The MAX9025–MAX9028 nanopower comparators in space-saving chip-scale (UCSP™) packages feature Beyond-the-Rails™ inputs and are guaranteed to operate down to +1.8V. The MAX9025/MAX9026 feature an on-board 1.236V ±1% reference and draw an ultra-low supply current of only 1µA, while the MAX9027/MAX9028 (without reference) require just 0.6µA of supply current. These features make the MAX9025–MAX9028 family of comparators ideal for all 2-cell battery-monitoring/management applications. The unique design of the output stage limits supply-current surges while switching, virtually eliminating the supply glitches typical of many other comparators. This design also minimizes overall power consumption under dynamic conditions. The MAX9025/MAX9027 have a push-pull output stage that sinks and sources current. Large internal-output drivers allow rail-to-rail output swing with loads up to 5mA. The MAX9026/MAX9028 have an open-drain output stage that makes them suitable for mixed-voltage system design. All devices are available in the miniature 6-bump UCSP packages. Refer to the MAX9117 data sheet for similar comparators in 5-pin SC70 packages and the MAX9017 data sheet for similar dual comparators in 8-pin SOT23 packages. Applications * 2-Cell Battery Monitoring/Management * Medical Instruments * Mobile Communications * Notebooks and PDAs * Sensing at Ground or Supply Line * Telemetry and Remote Systems * Ultra-Low-Power Systems * Space-Saving UCSP Package (1mm x 1.52mm) * Ultra-Low Supply Current * 0.6µA (MAX9027/MAX9028) * 1µA with Reference (MAX9025/MAX9026) * Guaranteed to Operate Down to +1.8V * Internal 1.236V ±1% Reference (MAX9025/MAX9026) * Input Voltage Range Extends 200mV Beyond-the-Rails * CMOS Push-Pull Output with ±5mA Drive Capability (MAX9025/MAX9027) * Open-Drain Output Versions Available (MAX9026/MAX9028) * Crowbar-Current-Free Switching * Internal Hysteresis for Clean Switching * No Phase Reversal for Overdriven Inputs