Texas Instruments BQ24018 (bqTINY) Evaluation Module BQ24018EVM BQ24018EVM Datenbogen
Produktcode
BQ24018EVM
www.ti.com
2.2.1
Equipment
+
Power Supply
5.1± 0.1 V
Current Limit 1± 0.1 A
5.1± 0.1 V
Current Limit 1± 0.1 A
DC+
DC-
BAT+
BAT-
S1
S2
S3
S4
R3
3 k , 0.25 W
3 k , 0.25 W
W
R6
10 k , 0.25 W
10 k , 0.25 W
W
R4
66.5
66.5
, 0.25 W
W
R5
66.5
66.5
, 0.25 W
W
1N4148
D1
Q1
Si4410DY
Si4410DY
R7
10 k , 0.25 W
W
Q2
Si4410DY
Si4410DY
C1
2000 F, 25 V
2000 F, 25 V
m
R1
5
5
, 5 W
W
Load Board
for HPA261
2.2.2
Equipment Setup
Test Summary
In place of a battery, a source meter that can sink current can easily be adjusted to test each mode.
Another way to briefly see each mode on a scope is to connect a 1-mF capacitor and a 10-k
Ω
resistor on
the output in place of a battery to observe the power-up and cycling between voltage regulation and fast
charge via the refresh threshold.
charge via the refresh threshold.
Note:
Because of the battery-detection circuit, it is not possible to switch-in static load resistors
to jump between regulation and constant-current modes. An alternate procedure
described below uses a dynamic load to replace the battery circuit. That procedure allows
testing of each mode.
to jump between regulation and constant-current modes. An alternate procedure
described below uses a dynamic load to replace the battery circuit. That procedure allows
testing of each mode.
This is an alternative way of testing the EVM using a dynamic load board in place of a battery. The circuit
is adjusted to work with the displayed parts and their inherent thresholds. The sequence of the test
procedure is important because of the active battery-detection circuit, refresh feature, and precharge and
fast-charge current levels (switching load in or out has different results in different modes). No damage
should occur, but results might be different than anticipated if the procedure is altered.
is adjusted to work with the displayed parts and their inherent thresholds. The sequence of the test
procedure is important because of the active battery-detection circuit, refresh feature, and precharge and
fast-charge current levels (switching load in or out has different results in different modes). No damage
should occur, but results might be different than anticipated if the procedure is altered.
1. Power source: current-limited 5-V lab supply with its current limit set to 1.0 A
±
0.1 Amp
2. Two Fluke 75, equivalent or better
3. Oscilloscope – TDS220 or better
4. Load test board:
1. Connect the load board to the BAT+ and BAT–. Set SW1 through SW4 in the closed position.
2. Connect a voltage meter to the BAT+/BAT– output to monitor the output voltage (range 0 to 5 V).
3. Set the lab supply for 5.1 V
±
0.1VDC, 1.0
±
0.1 A current limit, and then turn off the supply. Connect
the source supply to a current meter and to J1, noting polarity. (may use an internal source current
meter if it has 5% or better accuracy.)
meter if it has 5% or better accuracy.)
4. Install shunt jumpers on the LED pins 1 and 2 of each header J4 and J5.
SLUU279 – August 2007
bq24018 (bqTINY™)
3