1 Features
• 3-series cell to 5-series cell protection
• High-accuracy overvoltage protection
– ±10 mV at 25°C
– ±20 mV from 0°C to 60°C
• Overvoltage protection options from 3.55 V to
5.1 V
• Open-wire connection detection
• Random cell connection
• Functional safety-capable
• Fixed internal delay timers
• Fixed detection thresholds
• Fixed output drive type
– Active high or active low
– Active high drive to 6 V
– Open drain with the ability to be pulled up
externally to VDD
• Low power consumption ICC ≈ 1 μA
(VCELL(ALL) < VOV)
• Low leakage current per cell input < 100 nA with
open wire detection disabled
• Package footprint options:
– 8-pin DGK with 0.65-mm lead pitch

2 Applications
• Protection for Li-ion battery packs used in:
– Handheld garden tools
– Handheld power tools
– Cordless vacuum cleaners
– UPS battery backup
– Light electric vehicles (eBike, eScooter, pedalassist
bicycles)

3 Description
The BQ77205 family of products provides a range
of voltage and temperature monitoring, including
overvoltage protection (OVP) and open-wire (OW)
protection for Li-ion battery pack systems. Each cell
is monitored independently for overvoltage and openwire
conditions.
In the BQ77205 device, an internal delay timer is
initiated upon detection of an overvoltage or openwire
condition. Upon expiration of the delay timer,
the respective output is triggered into its active state
(either high or low, depending on the configuration).
The overvoltage triggers the OUT pin if a fault is
detected. If an open-wire fault is detected, then the
OUT is triggered. For quicker production-line testing,
the BQ77205 device provides a Customer Test Mode
(CTM) with significantly reduced delay time.