Application of GXSC voltage, current and temperature measurement chip GX2991 replacing LTC2991 in high-precision current measurement

Current measurement is the process of evaluating device power consumption, determining circuit health status, and achieving precise control. There are significant differences in the demand for current measurement in different scenarios: industrial motor control requires monitoring the dynamic changes of high currents, new energy battery management requires precise measurement of microampere level sleep current and ampere level charge and discharge current, and consumer electronics require low-power, small-sized current monitoring solutions.

The GXSC measurement chip GX2991 can meet the current measurement needs of multiple scenarios and is suitable for applications such as board level system voltage, current, and temperature monitoring. GX2991 has a single ended voltage resolution as low as 305.18mV, a differential voltage resolution as low as 19.075uV, and a temperature resolution as low as 0.0625 ℃. The chip has a voltage measurement accuracy of better than 0.25%, current measurement accuracy of better than 0.75%, and temperature measurement accuracy of better than 1.8 ℃ in the range of -40 ℃~125 ℃, which is very suitable for single or mixed system application requirements of voltage, current, and temperature.

The measurement chip GX2991 supports two input methods: 8-channel single ended voltage and 4-channel differential voltage, which can achieve voltage measurement, current measurement, or remote BIT temperature measurement. It supports standard FC dual line interface, standard C protocol, and has 3 hardware optional address bits, which can expand up to 8 chips. GX2991 integrates a temperature sensor and a voltage sensor internally to monitor the operating temperature and voltage of the chip itself.

GX2991 integrates a high-precision benchmark with a temperature drift of 10ppm ° C internally, which does not require external benchmark references. Therefore, compared with other solutions, it reduces the number of components and material costs required for engineering applications, and also reduces the PCB footprint, improving the integration of the board. And the chip also supports connecting BJT temperature measurement output PWM signals based on V7.V8 channels. According to engineering application requirements, this PWM output signal can be used to control fan speed or heater heat generation. Its characteristics are as follows:

Can measure 8 single ended voltages or 4 differential voltages (currents) or 4 remote temperatures

A single or any combination of measurable voltage, current, and temperature

Measurable chip‘s own operating voltage and temperature

Better than 0.75% single ended voltage measurement accuracy and 305.18uV resolution

Better than 0.75% differential voltage and current measurement accuracy, 19.075V resolution

Remote temperature measurement accuracy better than 2.0 ℃, resolution of 0.0625 ℃

Internal temperature measurement accuracy better than 1.5 ℃, resolution of 0.0625 ℃

14 bit ADC for measuring voltage/current

PWM dynamic adjustment output

Operating range of 2.9V to 5.5V power supply

FC interface, 8 address options available, can share up to 8 buses

Internal 10ppm/℃ voltage reference

The rated ESD protection level of V1-V8 analog input pins is 6kV HBM

PIN TO PIN Replacement LTC2991