LT1674CS#TRPBF

LT1672/LT1673/LT1674 2µA Max, AV ≥ 5 Single, Dual and Quad Over-The-Top Precision Rail-to-Rail Input and Output Op Amps U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Gain of 5 Stable Low Supply Current: 2µA Max per Amplifier Rail-to-Rail Input and Output Low Offset Voltage: 375µV Max Over-The-TopTM Inputs Operate Above V+ Gain Bandwidth Product: 12kHz Wide Supply Range: 2.2V to 36V Single Supply Input Range: – 0.3V to 36V Low Input Bias Current: 250pA Low Input Offset Current: 20pA High AVOL: 100V/mV Minimum Driving 100kΩ Load Output Sources and Sinks 500µA Load Current Reverse Battery Protected to 18V U APPLICATIO S ■ ■ ■ ■ ■ ■ The LT ®1672/LT1673/LT1674 are ultralow power (IS ≤ 2µA) decompensated (AV ≥ 5) op amps with precision specifications. The extremely low supply current is combined with excellent amplifier specifications: input offset voltage is 375µV maximum with a typical drift of only 0.4µV/°C, input offset current is 100pA maximum. A minimum open-loop gain (AVOL) of 100V/mV ensures that gain errors are small. The devices’ characteristics change little over the supply range of 2.2V to ±15V. Supply rejection is 90dB and the common mode rejection ratio is 90dB. Operation is specified for 3V, 5V and ±15V supplies. Reverse battery protection (–18V min) and inputs that operate above the positive supply make the LT1672/ LT1673/LT1674 easy to use in harsh environments. The low bias currents and offset current of the amplifier permit the use of megohm level source resistors without introducing significant errors. Voltage noise at 4µVP-P is remarkably low considering the low supply current. For unity gain stable versions of these amplifiers, see the LT1494/LT1495/LT1496. Battery- or Solar-Powered Systems Portable Instrumentation Remote Sensor Amplifier Micropower Filter Photodiode Amplifier High Impedance Circuits The LT1672 is available in the 8-pin MSOP, PDIP and SO packages. The LT1673 is available in plastic 8-pin PDIP and SO-8 packages with the standard dual op amp pinout. The LT1674 is available in 14-pin 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 TYPICAL APPLICATION TC VOS Distribution Single Supply, 60µW Precision Instrumentation Amplifier 80 120 AMPLIFIERS 70 VS = ±2.5V – 40°C to 85°C 5V 100k* VIN1 + 1M 60 1/2 LT1673 – 1000pF 1M 100k 1M 100k 110k – 100k* VIN2 1/2 LT1673 UNITS 110k 50 5V – LT1672 30 VOUT 20 + 1M 10 1M 5V 0.0047µF 40 LT1389-2.5 + 1672/3/4 TA01 AV = 100 BANDWIDTH = 1kHz CMRR = 65dB AT 120Hz *500V TRANSIENT PROTECTION TOTAL SUPPLY CURRENT = 12µA 0 –1.5 – 0.9 – 0.3 0.3 TC VOS (µV/°C) 0.9 1.5 1672/3/4 TA02 1 LT1672/LT1673/LT1674 W W W AXI U U ABSOLUTE RATI GS (Note 1) Total Supply Voltage (V + to V –) .............................. 36V Differential Input Voltage ......................................... 