® OPA241 OPA251 OPA OPA 251 241 OPA 251 OPA 241 Single-Supply, MicroPOWER OPERATIONAL AMPLIFIERS FEATURES ● ● ● ● ● ● ● ● DESCRIPTION MicroPOWER: IQ = 24µA SINGLE SUPPLY OPERATION RAIL-TO-RAIL OUTPUT SWING WIDE SUPPLY RANGE Single Supply: +2.7V to +36V Dual Supply: ±1.35V to ±18V LOW OFFSET VOLTAGE: ±250µV max HIGH COMMON-MODE REJECTION: 124dB HIGH OPEN-LOOP GAIN: 128dB 8-PIN DIP AND SO-8 PACKAGES APPLICATIONS ● BATTERY OPERATED INSTRUMENTS ● PORTABLE DEVICES ● MEDICAL INSTRUMENTS ● TEST EQUIPMENT The OPA241 and OPA251 are specifically designed for battery powered, portable applications. In addition to very low power consumption (24µA), these amplifiers feature low offset voltage, rail-to-rail output swing, high common-mode rejection, and high openloop gain. The OPA241 is optimized for operation at low power supply voltage while the OPA251 is optimized for high power supplies. Both op amps can operate from either single (+2.7V to +36V) or dual supplies (±1.35V to ±18V). The input common-mode voltage range extends 200mV below the negative supply—ideal for single supply applications. The OPA241 and OPA251 are unity-gain stable and can drive large capacitive loads. Special design considerations assure that these products are easy to use. High performance is maintained as the amplifiers swing to their specified limits. Because the initial offset voltage (±250µV max) is so low, user adjustment is usually not required. However, external trim pins are provided for special applications. The OPA241 and OPA251 are available in standard 8-pin DIP and SO-8 surface-mount packages. Both are fully specified from –40°C to +85°C and operate from –55°C to +125°C. OPA251 OPA241 Offset Trim 1 8 NC Offset Trim 1 8 NC 2 7 V+ –In 2 7 V+ –In +In 3 6 Output +In 3 6 Output V– 4 5 Offset Trim V– 4 5 Offset Trim 8-Pin DIP, SO-8 8-Pin DIP, SO-8 International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111 Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 ® © 1997 Burr-Brown Corporation PDS-1406A 1 OPA241, 251 Printed in U.S.A. September, 1997 SPECIFICATIONS: VS = 2.7V to 5V At TA = +25°C, RL = 100kΩ connected to VS/2, unless otherwise noted. Boldface limits apply over the specified temperature range, TA = –40°C to +85°C. OPA241UA, PA TYP(1) MAX ±50 ±250 ±400 3 30 30 IB –4 IOS ±0.1 –20 –25 ±2 ±2 en in 1 45 40 PARAMETER CONDITION OFFSET VOLTAGE Input Offset Voltage TA = –40°C to +85°C vs Temperature vs Power Supply TA = –40°C to +85°C dVOS/dT PSRR NOISE Input Voltage Noise, f = 0.1 to 10kHz Input Voltage Noise Density, f = 1kHz Current Noise Density, f = 1kHz INPUT VOLTAGE RANGE Common-Mode Voltage Range Common-Mode Rejection Ratio TA = –40°C to +85°C MIN VOS INPUT BIAS CURRENT Input Bias Current(2) TA = –40°C to +85°C Input Offset Current TA = –40°C to +85°C VCM CMRR ±100 ±0.4 TA = –40°C to +85°C VS = 2.7V to 36V VS = 2.7V to 36V VCM = –0.2V to (V+) –1V VCM = 0V to (V+) –1V –0.2 80 80 INPUT IMPEDANCE Differential Common-Mode OPEN-LOOP GAIN Open-Loop Voltage Gain TA = –40°C to +85°C AOL TA = –40°C to +85°C FREQUENCY RESPONSE Gain-Bandwidth Product Slew Rate Overload Recovery Time GBW SR OUTPUT Voltage Output Swing from Rail(3) 100 100 100 100 VS = 5V, G = 1 VIN • G = VS ISC CLOAD POWER SUPPLY Specified Voltage Range Operating Voltage Range Quiescent Current TA = –40°C to +85°C TEMPERATURE RANGE Specified Range Operating Range Storage Range Thermal Resistance 8-Pin DIP SO-8 Surface Mount RL = 100kΩ, VO = (V–)+100mV to (V+)–100mV RL = 100kΩ, VO = (V–)+100mV to (V+)–100mV RL = 10kΩ, VO = (V–)+200mV to (V+)–200mV RL = 10kΩ, VO = (V–)+200mV to (V+)–200mV RL = 100kΩ to VS /2, AOL ≥ 70dB RL = 100kΩ to VS /2, AOL ≥ 100dB RL = 100kΩ to VS /2, AOL ≥ 96dB RL = 10kΩ to VS /2, AOL ≥ 100dB RL = 10kΩ to VS /2, AOL ≥ 96dB TA = –40°C to +85°C TA = –40°C to +85°C Short-Circuit Current Capacitive Load Drive OPA251UA, PA ±100 ±130 ±0.6 ✻ ✻ ✻ MAX UNITS ✻ ✻ µV µV µV/°C µV/V µV/V ✻ ✻ ✻ ✻ nA nA nA nA µVp-p nV/√Hz fA/√Hz 106 ✻ V dB dB 107 || 2 109 || 4 ✻ ✻ Ω || pF Ω || pF 120 ✻ 120 ✻ dB dB dB dB 35 0.01 60 ✻ ✻ ✻ kHz V/µs µs ✻ ✻ mV mV mV mV mV mA (V+) –1 100 100 100 200 200 ✻ ✻ ✻ –24/+4 See Typical Curve ✻ +2.7 to +5 +2.7 ±24 IO = 0 IO = 0 TYP(1) ✻ ✻ ✻ 50 75 VS IQ MIN –40 –55 –55 +36 ±28 ±34 ✻ +85 +125 +125 ✻ ✻ ✻ ✻ ✻ ✻ ✻ ✻ θJA 100 150 ✻ ✻ V V µA µA °C °C °C °C/W °C/W ✻ Specifications the same as OPA241UA, PA. NOTES: (1) VS = +5V. (2) The negative sign indicates input bias current flows out of the input terminals. (3) Output voltage swings are measured between the output and power supply rails. The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems. ® OPA241, 251 2 SPECIFICATIONS: VS = ±15V At TA = +25°C, RL = 100kΩ connected to ground, unless otherwise noted. Boldface limits apply over the specified temperature range, TA = –40°C to +85°C. OPA241UA, PA PARAMETER OFFSET VOLTAGE Input Offset Voltage T A = –40°C to +85°C vs Temperature vs Power Supply TA = –40°C to +85°C CONDITION dVOS/dT PSRR NOISE Input Voltage Noise, f = 0.1 to 10kHz Input Voltage Noise Density, f = 1kHz Current Noise Density, f = 1kHz TA = –40°C to +85°C VS = ±1.35V to ±18V VS = ±1.35V to ±18V IB ✻ IOS ✻ en in ✻ ✻ ✻ VCM CMRR AOL GBW SR OUTPUT Voltage Output Swing from Rail(2) POWER SUPPLY Specified Voltage Range Operating Voltage Range Quiescent Current T A = –40°C to +85°C TEMPERATURE RANGE Specified Range Operating Range Storage Range Thermal Resistance 8-Pin DIP SO-8 Surface Mount TYP MAX UNITS ±50 ±250 ±300 ✻ ✻ 3 30 30 µV µV µV/°C µV/V µV/V ✻ ✻ ✻ ✻ –4 –20 –25 ±2 ±2 nA nA nA nA ±100 ±0.5 ±0.1 (V–) –0.2 100 100 ISC CLOAD (V+) –1 V dB dB 106 || 2 106 || 4 Ω || pF Ω || pF 128 dB dB dB dB 128 35 0.01 60 ✻ ✻ 50 75 ✻ 100 ✻ ✻ –21/+4 See Typical Curve ✻ ✻ ±1.35 ✻ IO = 0 IO = 0 124 ✻ ✻ ✻ ✻ VS IQ 100 100 100 100 ✻ G=1 VIN • G = VS µVp-p nV/√Hz fA/√Hz 1 45 40 ✻ RL = 100kΩ, VO = –14.75V to +14.75V RL = 100kΩ, VO = –14.75V to +14.75V RL = 20kΩ, VO = –14.7V to +14.7V RL = 20kΩ, VO = –14.7V to +14.7V RL = 100kΩ, AOL ≥ 70dB RL = 100kΩ, AOL ≥ 100dB RL = 100kΩ, AOL ≥ 96dB RL = 20kΩ, AOL ≥ 100dB RL = 20kΩ, A OL ≥ 96dB T A = –40°C to +85°C T A = –40°C to +85°C Short-Circuit Current Capacitive Load Drive MIN ✻ ✻ T A = –40°C to +85°C FREQUENCY RESPONSE Gain-Bandwidth Product Slew Rate Overload Recovery Time MAX ✻ VCM = –15.2V to 14V VCM = –15V to 14V INPUT IMPEDANCE Differential Common-Mode OPEN-LOOP GAIN Open-Loop Voltage Gain T A = –40°C to +85°C TYP ±100 ±150 ±0.6 ✻ VOS INPUT BIAS CURRENT Input Bias Current(1) T A = –40°C to +85°C Input Offset Current T A = –40°C to +85°C INPUT VOLTAGE RANGE Common-Mode Voltage Range Common-Mode Rejection Ratio T A = –40°C to +85°C MIN