Dual/Quad Rail-to-Rail Operational Amplifiers OP295/OP495 FEATURES Rail-to-Rail Output Swing Single-Supply Operation: 3 V to 36 V Low Offset Voltage: 300 mV Gain Bandwidth Product: 75 kHz High Open-Loop Gain: 1,000 V/mV Unity-Gain Stable Low Supply Current/Per Amplifier: 150 A max PIN CONNECTIONS 8-Lead Narrow-Body SOIC (S Suffix) OUT A 1 8 V+ -IN A 2 7 OUT B +IN A 3 6 -IN B V- APPLICATIONS Battery-Operated Instrumentation Servo Amplifiers Actuator Drives Sensor Conditioners Power Supply Control GENERAL DESCRIPTION Rail-to-rail output swing combined with dc accuracy are the key features of the OP495 quad and OP295 dual CBCMOS operational amplifiers. By using a bipolar front end, lower noise and higher accuracy than that of CMOS designs has been achieved. Both input and output ranges include the negative supply, providing the user zero-in/zero-out capability. For users of 3.3 V systems such as lithium batteries, the OP295/OP495 is specified for 3 V operation. Maximum offset voltage is specified at 300 V for 5 V operation, and the open-loop gain is a minimum of 1000 V/mV. This yields performance that can be used to implement high accuracy systems, even in single-supply designs. The ability to swing rail-to-rail and supply 15 mA to the load makes the OP295/OP495 an ideal driver for power transistors and "H" bridges. This allows designs to achieve higher efficiencies and to transfer more power to the load than previously possible without the use of discrete components. For applications such as transformers that require driving inductive loads, OP295 4 5 +IN B 14-Lead PDIP (P Suffix) 8-Lead Narrow-Body SOIC (S Suffix) OUT A 1 8 V+ OP295 -IN A 2 7 OUT B +IN A 3 6 -IN B V- 4 5 +IN B 14-Lead PDIP (P Suffix) OUT A 1 14 OUT D OUT A 1 16 OUT D -IN A 2 13 -IN D -IN A 2 15 -IN D +IN A 3 12 +IN D +IN A 3 14 +IN D V+ 4 OP495 11 V- +IN B 5 10 +IN C 6 9 -IN C -IN B OUT B 7 8 OUT C OP495 V- TOP VIEW +IN B 5 (Not to Scale) 12 +IN C V+ 4 13 -IN B 6 11 -IN C OUT B 7 10 OUT C NC 8 9 NC NC = NO CONNECT increases in efficiency are also possible. Stability while driving capacitive loads is another benefit of this design over CMOS rail-to-rail amplifiers. This is useful for driving coax cable or large FET transistors. The OP295/OP495 is stable with loads in excess of 300 pF. The OP295 and OP495 are specified over the extended industrial (-40C to +125C) temperature range. OP295s are available in 8-lead plastic DIP plus SOIC-8 surface-mount packages. OP495s are available in 14-lead plastic and SOIC-16 surfacemount packages. REV. D Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 www.analog.com Fax: 781/326-8703 (c) 2004 Analog Devices, Inc. All rights reserved. OP295/OP495-SPECIFICATIONS ELECTRICAL CHARACTERISTICS (@ V = 5.0 V, V S Parameter Symbol INPUT CHARACTERISTICS Offset Voltage VOS Input Bias Current IB Input Offset Current IOS Input Voltage Range Common-Mode Rejection Ratio Large Signal Voltage Gain VCM CMRR AVO Offset Voltage Drift OUTPUT CHARACTERISTICS Output Voltage Swing High VOS/T VOH Output Voltage Swing Low VOL Output Current POWER SUPPLY Power Supply Rejection Ratio IOUT Supply Current Per Amplifier DYNAMIC PERFORMANCE Skew Rate Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Voltage Noise Voltage Noise Density Current Noise Density ISY PSRR CM = 2.5 V, TA = 25C, unless otherwise noted.) Conditions Min -40C TA +125C Max Unit 30 300 800 20 30 3 5 4.0 V V nA nA nA nA V dB V/mV V/mV V/C 8 -40C TA +125C 1 -40C TA +125C 0 V VCM 4.0 V, -40C TA +125C RL = 10 k, 0.005 VOUT 4.0 V RL = 10 k, -40C TA +125C Typ 0 90 1,000 500 110 10,000 1 RL = 100 k to GND RL = 10 k to GND IOUT = 1 mA, -40C TA +125C RL = 100 k to GND RL = 10 k to GND IOUT = 1 mA, -40C TA +125C 1.5 V VS 15 V 1.5 V VS 15 V, -40C TA +125C VOUT = 2.5 V, RL = , -40C TA +125C 4.98 4.90 11 5.0 4.94 4.7 0.7 0.7 90 18 90 110 5 2 2 V V V mV mV mV mA dB 85 150 dB A SR GBP O RL = 10 k 0.03 75 86 V/s kHz Degrees en p-p en in 0.1 Hz to 10 Hz f = 1 kHz f = 1 kHz 1.5 51 <0.1 V p-p nV/Hz pA/Hz Specifications subject to change without notice. ELECTRICAL CHARACTERISTICS (@ V = 3.0 V, V S Parameter INPUT CHARACTERISTICS Offset Voltage Input Bias Current Input Offset Current Input Voltage Range Common-Mode Rejection Ratio Large