Single/Dual, +3V/+5V Dual-Speed Comparators with Auto-Standby

The MAX975/MAX977 single/dual comparators feature three different operating modes, and are optimized for +3V and +5V single-supply applications. The operating modes are as follows: high speed, high speed with auto-standby, and low power. Propagation delay is 28ns in high-speed mode, while supply current is only 250µA. Supply current is reduced to 3µA in low-power mode.

The auto-standby feature allows the comparator to automatically change from low-power mode to highspeed mode upon receipt of an input signal. In the absence of an input signal, the comparator reverts back to low-power mode after an adjustable timeout period. The timeout period for the MAX975 to enter standby is set by a single capacitor. The dual MAX977 features independently adjustable timeout periods for each comparator using separate capacitors.

The MAX975/MAX977's inputs have a common-mode voltage range of -0.2V to (VCC - 1.2V). The differential input voltage range extends rail to rail. The outputs are capable of rail-to-rail operation without external pull-up circuitry, making these devices ideal for interface with CMOS/TTL logic. All inputs and outputs can tolerate a continuous short-circuit fault condition to either rail. The comparator's internal hysteresis in high-speed mode ensures clean output switching, even with slow-moving input signals.

The single MAX975 is available in 8-pin SO and 8-pin µMAX® packages, while the dual MAX977 is available in 14-pin SO and 16-pin QSOP packages.

Applications

* 3V Systems * Battery-Powered Applications * Digital-Line Receivers * IR Receivers * Keyless Entry * RF ID Tags * Threshold Detectors/Discriminators

* Three Operating Modes:

* High Speed

* High Speed with Auto-Standby

* Low Power

* 28ns Propagation Delay (high-speed mode)

* 5µA Max Supply Current in Low-Power/Auto-Standby Modes

* +3V/+5V Single-Supply Operation

* Rail-to-Rail Outputs

* Ground-Sensing Input

* Internal Hysteresis (high-speed mode)

* Adjustable Timeout Period

* µMAX Package (MAX975) QSOP-16 Package (MAX977)