) 100 1784 G13 VS = ±2.5V AV = –1 RF = RG = 10k f = 5kHz 2.2 2.0 10k LOAD RESISTANCE (Ω) 1k POWER SUPPLY REJECTION RATIO (dB) GAIN BANDWIDTH PRODUCT PHASE MARGIN (DEG) GAIN BANDWIDTHPRODUCT (MHz) 60 55 2.4 80 2.5 CMRR vs Frequency 120 POSITIVE SUPPLY 50 40 NEGATIVE SUPPLY 30 20 10 0 –10 10k 100k FREQUENCY (Hz) 1k 100 90 80 70 60 50 40 30 20 10k 1M 1M AV = 10 1 AV = 1 1M Settling Time to 0.1% vs Output Step 5 VS = ±2.5V VPIN 5 = 2.5V VS = ±5V 4 AV = 1 3 100k OUTPUT STEP (V) OUTPUT IMPEDANCE (Ω) 10 100k FREQUENCY (Hz) 1784 G18 Disabled Output Impedance vs Frequency AV = 100 VS = ±2.5V 110 1784 G17 VS = ±2.5V 18 1784 G15 60 100k 100 6 4 8 10 12 14 16 TOTAL SUPPLY VOLTAGE (V) 2 0 VS = ±2.5V 70 Output Impedance vs Frequency OUTPUT IMPEDANCE (Ω) 2.6 2.4 125 1784 G16 1k GAIN BANDWIDTH PRODUCT 2.7 PSRR vs Frequency 90 65 2.6 60 1784 G14 Gain Bandwidth and Phase Margin vs Load Resistance PHASE MARGIN PHASE MARGIN 55 COMMON MODE REJECTION RATIO (dB) 2.2 –50 –25 65 AV = –1 RF = RG = 10k f = 5kHz PHASE MARGIN (DEG) GAIN BANDWIDTH PRODUCT (MHz) 2.8 Gain Bandwidth Product and Phase Margin vs Supply Voltage Slew Rate vs Temperature 10k 1k AV = –1 2 1 0 –1 –2 AV = 1 –3 0.1 AV = –1 –4 0.01 100 1k 10k 100k FREQUENCY (Hz) 1M 1784 G19 100 100 –5 1k 10k 100k FREQUENCY (Hz) 1M 1784 G20 0 1 2 4 6 5 3 SETTLING TIME (µs) 7 8 1784 G21 7 LT1784 U W TYPICAL PERFOR A CE CHARACTERISTICS Capacitive Load Handling Overshoot vs Capacitive Load 12 AV = 1 10 OVERSHOOT (%) 50 40 AV = 5 30 20 AV = 10 10 100 CAPACITIVE LOAD (pF) 8 6 VS = ±2.5V 4 0 1000 1k 10k 100k FREQUENCY (Hz) 1784 G22 VS = ±1.5V VIN = ±1V 10 THD + NOISE (%) THD + NOISE (%) 0.001 0.0001 100 FREQUENCY = 1kHz VCM = HALF SUPPLY AV = 1 VS = 3V, 0V 0.1 AV = –1 VS = 3V, 0V RF = RG = 10k AV = 1 VS = ±1.5V AV = –1 VS = ±1.5V RF = RG = 10k 0.01 0.001 1k 10k 100k 0 LOAD RESISTANCE TO GROUND (Ω) 1 2 OUTPUT VOLTAGE AMPLITUDE (VP-P) Supply Current vs SHDN Pin Voltage 600 AV = 1 0.001 0.0001 10 100 1k 10k FREQUENCY (Hz) Open-Loop Gain 3 VS = ±5V RL = 2k RL = 10k RL = 50k –6 –5 –4 –3 –2 –1 0 1 2 3 OUTPUT VOLTAGE (V) Small Signal Response Large Signal Response TA = 125°C 500 TA = 25°C 450 400 TA = –55°C 350 20mV/DIV 2V/DIV 300 250 200 150 100 VS = ±5V AV = 1 CL = 15pF 50 0 0 2 0.5 1.5 1 SHUTDOWN PIN VOLTAGE (V) 2.5 1784 G28 8 5µs/DIV 4 5 6 1784 G27 VS = 5V, 0V 550 100k 1784 G24 1784 G26 1784 G25 SUPPLY CURRENT (µA) 1M 1 0.1 VS = 3V, 0V VIN = 0.1V TO 2.1V AV = –1 Total Harmonic Distortion + Noise vs Output Voltage Amplitude AV = 1 VS = 3V TOTAL VIN = 2VP-P AT 1kHz 0.01 0.01 1784 G23 Total Harmonic Distortion + Noise vs Load Resistance 1 RL = 10k VS = 3V, 0V VOUT = 1.8VP-P VCM = 1V 2 0 10 VS = ±5V THD + NOISE (%) 60 0.1 DISTORTION ≤ 1% AV = 1 INPUT OFFSET VOLTAGE CHANGE (50µV/DIV) VS = 5V, 0V VCM = 2.5V OUTPUT SWING (VP-P) 70 Total Harmonic Distortion + Noise vs Frequency Undistorted Output Swing vs Frequency VS = ±5V AV = 1 CL = 15pF 2µs/DIV LT1784 U W U U APPLICATIO S I FOR ATIO Supply Voltage Output The positive supply pin of the LT1784 should be bypassed with a small capacitor (typically 0.1µF) within an inch of the pin. When driving heavy loads, and additional 4.7µF electrolytic capacitor should be used. When using split supplies the same is true for the negative supply pin. The output of the LT1784 can swing to within 80mV of the positive rail and within 4mV of the negative rail with no load. When monitoring input voltages within 80mV of the positive rail or within 4mV of the negative rail, gain should be taken to keep the output from clipping. The LT1784 can typically sink and source over 25mA at ±5V supplies, sourcing current is reduced to 7.5mA at 3V