Voltage Gain Offset Voltage Drift OUTPUT CHARACTERISTICS Output Voltage Swing High Output Voltage Swing Low POWER SUPPLY Power Supply Rejection Ratio Supply Current Per Amplifier DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Voltage Noise Voltage Noise Density Current Noise Density Symbol VOS IB IOS VCM CMRR AVO VOS/T CM = 1.5 V, TA = 25C, unless otherwise noted.) Conditions Min 0 V VCM 2.0 V, -40C TA +125C RL = 10 k 0 90 VOH VOL RL = 10 k to GND RL = 10 k to GND 2.9 PSRR 1.5 V VS 15 V 1.5 V VS 15 V, -40C TA +125C VOUT = 1.5 V, RL = , -40C TA +125C 90 ISY Typ Max Unit 100 8 1 500 20 3 2.0 V nA nA V dB V/mV V/C 110 750 1 0.7 2 110 V mV dB 85 150 dB A SR GBP O RL = 10 k 0.03 75 85 V/s kHz Degrees en p-p en in 0.1 Hz to 10 Hz f = 1 kHz f = 1 kHz 1.6 53 <0.1 V p-p nV/Hz pA/Hz Specifications subject to change without notice. -2- REV. D OP295/OP495 ELECTRICAL CHARACTERISTICS (@ V = 15.0 V, T = 25C, unless otherwise noted.) S Parameter Symbol INPUT CHARACTERISTICS Offset Voltage VOS Input Bias Current IB Input Offset Current IOS Input Voltage Range Common-Mode Rejection Ratio Large Signal Voltage Gain Offset Voltage Drift VCM CMRR AVO VOS/T OUTPUT CHARACTERISTICS Output Voltage Swing High VOH Output Voltage Swing Low VOL Output Current IOUT POWER SUPPLY Power Supply Rejection Ratio PSRR Supply Current ISY Supply Voltage Range VS A Conditions Min Typ Max Unit 300 500 800 20 30 3 5 13.5 110 4,000 1 V V nA nA nA nA V dB V/mV V/C 15 25 V V V V mA 90 85 110 -40C TA +125C VCM = 0 V VCM = 0 V, -40C TA +125C VCM = 0 V VCM = 0 V, -40C TA +125C -15.0 V VCM +13.5 V, -40C TA +125C RL = 10 k RL = 100 k to GND RL = 10 k to GND RL = 100 k to GND RL = 10 k to GND VS = 1.5 V to 15 V VS = 1.5 V to 15 V, -40C TA +125C VO = 0 V, RL = , VS = 18 V, -40C TA +125C 7 1 -15 90 1,000 14.95 14.80 -14.95 -14.85 dB dB 175 36 ( 18) 3 ( 1.5) A V DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Phase Margin SR GBP O RL = 10 k 0.03 85 83 V/s kHz Degrees NOISE PERFORMANCE Voltage Noise Voltage Noise Density Current Noise Density en p-p en in 0.1 Hz to 10 Hz f =1 kHz f = 1 kHz 1.25 45 <0.1 V p-p nV/Hz pA/Hz Specifications subject to change without notice. REV. D -3- OP295/OP495 ABSOLUTE MAXIMUM RATINGS 1, 2 NOTES 1 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; and functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2 Absolute maximum ratings apply to packaged parts, unless otherwise noted. 3 For supply voltages less than 18 V, the absolute maximum input voltage is equal to the supply voltage. Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 V Input Voltage2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 V Differential Input Voltage3. . . . . . . . . . . . . . . . . . . . . . . . . 36 V Output Short-Circuit Duration . . . . . . . . . . . . . . . . . Indefinite Storage Temperature Range P, S Package . . . . . . . . . . . . . . . . . . . . . . . . -65C to +150C Operating Temperature Range OP295G, OP495G . . . . . . . . . . . . . . . . . . . -40C to +125C Junction Temperature Range P, S Package . . . . . . . . . . . . . . . . . . . . . . . . -65C to +150C Lead Temperature Range (Soldering, 60 sec) . . . . . . . . 300C Package Type JA* JC Unit 8-Lead Plastic DIP (P) 8-Lead SOIC (S) 14-Lead Plastic DIP (P) 16-Lead SOIC (S) 103 158 83 98 43 43 39 30 C/W C/W C/W C/W *JA is specified for worst case mounting conditions, i.e., JA is specified for device in socket for CERDIP, PDIP, and LCC packages; JA is specified for device soldered to printed circuit board for SOIC package. ORDERING GUIDE Model Temperature Range Package Description Package Option OP295GP OP295GS OP295GS-REEL OP295GS-REEL7 OP495GP OP495GS OP495GS-REEL OP495GSZ* OP495GSZ-REEL7* -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C 8-Lead Plastic DIP 8-Lead SOIC 8-Lead SOIC 8-Lead SOIC 14-Lead Plastic DIP 16-Lead SOIC 16-Lead SOIC 16-Lead SOIC 16-Lead SOIC P-8 (N-8) S-8 (R-8) S-8 (R-8) S-8 (R-8) P-14 (N-14) S-16 (RW-16) S-16 (RW-16) S-16 (RW-16) S-16 (RW-16) *Z = Pb-free part. CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the OP295/OP495 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. Typical Performance Characteristics + OUTPUT SWING - V 140 100 VS = 36V VS = 5V 80 VS = 15V RL = 100k 15.0 14.8 RL = 