LT1784 2.5MHz, Over-The-Top Low Power, Rail-to-Rail Input and Output Op Amp in SOT-23 DESCRIPTION FEATURES n n n n n n n n n n n n n n Operates with Inputs Above V+ Rail-to-Rail Input and Output 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 Low Profile (1mm) ThinSOT™ Package n n n n n The input range of the LT1784 includes ground, and a unique feature of this device is its Over-The-Top® 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. APPLICATIONS n 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. Portable Instrumentation Battery-Powered Systems Sensor Conditioning Supply Current Sensing MUX Amplifiers 4mA to 20mA Transmitters L, LT, LTC, LTM, Linear Technology, the Linear logo and Over-The-Top are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Programmable Gain, AV = 2, AV = 20, 100kHz Amplifier Programmable Gain Amplifier Frequency Response VCC AV = 20 30 AV = 2 25 SHDN 15 SHDN OUT LT1784 VCC – + VEE 10 5 AV = 2 0 –5 LT1782 –10 – VEE R1 R2 9.09k 10k GAIN (dB) + IN AV = 20 20 VCC AV = 1+ OR 1+ ( ( R1 + R2 R3 R1 R2 + R3 ) ) –15 –20 1k 10k 100k 1M FREQUENCY (Hz) 10M 1784 TA01b R3 1k 1784 TA01a 1784fa 1 LT1784 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 PIN CONFIGURATION TOP VIEW TOP VIEW 5 V+ OUT 1 V– 2 V– 2 + – +IN 3 + 6 V OUT 1 + – 4 –IN +IN 3 4 –IN 5 SHDN S6 PACKAGE 6-LEAD PLASTIC TSOT-23 S5 PACKAGE 5-LEAD PLASTIC TSOT-23 TJMAX = 150°C, θJA = 230°C/W TJMAX = 150°C, θJA = 250°C/W ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1784CS5#PBF LT1784CS5#TRPBF LTJD 5-Lead Plastic TSOT-23 –40°C to 85°C LT1784IS5#PBF LT1784IS5#TRPBF LTSN 5-Lead Plastic TSOT-23 –40°C to 85°C LT1784CS6#PBF LT1784CS6#TRPBF LTIW 6-Lead Plastic TSOT-23 –40°C to 85°C LT1784IS6#PBF LT1784IS6#TRPBF LTIX 6-Lead Plastic TSOT-23 –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at 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 Input Offset Voltage ΔVOS /ΔT IOS Input Offset Voltage Drift (Note 7) TA = 25°C 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C –40°C ≤ TA ≤ 85°C Input Offset Current VCM = 18V (Note 3) MIN l l TYP MAX UNITS 1.5 3.5 4.2 4.5 15 mV mV mV μV/°C 50 50 nA μA l 5 l l 25 1784fa 2 LT1784 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at 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 IB Input Bias Current ΔIB /ΔT Input Bias Current Drift en in RIN Input Noise Voltage Input Noise Voltage Density Input Noise Current Density Input Resistance CIN VCM CMRR PSRR AVOL Input Capacitance Input Voltage Range Common Mode Rejection Ratio (Note 3) Power Supply Rejection Ratio Large-Signal Voltage Gain VOL Output Voltage Swing LOW VOH Output Voltage Swing HIGH ISC Short-Circuit Current (Note 2) IS Minimum Supply Voltage Reverse Supply Voltage Supply Current (Note 4) Supply Current, Shutdown SHDN Pin Current ISHDN VIL VIH tON tOFF Output Leakage Current, Shutdown Maximum SHDN Pin Current SHDN Pin Input Low Voltage SHDN Pin Input High Voltage Turn-On Time Turn-Off Time CONDITIONS VCM = 18V (Note 3) SHDN or VS = 0V, VCM = 0V to 18V –40°C ≤ TA ≤ 85°C MIN l l l 0.1Hz to 10Hz f = 10kHz f = 10kHz Differential Common Mode, VCM = 0V to (VCC – 1.2V) Common Mode, VCM = 0V to 18V 100 45 l VCM = 0V to VCC – 1.2V VCM = 0V to 18V (Note 6) VS = 3V to 12.5V, VCM = VO = 1V VS = 3V, VO = 500mV to 2.5V, RL = 10k VS = 3V, 0°C ≤ TA ≤ 70°C VS = 3V, –40°C ≤ TA ≤ 85°C VS = 5V, VO = 500mV to 4.5V, RL = 10k VS = 5V, 0°C ≤ TA ≤ 70°C VS = 5V, –40°C ≤ TA ≤ 85°C No Load ISINK = 5mA VS = 5V, ISINK = 10mA VS = 3V, No Load VS = 3V, ISOURCE = 3mA VS = 5V, No Load VS = 5V, ISOURCE = 10mA VS = 3V, Short to