VC5

Vss

SRP

SRN

CHG

DSG

TS

VTB

CTRD

CTRC

LD

VDD

VC5

Vss

SRP

SRN

CHGU

DSG

TS

VTB

LD

VDD

bq77094/5

bq77094/5

PACK+

PACK-

Copyright © 2016, Texas Instruments Incorporated

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An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.

bq77904, bq77905

SLUSCM3A – JUNE 2016 – REVISED JUNE 2016

bq77905, bq77904 3-5S Ultra Low-Power Voltage, Current, Temperature,

and Open Wire Stackable Lithium-ion Battery Protector

1

1 Features

1

•

Voltage Protection (Accuracy ±10 mV)

–

Overvoltage: 3 V to 4.575 V

–

Undervoltage: 1.2 V to 3 V

•

Open Cell and Open Wire Detection (OW)

•

Current Protection

–

Overcurrent Discharge 1: –10 mV to –85 mV

–

Overcurrent Discharge 2: –20 mV to 170 mV

–

Short Circuit Discharge: –40 mV to 340 mV

–

Accuracy ±20% for

≤ 20 mV, ±30% for > 20

mV across full temperature

•

Temperature Protection

–

Overtemperature Charge: 45°C or 50°C

–

Overtemperature Discharge: 65°C or 70°C

–

Undertemperature Charge: –5°C or 0°C

–

Undertemperature Discharge: –20°C or –10°C

•

Additional Features

–

Independent Charge (CHG) and Discharge

(DSG) FET Drivers

–

SimpleStack Interface for Easy Stacking

–

36-V Absolute Maximum Rating Per Cell Input

–

Built-In-Self-Test Functions For High Reliability

•

Normal Mode: 6 µA (bq77904/bq77905)

•

Shutdown Mode: 0.5 µA Maximum

2 Applications

•

Power Tools, Garden Tools

•

Start-Stop Battery Packs

•

Lead-Acid (PbA) Replacement Batteries

•

Light Electric Vehicles

•

Energy Storage Systems, Uninterruptible Power

Supplies (UPS)

•

10.8 V to 72 V Packs

3 Description

The bq77904 and bq77905 devices are low-power

battery pack protectors that implement a suite of

voltage, current, and temperature protections without

microcontroller (MCU) control. Protection thresholds

and delays are factory-programmed and available in

a variety of configurations. Separate overtemperature

and undertemperature thresholds for discharge (OTD

and UTD) and charge (OTC and UTC) are provided

for added flexibility.

The

device

achieves

pack

protection

via

the

integrated independent CHG and DSG low-side

NMOS FET drivers, which may be disabled via two

control pins. These control pins may also be used to

achieve cell protection solutions for higher series (6S

and beyond) in a simple and economical manner. To

do this, simply cascade a higher device CHG and

DSG outputs to the immediate lower device control

pins. For reduced component count, all protection

faults use internal delay timers.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

bq77904

TSSOP (20)

6.50 × 4.40 mm

bq77905

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Simplified Schematic