Preliminary
bq2150H
Li-Ion Power Gauge鈩?Module
Features
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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
鈥淟鈥?version includes push-button activated LEDs to
display state-of-charge information
Nominal capacity pre-configured
Compact size for battery pack integration
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.
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.
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碌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
10/97
2)
Pin Descriptions
P1
P2
P3
P4
P5
P6
P7
P8
P9
HDQ/Serial Communications port
PSTAT/Protector status input
BAT+/Battery positive/pack positive
SD/Shutdown
RBI/Register backup input
GND/Ground
PACK-/Pack negative
BAT-/Battery negative
CFC/Charge FET control output
1
1
2
3
4
5
