Allgemeine Beschreibung

The amplifiers in the MAX9003/MAX9004/MAX9005 are stable for closed-loop gains of +10V/V or greater with an 8MHz gain-bandwidth product. The input commonmode voltage extends from 150mV below the negative supply to within 1.2V of the positive supply for the amplifier, and to within 1.1V for the comparator. The amplifier and comparator outputs can swing Rail-to-Rail® and deliver up to ±2.5mA and ±4.0mA, respectively, to an external load while maintaining excellent DC accuracy. The unique design of the comparator output stage substantially reduces switching current during output transitions, virtually eliminating power-supply glitches.

The comparator’s ±2mV of built-in hysteresis provides noise immunity and prevents oscillations even with a slow-moving input signal. The MAX9000/MAX9001/MAX9003/MAX9004 have an internal 1.230V ±1% precision reference with a low 8ppm/°C temperature coefficient that can sink or source up to 1mA. The amplifier and reference are stable with capacitive loads up to 250pF and 100nF, respectively. The comparator’s inverting input is internally connected to the reference output in the MAX9000/MAX9003.

 

Detaillierte Beschreibung

The MAX9001–MAX9005 are combinations of a highspeed operational amplifier, a 185ns comparator, and a 1%-accurate, 8ppm/°C, 1.230V reference. The devices are offered in space-saving 8-pin and 10-pin µMAX packages. The comparator’s inverting input is internally connected to the reference output in the MAX9000/MAX9003.

The MAX9000/MAX9001/MAX9003/MAX9004 typically consume only 410µA of quiescent current, while the MAX9002/MAX9004 typically consume 340µA. These low-power,Rail-to-Rail devices provide excellent AC and DC performance and are ideally suited to operate from a single supply. The MAX9001/MAX9004 feature a shutdown mode that sets the outputs in a high-impedance state and reduces the supply current to 2µA, making these devices ideal for portable and battery-powered systems.

 

Op Amp

The amplifiers in the MAX9003/MAX9004/MAX9005 are stable at closedloop gains greater than or equal to 10V/V, with a gainbandwidth product of 8MHz and a slew rate of 6.0V/µs.

The common-mode input voltage range extends from 150mV below the negative rail to within 1.2V of the positive rail. The amplifier output does not undergo phase reversal when the common-mode input range is exceeded, and the input impedance is relatively constant for input voltages within both supply rails. The MOS differential inputs of the amplifiers feature extremely high input impedance and ultra-low input bias currents. The CMOS output stage achieves true rail-to-rail operation; the outputs swing to within a few millivolts of the supply rails, thus extending the dynamic range. A proprietary design achieves high open-loop gain, enabling these devices to operate at low quiescent currents yet maintain excellent DC and AC characteristics under various load conditions. These devices have been designed to maintain low offset voltage over the entire operating-temperature, commonmode, and supply-voltage ranges.

 

Comparator

The common-mode input range extends from 150mV below the negative rail to within 1.1V of the positive rail. The bipolar differential inputs of the comparator feature high input impedance and low input bias currents. The comparators are designed to maintain low offset voltage over the entire operating-temperature, commonmode, and supply-voltage ranges. In the MAX9000/ MAX9003, the comparator’s inverting input is internally connected to the reference output.

The CMOS output stage achieves true rail-to-rail operation; the outputs swing to within a few millivolts of the supply rails. The comparator’s propagation delay is 185ns and is a function of the overdrive (see Typical Operating Characteristics). TTL/CMOS compatibility is maintained even with a ±4mA output load. A proprietary design of the output stage substantially reduces the cross-conduction current during output transitions, thereby minimizing power-supply glitches typical of most comparators. In addition, the comparator’s ±2mV of built-in hysteresis provides noise immunity and prevents unstable outputs even with slow-moving input signals.