36V Input Current ...................................................... ±10mA Output Short-Circuit Duration ....................... Continuous Operating Temperature Range (Note 2) .. – 40°C to 85°C Specified Temperature Range (Note 3) ... – 40°C to 85°C Storage Temperature Range ................. – 65°C to 150°C Junction Temperature ........................................... 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U U W PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER TOP VIEW NC –IN +IN V– 1 2 3 4 8 7 6 5 NC V+ OUT NC MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 150°C, θJA = 250°C/ W LT1672CMS8 LT1672IMS8 MS8 PART MARKING LTFH LTFJ ORDER PART NUMBER TOP VIEW OUT A 1 8 –IN A 2 A +IN A 3 V– 4 N8 PACKAGE 8-LEAD PDIP V+ 7 OUT B 6 –IN B 5 +IN B B S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 150°C/ W (N8) TJMAX = 150°C, θJA = 190°C/ W (S8) LT1673CN8 LT1673CS8 LT1673IN8 LT1673IS8 S8 PART MARKING 1673 1673I ORDER PART NUMBER TOP VIEW NC 1 8 NC –IN 2 7 V+ +IN 3 6 OUT V– 4 5 NC N8 PACKAGE 8-LEAD PDIP LT1672CN8 LT1672CS8 LT1672IN8 LT1672IS8 S8 PART MARKING S8 PACKAGE 8-LEAD PLASTIC SO 1672 1672I TJMAX = 150°C, θJA = 130°C/ W (N8) TJMAX = 150°C, θJA = 190°C/ W (S8) ORDER PART NUMBER TOP VIEW 14 OUT D OUT A 1 –IN A 2 +IN A 3 A D V+ 4 +IN B 5 LT1674CN LT1674CS LT1674IN LT1674IS 13 –IN D 12 +IN D 11 V – B C 10 +IN C –IN B 6 9 –IN C OUT B 7 8 OUT C N PACKAGE 14-LEAD PDIP S PACKAGE 14-LEAD PLASTIC SO TJMAX = 150°C, θJA = 110°C/ W (N) TJMAX = 150°C, θJA = 150°C/ W (S) Consult factory for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS TA = 25°C, VS = 5V, 0V; VS = 3V, 0V; VCM = VO = half supply, unless otherwise noted. SYMBOL VOS PARAMETER Input Offset Voltage IB Input Bias Current IOS Input Offset Current Input Noise Voltage 2 CONDITIONS VS = 5V VS = 3V VS = 5V, MS8 Package VS = 3V, MS8 Package (Note 5) VCM = 10V (Note 6) (Note 5) 0.1Hz to 10Hz MIN TYP 150 200 150 200 250 180 20 4 MAX 375 475 475 575 1000 360 100 UNITS µV µV µV µV pA nA pA µVP-P LT1672/LT1673/LT1674 ELECTRICAL CHARACTERISTICS TA = 25°C, VS = 5V, 0V; VS = 3V, 0V; VCM = VO = half supply, unless otherwise noted. SYMBOL en in AVOL PARAMETER Input Noise Voltage Density Input Noise Current Density Large-Signal Voltage Gain CMRR Input Voltage Range Common Mode Rejection Ratio PSRR VOL VOH ISC IS SR GBW CONDITIONS f = 100Hz f = 100Hz VS = 5V, VO = 0.25V to 4.5V, RL = 100k VS = 3V, VO = 0.25V to 2.5V, RL = 100k MIN 100 50 0 90 74 90 VCM = 0V to 4V, VS = 5V VCM = 0V to 10V, VS = 5V VS = 2.2V to 12V, VCM = VO = 0.5V Power Supply Rejection Ratio Minimum Operating Supply Voltage Output Voltage Swing LOW No Load ISINK = 100µA Output Voltage Swing HIGH No Load ISOURCE = 100µA Short-Circuit Current (Note 5) Supply Current per Amplifier (Note 6) Reverse Supply Voltage IS = 10µA per Amplifier Slew Rate AV = – 5, VS = ±10V Gain Bandwidth Product f = 100Hz V+ – 0.07 V+ – 0.32 0.7 –18 1.6 TYP 185 10 500 250 MAX 36 106 95 99 2.1 50 210 V+ – 0.035 V+ – 0.160 1.3 1.5 2.2 100 410 2 5 12 UNITS nV/√Hz fA/√Hz V/mV V/mV V dB dB dB V