referenced voltage is then connected to a set of over-

voltage and undervoltage comparators. The threshold

references for the comparators are set by the UVSEL_

and OVSEL_ input pins. When one of the cell voltages

internal cell out-of-range signal for the given cell is set

and logically ORed with the same signal for the other

cell positions to create an overall out-of-range signal.

When any cells are out-of-range as indicated by the

internal out-of-range signal, an internal current source

with pulses occurring every 250µs. If all cell voltages

transition from out-of-range to in-range before the volt-

because the delay had not yet expired, no alarm

time occurs for the next overvoltage or undervoltage

12-Channel, High-Voltage Battery-Pack

Fault Monitor

______________________________________________________________________________________

13

75mV

HYSTERESIS

75mV

HYSTERESIS

SHORT-CIRCUIT

DETECTOR

UNDERVOLTAGE

COMPARATOR

ENABLE

CELL

OUT-OF-RANGE

11

OUT-OF-RANGE

40M

Ω

TYP

2M

Ω

TYP

AGND

+

-

+

-

6M

Ω

TYP

+

-

CELLS 2-12

CELL 1

HV

Figure 7. Cell Differential Input and Comparator Block Diagram

11

CELL OUT-OF-RANGE

1 TO 12

OUT-OF-RANGE

6.1

µA

THRESHOLD

ALARM

CD

6k

Ω