Datasheet

Fixed Configuration
The DV2003S1 board has the following fixed character
-
istics :
V
CC
(4.75–5.25V) is regulated on-board from the supply
at connector JP6 DC+.
LEDs indicate charge status and temperature fault status.
Pin CCMD is grounded, providing charge initiation on
the later application of the battery or DC+, which pro
-
vides V
CC
to the bq2003.
Pin DCMD is pulled to ground through R12. A toggle of
switch S1 momentarily pulls DCMD high and initiates a
discharge-before-charge. The bq2003 output activates
FET Q4, allowing current to flow through an external
current-limiting load between BAT+ and DSCHG on
connector JP6.
Trickle current is limited by a 150
Ω
/2W resistor R10 be
-
tween DC+ and BAT+ (maximum potential across R10 =
17.3V). Note that too large a voltage between DC+ and
BAT+ may exceed the wattage rating of resistor R10.
As shipped from Benchmarq, the DV2003S1 buck-type
switch-mode regulator is configured to a charging cur-
rent of 2.35A. This current level is controlled by the
value of sense resistor R26 by the relationship:
I
CHG
=
0.235V
R26
The value of R26 at shipment is 0.100Ω. This resistor
can be changed depending on the application.
The suggested maximum ICHG for the DV2003S1 board
is 3A. A location for a second sense resistor (R27) is pro
-
vided on the DV2003S1 Board. R27 is electrically in
parallel with R26, which assists in user modification of
I
CHG
, if needed.
Charge current can be halted at any time via external
stimulus. Connector JP5 provides a +5V DC source (+V)
and an inhibit input (IN) node for this function. To in
-
hibit charge current, the JP5 inhibit in;put (IN) is driven
by +5V DC. To reinitiate charge, remove the voltage
source from the inhibit input.
The maximum cell voltage (MCV) setting is 1.8V.
Zener diode D( is used to limit Q1 VGS per a given DC+
voltage. Benchmarq ships a 1N751A (5.1V Zener) at lo
-
cation D9. This voltage value was selected as an appro
-
priate value for most development work. The user can
modify this Zener diode for the application. Refer to Ta
-
ble 1 for suggested D9 values for DC+ voltages.
With the provided NTC thermistor connected between
THERM and BAT–, values are: LTF = 10°C, HTF = 45°C,
and TCO = 50°C. The
∆
T/
∆
t settings at 30°C(T
∆
T
) are:
minimum = 0.82°C/minute, typical = 1.10°C/minute.
The thermistor is identified by the serial number suffix
as follows:
Jumper-Selectable Configuration
The DV2003L1 must be configured as described below.
DVEN (JP1): Enables/disables -
∆
V termination (see
bq2003 data sheet).
TM1 and TM2 (JP2 and JP3): Select fast charge safety
time/hold-off/top-off (see bq2003 data sheet).
2
DV2003S1
Identifier Thermistor
K1 Keystone RL0703-5744-103-S1
(blank) Philips 2322-640-63103
F1 Fenwal Type 16, 197-103LA6-A01
Jumper Setting Pin State
[ 1 2 ] 3 Enabled (high)
1 [ 2 3 ] Disabled (low)
Jumper Setting Pin State
[ 1 2 ] 3 High
1 [ 2 3 ] Low
1 2 3 Float
+VDC Input
(Volts)
Motorola
Part No.
Nominal Zener
Voltage
Below 15 Shorted 0
15–18 1N749 4.3
18–21 1N755 7.5
21–24 1N758 10
24–27 1N964A 13
27–30 1N966A 16
30–32 1N967A 18
32–35 1N968A 20
Table 1. Lookup Table for D9 Selection