Instrumentation Amplifiers Use Autozero to Achieve 20µV (max) Offset
The MAX4208/MAX4209 ultra-low offset and drift instrumentation amplifiers feature exceptional precision specifications, low power consumption, rail-to-rail output, excellent gain-bandwidth product, and buffered REFIN/MODE input in a very small µMAX® package. These devices use a spread-spectrum, autozeroing technique that constantly measures and corrects the input offset, eliminating drift over time and temperature and the effect of 1/f noise. This technique achieves less than 20µV offset voltage, allows ground-sensing capability, provides ultra-low CMOS input bias current and increased common-mode rejection performance. The MAX4208/MAX4209 provide high-impedance inputs optimized for small-signal differential voltages (±100mV). All devices provide a gain-bandwidth product of 750kHz. The MAX4208 provides an adjustable gain with two external resistors or unity gain with FB connected to OUT. The MAX4209 is available with a fixed gain of 100V/V with ±0.03% (typ) accuracy. Both devices include a reference input (REF) to level-shift the output, allowing for bipolar signals in single-supply applications. In both devices, REFIN/MODE is an input to a precision unity-gain buffer, which sets the REF voltage to level-shift the output. The internal REF buffer allows the reference to be set by a simple resistive divider or an ADC reference without any loading error. The MAX4208/MAX4209 operate with a 2.85V to 5.5V single-supply voltage and consume only 750µA of quiescent current (when the internal buffer is off) and only 1.4µA in shutdown mode. These amplifiers also operate with ±2.5V dual supplies with REF connected to ground and REFIN/MODE to VSS. The MAX4208/MAX4209 are available in space-saving 8-pin µMAX packages and are specified over the automotive operating temperature range (-40°C to +125°C).
title | Download file |
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MAX4208-MAX4209 Data Sheet | MAX4208-MAX4209.pdf |
Part Number | Architecture | Amps. | VCMVR | Rail to Rail | AV (V/V) | VSUPPLY (Total) (V) | VSUPPLY (Total) (V) | ICC per Amp. (mA) | ICC per Amp. (mA) | VOS (µV) | CMRR @DC (dB) | PSRR @DC (dB) | Input IBIAS (nA) | Unity Gain BW (MHz) | Slew Rate (V/µs) | VCMVR (V) | en (nV/√Hz) | Noise Spec'd @ | Low Pwr. Shutdn | Oper. Temp. (°C) | Package/Pins | Budgetary Price |
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to Neg. Rail | min | max | typ | max | max | typ | typ | max | typ | typ | < | See Notes | ||||||||||
MAX4208 | Indirect Current-Feedback | 1 | Yes | Output Only | Adj. | 2.85 | 5.5 | 0.75 | 1.3 | 20 | 135 | 125 | 0.01 | 0.75 | 0.08 | VSS-0.1 to VDD-1.3 | 140 | 1kHz | Yes | -40 to +125 | µMAX/8 | $1.65 @1k |
MAX4209 | 10 100 1000 | µMAX/8 | $1.62 @1k | |||||||||||||||||||
Part Number | Status | Recommended Replacement | Package | Temp | RoHS |
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MAX4208AUA+ | Active | µMAX,;8 pin;15.6 mm² | -40°C to +125°C | Lead Free | |
MAX4208AUA+T | Active | µMAX,;8 pin;15.6 mm² | -40°C to +125°C | Lead Free |