total supplies as noted in the electrical characteristics. The LT1784 is protected against reverse battery voltages up to 18V. In the event a reverse battery condition occurs the supply current is less than 1nA. Inputs The LT1784 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 Characteristic Curve. For input voltages about 1V or more below V +, the PNP input stage is active and the input bias current is typically –250nA. When the input common mode voltage is within 0.6V of the positive rail, the NPN stage is operating and the input bias current is typically 500nA. Increases in temperature will cause the voltage at which operation switches from the PNP input stage to the NPN input stage to move towards V +. The input offset voltage of the NPN stage is untrimmed and is typically 3mV. A Schottky diode in the collector of the input transistors, along with special geometries for these NPN transistors, allow the LT1784 to operate with either or both of its inputs above V +. At about 0.3V above V +, the NPN input transistors is fully saturated and the input bias current is typically 200µA at room temperature. The input offset voltage is typically 3mV when operating above V +. The LT1784 will operate with inputs 18V above V – regardless of V+. The inputs are protected against excursions as much as 10V below V – by an internal 1k resistor in series with each input and a diode from the input to the negative supply. The input stage of the LT1784 incorporates phase reversal protection to prevent the output from phase reversing for inputs up to 9V below V –. There are no clamping diodes between the inputs and the maximum differential input voltage is 18V. The LT1784 is internally compensated to drive at least 400pF 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 10,000pF at all output currents. Distortion There are two main contributors to distortion in op amps: output crossover distortion as the output transitions from sourcing to sinking current, and distortion caused by nonlinear common mode rejection. If the op amp is operating inverting, there is no common mode induced distortion. If the op amp is operating in the PNP input stage (input not within 1V of V +), the CMRR is very good, typically 95dB. When the LT1784 switches between input stages, there is significant nonlinearity in the CMRR. Lower load resistance increases the output crossover distortion but has no effect on the input stage transition distortion. For lowest distortion, the LT1784 should be operated single supply, with the output always sourcing current and with the input voltage swing between ground and (V + –1V). See Typical Performance Characteristics Curve, “Total Harmonic Distortion + Noise vs Output Voltage Amplitude.” Gain The open-loop gain is almost independent of load when the output is sourcing current. This optimizes performance in single supply applications where the load is returned to ground. The Typical Performance Characteric Curve “Open-Loop Gain” for various loads shows the details. 9 LT1784 U W U U APPLICATIO S I FOR ATIO Shutdown The 6-lead part includes a shutdown feature that disables the part, reducing quiescent current and making the output high impedance. The part can be shut down by bringing the SHDN pin 1.2V or more above V –. When shut down, the supply current is less than 1µA (V – ≤ VOUT ≤ V +). In normal operation, the SHDN pin can be tied to V – or left floating. See Typical Performance Characteristics Curve, “Supply Current vs SHDN pin Voltage.” U TYPICAL APPLICATIO S Adjustable Clamp Negative Rectifier V+ – LT1784 + – - ~80mV OUT LT1784 + VIN + VIN 10k V– VOUT LT1784 WORKS