10k 14.6 14.4 RL = 2k 14.2 VS = 3V - OUTPUT SWING - V SUPPLY CURRENT - A 120 15.2 60 40 20 -50 -25 0 25 50 75 100 -14.4 RL = 2k -14.6 RL = 10k -14.8 -15.0 RL = 100k -15.2 -50 TEMPERATURE - C -25 0 25 50 TEMPERATURE - C 75 100 TPC 2. Output Voltage Swing vs. Temperature TPC 1. Supply Current Per Amplifier vs. Temperature -4- REV. D OP295/OP495 5.10 3.10 VS = 3V VS = 5V 5.00 OUTPUT VOLTAGE SWING - V OUTPUT VOLTAGE SWING - V 3.00 RL = 100k 2.90 RL = 10k 2.80 2.70 RL = 2k 2.60 RL = 100k 4.90 RL = 10k 4.80 4.70 RL = 2k 4.60 2.50 -50 -25 0 25 50 75 4.50 -50 100 -25 0 TEMPERATURE - C 25 50 75 100 TEMPERATURE - C TPC 3. Output Voltage Swing vs. Temperature TPC 6. Output Voltage Swing vs. Temperature 200 500 BASED ON 600 OP AMPS BASED ON 1200 OP AMPS VS = 5V 175 VS = 5V TA = 25C 450 TA = 25C 400 150 350 300 UNITS UNITS 125 100 250 200 75 150 50 100 25 50 0 -250 -200 -150 -100 -50 0 50 100 150 200 0 -100 250 -50 INPUT OFFSET VOLTAGE - V TPC 4. OP295 Input Offset (VOS) Distribution 250 300 500 BASED ON 600 OP AMPS BASED ON 1200 OP AMPS VS = 5V -40 TA 450 +85C 200 400 175 350 150 300 UNITS UNITS 50 100 150 200 INPUT OFFSET VOLTAGE - V TPC 7. OP495 Input Offset (VOS) Distribution 250 225 125 100 VS = 5V -40 TA +85C 250 200 75 150 50 100 25 50 0 0 0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 0 TC - V OS - V/C 0.4 0.8 1.2 1.6 2.0 TC - V OS - V/C 2.4 2.8 TPC 8. OP495 TC-VOS Distribution TPC 5. OP295 TC-VOS Distribution REV. D 0 -5- 3.2 OP295/OP495 12 20 VS = 5V VO = 4V VS = 5V 10 OPEN-LOOP GAIN - V/V INPUT BIAS CURRENT - nA 16 12 8 RL = 100k 6 RL = 10k 4 RL = 2k 4 0 -50 8 2 -25 0 25 50 TEMPERATURE - C 75 0 -50 100 -25 0 25 50 75 100 TEMPERATURE - C TPC 12. Open-Loop Gain vs. Temperature TPC 9. Input Bias Current vs. Temperature 40 SOURCE VS = 5V TA = 25C TO RAIL 30 VS = 15V SINK 25 SOURCE OUTPUT VOLTAGE OUTPUT CURRENT - mA 35 20 SINK 15 VS = 5V 10 1V 100mV SOURCE 10mV SINK 1mV 5 0 -50 -25 0 25 50 75 100V 1A 100 TEMPERATURE - C 10A 1mA 100A LOAD CURRENT 10mA TPC 13. Output Voltage to Supply Rail vs. Load Current TPC 10. Output Current vs. Temperature 100 OPEN-LOOP GAIN - V/V VS = 15V VO = 10V RL = 100k 10 RL = 10k RL = 2k 1 -50 -25 0 25 50 75 100 TEMPERATURE - C TPC 11. Open-Loop Gain vs. Temperature -6- REV. D OP295/OP495 APPLICATIONS Rail-to-Rail Application Information 0.1F The OP295/OP495 has a wide common-mode input range extending from ground to within about 800 mV of the positive supply. There is a tendency to use the OP295/OP495 in buffer applications where the input voltage could exceed the commonmode input range. This may initially appear to work because of the high input range and rail-to-rail output range. But above the common-mode input range, the amplifier is, of course, highly nonlinear. For this reason, it is always required that there be some minimal amount of gain when rail-to-rail output swing is desired. Based on the input common-mode range, this gain should be at least 1.2. LED 3 VIN R2 27k R3 R5 10k C2 10F VOUT 1 C1 1500pF R8 100 3 4 OP295/OP495 R4 The input noise is controlled by the MAT03 transistor pair and the collector current level. Increasing the collector current reduces the voltage noise. This particular circuit was tested with 1.85 mA and 0.5 mA of current. Under these two cases, the input voltage noise was 3.1 nV/Hz and 10 nV/Hz, respectively. The high collector currents do lead to a tradeoff in supply current, bias current, and current noise. All of these parameters increase with increasing collector current. For example, typically the MAT03 has an hFE = 165. This leads to bias currents of 11 A and 3 A, respectively. Based on the high bias currents, this circuit is best suited for applications with low source impedance such as magnetic pickups or low impedance strain gages. Furthermore, a high source impedance degrades the noise performance. For example, a 1 k resistor generates 4 nV/Hz of broadband noise, which is already greater than the noise of the preamp. VOUT = 4.5V 1F TO 10 F 1/2 OP295/OP495 Figure 1. 