mV mV V V mA µA V V/ms kHz The ● denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C. VS = 5V, 0V; VS = 3V, 0V; VCM = VO = half supply, unless otherwise noted. (Note 3) SYMBOL PARAMETER Input Offset Voltage VOS VOS TC IB Input Offset Voltage Drift Input Bias Current IOS AVOL Input Offset Current Large-Signal Voltage Gain CMRR Input Voltage Range Common Mode Rejection Ratio PSRR VOL Power Supply Rejection Ratio Minimum Operating Supply Voltage Output Voltage Swing LOW VOH Output Voltage Swing HIGH ISC IS Short-Circuit Current Supply Current per Amplifier CONDITIONS VS = 5V VS = 3V VS = 5V, MS8 Package VS = 3V, MS8 Package (Note 4) (Note 5) VCM = 10V (Note 6) (Note 5) VS = 5V, VO = 0.25V to 4.5V, RL = 100k VS = 3V, VO = 0.25V to 2.5V, RL = 100k MIN ● ● ● ● ● ● ● ● ● ● ● VCM = 0.2V to 4V, VS = 5V VCM = 0.2V to 10V, VS = 5V VS = 2.4V to 12V, VCM = VO = 0.5V ● ● ● 75 40 0.2 89 64 89 ● No Load ISINK = 100µA No Load ISOURCE = 100µA (Note 5) (Note 6) ● ● ● ● ● ● V+ – 0.08 V+ – 0.36 0.6 TYP 175 225 175 225 0.4 250 240 20 280 150 MAX 425 525 525 625 2 1200 500 120 36 106 85 99 2.3 55 225 V+ – 0.04 V+ – 0.18 1.1 1.9 2.4 110 450 2.8 UNITS µV µV µV µV µV/°C pA nA pA V/mV V/mV V dB dB dB V mV mV V V mA µA 3 LT1672/LT1673/LT1674 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the temperature range of – 40°C ≤ TA ≤ 85°C. VS = 5V, 0V; VS = 3V, 0V; VCM = VO = half supply, unless otherwise noted. (Note 3) SYMBOL PARAMETER VOS Input Offset Voltage VOS TC IB Input Offset Voltage Drift Input Bias Current IOS AVOL Input Offset Current Large-Signal Voltage Gain CMRR Input Voltage Range Common Mode Rejection Ratio PSRR VOL Power Supply Rejection Ratio Minimum Operating Supply Voltage Output Voltage Swing LOW VOH Output Voltage Swing HIGH ISC IS Short-Circuit Current Supply Current per Amplifier CONDITIONS VS = 5V VS = 3V VS = 5V, MS8 Package VS = 3V, MS8 Package (Note 4) (Note 5) VCM = 10V (Note 6) (Note 5) VS = 5V, VO = 0.25V to 4.5V, RL = 100k VS = 3V, VO = 0.25V to 2.5V, RL = 100k MIN ● ● ● ● ● ● ● ● ● ● ● VCM = 0.2V to 4V, VS = 5V VCM = 0.2V to 10V, VS = 5V VS = 2.7V to 12V, VCM = VO = 0.5V ● ● ● 55 30 0.2 88 62 88 ● No Load ISINK = 100µA No Load ISOURCE = 100µA (Note 5) (Note 6) ● ● ● ● ● V+ – 0.10 V+ – 0.38 0.4 ● TYP 200 250 200 250 0.4 250 275 20 215 115 MAX 475 575 575 675 2 1700 750 170 36 106 75 99 2.6 60 245 V+ – 0.05 V+ – 0.19 0.9 2.1 2.7 120 490 3.1 UNITS µV µV µV µV µV/°C pA nA pA V/mV V/mV V dB dB dB V mV mV mV mV mA µA TA = 25°C, VS = ±15V, VCM = VO = 0V, unless otherwise noted. SYMBOL PARAMETER Input Offset Voltage VOS CONDITIONS MIN MS8 Package IB IOS AVOL CMRR PSRR VOL Input Bias Current Input Offset Current Large-Signal Voltage Gain Input Voltage Range Common Mode Rejection Ratio Power Supply Rejection Ratio Output Voltage Swing LOW VOH Output Voltage Swing HIGH ISC IS Short-Circuit Current Supply Current per Amplifier 4 VO = ±10V, RL = 100k VCM = – 15V to 14V VS = ±5V to ±15V