1 Features

? 2-series, 3-series, and 4-series cell overvoltage

protection (OVP)

? Factory programmed OVP threshold (3.6V to 5.2V)

with ±12mV accuracy

? Fixed delay timer to trigger FET drive output

(0.25s to 6.5s options)

? Control input pin, which can implement cell

overtemperature protection (OT) using external

PTC thermistor

? Integrated 3mA regulated output programmable to

3.8V, 3.3V, 3.15V, 3.0V, 2.5V, 1.8V, or 1.5V

? Factory programmed undervoltage (UV) detection

threshold (1V to 4.15V) to disable regulator

– OVP and OT remains operational even in

undervoltage condition

? Output pin options:

– Active high

– Open-drain - active pulldown

– Open-drain - inactive pulldown

? Multiple power modes:

– NORMAL mode - no OV or UV: ICC ? 1.23μA

– Undervoltage or disable mode - UV detected or

control input low: ICC ? 0.25μA

– Overvoltage mode - OV detected: ICC ? 15μA

? Low leakage current per cell input < 100nA

? Small package footprint

– 8-Pin WSON (2mm × 2mm)

2 Applications

? Notebook PC

? Ultrabooks

? Portable medical electronics

? UPS battery backup systems

3 Description

The BQ2969T family is a high-accuracy, low-power

overvoltage protector with a 3mA regulated output

supply and control / PTC input for Li-ion and LiFePO4

(LFP) battery pack applications.

Each cell in a 2-series to 4-series cell stack is

individually monitored for an overvoltage condition. An

internal fixed-delay timer is initiated upon detection of

an overvoltage condition on any cell. Upon expiration

of the delay timer, the output pin is triggered into an

active state to indicate that an overvoltage condition

has occurred.

The regulated output supply delivers up to 3mA

output current to drive always-on circuits, such as a

real-time clock (RTC) oscillator. The BQ2969T family

has a self-disable function to turn off the regulated

output if any cell voltage falls below a programmable

undervoltage threshold, thereby preventing drain on

the battery.

The BQ2969T family includes a CTL pin which can be

used to assert the OUT pin upon demand. The device

also supports overtemperature (OT) protection when

a PTC thermistor is attached between the CTL and

VDD pins on the device.

The BQ2969T family provides exceptionally low

power operation, drawing only 1.23μA during normal

operation (excluding regulator load current), and

dropping to 0.25uA when in an undervoltage

condition. Even when in the undervoltage state, the

device can still detect an overvoltage condition on any

other cell (which can occur in an imbalanced pack)

and can assert the output pin.