4.5 V, Low Drop-Out Reference Low Noise, Single-Supply Preamplifier Most single-supply op amps are designed to draw low supply current at the expense of having higher voltage noise. This tradeoff may be necessary because the system must be powered by a battery. However, this condition is worsened because all circuit resistances tend to be higher; as a result, in addition to the op amp's voltage noise, Johnson noise (resistor thermal noise) is also a significant contributor to the total noise of the system. The collector current is set by R1 in combination with the LED and Q2. The LED is a 1.6 V Zener diode that has a temperature coefficient close to that of Q2's base-emitter junction, which provides a constant 1.0 V drop across R1. With R1 equal to 270 , the tail current is 3.7 mA and the collector current is half that, or 1.85 mA. The value of R1 can be altered to adjust the collector current. Whenever R1 is changed, R3 and R4 should also be adjusted. To maintain a common-mode input range that includes ground, the collectors of the Q1 and Q2 should not go above 0.5 V--otherwise they could saturate. Thus, R3 and R4 must be small enough to prevent this condition. Their values and the overall performance for two different values of R1 are summarized in Table I. Lastly, the potentiometer, R8, is needed to adjust the offset voltage to null it to zero. Similar performance can be obtained using an OP90 as the output amplifier with a savings of about 185 A of supply current. However, the output swing will not include the positive rail, and the bandwidth will reduce to approximately 250 Hz. The choice of monolithic op amps that combine the characteristics of low noise and single-supply operation is rather limited. Most single-supply op amps have noise on the order of 30 nV/Hz to 60 nV/Hz and single-supply amplifiers with noise below 5 nV/Hz do not exist. In order to achieve both low noise and low supply voltage operation, discrete designs may provide the best solution. The circuit in Figure 2 uses the OP295/OP495 rail-to-rail amplifier and a matched PNP transistor pair--the MAT03--to achieve zero-in/ zero-out single-supply operation with an input voltage noise of 3.1 nV/Hz at 100 Hz. R5 and R6 set the gain of 1,000, making this circuit ideal for maximizing dynamic range when amplifying low level signals in single-supply applications. The OP295/OP495 provide rail-to-rail output swings, allowing this circuit to operate with 0 V to 5 V outputs. Only half of the OP295/OP495 is used, leaving the other uncommitted op amp for use elsewhere. REV. D 8 Figure 2. Low Noise Single-Supply Preamplifier 5V 4 7 R7 510 0.001F 6 Q2 2 20k REF43 MAT-03 R6 10 6 1 16k 10 5 2 Q1 The OP295/OP495 can be used to gain up a 2.5 V or other low voltage reference to 4.5 V for use with high resolution ADCs that operate from 5 V only supplies. The circuit in Figure 1 will supply up to 10 mA. Its no-load drop-out voltage is only 20 mV. This circuit will supply over 3.5 mA with a 5 V supply. 2 10F Q2 2N3906 Low Drop-Out Reference 5V R1 -7- OP295/OP495 Table I. Single-Supply Low Noise Preamp Performance R1 R3, R4 en @ 100 Hz en @ 10 Hz ISY IB Bandwidth Closed-Loop Gain IC = 1.85 mA IC = 0.5 mA 270 200 3.15 nV/Hz 4.2 nV/Hz 4.0 mA 11 A 1 kHz 1,000 1.0 k 910 8.6 nV/Hz 10.2 nV/Hz 1.3 mA 3 A 1 kHz 1,000 Direct Access Arrangement OP295/OP495 can be used in a single-supply direct access arrangement (DAA) as is shown in Figure 4. This figure shows a portion of a typical DM capable of operating from a single 5 V supply and it may also work on 3 V supplies with minor modifications. Amplifiers A2 and A3 are configured so that the transmit signal TxA is inverted by A2 and is not inverted by A3. This arrangement drives the transformer differentially so that the drive to the transformer is effectively doubled over a single amplifier arrangement. This application takes advantage of the OP295/ OP495's ability to drive capacitive loads, and to save power in single-supply applications. Driving Heavy Loads 390pF The OP295/OP495 is well suited to drive loads by using a power transistor, Darlington, or FET to increase the current to the load. The ability to swing to either rail can assure that the device is turned on hard. This results in more power to the load and an increase in efficiency over using standard op amps with their limited output swing. Driving power FETs is also possible with the OP295/OP495 because of its ability to drive capacitive loads of several hundred picofarads without oscillating. 