RL = 1M RL = 100k RL = 1M RL = 100k 100 – 15 100 96 14.78 14.62 0.7 TYP 200 200 25 20 360 MAX 575 675 1000 100 21 120 120 –14.85 –14.75 14.89 14.81 1.5 1.9 –14.70 –14.50 2.8 UNITS µV µV pA pA V/mV V dB dB V V V V mA µA LT1672/LT1673/LT1674 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C, VS = ±15V, VCM = VO = 0V, unless otherwise noted. (Note 3) SYMBOL PARAMETER Input Offset Voltage VOS CONDITIONS MS8 Package IB IOS AVOL CMRR PSRR VOL Input Bias Current Input Offset Current Large-Signal Voltage Gain Input Voltage Range Common Mode Rejection Ratio Power Supply Rejection Ratio Output Voltage Swing LOW VOH Output Voltage Swing HIGH ISC IS Short-Circuit Current Supply Current per Amplifier MIN ● ● ● ● VO = ±10V, RL = 100k ● ● VCM = –14.8V to 14V VS = ±5V to ±15V RL = 1M RL = 100k RL = 1M RL = 100k ● ● 60 – 14.8 98 94 ● ● ● ● ● 14.76 14.58 0.6 ● TYP 225 225 250 20 240 MAX 625 725 1200 120 21 120 120 –14.84 –14.73 14.88 14.79 1.3 2.4 –14.67 –14.46 3.5 UNITS µV µV pA pA V/mV V dB dB V V V mV mA µA The ● denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C, VS = ±15V, VCM = VO = 0V, unless otherwise noted. (Note 3) SYMBOL PARAMETER VOS Input Offset Voltage CONDITIONS MS8 Package IB IOS AVOL CMRR PSRR VOL Input Bias Current Input Offset Current Large-Signal Voltage Gain Input Voltage Range Common Mode Rejection Ratio Power Supply Rejection Ratio Output Voltage Swing LOW VOH Output Voltage Swing HIGH ISC IS Short-Circuit Current Supply Current per Amplifier MIN ● ● ● ● VO = ±10V, RL = 100k ● ● VCM = –14.8V to 14V VS = ±5V to ±15V RL = 1M RL = 100k RL = 1M RL = 100k Note 1: Absolute Maximum Ratings are those values beyond which the life of the device may be impaired. Note 2: The LT1672C/LT1673C/LT1674C and LT1672I/LT1673I/LT1674I are guaranteed functional over the Operating Temperature Range of – 40°C to 85°C. Note 3: The LT1672C/LT1673C/LT1674C are guaranteed to meet specified performance from 0°C to 70°C. The LT1672C/LT1673C/LT1674C are designed, characterized and expected to meet specified performance from ● ● 50 – 14.8 96 92 ● ● ● ● ● ● 14.74 14.54 0.4 TYP 250 250 250 20 200 MAX 675 775 1700 170 21 114 120 –14.83 –14.72 14.87 14.77 1.1 2.8 –14.66 –14.44 4.2 UNITS µV µV pA pA V/mV V dB dB V V V V mA µA – 40°C to 85°C but are not tested or QA sampled at these temperatures. The LT1672I/LT1673I/LT1674I are guaranteed to meet specified performance from – 40°C to 85°C. Note 4: This parameter is not 100% tested. Note 5: VS = 5V limit guaranteed by correlation to VS = 3V and VS = ±15V tests. Note 6: VS = 3V limit guaranteed by correlation to VS = 5V and VS = ±15V tests. 