مدار مجتمع (آی سی) آی سی‌کاربرد ویژه

Product Attributes

Introduction

Designed as a general-purpose analog processing subsystem, the GAP-01 combines many commonly used system building blocks within a single integrated circuit. The basic circuit versatility stems from the GAP-01's architecture. The circuit features two differential input transconductance amplifiers, two low-glitch current mode switches, an output voltage buffer amplifier, and a precision comparator. Both transconductance amplifier outputs are switched by current-mode switches into the voltage follower output buffer, thus providing two digitally selectable signal paths through the device. Gain through the two channels maybe different in both sign and magnitude depending upon feedback selection. An external capacitor provides loop compensation and doubles as a hold or "memory" capacitor when the GAP-01 functions as a dual-channel sample/hold amplifier. Offset voltage and charge transfer errors are trimmed by using the "Zener-Zap" trim technique. The output buffer features a FET input stage to reduce droop rate error in S/H applications. A bias current cancellation circuit minimizes droop error at high ambient temperature. The inclusion of a precision comparator on chip increases the GAP-01's versatility and cost effectiveness in data conversion applications. The output high voltage level is set by external resistors. This scheme maximizes noise immunity and permits interface to all standard logic families. Several applications exploit the ability to select the signal path through the GAP-01. As a two-channel multiplexer or analog switch, the GAP-01 high input impedance offers advantages when switching high impedance signals. Gain through the "MUX" is also possible. The GAP-01 operates as a sample/hold amplifier in the hold mode when both transconductance amplifiers are unselected. With the on-board comparator, a two-channel successive approximation analog to-digital conversion (ADC) system may be constructed. Combining a sign-magnitude, digital-to-analog (DAC) converter with the GAP-01 results in a four-quadrant multiplying DAC. The GAP-01 contains all the functional devices needed to perform synchronous demodulation or implement the absolute value function.

Features

• Low Offset Voltage ... 3mV
• Low Zero-Scale Error ... 4mV
• Low Droop Rate ... 0.1mV/ms
• Wide Bandwidth ... 400kHz
• Digitally Selected Signal Path
• Uncommitted Comparator On Chip
• Wide Application Versatility
• Synchronous Demodulator
• Absolute Value Amplifier
• Two-Channel S/H Amplifier
• Two-Channel Multiplexer With Gain