37.4k 0.1F RXA 5V 2N2222 2N2222 10k 0 VIN 20k A1 0.0047F 3.3k 20k 475 Without the addition of external transistors, the OP295/OP495 can drive loads in excess of 15 mA with 15 V or +30 V supplies. This drive capability is somewhat decreased at lower supply voltages. At 5 V supplies, the drive current is 11 mA. Driving motors or actuators in two directions in a single-supply application is often accomplished using an "H" bridge. The principle is demonstrated in Figure 3a. From a single 5 V supply, this driver is capable of driving loads from 0.8 V to 4.2 V in both directions. Figure 3b shows the voltages at the inverting and non- inverting outputs of the driver. There is a small crossover glitch that is frequency dependent and would not cause problems unless this was a low distortion application such as audio. If this is used to drive inductive loads, be sure to add diode clamps to protect the bridge from inductive kickback. OP295/ OP495 OP295/ OP495 A2 22.1k 0.1F 20k 750pF TXA 0.033F 20k 1:1 20k OP295/ OP495 2.5V REF A3 Figure 4. Direct Access Arrangement A Single-Supply Instrumentation Amplifier The OP295/OP495 can be configured as a single-supply instrumentation amplifier as in Figure 5. For our example, VREF is set equal to V+/2 and VO is measured with respect to VREF. The input common-mode voltage range includes ground and the output swings to both rails. OUTPUTS 2.5V 5k V+ 1.67V 10k 10k 2N2907 2N2907 1/2 OP295/ OP495 VIN 5 8 6 4 1/2 OP295/ OP495 7 VO 3 1 2 Figure 3a. "H" Bridge R1 R2 100k 20k VREF R4 20k 100k RG 100 90 R3 VO = 5 + 200k VIN + V REF RG Figure 5. Single-Supply Instrumentation Amplifier Resistor RG sets the gain of the instrumentation amplifier. Minimum gain is 6 (with no RG). All resistors should be matched in absolute value as well as temperature coefficient to maximize common-mode rejection performance and minimize drift. This instrumentation amplifier can operate from a supply voltage as low as 3 V. 10 0% 2V 2V 1ms Figure 3b. "H" Bridge Outputs -8- REV. D OP295/OP495 bath or oven and adjust the scale-adjust potentiometer for an output voltage of 2.50 V, which is equivalent to 250C. Within this temperature range, the K-type thermocouple is quite accurate and produces a fairly linear transfer characteristic. Accuracy of 3C is achievable without linearization. A Single-Supply RTD Thermometer Amplifier This RTD amplifier takes advantage of the rail-to-rail swing of the OP295/OP495 to achieve a high bridge voltage in spite of a low 5 V supply. The OP295/OP495 amplifier servos a constant 200 A current to the bridge. The return current drops across the parallel resistors 6.19 k and the 2.55 M, developing a voltage that is servoed to 1.235 V, which is established by the AD589 band gap reference. The 3-wire RTD provides an equal line resistance drop in both 100 legs of the bridge, thus improving the accuracy. Even if the battery voltage is allowed to decay to as low as 7 V, the rail-to-rail swing allows temperature measurements to 700C. However, linearization may be necessary for temperatures above 250C where the thermocouple becomes rather nonlinear. The circuit draws just under 500 A supply current from a 9 V battery. The AMP04 amplifies the differential bridge signal and converts it to a single-ended output. The gain is set by the series resistance of the 332 resistor plus the 50 potentiometer. The gain scales the output to produce a 4.5 V full scale. The 0.22 F capacitor to the output provides a 7 Hz low-pass filter to keep noise at a minimum. ZERO ADJ 200 10-TURNS 26.7k 0.5% 7 1 3 8 0.22F 2 2 3 4 1.235 5V 8 R1 17.8k 4.5V = 450C 0V = 0C 1.23V 6.19k 1% 2.55M 1% 5V VO 6 5 1/2 OP295/ OP495 1 100 0.5% The output voltage from the DAC is the binary weighted voltage of the reference, which is gained up by the output amplifier such that the DAC has a 1 mV per bit transfer function. 332 AMP04 100 RTD Figure 8 shows a complete voltage output DAC with wide output voltage swing operating off a single 5 V supply. The serial input 12-bit DAC is configured as a voltage output device with the 1.235 V reference feeding the current output pin (IOUT) of the DAC. The VREF, which is normally the input now becomes the output. 