2.4.3
Charge Current and AC Current Regulation (DPM)
BQ24740 EVM
ACPWR
J1
GND
SYS
J8
GND
BAT
J20
/EXTPWR
APPLICATION CIRCUIT
PH
BAT
SYS
ACPWR
J6
J11
J12
J15
J2
U1
J5
J7
J17 J18
J14
J10
J16
J4
J3
J21
J9
J19
J13
BQ24740 EVM
ACPWR
J1
GND
SYS
J8
GND
BAT
J20
/EXTPWR
APPLICATION CIRCUIT
PH
BAT
SYS
ACPWR
J6
J11
J12
J15
J2
U1
J5
J7
J17 J18
J14
J10
J16
J4
J3
J21
J9
J19
J13
J1
V
Iin
I
Power
supply #1
Power
supply #2
V
V
I
Load
#1
Load
#2
I
V
V
I
Load
#1
Load
#2
I
2.4.4
Power Path Selection
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Test Summary
1. Install J20 disable the charging (for bq24740 only). Uninstall J20 disable the charging (for bq24741
only).
2. Connect the Load #2 in series with a current meter (multimeter) to J8 (BAT, GND). Ensure that a
voltage meter is connected across J8 (BAT, GND). Turn on the Load #2. Use the constant voltage
mode. Set the output voltage to 10.5 V.
3. Connect the output of the Load #1 in series with a current meter (multimeter) to J8 (SYS, GND).
Ensure that a voltage meter is connected across J8 (SYS, GND). Turn on the power of the Load #1.
Set the load current to 4 A
±
50 mA (for bq24740 only) or 3.4A
±
50mA (for bq24741 only), but disable
the output. The setup is now like
for HPA206. Ensure that Ibat = 0 A
±
10 mA and Isys = 0 A
±
10 mA.
Figure 2. Test Setup for HPA206 (bq24740EVM)
4. Uninstall J20 Enable the charging (for bq24740 only).
Observe
→
D5 (CHGEN) on
Install J20 Enable the charging (for bq24741 only).
Observe
→
D5 (CE) off.
5. Measure
→
Ibat = 3000 mA
±
200 mA
6. Enable the output of the Load #1.
Observe
→
D6 (DPMDET) on
Measure
→
Isys = 4000 mA
±
200 mA, Ibat = 1000 mA
±
500 mA, Iin = 4500 mA
±
400 mA (for bq24740
only)
Measure
→
Isys = 3400 mA
±
200mA, Ibat = 1000 mA
±
500 mA, Iin = 4000 mA
±
400 mA (for bq24741
only)
7. Turn off the Load #1.
Measure
→
Isys = 0
±
100 mA, Ibat = 3000 mA
±
200 mA
1. Install J20. (Disable the charging) (for bq24740 only).
Observe
→
D5 (CHGEN) off.
Uninstall J20 disable the charging (for bq24741 only)
Observe
→
D5 (CE) on
2. Replace Load #2 and current meter with PS#3. Ensure that a voltage meter is connected across J8
(BAT, GND). Enable the output of the PS #3. Ensure that the output voltage is 10.5 V
±
500 mV.
3.
Measure
→
V(J8(SYS)) = 19 V
±
1 V (adapter connected to system)
Observe
→
D2(BYPASS) on, D3 (ACDRV) on, D4 (BATDRV) off
4. Turn off PS#1.
Measure
→
V(J8(SYS)) = 10.5 V
±
1 V (battery connected to system)
5.
Observe
→
D2(BYPASS) off, D3 (ACDRV off, D4 (BATDRV) on.
SLUU284A – June 2007 – Revised October 2008
bq24740/1EVM (HPA206) For Multicell Synchronous Notebook Charger
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