Texas Instruments BQ2114MODULE, BQ2114LMODULE, BQ2114LB-KT, BQ2114LB-018, BQ2114LB-016 Datasheet

Features

ä

Complete bq2014 Gas Gauge solution for NiCd or
NiMH battery packs

ä

Charge-control output allows communication to
external charge controller (bq2004)

ä

Battery information available over a single-wire
bidirectional serial port

ä

Battery state-of-charge monitoring for 4- to 12-cell
series applications

ä

On-board regulator allows direct connection to the
battery

ä

“L” version includes push-button activated LEDs to
display state-of-charge information

ä

Nominal capacity and cell chemistry pre-configured

ä Compact size for battery pack integration

General Description

The bq2114 Gas Gauge Module provides a complete and
compact solution for capacity monitoring of NiCd and
NiMH battery packs. Designed for battery pack integra­tion, the bq2114 incorporates a bq2014 Gas Gauge IC, a
current sense resistor, and all other components neces­sary to accurately monitor and display the capacity of 4
to 12 series cells. The bq2114L includes five surface­mounted LEDs to display remaining capacity in 20% in

­crements of the learned capacity (relative mode). The
LEDs are activated with the onboard push-button
switch.

Contacts are provided on the bq2114 for direct connec

­tion to the battery stack (BAT+, BAT-), the serial com

­munications port (DQ), the empty indicator (EMPTY),
and the charge control output (CHG). Please refer to the
bq2014 data sheet for the specifics on the operation of
the Gas Gauge.

Unitrode configures the bq2114 based on the informa

­tion requested in Table 1. The configuration defines the
number of series cells, the nominal battery pack capac

­ity, and the self-discharge rate.

A module development kit is also available for the
bq2114. The bq2114B-KT or bq2114LB-KT includes one
configured module and the following:

1) An interface board that allows connection to the se­rial port of an AT-compatible computer.

2) Menu-driven software with the bq2114 to display
charge/discharge activity and to allow user inter­face to the bq2014 from any standard DOS PC.

3) Source code for the TSR.

Pin Descriptions

P1

DQ/Serial communication port

P2

BAT+/Battery positive/pack positive

P3

CHG/Charge control output

P4

EMPTY/Empty indicator output

P5

GND/Ground

P6

PACK-/Pack negative

P7

BAT-/Battery negative

1

NiCd or NiMH Gas Gauge Module

with Charge-Control Output

bq2114

5/99 B

2

bq2114

Customer Name: ___________________________________________________________________________

Contact: _________________________________________ Phone: ______________________________

Address: _________________________________________________________________________________

_________________________________________________________________________________

Sales Contact: ____________________________________ Phone: ______________________________

Number of series battery cells (4–12) ________________________________________

Battery type (NiCd or NiMH) ________________________________________

Battery pack capacity (mAh) ________________________________________

Discharge rate into load (3.0A max.) Min.

Avg. Max.

Charge rate (3.0A max.) ________________________________________

LEDs and switch (Y/N) ________________________________________

FAE approval: _____________________________________ Date: ________________________________

Table 1. bq2114 Module Configuration

FG211401.eps

Battery Pack

P7

P6

P2bq2114

Load

Charger

Cells

PACK+PACK-

Figure 1. Module Connection Diagram

3

bq2114

bq2114 Schematic

Note: Schematic shows components which may not be placed on the

board, depending upon the configuration.

4

bq2114

bq2114 Board

5

bq2114

Absolute Maximum Ratings

Symbol Parameter Minimum Maximum Unit Conditions

V

CC

Relative to V

SS

-0.3 +7.0 V bq2014

All other pins Relative to V

SS

-0.3 +7.0 V bq2014

P

SR

Continuous sense resis

-

tor power dissipation

- 3 W Thru-hole sense resistor

- 1 W Surface-mount sense resistor

I

CHG

Continuous charge/
discharge current

- 3.0 A

T

OPR

Operating temperature 0 +70 °C Commercial

T

STR

Storage Temperature -40 +85 °C

Note: Permanent device damage may occur if Absolute Maximum Ratings are exceeded. Functional operation

should be limited to the Recommended DC Operating Conditions detailed in this data sheet. Exposure to con

-

ditions beyond the operational limits for extended periods of time may affect device reliability.

DC Electrical Characteristics (T

A

= T

OPR

)

Symbol Parameter Minimum Typical Maximum Unit Conditions/Notes

NumCell

Number of series cells in
battery pack

4 - 12 -

BAT+ Positive terminal of pack GND

NumCell 1.2V∗ NumCell 1.8V∗

V

BAT- Negative terminal of pack GND - 0.3 - GND+2.0 V

I

CC

Supply current at BAT+
terminal (no external
loads)

- 200 300

µ

A

R

DQ

Internal pull-down 500k - -

Ω

1

I

OL

Open-drain sink current
DQ, EMPTY, CHG

- - 5.0 mA

1

V

OL

Open-drain output low,
DQ, EMPTY, CHG

- - 0.5 V

1

IOL< 5mA

V

IHDQ

DQ input high 2.5 - - V

1

V

ILDQ

DQ input low - - 0.8 V

1

V

OS

Voltage offset - - 150

µ

V

1

Note: 1. Characterized on PCB, IC 100% tested.

6

bq2114

DC Voltage Thresholds (T

A=TOPR

)

Symbol Parameter Minimum Typical Maximum Unit Notes

V

EDVF

Final empty warning 0.93 0.95 0.97 V BAT+/NumCell

1

V

EDV1

First empty warning 1.03 1.05 1.07 V BAT+/NumCell

1

V

MCV

Maximum single-cell voltage 2.20 2.25 2.30 V BAT+/NumCell

1

V

SRO

Sense resistor range -300 - +2000 mV VSR+ V

OS

2

V

SRQ

Valid charge 375 - -

µ

VVSR+V

OS

2, 3

V

SRD

Valid discharge - - -300

µ

VVSR+V

OS

2, 3

Notes: 1. At SB input of bq2014.

2. At SR input of bq2014.

3. Default value; value set in DMF register.

LED Option:

L = LEDs plus switch
Blank = No LEDs or switch

bq2114 B –

Package Option:

B = Board-level product

Device:

NiCd or NiMH Gas Gauge Module with Charge-Control Output

Customer Code:

Blank = Sample or Pre-production

1

KT = Evaluation system
XXX = Customer-specific; assigned by Unitrode

2

Ordering Information

Notes: 1. Requires configuration sheet (see Table 1)

2. Example production part number: bq2114LB-003

Change No. Page No. Description

1 2 Updated Table 1 to include 3.0A limit

1 5 Added 3.0A maximum continuous charge/discharge current specification

Note: Change 1 = May 1999 B changes from Sept. 1996.

Data Sheet Revision History

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