OPA251UA, PA ✻ ✻ ✻ ✻ ✻ ✻ ±15 ±27 –40 –55 –55 θJA ✻ ✻ 100 150 kHz V/µs µs 250 250 300 300 mV mV mV mV mV mA ±18 ±38 ±45 V V µA µA +85 +125 +125 °C °C °C °C/W °C/W ✻ Specifications the same as OPA251UA, PA. NOTES: (1) The negative sign indicates input bias current flows out of the input terminals. (2) Output voltage swings are measured between the output and power supply rails. ® 3 OPA241, 251 ABSOLUTE MAXIMUM RATINGS(1) ELECTROSTATIC DISCHARGE SENSITIVITY Supply Voltage, V+ to V– .................................................................... 36V Input Voltage(2) ................................................. (V–) –0.5V to (V+) +0.5V Output Short Circuit to Ground ................................................ Continuous Operating Temperature ................................................. –55°C to +125°C Storage Temperature ..................................................... –55°C to +125°C Junction Temperature ...................................................................... 150°C Lead Temperature (soldering, 10s) ................................................. 300°C This integrated circuit can be damaged by ESD. Burr-Brown recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. NOTES: (1) Stresses above these ratings may cause permanent damage. (2) Input terminals are diode-clamped to the power supply rails. Input signals that can swing more that 0.5V beyond the supply rails should be currentlimited to 5mA or less. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. PACKAGE/ORDERING INFORMATION PRODUCT PACKAGE PACKAGE DRAWING NUMBER(1) OPA241PA OPA241UA 8-Pin Plastic DIP SO-8 Surface Mount 006 182 –40°C to +85°C –40°C to +85°C OPA251PA OPA251UA 8-Pin Plastic DIP SO-8 Surface Mount 006 182 –40°C to +85°C –40°C to +85°C TEMPERATURE RANGE NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. ® OPA241, 251 4 TYPICAL PERFORMANCE CURVES At TA = +25°C, and RL = 100kΩ connected to VS/2 (ground for VS = ±15V), unless otherwise noted. Curves apply to OPA241 and OPA251 unless specified. POWER SUPPLY REJECTION vs FREQUENCY 140 160 120 140 G 100 120 80 Φ 100 60 80 40 60 20 40 VS = ±15V VS = +5V 0 –20 0.01 20 1 0.1 120 10 100 1k 10k Power Supply Rejection (dB) 180 Phase (°) Voltage Gain (dB) OPEN-LOOP GAIN/PHASE vs FREQUENCY 160 0 100k 100 80 +PSRR 60 –PSRR 40 20 0 0.1 1 10 100 1k 10k Frequency (Hz) Frequency (Hz) COMMON-MODE REJECTION vs FREQUENCY INPUT VOLTAGE AND CURRENT NOISE SPECTRAL DENSITY vs FREQUENCY 140 100k 1k 1k VS = +5V 100 80 60 40 Current Noise 100 Voltage Noise 20 0 10 10 100 1k 10k 100k 10 0.1 1 Frequency (Hz) 10 100 1k 10k Frequency (Hz) QUIESCENT CURRENT vs SUPPLY VOLTAGE QUIESCENT CURRENT vs TEMPERATURE 30 40 Quiescent Current (µA) Quiescent Current (µA) 100 28 26 24 22 35 VS = ±15V 30 25 VS = +5V 20 15 0 5 10 15 20 25 30 35 40 –75 Total Supply Voltage (V) –50 –25 0 25 50 75 100 125 Temperature (°C) ® 5 OPA241, 251 Current Noise (fA/√Hz) 120 Voltage Noise (nV/√Hz) Common-Mode Rejection (dB) VS = ±15V TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, and RL = 100kΩ connected to VS/2 (ground for VS = ±15V), unless otherwise noted. Curves apply to OPA241 and OPA251 unless specified. INPUT BIAS CURRENT vs INPUT COMMON-MODE VOLTAGE INPUT BIAS CURRENT vs TEMPERATURE –5 –6 Input Bias Current (nA) Input Bias Current (nA) IB –4 IB –2 IOS 0 –4 –3 –2 –1 IOS 2 0 –75 –50 –25 0 25 50 75 100 0 125 5 15 20 25 30 COMMON-MODE REJECTION vs TEMPERATURE SHORT-CIRCUIT CURRENT vs TEMPERATURE 35 140 30 120 VS = ±15V Common-Mode Rejection (dB) Short-Circuit Current (mA) 10 Common-Mode Voltage (V) Temperature (°C) –ISC 25 VS = +5V 20 15 VS = ±15V 10 +ISC,VS = +5V, ±15V 5 VS = +2.7V, +5V 100 80 60 40 VCM = (V–) –0.2V to (V+) –1V VCM = (V–) –0.1V to (V+) –1V VCM = (V–) to (V+) –1V 20 0 0 –75 –50 –25 0 25 50 75 100 –75 125 –50 –25 0 25 50 75 100 125 Temperature (°C) Temperature (°C) OPEN-LOOP GAIN AND POWER SUPPLY REJECTION vs TEMPERATURE OUTPUT VOLTAGE SWING vs OUTPUT CURRENT (V+) 140 T = +25°C RL = 20kΩ, 100kΩ AOL, PSR (dB) 130 RL = 100kΩ 120 RL = 10kΩ 110 AOL, VS = ±15V AOL, VS = +5V Output Voltage Swing (V) (V+) –0.1V T = –55°C T = +125°C (V+) –0.2V (V+) –0.3V (V–) +0.3V T = +125°C (V–) +0.2V T = +25°C, –55°C (V–) +0.1V PSRR (V–) 100 –75 –50 –25 0 25 50 75 100 0.1 125 ® OPA241, 251 ±1 Output Current (mA) Temperature (°C) 6 ±10 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, and RL = 100kΩ connected to VS/2 (ground for VS = ±15V), unless otherwise noted. Curves apply to OPA241 and OPA251 unless specified. OPEN-LOOP GAIN vs OUTPUT VOLTAGE SWING MAXIMUM OUTPUT VOLTAGE vs FREQUENCY 140 30 Open-Loop Gain (dB) Maximum Output Voltage (Vp-p) RL = 20kΩ VS = ±15V RL = 100kΩ 130 VS = +5V 120 VS = +2.7V 110 RL = 10kΩ 100 90 80 400 300 200 100 15 10 VS = +5V 5 VS = 2.7V 10 0 1k 10k Frequency (Hz) OPA241 OFFSET VOLTAGE PRODUCTION DISTRIBUTION OPA241 OFFSET VOLTAGE DRIFT PRODUCTION DISTRIBUTION 100k 25 Typical production distribution of packaged units. VS = +5V VS = +5V Percent of Amplifiers (%) 25 100 Output Voltage Swing from Rail (mV) 30 Percent of Amplifiers (%) 20 0 500 Maximum output voltage without slew rate-induced distortion. VS = ±15V 25 20 15 10 5 20 Typical production distribution of packaged units. 15 10 5 0 –225 –200 –175 –150 –125 –100 –75 –50 –25 0 25 50 75 100 125 150 175 200 225 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 Offset Voltage (µV/°C) Offset Voltage (µV) OPA251 OFFSET VOLTAGE PRODUCTION DISTRIBUTION OPA251 OFFSET VOLTAGE DRIFT PRODUCTION DISTRIBUTION 30 20 18 20 15 10 5 16 VS = ±15V Typical production distribution of packaged units. 14 12 10 8 6 4 2 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 0 –225 –200 –175 –150 –125 –100 –75 –50 –25 0 25 50 75 100 125 150 175 200 225 Percent of Amplifiers (%) 25 Typical production distribution of packaged units. Percent of Amplifiers (%) VS = ±15V Offset Voltage (µV) Offset Voltage Drift (µV/°C) ® 7 OPA241, 251 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, and RL = 100kΩ connected to VS/2 (ground for VS ±15V), unless otherwise noted. Curves apply to OPA241 and OPA251 unless specified. QUIESCENT CURRENT PRODUCTION DISTRIBUTION QUIESCENT CURRENT PRODUCT DISTRIBUTION 35 25 Typical production distribution of packaged units. Percent of Amplifiers (%) 20 Typical production distribution of packaged units. VS = ±15V 30 15 10 5 25 20 15 10 5 Quiescent Current (µA) Quiescent Current (µA) OPA241 SMALL-SIGNAL STEP RESPONSE VS = +5V, G = +1, RL = 100kΩ, CL = 100pF 0.5V/div 50mV/div OPA241 LARGE-SIGNAL STEP RESPONSE VS = +5V, G + 1, RL = 100kΩ, CL = 100pF 200µs/div 200µs/div OPA251 SMALL-SIGNAL STEP