Texas Instruments' LMP92064 is a precision low-side digital current sensor and voltage monitor with a digital SPI interface. This analog front-end (AFE) includes a precision current-sense amplifier to measure a load current across a shunt resistor and a buffered voltage channel to measure the voltage supply of the load. The current and voltage channels are sampled simultaneously by independent 125 kSPS 12-bit ADC converters, allowing for very-accurate power calculations in unidirectional sensing applications.
The LMP92064 includes an internal 2.048 V reference for the ADCs, eliminating the need of an external reference and reducing component count and board space.
A host can communicate with the LMP92064 using a four-wire SPI interface running at speeds of up to 20 MHz. The fast SPI interface allows the user to take advantage of the higher bandwidth ADC to capture fast varying signals. The four-wire interface with dedicated unidirectional input and output lines also allows for an easy interface to digital isolators in applications where isolation is required.