WELL TO 100kHz V– VCLAMP – VCLAMP - ~80mV 10k WORKS WELL TO 100kHz V– 1784 TA07 W W SI PLIFIED SCHE ATIC V+ Q2 Q1 Q3 Q22 D1 SHDN R1 6k D3 R2 1k Q4 R6 1.5k R7 1.5k Q17 Q20 + J1 Q19 – IN Q7 R3 1k 20µA Q11 Q8 OUT Q12 Q16 Q18 +IN R8 0.75k Q9 Q26 Q25 Q23 Q24 Q5 Q6 D4 D5 R9 0.75k Q10 Q15 Q13 Q14 R4 2k Q21 R5 2k V– 1784 SS 10 LT1784 U PACKAGE DESCRIPTIO S5 Package 5-Lead Plastic SOT-23 (Reference LTC DWG # 05-08-1633) (Reference LTC DWG # 05-08-1635) 2.80 – 3.10 (.110 – .118) (NOTE 3) A SOT-23 (Original) .90 – 1.45 (.035 – .057) SOT-23 (ThinSOT) 1.00 MAX (.039 MAX) A1 .00 – .15 (.00 – .006) .01 – .10 (.0004 – .004) A2 .90 – 1.30 (.035 – .051) .80 – .90 (.031 – .035) L .35 – .55 (.014 – .021) .30 – .50 REF (.012 – .019 REF) 2.60 – 3.00 (.102 – .118) 1.50 – 1.75 (.059 – .069) (NOTE 3) PIN ONE .95 (.037) REF .25 – .50 (.010 – .020) (5PLCS, NOTE 2) .20 (.008) A DATUM ‘A’ L NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) A2 1.90 (.074) REF .09 – .20 (.004 – .008) (NOTE 2) A1 S5 SOT-23 0401 3. DRAWING NOT TO SCALE 4. DIMENSIONS ARE INCLUSIVE OF PLATING 5. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 6. MOLD FLASH SHALL NOT EXCEED .254mm 7. PACKAGE EIAJ REFERENCE IS: SC-74A (EIAJ) FOR ORIGINAL JEDEC MO-193 FOR THIN S6 Package 6-Lead Plastic SOT-23 (Reference LTC DWG # 05-08-1634) (Reference LTC DWG # 05-08-1636) 2.80 – 3.10 (.110 – .118) (NOTE 3) SOT-23 (Original) SOT-23 (ThinSOT) A .90 – 1.45 (.035 – .057) 1.00 MAX (.039 MAX) A1 .00 – 0.15 (.00 – .006) .01 – .10 (.0004 – .004) A2 .90 – 1.30 (.035 – .051) .80 – .90 (.031 – .035) L .35 – .55 (.014 – .021) .30 – .50 REF (.012 – .019 REF) 2.60 – 3.00 (.102 – .118) 1.50 – 1.75 (.059 – .069) (NOTE 3) PIN ONE ID .95 (.037) REF .25 – .50 (.010 – .020) (6PLCS, NOTE 2) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) .20 (.008) A DATUM ‘A’ L .09 – .20 (.004 – .008) (NOTE 2) A2 1.90 (.074) REF A1 S6 SOT-23 0401 3. DRAWING NOT TO SCALE 4. DIMENSIONS ARE INCLUSIVE OF PLATING 5. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 6. MOLD FLASH SHALL NOT EXCEED .254mm 7. PACKAGE EIAJ REFERENCE IS: SC-74A (EIAJ) FOR ORIGINAL JEDEC MO-193 FOR THIN 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. 11 LT1784 U TYPICAL APPLICATIO S Protected Fault Conditions 5V V+ + + LT1784 5V V+ LT1784 – 24V + 18V + – 5V + + LT1784 LT1784 – – 10V + –18V 1784 TA02 REVERSE BATTERY INPUT OVERVOLTAGE INPUT DIFFERENTIAL VOLTAGE Simple Peak Detector Single Supply Full Wave Rectifier 1k 5V OUT + VIN INPUTS BELOW GROUND ACCURACY 98% 90% 3dB LT1784 – BAT54 BANDWIDTH 3kHz TO 5.7kHz 116Hz TO 47kHz 34Hz TO 96kHz 1k 1k IN – LT1784 VOUT 1µF BAT54 5V + WORKS WELL TO 15kHz 100k VIN = 3VP-P, VCM = 2.5V 1785 TA05 1784 TA04 Simple Polarity Selector 1k V+ 1k IN IN 1V/DIV – LT1784 + SHDN V– OUT FOLLOW INVERT OUT 1V/DIV 0V V– SHDN 5V/DIV 1785 TA06a 100µs/DIV VS = ±5V VIN = 3VP-P AT 5kHz 1785 TA06b RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1782 Micropower Over-The-Top Rail-to-Rail In/Out Op Amp in SOT-23 55µA Max Supply Current, 800µV Max Offset Voltage LT1783 1.25MHz Over-The-Top Rail-to-Rail In/Out Op Amp in SOT-23 300µA Max Supply Current, 800µV Max Offset Voltage LT1797 10MHz Rail-to-Rail In/Out Op Amp in SOT-23 Unity-Gain Stable, 2.25µV/µs Slew Rate LT1637 1.1MHz Over-The-Top Rail-to-Rail In/Out Op Amp Micropower, 0.4V/µs Slew Rate LT1638/LT1639 Dual/Quad 1.2MHz Over-The-Top Rail-to-Rail In/Out Op Amp Micropower 230µA Max, 0.4V/µs Slew Rate LT1880 SOT-23 Pico Amp Input, Precision, Rail-to-Rail Output Op Amp 150µV Offset, 900pA Bias Current 12 Linear Technology Corporation 1784f LT/TP 0601 2K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2000