GND VS = 3V, Short to VCC VS = 5V, Short to GND VS = 5V, Short to VCC l l l l l l l 0 84 60 90 133 90 60 266 180 120 l l l l l 2.885 2.600 l 4.885 l 4.400 4 15 12.5 20.0 l IS = –100μA l l VPIN5 = 2V, No Load (Note 8) VPIN5 = 18V, No Load (Note 8) (Note 8) (Note 8) VPIN5 = 5V to 0V, RL = 10k (Note 8) VPIN5 = 0V to 5V, RL = 10k (Note 8) l MAX UNITS 250 225 0.1 0.4 500 400 nA μA nA nA/°C 1.5 25 0.3 200 150 80 5 18 95 70 100 1000 1000 4 200 350 2.93 2.8 4.93 4.7 7.5 30 22 40 2.5 10 400 600 500 750 900 18 7 0.5 2.0 5.0 l l 0.05 10 l l l 2.7 18 l VPIN5 = 2V, No Load (Note 8) VPIN5 = 0.3V (On), No Load (Note 8) VPIN5 = 2V (Shutdown), No Load (Note 8) VPIN5 = 5V (Shutdown), No Load (Note 8) TYP 2 18 2.2 8 1 30 0.3 μVP-P nV/√Hz pA/√Hz kΩ MΩ kΩ pF V dB dB dB V/mV V/mV V/mV V/mV V/mV V/mV mV mV mV V V V V mA mA mA mA V V μA μA μA nA μA μA μA μA V V μs μs 1784fa 3 LT1784 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at 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 MIN TYP GBW Gain Bandwidth Product (Note 4) f = 5kHz 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C l l 2.5 SR Slew Rate (Note 5) l l FPBW tS Full-Power Bandwidth (Note 9) Settling Time AV = –1, RL = ∞ 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C VOUT = 2VP-P 1.5 1.2 1.1 1.2 1.1 1.0 THD Distortion VS = 5V, ΔVOUT = 2V to 0.1%, AV = –1 VS = 3V, VO = 1.8VP-P , AV = 1, RL = 10k, f = 1kHz MAX UNITS MHz MHz MHz V/μs V/μs V/μs 2.1 350 3.7 kHz μs 0.001 % The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at 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 Input Offset Voltage ΔVOS/ΔT IOS IB Input Offset Voltage Drift (Note 7) TA = 25°C 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C –40°C ≤ TA ≤ 85°C ΔIB/ΔT Input Offset Current Input Bias Current Input Bias Current Drift en in RIN Input Noise Voltage Input Noise Voltage Density Input Noise Current Density Input Resistance CIN VCM CMRR AVOL Input Capacitance Input Voltage Range Common Mode Rejection Ratio Large-Signal Voltage Gain VOL Output Voltage Swing LOW VOH Output Voltage Swing HIGH ISC Short-Circuit Current (Note 2) PSRR IS Power Supply Rejection Ratio Supply Current ISHDN Supply Current, Shutdown SHDN Pin Current Maximum SHDN Pin Current Output Leakage Current, Shutdown MIN l l 0°C ≤ TA ≤ 70°C VCM = –5V to 13V VO = ±4V, RL = 10k 0°C ≤ TA ≤ 70°C No Load ISINK = 5mA ISINK = 10mA No Load ISOURCE = 5mA ISOURCE = 10mA Short to GND 0°C ≤ TA ≤ 70°C VS = ±1.5V to ±9V UNITS 3.75 4.50 4.80 15 mV mV mV μV/°C 50 500 nA nA nA/°C 5 l 25 250 0.4 l l l 100 45 l –5 60 50 35 l l l l l l l l 4.885 4.550 4.400 15 l 10 l 90 l VPIN5 = –3V, VS = ±5V, No Load (Note 8) VPIN5 = –4.7V (On), VS = ±5V, No Load (Note 8) VPIN5 = –3V (Shutdown), VS = ±5V, No Load (Note 8) VPIN5 = 9V, VS = ±9V (Note 8) VPIN5 = –7V, VS = ±9V, No Load (Note 8) MAX 1.6 l l 0.1Hz to 10Hz f = 1kHz f = 1kHz Differential Common Mode, VCM = –5V to 13V TYP l l l l l 1.5 25 0.3 200 80 5 13 70 100 –4.996 –4.800 –4.650 4.92 4.75 4.65 27 100 540 8 0.5 2.0 10 0.05 –4.99 –4.60 –4.40 800 975 20 8 30 1 μVP-P nV/√Hz pA/√Hz kΩ kΩ pF V dB V/mV V/mV V V V V V V mA mA dB μA μA μA nA μA μA μA 1784fa 4 LT1784 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at 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 VIL VIH tON tOFF GBW SHDN Pin Input Low Voltage SHDN Pin Input High Voltage Turn-On Time Turn-Off Time Gain Bandwidth Product VS = ±5V (Note 8) VS = ±5V (Note 8) VPIN5 = 0V to –5V, RL = 10k (Note 8) VPIN5 = –5V to 0V, RL = 10k (Note 8) f = 5kHz 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C MIN SR Slew Rate FPBW tS Full-Power Bandwidth (Note 9) Settling Time AV = –1, RL = ∞, VO = ±4V, Measured at VO = ±2V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C VOUT = 8VP-P TYP l l UNITS –4.7 V V μs μs MHz MHz MHz V/μs V/μs V/μs –3 l 18 2.2 2.6 l 1.55 1.30 1.20 1.3 1.2 1.1 l l l l 2.2 94 3.4 VS = 5V, ΔVOUT = 4V to 0.1%, AV = 1 Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. 