Features
Complete bq2050H Power Gauge solution for Li-Ion
battery packs
Battery information available over a single-wire
(HDQ) bidirectional serial port
Control signals to enhance pack protection
Battery state-of-charge monitoring for 2- to 5-cell
series applications
On-board regulator allows direct connection to the
battery
"L" version includes push-button activated LEDs to
display state-of-charge information
Nominal capacity pre-configured
Compact size for battery pack integration
General Description
The bq2150H Power Gauge Module provides a complete
and compact solution for capacity monitoring of Li-Ion bat-
tery packs. Designed for battery pack integration, the
bq2150 incorporates a bq2150H Gas Gauge IC, a current
sense resistor, and all other components necessary to accu-
rately monitor and display the capacity of 2 to 5 series
cells.
The bq2150L includes five LEDs to display remaining ca-
pacity in 20% increments of the learned capacity.
The
LEDs are activated with the onboard push-button switch.
Contacts are provided on the bq2150H for direct connec-
tion to the battery stack (BAT+, BAT-) and the serial
communications port (HDQ). The RBI input provides
backup power to the bq2150H in the event that the cells
are removed or the battery is turned off. The bq2150H
has a 1
F capacitor onboard connected to RBI to supply
backup power for about an hour. In battery packs that
use high-side FETs to control the charge/discharge of
the Li-Ion cells, the RBI input can be wired to a single
cell to provide prolonged data retention times. The SD
input allows an external signal (active low) to turn the
bq2050H IC off to minimize internal current consump-
tion of the battery pack and maximize storage life of the
pack in the system. When turned off, the bq2150H is
non-functional, and the RBI power source maintains
register information. Please refer to the bq2050H data
sheet for the specifics on the operation of the Gas Gauge.
Unitrode configures the bq2150H 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 Li-Ion battery type (coke or graphite anode).
Figure 1 shows how the module connects to the cells.
A module development kit is also available for the
bq2150. The bq2150HB-KT or the bq2150HLB-KT in-
cludes one configured module and the following:
1)
An EV2200-50H interface board that allows con-
nection to the serial port of an AT-compatible com-
puter.
2)
Menu-driven software to display charge/discharge
activity and to allow user interface to the bq2150H
from any standard Windows 3.1x or 95 PC.
Pin Descriptions
P1
HDQ/Serial Communications port
P2
PSTAT/Protector status input
P3
BAT+/Battery positive/pack positive
P4
SD/Shutdown
P5
RBI/Register backup input
P6
GND/Ground
P7
PACK-/Pack negative
P8
BAT-/Battery negative
P9
CFC/Charge FET control output
1
Li-Ion Power GaugeTM Module
Preliminary
bq2150H
10/97
2
bq2150H
Preliminary
Customer Name: ___________________________________________________________________________
Contact: _________________________________________
Phone: ______________________________
Address: _________________________________________________________________________________
_________________________________________________________________________________
Sales Contact: ____________________________________
Phone: ______________________________
Number of series battery cells (2-5)
____________________
Coke or graphite cell anode
____________________
Battery pack capacity (mAh)
____________________
Discharge rate into load (A)
min. ________ avg. _________ max. _________
Charge rate
____________________
Self-discharge compensation (Y/N)
____________________
LEDs and switch (Y/N)
____________________
FAE Approval: __________________________________
Date: _______________________________
Table 1. bq2150H Module Configuration
FG2150H1.eps
Battery Pack
P8
P7
P3
bq2150H
Load
Charger
Cells
PACK+
PACK-
Figure 1. Module Connection Diagram
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