50 5V 26.7k 0.5% A 5 V Only, 12-Bit DAC That Swings 0 V to 4.095 V VDD 5V 2 RFB 1 3 IOUT VREF 3 GND CLK SRI LD 2 DAC8043 AD589 AD589 4 7 6 R2 41.2k DIGITAL CONTROL A Cold Junction Compensated, Battery-Powered Thermocouple Amplifier 1N914 1.5M 1% ALUMEL 24.9k 1% COLD JUNCTIONS 20k 4.99k 1% 500 10-TURN ZERO ADJUST CR CHROMEL K-TYPE THERMOCOUPLE 40.7V/ C Figure 9 shows a self-powered 4 to 20 mA current loop transmitter. The entire circuit floats up from the single-supply (12 V to 36 V) return. The supply current carries the signal within the 4 to 20 mA range. Thus the 4 mA establishes the baseline current budget with which the circuit must operate. This circuit consumes only 1.4 mA maximum quiescent current, making 2.6 mA of current available to power additional signal conditioning circuitry or to power a bridge circuit. SCALE ADJUST 475 1% NULL ADJ 8 SPAN ADJ 1 3 4 OP295/ OP495 VO 5V = 500C 0V = 0C 2 GND 100k 10-TURN 4 5V 10k 182k 1.21M 1% 10-TURN 1% 100 VIN 0 + 3V 3 8 12V TO 36V 220 1 2.1k 1% 2 Figure 7. Battery-Powered, Cold-Junction Compensated Thermocouple Amplifier 4 1/2 OP295/ OP495 2N1711 4 TO 20mA RL 100 220pF HP 5082-2800 To calibrate, immerse the thermocouple measuring junction in a 0C ice bath, adjust the 500 zero-adjust potentiometer to 0 V out. Then immerse the thermocouple in a 250C temperature REV. D REF02 6 1.33M 2 AL 4 mA to 20 mA Current Loop Transmitter 24.9k 24.3k 1% R3 5k Figure 8. A 5 V 12-Bit DAC with 0 V to 4.095 Output Swing 9V 7.15k 1% R4 100k TOTAL POWER DISSIPATION = 1.6mW The OP295/OP495's 150 A quiescent current per amplifier consumption makes it useful for battery-powered temperature measuring instruments. The K-type thermocouple terminates into an isothermal block where the terminated junctions' ambient temperatures can be continuously monitored and corrected by summing an equal but opposite thermal EMF to the amplifier, thereby canceling the error introduced by the cold junctions. ISOTHERMAL BLOCK OP295/ OP495 4 5 Figure 6. Low Power RTD Amplifier 1.235V D (4.096V) 4096 1 5V 37.4k AD589 VO = 8 100k 1% 100 1% Figure 9. 4 to 20 mA Current Loop Transmitter -9- OP295/OP495 A 3 V Low-Dropout Linear Voltage Regulator Figure 10 shows a simple 3 V voltage regulator design. The regulator can deliver 50 mA load current while allowing a 0.2 V dropout voltage. The OP295/OP495's rail-to-rail output swing handily drives the MJE350 pass transistor without requiring special drive circuitry. At no load, its output can swing less than the pass transistor's base-emitter voltage, turning the device nearly off. At full load, and at low emitter-collector voltages, the transistor beta tends to decrease. The additional base current is easily handled by the OP295/OP495 output. The amplifier servos the output to a constant voltage, which feeds a portion of the signal to the error amplifier. Higher output current, to 100 mA, is achievable at a higher dropout voltage of 3.8 V. the drive to the power MOSFET transistor, thereby effectively removing the A1 voltage regulation loop from the circuit. If the output current greater than 1 A persists, the current limit loop forces a reduction of current to the load, which causes a corresponding drop in output voltage. As the output voltage drops, the current limit threshold also drops fractionally, resulting in a decreasing output current as the output voltage decreases, to the limit of less than 0.2 A at 1 V output. This "fold-back" effect reduces the power dissipation considerably during a short circuit condition, thus making the power supply far more forgiving in terms of the thermal design requirements. Small heat sinking on the power MOSFET can be tolerated. The OP295's rail-to-rail swing exacts higher gate drive to the power MOSFET, providing a fuller enhancement to the transistor. The regulator exhibits 0.2 V dropout at 500 mA of load current. At 1 A output, the dropout voltage is typically 5.6 V. IL < 50mA MJE 350 VO 44.2k 1% VIN 5V TO 3.2V 8 100F 3 30.9k 1% 1 4 2 6V 43k 8 1N4148 AD589 1/2 OP295/ OP495 100k 5% 210k 1% 205k 1% 45.3k 1% 45.3k 1% 5 A2 7 1.235V IO (NORM) = 0.5A IO (MAX) = 1A 5V VO G 1/2 OP295/ OP495 1000pF RSENSE 0.1 1/4W IRF9531 S D 6 0.01F 3 Figure 10. 