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. MAX kHz μs 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. TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs Supply Voltage 5 400 650 TA = 125°C 600 TA = 25°C 550 500 TA = –55°C 450 400 350 VS = 5V, 0V 300 4 200 100 TA = 125°C 0 TA = –55°C VOUT (V) INPUT OFFSET VOLTAGE CHANGE (μV) 700 SUPPLY CURRENT (μA) Output Voltage vs Large Input Voltage Minimum Supply Voltage TA = 25°C –100 2 4 6 8 10 12 14 SUPPLY VOLTAGE (V) 16 18 1784 G01 2 5V VIN –200 1 + – –300 –400 300 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 1784fa 5 LT1784 TYPICAL PERFORMANCE CHARACTERISTICS Output Saturation Voltage vs Load Current (Output High) 1 300,000 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 VS = 5V, 0V OUTPUT SATURATION VOLTAGE (V) 250,000 Output Saturation Voltage vs Load Current (Output Low) 0.1 OUTPUT SATURATION VOLTAGE (V) Input Bias Current vs Common Mode Voltage TA = 125°C TA = 25°C TA = –55°C VS = p2.5V VOD = 30mV TA = 125oC 0.1 TA = 25oC 0.01 TA = –55oC –200 0.01 –400 3.5 4.5 5 5.5 14 16 18 4 COMMON MODE VOLTAGE (V) 1 10 1000 100 SOURCING LOAD CURRENT (μA) 0.001 1 Output Saturation Voltage vs Input Overdrive 100 0.1Hz to 10Hz Noise Voltage 50 VS = ±2.5V VS = ±5V OUTPUT HIGH NOISE VOLTAGE (400nV/DIV) OUTPUT CURRENT (mA) 45 OUTPUT LOW 40 SINKING 35 30 VS = ±2.5V NO LOAD SOURCING 1 0 10 20 30 40 50 INPUT OVERDRIVE (mV) 25 –50 60 –25 75 50 25 0 TEMPERATURE (°C) 100 1784 G07 60 50 40 30 20 10 0 1 10 100 1k FREQUENCY (Hz) 10k 100k 1784 G10 3 4 5 6 TIME (sec) 7 8 9 70 VS = ±2.5V 120 VS = ±2.5V 60 1.4 50 1.2 1.0 0.8 0.6 0.4 10 Gain and Phase Shift vs Frequency GAIN (dB) INPUT NOISE CURRENT DENSITY (pA/√Hz) 70 2 100 80 PHASE 40 60 30 40 20 20 GAIN 10 0 PHASE (DEG) INPUT NOISE VOLTAGE DENSITY (nV/√Hz) 1.6 80 1 1784 G09 Input Noise Current vs Frequency VS = ±2.5V 90 0 125 1784 G08 Noise Voltage Density vs Frequency 100 10000 1784 G06 Output Short-Circuit Current vs Temperature 10 10 100 1000 SINKING LOAD CURRENT (µA) 1784 G05 1784 G04 OUTPUT SATURATION VOLTAGE (mV) 10000 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 1784fa 6 LT1784 TYPICAL PERFORMANCE CHARACTERISTICS Gain Bandwidth Product vs Temperature 3.0 VS = ±2.5V f = 5kHz 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 1k 10k LOAD RESISTANCE (Ω) POWER SUPPLY REJECTION RATIO (dB) GAIN BANDWIDTH PRODUCT (MHz) VS = ±2.5V AV = –1 RF = RG = 10k f = 5kHz PHASE MARGIN (DEG) GAIN BANDWIDTH PRODUCT 2.4 2.0 90 60 55 2.2 2.6 2.5 2.4 6 4 8 10 12 14 16 TOTAL SUPPLY VOLTAGE (V) 2 0 80 1784 G15 100k CMRR vs Frequency VS = ±2.5V 70 POSITIVE SUPPLY 60 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 OUTPUT IMPEDANCE (Ω) 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) VS = ±2.5V 10 100k FREQUENCY (Hz) 1784 G18 Disabled Output Impedance vs Frequency AV = 100 VS = ±2.5V 110 1784 G17 Output Impedance vs Frequency 100 18 120 1784 G16 1k GAIN BANDWIDTH PRODUCT 2.7 PSRR vs Frequency 65 PHASE MARGIN 60 1784 G14 Gain Bandwidth and Phase Margin vs Load Resistance 2.6 125 PHASE MARGIN 55 COMMON MODE REJECTION RATIO (dB) 2.2 –50 –25 OUTPUT IMPEDANCE (Ω) GAIN BANDWIDTH PRODUCT (MHz) 2.7 65 AV = –1 RF = RG = 10k f = 5kHz VS = ±5V 