Replacing LTC2990 with GX2990 Quad I2C Voltage, Current and Temperature Monitor for UAV Applications

The propulsion system of a UAV relies primarily on onboard battery packs, and lithium batteries exhibit significantly nonlinear characteristics under high-rate discharge, severe temperature variations, and vibration environments. Unexpected shutdown of UAV batteries often stems from a single cell‘s voltage dropping below the cutoff threshold. Therefore, real-time and precise monitoring of cell-level voltage and temperature is the first line of defense for the battery management system against over-discharge and thermal runaway.

Traditional discrete solutions typically require multiple operational amplifiers, ADCs, and temperature sensor chips working in coordination, occupying PCB area and increasing wiring complexity. Domestic quad I2C voltage, current and temperature monitor chips provide a highly integrated alternative for space-constrained UAV flight control boards or battery management boards. The GXSC GX2990 chip is benchmarked against the LTC2990 and enables rapid replacement.

The GX2990 is well suited for board-level system voltage, current, and temperature monitoring. Its single-ended voltage resolution is as low as 305.18 μV, differential voltage resolution as low as 19.075 μV, and temperature resolution as low as 0.0625°C. The internal temperature sensor can be used to monitor the ambient temperature of the device itself and the surrounding PCB, helping to determine whether the monitoring circuit is in an abnormally hot environment.

Key features of the GX2990:

Can measure 4 single-ended voltages or 2 differential voltages (current) or 2 remote temperatures

Can measure voltage, current, and temperature individually or in any combination

Can measure the chip‘s own operating voltage and temperature

Single-ended voltage measurement accuracy better than 0.75%, resolution 305.18 μV

Differential voltage and current measurement accuracy better than 0.75%, resolution 19.075 μV

Remote temperature measurement accuracy better than 1.8°C, resolution 0.0625°C

Internal temperature measurement accuracy better than 1.5°C, resolution 0.0625°C

14-bit ADC for voltage/current measurement

2.9V to 5.5V supply operating range

I2C interface, 4 selectable addresses, up to 4 devices sharing the bus

Internal 10 ppm/°C voltage reference

ESD protection rating of 6 kV HBM on V1–V4 analog input pins