Charger Control - LG TU750 Service Manual

3.5 Charger control

A programmable charger in AB3100 is used for battery charging. It is possible to set limits for the
output voltage at CHSENSEN and the output current from DCIO via the sense resistor to
CHSENSEN. The voltage at CHSENSEN and the current feed to CHSENSEN cannot be measured
directly by the GPADC. Instead, the two measuring amplifiers translate these inputs to a voltage
proportional to the input and within the range of the GPADC. (Fig.2-5-1) shows the schematic of
charging control part.
Name
CHSENSEP
CHSENSEN
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
CHARGING CIRCUIT
VBUS
Q302 SIA911DJ
S2 G2
D2
D4
D3
D1
S1 G1
CHREG
DCIO_INT
VBAT_D VBAT
CHS+
R313
2012 R315
Route as a differential pair
1/4W
0.1
1%
0
CHS-
USB charging path
C334 C335
22p 33u
D303
C1
1 A1_C2
BDATA
3
A2
2
C340
R319
KDS221E_RTK
22p 300K
G2 G1
3 2 1
2012
R324
Route as a differential pair
1/4W
0.025
BATT_GND 1%
Fig. 3-5-1. Battery charging circuit
Charger type select
3.9V
DCIO
DCIO_INT
M2 RCHDISABLE
15kOhm
CHREG
M1
CHSENSE+
ICH RCHSENSE=100m
CHSENSE-
VBAT_I
VBAT D
Voltage
VDD_REF regulator
TRICKLE
Fig. 3-5-2. Battery charging block diagram
Type Unused
Analog VBAT
Analog VBAT
Table 3-5-1. Charger Control channel spec
- 63 -
A11
BDATA BDATA
J14
FGS+ FGSENSEP
FGS- C325
47p
VBAT_D
J13
FGSENSEN
CHS+
G2
VBAT_D
CHS-
H1
CHSENSEP
CHREG
DCIO_INT
H2
CHSENSEN
H3
VBUS CHREG
R311
OTP
1u
J2
D302 DCIO_INT
F1
R314
DCIO
E2
VBUS VBUS
USFB13L F2
0
TRICKLE TRICKLE
C5
RF_CTRL_DATA DAC_DAT
VBAT
B5
RF_CTRL_STR_1 DAC_STR
C4
RF_CTRL_CLK DAC_CLK
P7
VDD_SPKR
P6
VDD_BEAR
VDDC_2V65
P13
VDD_AUDIO
P3
VDD_AUXO
G1
VDD_REF
VDD_REF
C343 C344
0.1u 1u
VDDE_1V8 A12
C347 VDD_IO
0.1u
D12
TEST
A13
VREF
A14
C352 IREF
0.1u
C353 R320
1u 100K
FGS+
FGS-
Ericsson AB 3100
DCIO detect
TXON Clk
ISET
REGULATOR
VSET
CONTROL
PWM
(Digital)
2
I C Control Bus
VIMEAS to GPADC
VMEAS to GPADC
Block supply
Supply
switch
Description
Current sensing input positive
Current sensing input negative
3. TECHNICAL BRIEF
LGE Internal Use Only