LPC661 LPC661 Low Power CMOS Operational Amplifier Literature Number: SNOS620A
LPC661 Low Power CMOS Operational Amplifier General Description The LPC661 CMOS operational amplifier is ideal for operation from a single supply. It features a wide range of operating supply voltage from +5V to +15V, rail-to-rail output swing and an input common-mode range that includes ground. Performance limitations that have plagued CMOS amplifiers in the past are not a problem with this design.
LPC661 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (V+ − V−) Differential Input Voltage Output Short Circuit to V+ Output Short Circuit to V− Storage Temperature Range Lead Temperature (Soldering, 10 sec.) Junction Temperature (Note 3) Power Dissipation ESD Rating (C=100 pF, R=1.5 kΩ) Current at Input Pin ± 18 mA (V+) +0.3V, (V−) −0.
(Continued) The following specifications apply for V+ = 5V, V− = 0V, VCM = 1.5V, VO = 2.5V, and RL = 1M unless otherwise noted. Boldface limits apply at the temperature extremes; all other limits TJ = 25˚C. Symbol VO Parameter Output Swing Conditions LPC661AM LPC661AI LPC661I Limit Limit Limit (Note 4) (Note 4) (Note 4) 4.970 4.970 4.940 V 4.950 4.950 4.910 min 0.004 0.030 0.030 0.060 V 0.050 0.050 0.090 max 4.940 4.850 4.850 4.750 V 4.750 4.750 4.650 min 0.040 0.
LPC661 AC Electrical Characteristics (Continued) Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Note 2: Applies to both single supply and split supply operation.
VS = ± 7.5V, TA = 25˚C unless otherwise specified (Continued) Output Characteristics Current Sourcing Input Voltage Noise vs Frequency DS011227-30 CMRR vs Frequency DS011227-31 CMRR vs Temperature DS011227-32 Power Supply Rejection Ratio vs Frequency DS011227-33 Open-Loop Voltage Gain vs Temperature DS011227-35 DS011227-34 5 www.national.
LPC661 Typical Performance Characteristics VS = ± 7.5V, TA = 25˚C unless otherwise specified (Continued) Open-Loop Frequency Response Gain and Phase Responses vs Load Capacitance DS011227-36 DS011227-37 Gain and Phase Responses vs Temperature Gain Error (VOSvs VOUT) DS011227-38 Non-Inverting Slew Rate vs Temperature DS011227-39 Inverting Slew Rate vs Temperature DS011227-40 www.national.
VS = ± 7.5V, TA = 25˚C unless otherwise specified (Continued) Large-Signal Pulse Non-Inverting Response (AV = +1) Non-Inverting Small Signal Pulse Response (AV = +1) DS011227-42 Inverting Large-Signal Pulse Response DS011227-43 Inverting Small-Signal Pulse Response DS011227-44 DS011227-45 7 www.national.
LPC661 Typical Performance Characteristics VS = ± 7.5V, TA = 25˚C unless otherwise specified (Continued) Stability vs Capacitive Load Stability vs Capacitive Load DS011227-4 DS011227-5 Note: Avoid resistive loads of less than 500Ω, as they may cause instability. Application Hints ing load resistance of 5 kΩ or less, the gain will be reduced as indicated in the Electrical Characteristics. The op amp can drive load resistance as low as 500Ω without instability.
LPC661 Application Hints (Continued) DS011227-24 FIGURE 3. Compensating for Large Capacitive Loads with A Pull Up Resistor DS011227-7 FIGURE 2. Rx, Cx Improve Capacitive Load Tolerance PRINTED-CIRCUIT-BOARD LAYOUT FOR HIGH-IMPEDANCE WORK It is generally recognized that any circuit which must operate with less than 1000 pA of leakage current requires special layout of the PC board. When one wishes to take advantage of the ultra-low bias current of the LPC661, typically less than 0.
LPC661 Application Hints (Continued) DS011227-8 FIGURE 4. Example of Guard Ring in P.C. Board Layout, Using the LPC660 DS011227-9 FIGURE 5. Inverting Amplifier Guard Ring Connections DS011227-12 FIGURE 8.
LPC661 Application Hints (Continued) DS011227-13 (Input pins are lifted out of PC board and soldered directly to components. All other pins connected to PC board.) DS011227-14 FIGURE 9. Air Wiring FIGURE 10. Simple Input Bias Current Test Circuit BIAS CURRENT TESTING The test method of Figure 10 is appropriate for bench-testing bias current with reasonable accuracy. To understand its operation, first close switch S2 momentarily.
LPC661 Typical Single-Supply Applications (V+ = 5.0 VDC) (Continued) Low-Leakage Sample-and-Hold DS011227-17 Sine-Wave Oscillator DS011227-18 Oscillator frequency is determined by R1, R2, C1, and C2: fOSC = 1/2πRC where R = R1 = R2 and C = C1 = C2. This circuit, as shown, oscillates at 2.0 kHz with a peak-to-peak output swing of 4.5V 1 Hz Square-Wave Oscillator Power Amplifier DS011227-20 DS011227-19 www.national.
LPC661 Typical Single-Supply Applications (V+ = 5.0 VDC) (Continued) 10 Hz Bandpass Filter 10 Hz High-Pass Filter (2 dB Dip) DS011227-22 DS011227-21 fO = 10 Hz Q = 2.1 Gain = 18.9 dB fc = 10 Hz d = 0.
LPC661 Physical Dimensions inches (millimeters) unless otherwise noted 8-Pin Small Outline Molded Package (M) Order Number LPC661AIM or LPC661IM NS Package Number M08A 8-Pin Molded Dual-In-Line Package (N) Order Number LPC661AIN, LPC661IN or LPC661AMN NS Package Number N08E www.national.
LPC661 Low Power CMOS Operational Amplifier Notes LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1.
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