RESPONSE VS = ±15V, G = +1, RL = 100kΩ, CL = 500pF OPA251 LARGE-SIGNAL STEP RESPONSE VS = ±15V, G = +1, RL = 100kΩ, CL = 500pF 2V/div 2ms/div 200µs/div ® OPA241, 251 8 38 37 36 35 34 33 32 31 30 29 28 27 26 25 21.5 22 22.5 23 23.5 24 24.5 25 25.5 26 26.5 27 24 22 21 23 0 0 50mV/div Percent of Amplifiers (%) VS = +5V APPLICATIONS INFORMATION voltage as shown in Figure 2. For example, an application with a total power supply voltage of +5V should limit input signal current to less than 2.5mA. Again, this precaution is only required if the input voltage can swing more than 0.5V below the V– supply rail. Figure 3 shows the output waveform when the input (VIN = ±20V) is greater than the supplies (VS = ±15V) for the configuration shown in Figure 1 with RIN = 1kΩ. The OPA241 and OPA251 are unity-gain stable and suitable for a wide range of general purpose applications. Power supply pins should be bypassed with 0.01µF ceramic capacitors. OPERATING VOLTAGE OPA241 is laser-trimmed for low offset voltage and drift at low supply voltage (VS = +5V). OPA251 is trimmed for ±15V operation. Both products operate over the full voltage range (+2.7V to +36V or ±1.35V to ±18V) with some compromises in offset voltage and drift performance. However, all other parameters have the same performance. Key parameters are guaranteed over the specified temperature range, –40°C to +85°C. Most behavior remains unchanged throughout the full operating voltage range. Parameters which vary significantly with operating voltage or temperature are shown in typical performance curves. 12 VIN = (V–) –0.5V Input Current (mA) 10 INPUT VOLTAGE The input common-mode range of the OPA241 and OPA251 extends from 200mV below the negative rail to 1V from the positive rail. For normal operation, inputs should be limited to this range. Input terminals are diode-clamped to the power supply rails for ESD protection. If the input voltage can exceed the supplies by 500mV, the input current should be limited to 5mA (or less). This is easily accomplished with an input resistor as shown in Figure 1. Many input signals are inherently current-limited, therefore, a limiting resistor may not be required. Operation above dashed line is not recommended. Damage can occur if input current exceeds 5mA. 8 6 4 2 0 0 5 10 15 20 25 30 35 40 Total Supply Voltage, VS (V) FIGURE 2. Output Phase Reversal is a Function of Input Current and Supply Voltage. VS = ±15V, VIN = ±20V, RIN = 1kΩ V+ OPA241 VOUT VOUT 5V/div IOVERLOAD 5mA max VIN RIN V– FIGURE 1. Input Current Protection for Voltage Exceeding the Supply Voltage. 2ms/div In non-inverting circuits, some op amps produce a phase reversal of the output when the input signal exceeds the amplifier’s linear common-mode range. Under most conditions, the OPA241 will not produce phase reversal. If, however, the input signal can swing more than 0.5V below ground (or V–) and the signal source can supply sufficient current, output inversion could occur. The signal input current that can cause inversion varies with the supply FIGURE 3. No Phase Inversion with Inputs Greater than the Power Supply Voltage. ® 9 OPA241, 251 OFFSET VOLTAGE TRIM As mentioned previously, offset voltage of the OPA241 is laser-trimmed at +5V. The OPA251 is trimmed at ±15V. Because the initial offset is so