4
3
2
1
REVISION HISTORY
ECO
REV
2
DESCRIPTION
PRODUCTION FAB
APPROVED
GEORGE B.
DATE
9 - 17- 13
-
E10
4
VIN
R1
1.40MEG
D4
DFLZ39
39V
C5
10µF
50V
1210
5V - 40V
4
D1
DFLS240L
JP2
RUN
ON
VIN > 11V
OFF
R11
100k
5%
R12
100k
5%
E9
GND
E8
nFAULT
E7
R2
412k
16
RUN
3
IN
U1
LTC4120-4.2EUD / LTC4120EUD
FAULT
CHRG
E1
Cx
EMBEDDED INDUCTOR
3
C2S1
4700pF
5%
50V
0805
C2P1
4700pF
5%
50V
0805
C2S2
0.022µF
5%
50V
0805
C2P2
1800pF
5%
50V
0603
D3
DFLS240L
D2
DFLS240L
INTVCC
FREQ
1.5 MHz
750 kHz
JP3
15
14
INTVCC
INTVCC
nCHRG
1
2
C4
2.2µF
C3
0.01µF
6.3V
L1
15.0uH
3
BOOST
DISCONNECTED
CONNECTED
E2
GND
43T
Embedded
Inductor
R3
10k
7
FREQ
JP1
SW
4
8
9
0603
6
CHGSNS
DHC
BAT
E3
NTC
Lr
47µH
12
NTC
C1
10uF
16V
0805
R12 TO BE CONNECTED TO " BAT "
NODE AT BAT TURRET (E6)
NC/FBG
GND
GND
VBAR
E6
C2
47uF
16V
E5
1210
BAT
2.7 V - 11V
400mA
GND
E4
PROG
R4
2.0k
5%
VPROG
10
13
BATSNS/FB
PROG
11
R9
*
R10
*
R5
3.01k
J1
OPT
1
2
3
BAT
GND
ENTC
5
17
2
2
DF3-3P-2DSA
R8
0
JP4
NTC
INT
R6
0
EXT
*
UNLESS NOTED:
RESISTORS: OHMS, 0402, 1%, 1/16W
CAPACITORS: uF, 0402, 10%, 50V
ASSY
-A
-B
U1
LTC4120 - 4.2EUD
LTC4120EUD
R9
OPEN
1.40MEG
R10
0 Ohm
1.05MEG
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
R7
10k
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
APPROVALS
PCB DES.
APP ENG.
NC
GEORGE B.
1
TECHNOLOGY
TITLE: SCHEMATIC
1
400mA WIRELESS SYNCHRONOUS BUCK BATTERY CHARGER
SIZE
IC NO.
N/A
SCALE = NONE
DATE:
LTC4120 - 4.2EUD / LTC4120EUD
DEMO CIRCUIT 1967A - A / B
SHEET 1
1
REV.
2
OF
2
9 - 17 - 13
4
3
2
4
3
2
1
VBAR
JP5
MONITOR
U2A
DISABLE
R13
10k
5%
C6
0.01µF
LTC1445CDHD
4
5
3
2
ENABLE
R32
1k
5%
D12
1
2
CHG CURRENT
94%
VPROG
4
14 17
9
3
U2B
LTC1445CDHD
7
1
6
1.221V
R14
432
C7
1µF
10V
R15
22.6k
R31
1k
5%
4
D11
1
2
81%
8
1.186V
11
14 17
9
3
U2E
LTC1445CDHD
V-REF
U2C
LTC1445CDHD
R16
34.8k
16
10
14 17
9
R30
1k
5%
D10
1
2
69%
9
3
R17
100k
U2D
LTC1445CDHD
3
13
15
12
14 17
9
3
R29
1k
5%
D9
1
2
56%
3
R18
100k
U3A
LTC1445CDHD
5
2
4
R28
1k
5%
D8
1
2
44%
R19
100k
1.186V
U3B
LTC1445CDHD
14 17
9
3
7
1
6
R27
1k
5%
D7
1
2
31%
2
R20
100k
U3C
LTC1445CDHD
R21
100k
11
14 17
9
3
16
10
14 17
9
3
2
R26
1k
5%
D6
1
2
19%
R22
100k
U3D
LTC1445CDHD
13
15
12
14 17
9
R25
1k
5%
D5
1
2
6%
UNLESS NOTED:
RESISTORS: OHMS, 0402, 1%, 1/16W
CAPACITORS: uF, 0402, 10%, 50V
R23
100k
1
R33
22.6k
8
V-REF
CUSTOMER NOTICE
R35
432
U3E
LTC1445CDHD
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
2
APPROVALS
PCB DES.
APP ENG.
NC
GEORGE B.
TECHNOLOGY
TITLE: SCHEMATIC
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
1
R24
49.9k
C8
0.01µF
U3.3
C9
0.01µF
U2.3
R34
787k
C10
1µF
10V
3
9
BAR GRAPH FOR 400mA WIRELESS SYNCHRONOUS
BUCK BATTERY CHARGER
SIZE
IC NO.
N/A
SCALE = NONE
DATE:
LTC4120 - 4.2EUD / LTC4120EUD
DEMO CIRCUIT 1967A-A/B
SHEET 2
1
REV.
2
OF
2
9 - 17 - 13
4