3 V Low Dropout Voltage Regulator A1 1 1/2 OP295/ OP495 Figure 11 shows the regulator's recovery characteristic when its output underwent a 20 mA to 50 mA step current change. 2 2V REF43 4 4 6 2 124k 1% 124k 1% 2.500V 100 STEP CURRENT CONTROL WAVEFORM 50mA 90 Figure 12. Low Dropout, 500 mA Voltage Regulator with Fold-Back Current Limiting Square Wave Oscillator 20mA OUTPUT The circuit in Figure 13 is a square wave oscillator (note the positive feedback). The rail-to-rail swing of the OP295/OP495 helps maintain a constant oscillation frequency even if the supply voltage varies considerably. Consider a battery-powered system where the voltages are not regulated and drop over time. The rail-to-rail swing ensures that the noninverting input sees the full V+/2, rather than only a fraction of it. 10 0% 20mV 1ms Figure 11. Output Step Load Current Recovery Low-Dropout, 500 mA Voltage Regulator with Fold-Back Current Limiting Adding a second amplifier in the regulation loop, as shown in Figure 12, provides an output current monitor as well as foldback current limiting protection. Amplifier A1 provides error amplification for the normal voltage regulation loop. As long as the output current is less than 1 A, amplifier A2's output swings to ground, reverse biasing the diode and effectively taking itself out of the circuit. However, as the output current exceeds 1 A, the voltage that develops across the 0.1 sense resistor forces the amplifier A2's output to go high, forward-biasing the diode, which in turn closes the current limit loop. At this point A2's lower output resistance dominates The constant frequency comes from the fact that the 58.7 k feedback sets up Schmitt trigger threshold levels that are directly proportional to the supply voltage, as are the RC charge voltage levels. As a result, the RC charge time, and therefore, the frequency, remains constant independent of supply voltage. The slew rate of the amplifier limits oscillation frequency to a maximum of about 800 Hz at a 5 V supply. Single-Supply Differential Speaker Driver Connected as a differential speaker driver, the OP295/OP495 can deliver a minimum of 10 mA to the load. With a 600 load, the OP295/OP495 can swing close to 5 V p-p across the load. -10- REV. D OP295/OP495 V+ 100k 58.7k 3 8 2 4 FREQ OUT 1 100k 1/2 OP295/ OP495 FOSC = 1 < 350Hz @ V+ = 5V RC R C Figure 13. Square Wave Oscillator Has Stable Frequency Regardless of Supply Changes 90.9k 10k V+ 2.2F VIN 10k 20k 20k V+ 1/4 OP295/ OP495 100k 1/4 OP295/ OP495 SPEAKER 1/4 OP295/ OP495 Figure 14. Single-Supply Differential Speaker Driver High Accuracy, Single-Supply, Low Power Comparator The OP295/OP495 makes an accurate open-loop comparator. With a single 5 V supply, the offset error is less than 300 V. Figure 15 shows the OP295/OP495's response time when operating open-loop with 4 mV overdrive. It exhibits a 4 ms response time at the rising edge and a 1.5 ms response time at the falling edge. 1V 100 90 INPUT (5mV OVERDRIVE @ OP-295 INPUT) OUTPUT 10 0% 2V 5ms Figure 15. Open-Loop Comparator Response Time with 5 mV Overdrive OP295/OP495 SPICE MODEL Macro-Model * Node Assignments * Noninverting Input * Inverting Input * Positive Supply * Negative Supply * Output * * .SUBCKT OP295 1 2 99 50 20 * * INPUT STAGE * REV. D I1 99 4 2E-6 R1 1 6 5E3 R2 2 5 5E3 CIN 1 2 2E-12 IOS 1 2 0.5E-9 D1 5 3 DZ D2 6 3 DZ EOS 7 6 POLY (1) (31,39) 30E-6 0.024 Q1 8 5 4 QP Q2 9 7 4 QP R3 8 50 25.8E3 R4 9 50 25.8E3 * * GAIN STAGE * R7 10 98 270E6 G1 98 10 POLY (1) (9,8) -4.26712E-9 27.8E-6 EREF 98 0 (39, 0) 1 R5 99 39 100E3 R6 39 50 100E3 * * COMMON MODE STAGE * ECM 30 98 POLY(2) (1,39) (2,39) 0 0.5 0.5 R12 30 31 1E6 R13 31 98 100 * * OUTPUT STAGE * I2 18 50 1.59E-6 V2 99 12 DC 2.2763 Q4 10 14 50 QNA 1.0 R11 14 50 33 M3 15 10 13 13 MN L=9E-6 W=102E-6 AD=15E-10 AD=15E-10 M4 13 10 50 50 MN L=9E-6 W=50E-6 AD=75E-11 AS=75E-11 D8 10 22 DX V3 22 50 DC 6 M2 20 10 14 14 MN L=9E-6 W=2000E-6 AD=30E-9 AS=30E-9 Q5 17 17 99 QPA 1.0 Q6 18 17 99 QPA 4.0 R8 18 99 2.2E6 Q7 18 19 99 QPA 1.0 R9 99 19 8 C2 18 99 20E-12 M6 15 12 17 99 MP L=9E-6 W=27E-6 AD=405E-12 AS=405E-12 M1 20 18 19 99 MP L=9E-6 W=2000E-6 AD=30E-9 AS=30E-9 D4 21 18 DX V4 99 21 DC 6 R10 10 11 6E3 C3 11 20 50E-12 .MODEL QNA NPN (IS=1.19E-16 BF=253 NF=0.99 VAF=193 