5 LT1672/LT1673/LT1674 U W TYPICAL PERFORMANCE CHARACTERISTICS Distribution of Input Offset Voltage 200 14 12 10 8 6 4 2 2.5 VS = ±15V 2.0 VS = ± 2.5V 1.5 1.0 0.5 0 –400 –300 –200 –100 0 100 200 300 400 INPUT OFFSET VOLTAGE (µV) SATURATION VOLTAGE (mV) SATURATION VOLTAGE (mV) 1000 TA = 85°C TA = 25°C TA = – 40°C 1 10 100 LOAD CURRENT (µA) 40 20 60 0 TEMPERATURE (°C) 1 100 TA = – 40°C 1.5 TA = 25°C 0.5 40 20 GAIN 0 20 –20 10 –40 0 –60 –80 10k 1672/3/4 G07 TA = – 40°C –1 0 TA = 85°C 1 2 3 4 5 6 7 8 COMMON MODE VOLTAGE (V) 9 10 Noise Current Spectrum 100 VS = ± 2.5V CURRENT NOISE (fA/√Hz) 40 NOISE VOLTAGE (nV/√Hz) VOLTAGE GAIN (dB) TA = 25°C 1672/3/4 G06 250 PHASE SHIFT (DEG) 60 50 6 300 100 30 TA = 85°C 200 – 0.5 1000 VS = 5V, 0V 1672/3/4 G05 80 1k FREQUENCY (Hz) Input Bias Current vs Common Mode Voltage TA = 25°C 10 100 LOAD CURRENT (µA) 5 1672/3/4 G03 TA = – 40°C 120 PHASE 3 2 4 TOTAL SUPPLY VOLTAGE (V) 1 Noise Voltage Spectrum 70 –10 100 0 300 TA = 85°C 10 0.1 1000 VS = ±2.5V 60 50 100 100 Gain and Phase Shift vs Frequency 80 80 VS = 5V, 0V 1672/3/4 G04 90 TA = 85°C Output Saturation Voltage vs Load Current (Output High) VS = 5V, 0V 10 0.1 TA = 25°C TA = – 40°C 100 1672/3/4 G02 Output Saturation Voltage vs Load Current (Output Low) 100 150 – 50 0 –40 –20 1672/73/74 G01 1000 CHANGE IN OFFSET VOLTAGE (µV) PERCENT OF UNITS (%) 16 SUPPLY CURRENT PER AMPLIFIER (µA) VS = 5V, 0V LT1672/73/74 5600 AMPLIFIERS 18 Minimum Supply Voltage Supply Current vs Temperature 3.0 INPUT BIAS CURRENT (nA) 20 200 150 100 50 0 VS = ± 2.5V 80 60 40 20 0 1 10 FREQUENCY (Hz) 100 1672/3/4 G08 1 10 FREQUENCY (Hz) 100 1672/3/4 G09 LT1672/LT1673/LT1674 U W TYPICAL PERFORMANCE CHARACTERISTICS Gain Bandwidth and Phase Margin vs Supply Voltage 60 GBW 10 50 8 40 PHASE MARGIN (DEG) 12 VS = ±15V VCM = 0V 70 PHASE MARGIN Capacitive Load Handling 80 VS = ± 2.5V 70 60 OVERSHOOT (%) MEASURED AT AV = 5 14 FREQUENCY (kHz) 80 OUTPUT VOLTAGE (2µV/DIV) 16 0.1Hz to 10Hz Output Voltage Noise 50 40 AV = 5 30 AV = 10 20 10 6 5 10 15 20 SUPPLY VOLTAGE (V) 25 30 30 0 TIME (1s/DIV) 1672/3/4 G10 Common Mode Rejection Ratio vs Frequency 80 70 60 50 40 30 20 10 0 100 100 VS = ± 2.5V 90 80 70 +PSRR 60 50 40 –PSRR 30 20 10k 20k 100 1k FREQUENCY (Hz) 10 1 10 OFFSET VOLTAGE CHANGE (µV) VS = ±15V 10 VS = ±2.5V –10 –20 –30 20 40 60 80 100 120 140 160 180 200 TIME AFTER POWER-UP (SEC) 1672/3/4 G16 10k 1672/3/4 G15 Open-Loop Gain VS = ±15V 15 10 5 RL = 1M 0 RL = 100k –5 –10 – 20 VS = ± 15V VS = 5V, 0V 60 40 RL = 100k 20 0 RL = 1M –20 – 40 – 60 –15 – 40 100 1k FREQUENCY (Hz) 80 20 30 OFFSET VOLTAGE CHANGE (µV) AV = 5 Open-Loop Gain VS = 5V, 0V 40 0 10 1672/3/4 G14 Warm-Up Drift vs Time 0 AV = 10 0.1 10k 1672/3/4 G13 20 VS = ± 2.5V 10 0 1k FREQUENCY (Hz) 10k Output Impedance vs Frequency 100 OUTPUT IMPEDANCE (kΩ) VS = ± 2.5V 90 100 1k CAPACITIVE LOAD (pF) 1672/3/4 G12 Power Supply Rejection Ratio vs Frequency POWER SUPPLY REJECTION RATIO (dB) COMMON MODE REJECTIO RATIO (dB) 100 10 1672/3/4 G07 OFFSET VOLTAGE CHANGE (µV) 0 0 1 2 4 3 OUTPUT VOLTAGE (V) 5 6 1672/3/4 G17 – 80 0 5 10 –20 –15 –10 –5 OUTPUT VOLTAGE (V) 15 20 1672/3/4 G18 7 LT1672/LT1673/LT1674 U W TYPICAL PERFORMANCE CHARACTERISTICS Small-Signal Response VS = ±15V CL = 100pF AV = 5 1672/3/4 G19 