MX844 (Data Sheet) is a fully integrated subsystem that measures temperature plus differential current and voltage. An internal temperature sensor measures ambient temperature with ±2.5°C accuracy. Current and voltage measurements are made differentially through a 4-input multiplexer connected to a programmable-gain, fully differential sense amplifier. The differential sense amplifier is optimized to measure very small positive or negative voltages near ground for low-side bidirectional sensing.
A dual-slope ADC converts the temperature sensor or sense amplifier outputs to a 12-bit digital word: 3-½ digits plus sign. The input multiplexer channel and programmable-gain amplifier range may be changed between ADC conversions. An on-chip voltage regulator enables the MX844 to operate over a wide input voltage range of 4.5V to 40V.
Controller interrupt or over-voltage/over-current signals may be generated by a pair of 12-bit digital comparators configured as a window comparator or as simple threshold detectors.
The serial port supports standard 4-wire synchronous serial data, or asynchronous serial “talk-only” data, and is compatible with most 3.3V and 5V microcontrollers. |