SLUSFQ1A December 2024 – December 2024 BQ41Z90
ADVANCE INFORMATION
Refer to the PDF data sheet for device specific package drawings
The BQ41Z90 device can support up to four external thermistors on the RADCx port pins. The device includes two 18-kΩ (typ) internal pullup resistors to bias a thermistor during measurement. The first is used for RADC0, RADC1, and RADC2 while the second is used for RADC3. RADC3 is also used as the temperature input to the hardware fault detection (SCOMP) block. The RADC3 resistor is trimmed and that trim is shared with the RADC0..2 resistor.
The two resistor values and RADCx pad resistance are measured during factory production and stored within the device for use during temperature calculations. Any additional internal interconnect resistance is < 1 Ω.
To provide a high precision temperature result, the device uses the same 1.8-V LDO voltage for the ADC reference as is used for biasing the thermistor pullup resistor, thereby implementing a ratiometric measurement that removes the error contribution from the LDO voltage level.
When the RADCx pin is not used it should be enabled with its internal weak pulldown.