Large-Signal Response VS = 5V CL = 100pF AV = 5 1672/3/4 G20 VS = 5V CL = 100pF AV = 5 1672/3/4 G21 U Small-Signal Response W U U APPLICATIO S I FOR ATIO Start-Up Characteristics V+ Micropower op amps are sometimes not micropower during start-up, wreaking havoc on low current supplies. In the worst case, there may not be enough supply current available to take the system up to nominal voltages. Figure 1 is a graph of LT1673 supply current vs supply voltage for the three limit cases of input offset that could occur during start-up. The circuits are shown in Figure 2. One circuit creates a positive offset, forcing the output to come up saturated high. Another circuit creates a negative offset, forcing the output to come up saturated low, while the last brings up the output at half supply. In all cases, the supply current is well behaved. Supply current is highest with the output forced high, so if one amplifier is unused, it is best to force the output low or at half supply. SUPPLY CURRENT PER AMPLIFIER (µA) 5 4 OUTPUT HIGH 3 OUTPUT LOW 2 0 0 1 3 4 2 TOTAL SUPPLY VOLTAGE (V) 5 1672/3/4 FO1 Figure 1. Start-Up Characteristics 8 V+ + + + – – – 820k V– V– OUTPUT HIGH OUTPUT LOW 200k V– 16/2/3/4 F02 OUTPUT AT VS /2 Figure 2. Circuits for Start-Up Characteristics Reverse Battery The LT1672/LT1673/LT1674 are protected against reverse battery voltages up to 18V. In the event a reverse battery condition occurs, the supply current is typically less than 100nA (inputs grounded and outputs open). For typical single supply applications with ground referred loads and feedback networks, no other precautions are required. If the reverse battery condition results in a negative voltage at either the input pins or output pin, the current into the pin should be limited by an external resistor to less than 10mA. Inputs OUTPUT VS/2 1 V+ While the LT1672/LT1673/LT1674 will function normally with its inputs taken above the positive supply, the common mode range does not extend beyond approximately 300mV below the negative supply at room temperature. LT1672/LT1673/LT1674 U W U U APPLICATIO S I FOR ATIO The device will not be damaged if the inputs are taken lower than 300mV below the negative supply as long as the current out of the pin is limited to less than 10mA. However, the output phase is not guaranteed and the supply current will increase. and (VCC – 0.8V), Q1 and Q2 are active. When the input common mode exceeds (VCC – 0.8V), Q7 turns on, diverting the current from diff amp Q1-Q2 to current mirror Q8-Q9. The current from Q8 biases on the other diff amp consisting of PNP’s Q5-Q6 and NPN’s Q3-Q4. Though Q5-Q6 are driven from the emitters rather than the base, the basic diff amp action is the same. When the common mode voltage is between (VCC – 0.8V) and VCC, devices Q3 and Q4 act as followers, forming a buffer between the amplifier inputs and the emitters of the Q5Q6. If the common mode voltage is taken above