IKF=2.76E-3 + ISE=2.57E-13 NE=5 BR=0.4 NR=0.988 VAR=15 IKR=1.465E-4 + ISC=6.9E-16 NC=0.99 RB=2.0E3 IRB=7.73E-6 RBM=132.8 RE=4 RC=209 + CJE=2.1E-13 VJE=0.573 MJE=0.364 FC=0.5 CJC=1.64E-13 VJC=0.534 MJC=0.5 + CJS=1.37E-12 VJS=0.59 MJS=0.5 TF=0.43E-9 PTF=30) .MODEL QPA PNP (IS=5.21E-17 BF=131 NF=0.99 VAF=62 IKF=8.35E-4 + ISE=1.09E-14 NE=2.61 BR=0.5 NR=0.984 VAR=15 IKR=3.96E-5 + ISC=7.58E-16 NC=0.985 RB=1.52E3 IRB=1.67E-5 RBM=368.5 RE=6.31 RC=354.4 + CJE=1.1E-13 VJE=0.745 MJE=0.33 FC=0.5 CJC=2.37E-13 VJC=0.762 MJC=0.4 + CJS =7.11E-13 VJS=0.45 MJS=0.412 TF=1.0E-9 PTF=30) .MODEL MN NMOS (LEVEL=3 VTO=1.3 RS=0.3 RD=0.3 + TOX=8.5E-8 LD=1.48E-6 NSUB=1.53E16 UO=650 DELTA=10 VMAX=2E5 + XJ=1.75E-6 KAPPA=0.8 ETA=0.066 THETA=0.01 TPG=1 CJ=2.9E4 PB=0.837 + MJ=0.407 CJSW=0.5E-9 MJSW=0.33) .MODEL MP PMOS (LEVEL=3 VTO=-1.1 RS=0.7 RD=0.7 + TOX=9.5E-8 LD=1.4E-6 NSUB=2.4E15 UO=650 DELTA=5.6 VMAX=1E5 + XJ=1.75E-6 KAPPA=1.7 ETA=0.71 THETA=5.9E-3 TPG=-1 CJ=1.55E-4 PB=0.56 + MJ=0.442 CJSW=0.4E-9 MJSW=0.33) .MODEL DX D(IS=1E-15) .MODEL DZ D (IS=1E-15, BV=7) .MODEL QP PNP (BF=125) .ENDS -11- OP295/OP495 OUTLINE DIMENSIONS 8-Lead Plastic Dual In-Line Package [PDIP] (N-8) P-Suffix 8-Lead Standard Small Outline Package [SOIC] Narrow Body (R-8) S-Suffix Dimensions shown in inches and (millimeters) Dimensions shown in millimeters and (inches) 0.375 (9.53) 0.365 (9.27) 0.355 (9.02) 8 5 4 1 5.00 (0.1968) 4.80 (0.1890) 0.295 (7.49) 0.285 (7.24) 0.275 (6.98) 4.00 (0.1574) 3.80 (0.1497) 0.325 (8.26) 0.310 (7.87) 0.300 (7.62) 0.100 (2.54) BSC 0.150 (3.81) 0.130 (3.30) 0.110 (2.79) 0.022 (0.56) 0.018 (0.46) 0.014 (0.36) 4 6.20 (0.2440) 5.80 (0.2284) 1.75 (0.0688) 1.35 (0.0532) 0.25 (0.0098) 0.10 (0.0040) COPLANARITY SEATING 0.10 PLANE 0.015 (0.38) 0.010 (0.25) 0.008 (0.20) SEATING PLANE 0.060 (1.52) 0.050 (1.27) 0.045 (1.14) 5 1 1.27 (0.0500) BSC 0.150 (3.81) 0.135 (3.43) 0.120 (3.05) 0.015 (0.38) MIN 0.180 (4.57) MAX 8 0.51 (0.0201) 0.31 (0.0122) 0.50 (0.0196) 45 0.25 (0.0099) 8 0.25 (0.0098) 0 1.27 (0.0500) 0.40 (0.0157) 0.17 (0.0067) COMPLIANT TO JEDEC STANDARDS MS-012AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN COMPLIANT TO JEDEC STANDARDS MO-095AA CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN 14-Lead Plastic Dual In-Line Package [PDIP] (N-14) P-Suffix 16-Lead Standard Small Outline Package [SOIC] Wide Body (RW-16) S-Suffix Dimensions shown in inches and (millimeters) Dimensions shown in millimeters and (inches) 0.685 (17.40) 0.665 (16.89) 0.645 (16.38) 14 8 1 7 0.295 (7.49) 0.285 (7.24) 0.275 (6.99) 7.60 (0.2992) 7.40 (0.2913) 0.325 (8.26) 0.310 (7.87) 0.300 (7.62) 0.015 (0.38) MIN 0.180 (4.57) MAX 0.022 (0.56) 0.060 (1.52) 0.018 (0.46) 0.050 (1.27) 0.014 (0.36) 0.045 (1.14) 9 16 0.100 (2.54) BSC 0.150 (3.81) 0.130 (3.30) 0.110 (2.79) 10.50 (0.4134) 10.10 (0.3976) SEATING PLANE 0.150 (3.81) 0.135 (3.43) 0.120 (3.05) 1.27 (0.0500) BSC 0.30 (0.0118) 0.10 (0.0039) 0.015 (0.38) 0.010 (0.25) 0.008 (0.20) COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-095-AB CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN 10.65 (0.4193) 10.00 (0.3937) 8 1 0.51 (0.0201) 0.31 (0.0122) 2.65 (0.1043) 2.35 (0.0925) SEATING PLANE 8 0.33 (0.0130) 0 0.20 (0.0079) 0.75 (0.0295) 45 0.25 (0.0098) 1.27 (0.0500) 0.40 (0.0157) COMPLIANT TO JEDEC STANDARDS MS-013AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN -12- REV. D OP295/OP495 Revision History Location Page 2/04--Data Sheet changed from REV. C to REV. D. Changes to GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Changes to SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Changes to Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Changes to ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Updated OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3/02--Data Sheet changed from REV. B to REV. C. Figure changes to PIN CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Deletion of OP295GBC and OP495GBC from ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Deletion of WAFER TEST LIMITS table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Changes to ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Deletion of DICE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 REV. D -13- -14- -15- -16- C00331-0-2/04(D)