low, user adjustment is usually not required. However, offset voltage trim connections are provided on pins 1 and 5. Offset voltage can be adjusted by connecting a potentiometer as shown in Figure 4. This adjustment should be used only to null the offset of the op amp, not to adjust system offset or offset produced by the signal source. Nulling offset could degrade the offset drift behavior of the op amp. While it is not possible to predict the exact change in drift, the effect is usually small. 100k Capacitive Load (pF) VS = +2.7V VS = +5V Operation above selected gain curve not recommended 10k G = 10 1k G = –1 Sinking Sourcing G = +1 100 CAPACITIVE LOAD AND STABILITY The OPA241 and OPA251 can drive a wide range of capacitive loads. However, all op amps under certain conditions may be unstable. Op amp configuration, gain, and load value are just a few of the factors to consider when determining stability. –1 –0.1 –0.01 0 0.01 0.1 1 Output Current (mA) FIGURE 5. Stability–Capacitive Load versus Output Current for Low Supply Voltage. Figures 5 and 6 show the regions where the OPA241 and OPA251 have the potential for instability. As shown, the unity gain configuration with low supplies is the most susceptible to the effects of capacitive load. With VS = +5V, G = +1, and IOUT = 0, operation remains stable with load capacitance up to approximately 200pF. Increasing supply voltage, output current, and/or gain significantly improves capacitive load drive. For example, increasing the supplies to ±15V and gain to 10 allows approximately 2700pF to be driven. 100k Capacitive Load (pF) VS = ±15V One method of improving capacitive load drive in the unity gain configuration is to insert a resistor inside the feedback loop as shown in Figure 7. This reduces ringing with large capacitive loads while maintaining dc accuracy. For example, with VS = ±1.35V and RS = 5kΩ, the OPA241 and OPA251 perform well with capacitive loads in excess of 1000pF. Without the series resistor, capacitive load drive is typically 200pF for these conditions. However, this method will result in a slight reduction of output voltage swing. 10k Operation above selected gain curve not recommended G = 10 G = –1 1k G = +1 Sinking Sourcing 100 –1 –0.1 –0.01 0 0.01 0.1 1 Output Current (mA) FIGURE 6. Stability–Capacitive Load versus Output Current for ±15V Supplies. V+ 0.01µF Use offset adjust pins only to null offset voltage of op amp—see text. 7 RS 5kΩ 2 6 3 OPA241 OPA241 CL 1 0.01µF 4 VOUT VIN 5 100kΩ Trim Range: ±2mV (V–) = 0V for single supply operation. FIGURE 7. Series Resistor in Unity Gain Configuration Improves Capacitive Load Drive. V– FIGURE 4. OPA241 and OPA251 Offset Voltage Trim Circuit. ® OPA241, 251 10 RH 10Ω To Load R5 383kΩ IH R1 38.3kΩ High-Side Current Sense R3 38.3kΩ V+ –In A1 +In OPA241 V+ for A1, A2 R4 20kΩ R2 19.1kΩ Out VO = 10 • IH • RH V– + 2.7V to ±15V R2 and R4 divide down the common-mode input to A1. R8 100kΩ V– for A1, A2 V+ –In A2 +In OPA241 V– R7 9.09kΩ R6 10kΩ RL 10Ω Out VO = 10 • IL • RL Low-Side Current Sense Common-mode range of A2 extends to V– for low-side sensing. Optional for IB Cancellation (R7 = R6 II R8) To Load IL NOTE: Low and high-side sensing circuits can be used independently. FIGURE 8. Low and High-Side Battery Current Sensing. ® 11 OPA241, 251