V CC, Schottky diodes D1 and D2 reverse bias and devices Q3 and Q4 then act as diodes. The diff amp formed by Q5-Q6 operates normally, however, the input bias current increases to the emitter current of Q5-Q6, which is typically 180nA. The graph, Input Bias Current vs Common Mode Voltage found in the Typical Performance Characteristics section, shows these transitions at three temperatures. Output The graph, Capacitive Load Handling, shows amplifier stability with the output biased at half supply. If the output is to be operated within about 100mV of the positive rail, the allowable load capacitance is less. With this output voltage, the worst case occurs at AV = 5 and light loads, where the load capacitance should be less than 500pF with a 5V supply and less than 100pF with a 30V supply. Rail-to-Rail Operation The simplified schematic, Figure 3, details the circuit design approach of the LT1672/LT1673/LT1674. The amplifier topology is a three-stage design consisting of a rail-to-rail input stage, that continues to operate with the inputs above the positive rail, a folded cascode second stage that develops most of the voltage gain, and a rail-torail common emitter stage that provides the current gain. The collector currents of the two-input pairs are combined in the second stage consisting of Q11 to Q16, which furnishes most of the voltage gain. Capacitor C1 sets the amplifier bandwidth. The output stage is configured for maximum swing by the use of common emitter output devices Q21 and Q22. Diodes D4 to D6 and current source Q15 set the output quiescent current. The input stage is formed by two diff amps Q1-Q2 and Q3Q6. For signals with a common mode voltage between V EE D1 D2 D3 Q10 D7 Q13 Q14 Q15 Q20 + I1 Q21 C1 IN + IN – OUT Q1 Q2 Q3 Q4 Q7 Q16 Q17 Q11 Q6 Q5 (V +) – 0.8V Q19 D4 Q12 D5 D6 Q18 Q9 Q8 R1 R2 Q22 I2 1672/3/4 F03 Figure 3. Simplified Schematic 9 LT1672/LT1673/LT1674 U TYPICAL APPLICATIO S Battery Current Monitor IL CHARGE Over-the-Top Comparator with Hysteresis RSENSE 0.1Ω 1M 5V (VCC) DISCHARGE RA RA – A2 1/2 LT1673 12V 5V RA IN1 (0V TO 12V) – 10k RA + VOUT LT1672 A1 1/2 LT1673 – + 1M 1M + 2N5087 2N3904 DISCHARGE OUT 2N3904 CHARGE OUT VO = IL RB () RB RSENSE RA 10k 1M 2N5210 V HYSTERESIS = CC 100 IS < 10µA FOR RA = 10k, RB = 100k (RB/RA ≥5) VO = 1V/A IL 1672/3/4 TA04 RB U PACKAGE DESCRIPTIO IN2 (0V TO 12V) 1672/3/4 TA03 Dimensions in inches (millimeters) unless otherwise noted. MS8 Package 8-Lead Plastic MSOP (LTC DWG # 05-08-1660) 0.043 (1.10) MAX 0.007 (0.18) 0.034 (0.86) REF 0.118 ± 0.004* (3.00 ± 0.102) 8 7 6 5 0° – 6° TYP 0.021 ± 0.006 (0.53 ± 0.015) SEATING PLANE 0.009 – 0.015 (0.22 – 0.38) 0.0256 (0.65) BSC 0.005 ± 0.002 (0.13 ± 0.05) * 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 0.118 ± 0.004** (3.00 ± 0.102) 0.193 ± 0.006 (4.90 ± 0.15) 1 2 3 MSOP (MS8) 1100 4 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) ( +0.035 0.325 –0.015 8.255 +0.889 –0.381 ) 0.045 – 0.065 (1.143 – 1.651) 0.130 ± 0.005 (3.302 ± 0.127) 0.065 (1.651) TYP 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.100 (2.54) BSC *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) 10 0.400* (10.160) MAX 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 ± 0.003 (0.457 ± 0.076) N8 1098 LT1672/LT1673/LT1674 U PACKAGE DESCRIPTIO Dimensions in inches (millimeters) unless otherwise noted. S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 7 8 5 6 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 3 2 4 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0°– 8° TYP 0.016 – 0.050 (0.406 – 1.270) 0.050 (1.270) BSC 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 SO8 1298 S Package 14-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.337 – 0.344* (8.560 – 8.738) 14 13 12 11 10 9 8 0.228 – 0.244 (5.791 – 6.197) 0.150 – 0.157** (3.810 – 3.988) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 2 3 4 5 6 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0° – 8° TYP 0.016 – 0.050 (0.406 – 1.270) 0.014 – 0.019 (0.355 – 0.483) TYP 7 0.050 (1.270) BSC *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 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. S14 1298 11 LT1672/LT1673/LT1674 U TYPICAL APPLICATIO Micropower Photodiode Amplifier C1 20pF R1 10M GAIN: AZ = 10MΩ = 10% TO 90% RISE TIME: tr = 260µs BANDWIDTH: BW = 1.7kHz VS+ IPHOTODIODE VOUT IPHOTODIODE – 880nm IR PHOTODIODE λ OPTO-DIODE CORP ODD-45W LT1672 CD 170pF VOUT + VS– VS = ±1.2V TO ±15V C1, CD SATISFY GAIN OF 5 STABILITY REQUIREMENT AT AC. 1672/3/4 TA05 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC®1440/41/42 Micropower Single/Dual Comparators with 1% Reference LTC1440: Single, LTC1441/42: Dual LTC1443/LTC1444/LTC1445 Micropower Quad Comparators with 1% Reference LTC1443: 1.182 Reference LTC1444/45: 1.221V Reference and Adjustable Hysteresis LT1466/LT1467 75µA Dual/Quad Rail-to-Rail Input and Output Op Amps 390µV VOS(MAX), Gain Bandwidth = 120kHz LT1490A/LT1491A 50µA Dual/Quad Rail-to-Rail Input and Output Op Amps 950µV VOS(MAX), Gain Bandwidth = 200kHz LT1494/LT1495/LT1496 1.5µA Max Single/Dual/Quad Over-the-Top Precision Rail-to-Rail Input and Output Op Amps Unity Gain Stable Version of the LT1672/LT1673/LT1674 LTC1540 Nanopower Single Comparator with 1% Reference 350nA Supply Current LT1636 Single Over-the-Top Micropower, Rail-to-Rail Input and Output Op Amp 225µV VOS(MAX), IS = 55µA (Max), Gain Bandwidth = 200kHz, Shutdown Pin, MSOP LT2078/LT2079 55µA Dual/Quad Single Supply Op Amps 120µV VOS(MAX), Gain Bandwidth = 200kHz LT2178/LT2179 17µA Dual/Quad Single Supply Op Amps 120µV VOS(MAX), Gain Bandwidth = 60kHz 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 in SOT-23 SOT-23, 800µV VOS(MAX) , IS = 300µA (Max), Gain-Bandwidth = 1.2MHz, Shutdown Pin 12 Linear Technology Corporation 167234f LT/TP 0101 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 2001