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 6 4 3 5 SETTLING TIME (μs) 7 8 1784 G21 1784fa 7 LT1784 TYPICAL PERFORMANCE 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 AV = 1 VS = 3V TOTAL VIN = 2VP-P AT 1kHz THD + NOISE (%) THD + NOISE (%) 0.01 VS = 3V, 0V VIN = 0.1V TO 2.1V 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 1 2 OUTPUT VOLTAGE AMPLITUDE (VP-P) 0.0001 10 100 1k 10k FREQUENCY (Hz) 100k 1784 G24 3 VS = ±5V RL = 2k RL = 10k RL = 50k –6 –5 –4 –3 –2 –1 0 1 2 3 OUTPUT VOLTAGE (V) 1784 G26 1784 G25 Supply Current vs SHDN Pin Voltage 4 5 6 1784 G27 Large Signal Response 600 AV = 1 0.001 Open-Loop Gain AV = 1 VS = 3V, 0V 0.1 LOAD RESISTANCE TO GROUND (Ω) Small Signal Response VS = 5V, 0V 550 TA = 125°C 500 SUPPLY CURRENT (μA) 1M FREQUENCY = 1kHz VCM = HALF SUPPLY 1 0.0001 100 AV = –1 Total Harmonic Distortion + Noise vs Output Voltage Amplitude 0.1 0.001 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 0.1 DISTORTION ≤ 1% AV = 1 VS = ±5V THD + NOISE (%) 60 Total Harmonic Distortion + Noise vs Frequency INPUT OFFSET VOLTAGE CHANGE (50μV/DIV) VS = 5V, 0V VCM = 2.5V OUTPUT SWING (VP-P) 70 Undistorted Output Swing vs Frequency 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) 5μs/DIV 1784 G29 VS = ±5V AV = 1 CL = 15pF 2μs/DIV 1784 G30 2.5 1784 G28 1784fa 8 LT1784 APPLICATIONS INFORMATION 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 section. 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. 1784fa 9 LT1784 APPLICATIONS INFORMATION 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.” TYPICAL APPLICATIONS Negative Rectifier Adjustable Clamp 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 TA02 SIMPLIFIED SCHEMATIC 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 1784fa 10 LT1784 PACKAGE DESCRIPTION S5 Package 5-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1635 Rev B) 0.62 MAX 0.95 REF 2.90 BSC (NOTE 4) 1.22 REF 2.80 BSC 1.4 MIN 3.85 MAX 2.62 REF 1.50 – 1.75 (NOTE 4) PIN ONE RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 TYP 5 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) NOTE: 1. 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 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 1.90 BSC S5 TSOT-23 0302 REV B S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636 Rev B) 0.62 MAX 2.90 BSC (NOTE 4) 0.95 REF 1.22 REF 3.85 MAX 2.62 REF 1.4 MIN 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE ID RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 6 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) 1.90 BSC NOTE: 1. 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 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 S6 TSOT-23 0302 REV B 1784fa 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 TYPICAL APPLICATIONS Protected Fault Conditions 5V V+ + + LT1784 5V V+ LT1784 – 24V 18V + + + LT1784 – + 5V LT1784 – – 10V + –18V 1784 TA03 REVERSE BATTERY INPUT OVERVOLTAGE INPUT DIFFERENTIAL VOLTAGE Simple Peak Detector Simple Supply Full Wave Rectifier 1k 5V OUT + VIN INPUTS BELOW GROUND LT1784 – BAT54 ACCURACY 98% 90% 3dB BANDWIDTH 3kHz TO 5.7kHz 116Hz TO 47kHz 34Hz TO 96kHz 5V 1k 1k IN VIN = 3VP-P, VCM = 2.5V – LT1784 VOUT 1μF BAT54 + 100k WORKS WELL TO 15kHz 1785 TA05 1784 TA04 Simple Polarity Selector 1k V+ 1k IN IN 1V/DIV – LT1784 + OUT FOLLOW SHDN INVERT V– OUT 1V/DIV 0V V– 1785 TA06a SHDN 5V/DIV 1785 TA06b 100μs/DIV VS = ±5V VIN = 3VP-P AT 5kHz 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 1784fa 12 Linear Technology Corporation LT 0609 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2000