Buffer Circuits

Ql and Q2 constitute a simple, high-speed FET input buffer. Ql functions as a source follower, with the Q2 current source load setting the drain-source channel current. The LT1010 buffer provides output drive capability for cables or whatever load is required. Normally, this open-loop configuration would be quite drifty because there is no de feedback. The LTC1052 contributes this function to stabilize the circuit. It does this by comparing the filtered circuit output.....

Digitally-programmable-precision-amplifier

The DG419looks into the high input impedance of the op amp, so the effects of Rvs(o"l are negligible. The DG441 is also connected in series with RIN and is not included in the feedback dividers, thus contributing negligible Views: 3 | Votes: 52 | Comments: 0 | Rating: 9 | Rank: 5 | Added: Mar 21, 2013 |

50Mhz-trigger

This has a stable trigger 100 m V sensitivity at 50 MHz. The FETs comprise a simple high-speed buffer and the LT1016 compares the buffer"s output to the potential at tbe trigger level potentiometer, which can be of either polarity. The 10-KO resistor provides hysteresis, eliminating "chattering"" caused by noisy input signals. ..

Polarity Gain Adjustment Circuit

By adjusting one potentiometer, this circuit`s output can be varied from a positive-going version of the input signal, smoothly through zero output, then to a negative-going version of the input (see the figure). If the input signal is a positive pulse of, for example, +2-V peak/the output pulse amplitude can be smoothly varied from +2-V through ground (no output) to a -2-V peak. Taking a closer look at the setup, assume that the signal has a +2-V peak input. The A.....

Buffer-amplifier-for-multiplexers

The precision input characteristics of the HA-5147 help simplify system error budgets, while its speed and drive capabilities provide fast charging of the multiplexer"s output capacitance. This speed eliminates an increased multiplexer acquisition time, which can be induced by more limited amplifiers. ..

Noninverting Ac Amplifier Circuit

A general-purpose noninverting ac amplifier for audio of other low-frequency applications is shown. Design equations are in the figure...

Safe-opamp-circuit

In intrinsically safe applications, it is sometimes necessary to separate sections of circuitry by resistors which limit current under fault conditions. The circuit shown provides an accurate analogue output with effectively zero output impedance, despite having resistors in series with the output. which is independent of RA and RB. ..

Low Noise And Drift Composite Amp Circuit

This circuit offers the best of both worlds. It can be combined with a low input offset voltage and drift without degrading the overall system`s dynamic performance. Compared to a standalone FET input operational amplifier, the composite amplifier circuit exhibits a 20-fold improvement in voltage offset and drift. In this circuit arrangement, A1 is a highspeed FET input op amp with a closed-loop gain of 100 (the source impedance was arbitrarily chosen to be 100 kfl). A2.....

Cable bootstrapping

Bootstrapping input shield for a follower reduces cable capacitance, leakage, and spurious voltages from cable flexing..

Power Op Amp Circuit

This circuit from Apex Microtcchnology can deliver 180 V p-p @ 90 kHz into a 4- load...

High Gbw Op-Amp Circuit

You can build a composite amplifier featuring high gain, wide bandwidth, and good dc accuracy by cascading the sections of a dual video amplifier and adding two appropriate phase-compen-sation components. ..

Unity-Gain Noninverting Amplifier Circuit

Biasing methods for an N-channel MOSFET to form a unity-gain noninverting amplifier..

Nonlinear Operational Amplifier Circuit

Using resistor and transistor feedback elements, this operational amplifier circuit can be used as a nonlinear amplifier...

Amplifier-for-signal-supply

This unity-gain follower amplifier has a CMOS p-channel input, an npn second-gain stage, and a CMOS inverter output. The IC building blocks are two CA3600E"s (CMOS transistor pairs) and a CA3046 npn transistor array. A zener-regulated leg provides bias for a 400-I"A p-channel source, feeding the input stage, which is terminated in an npn current mirror. The amplifier voltage-offset is nulled with the 10-K!l balance potentiometer. The second-stage current level is.....

Constant-bandwidth-amplifier

The traditional restnct1on of constant gainbandwidth products for a voltage amplifier can be overcome by employing feedback around a current amplifier. Two current mirrors, constructed from transistors in a CA3096AE array, effectively turn the LF351 op amp into a current amplifier. Feedback is then applied by using R2 and R1, turning the whole circuit into a feedback voltage amplifier with a noninverting gain of G of 1 + R112R2. ..

Op Amp Regulator

This op amp offers a straightforward method of developing a single-polarity stable voltage source (see the figure). TVansi..

Thermocouple-preamplifier

The MAX420 is operated at a gain of 191 to convert the 52 p.VI o C output of the type J thermocouple to a 10 mV/Â°C signal. The -2.2 mV/Â°C tempco of the 2N3904 is added into the summing junction with a gain of 42.2 to provide cold-junction compensation. The ICL8069 is used to remove the offset caused by the 600-m V initial voltage of the 2N3904. ..

Precision-Increasing Buffer

Adding an unity-gain buffer to your analog circuit can increase its precision. For example, by itself, the op a..

Wide-range-digitally-controlled-variable-gain-amplifier

The circuit uses the LTC1043 in a variable gain amplifier which features continuously variable gain, gain stability of 20 ppm/Â°C, and single-ended or differential inputs. The circuit uses two separate LTC1043s. LTC1043B is continuously clocked by a 1-kHz source, which could also be processor supplied. Both LTC1043s function as the sampled data equivalent of a resistor within the bandwidth set by Al"s 0.01-I"F value and the switched-capacitor equivalent feedback.....

Fast Composite Amplifier Circuit

An ultra-low-noise, low-distortion op ampthe AD797is combined with the ADS 11 op amp, which offers a high bandwidth and a 100-mA output drive capability. The composite-amplifier circuit serves quite well when driving high resolution ADC`s and ATE systems. The fast AD811 operates at twice the gain of the AD797 so that the slower amplifier need only slew one-half of the total output swing. Using the component values shown, the circuit is capable of better than -90 dB THD.....