ADBMS2950BCCSZ datasheet(81/97 Pages) AD

81 / 97 page

Data Sheet

ADBMS2950B

Rev. 0 | Page 81 of 97

Figure 64. Shunt Resistor with a Center Tap

VOLTAGE SENSE INPUTS

The V1 to V10, VBAT1, and VBAT2 inputs are typically

connected to high-impedance sources such as resistive high-

voltage dividers and NTC temperature sensors. The buffered

high-impedance inputs of the ADBMS2950B minimize errors

due to the source impedance and decouple the ADCs sampling

currents.

For the continuously converting VBAT inputs, the external

analog filter must remove signal components at frequencies at

least above half the sampling frequency (0.5 × 4.1 MHz

~2 MHz). However, due to limited damping of the first-order

SINC filter of the ADC and the typical external first-order RC

Filter, a cut-off frequency of 1 kHz or smaller is recommended.

Additional digital filtering is applied in the accumulated IxADC

and VBxADC result registers, IxACC and VBxACC, which can

be used for matched converted and filtered battery pack current

and voltage measurements, which allows the calculation of the

battery pack impedance.

The voltage inputs V1 to V10 are measured on-demand instead

of continuously, and the update rate is defined by the host that

triggers the conversions. For those inputs, a lower cut-off

frequency of the external filter may be required, which depends

on the frequency spectrum of the system noise and the accuracy

requirements. Long external time constants extend the time it

ADBMS2950BCCSZ 数据表(PDF) 81 Page - Analog Devices