Texas Instruments BQ2057T Evaluation Module for Li-Ion, linear (8.2V), two cells DV2057T DV2057T Scheda Tecnica
Codici prodotto
DV2057T
Features
➤
bq2057 charge-control evaluation and development
system for single- and dual-cell Li-Ion packs with
coke or graphite anodes
system for single- and dual-cell Li-Ion packs with
coke or graphite anodes
➤
Optional temperature monitoring before and during
charge
charge
➤
Proprietary AutoComp
charge-rate compensation
➤
Integrated trickle-charge for conditioning deeply
discharged batteries
discharged batteries
➤
Regulated charge current and voltage
➤
Charge status output for LED or host-processor
interface to indicate charge-in-progress,
full-capacity, and fault conditions
interface to indicate charge-in-progress,
full-capacity, and fault conditions
➤
Automatic battery-re-charge feature
➤
Charge termination by minimum current
➤
Direct battery connection
➤
500mA charge rate
➤
High-side current sensing
General Description
The DV2057/C/T/W are complete development and
evaluation environments for bq2057 series advanced
Li-Ion linear charge management ICs. The DV2057 fam-
ily supports both single- and dual-cell Li-Ion packs with
coke or graphite anodes:
evaluation environments for bq2057 series advanced
Li-Ion linear charge management ICs. The DV2057 fam-
ily supports both single- and dual-cell Li-Ion packs with
coke or graphite anodes:
Part Number
Regulation Voltage
DV2057
4.1V
DV2057C
4.2V
DV2057T
8.2V
DV2057W
8.4V
Full charge is preceded by charge qualification based on
battery temperature and voltage. The DV2057/C/T/W
suspend charge if the battery temperature is outside the
V
battery temperature and voltage. The DV2057/C/T/W
suspend charge if the battery temperature is outside the
V
TS1
to V
TS2
thresholds and wait until the battery tem-
p e r a t u r e
i s
w i t h i n
t h e
a l l o w e d
r a n g e.
T h e
DV2057/C/T/W also check the battery voltage. If the bat-
tery voltage is below the low-voltage threshold, V
tery voltage is below the low-voltage threshold, V
MIN,
the
DV2057/C/T/W use trickle charge to condition the bat-
tery. The conditioning charge rate, I
tery. The conditioning charge rate, I
COND
, is set at
approximately 10% of the regulation current. The condi-
tioning current also minimizes heat dissipation in the
external pass element during the initial stage of charge.
tioning current also minimizes heat dissipation in the
external pass element during the initial stage of charge.
Once the battery voltage reaches the internal threshold,
V
V
MIN
, full charge begins. The DV2057/C/T/W complete
the charge cycle in two phases. While the pack is below
the regulation voltage, a constant-current phase replen-
ishes approximately 70% of battery capacity. An accu-
rate voltage-regulation phase completes the charge. The
DV2057/C/T/W terminate charge when the current ta-
pers off to the V
the regulation voltage, a constant-current phase replen-
ishes approximately 70% of battery capacity. An accu-
rate voltage-regulation phase completes the charge. The
DV2057/C/T/W terminate charge when the current ta-
pers off to the V
TERM
threshold.
These boards feature the proprietary AutoComp tech-
nique to compensate safely for the internal impedance of
the battery. The AutoComp resistors, R
nique to compensate safely for the internal impedance of
the battery. The AutoComp resistors, R
COMP1
, and
R
COMP2
, must be set according to the characteristics of
the battery.
Before using these development boards, please review
the bq2057 data sheet.
the bq2057 data sheet.
Connection Descriptions
J1
DC+
Charger supply positive
DC-
Charger supply ground
J2
BAT+
Positive battery terminal
BAT-
Negative battery terminal
J3
TEM+
Thermistor connection
INH
Charge inhibit input
1
DV2057/C/T/W
SLUU056A - JANUARY 2000
Advanced Li-Ion Charger Development System
Control of On-Board Linear Regulator