Datasheet

Step-Up, Step-Down Regulator, Gate-On Charge Pump,
and Boost-Buck Regulator for TV TFT LCD Display
MAX17122
16 _____________________________________________________________________________________
Typical Operating Circuit
The typical operating circuit (Figure 1) of the MAX17122
is a complete power-supply system for TFT LCD TV
panels. The circuit generates a +3.3V logic supply, a
+15V source driver supply, a +28V positive gate-driver
supply, and a negative gate-driver supply that is derived
linearly between -7.5V and -12V. Table 1 lists some
selected components and Table 2 lists the contact infor-
mation of component suppliers.
Figure 1. Typical Operating Circuit
MAX17122
IN2
BST2
Q1
OUTB
2A
GOFF1
-7.5V
100mA
0.1
µF
16V
C7
22
µF
16V
C5
22
µF
6.3V
0.22
µF
25V
1
µ
F
10V
C6
2.2
µF
16V
C3
22
µF
25V
C2
22
µF x 2
25V
3A
30V
C4
1
µF
50V
1
µF
25V
22
µH
1.6A
IN
FROM SYSTEM
1A
50V
D3
D1
INCP
(AVDD)
GON
28V
100mA
GOFF2
-12V ~ -20V
450mA
AVDD
D4
FROM
SYSTEM
3.3V
POWER_GOOD
VGON
POWER_GOOD
C
DEL
C
SS
3.3V
3.3V
R4
22.1kI
R3
181kI
R
HVS
324kI
R2
33kI
R1
365kI
4.7
µH
3.5A
20V
100mI
L1
C1
C8
22nF
15V
2.2A
NTC
10kI
R
SET
7.5kI
C
COMP3P
10pF
C
COMP3
470pF
C
COMP1
330pF
C
COMP1P
10pF
R
COMP3
5kI
R
COMP1
40kI
8.2kI
47kI
C
P
R
P
P1
N1
R7
81.7kI
R5
226kI
510I
LX1
R6
10.5kI
10kI
R8
22.1kI
VGOFF2
510I
3.3V
3A
30V
D2
IN
VL
10I
(OPTIONAL)
L2
4.7
µH
3.5A
GATE
IN2
LX2
LX2
OUTB
FB2
IN
VL
AGND
AGND
EN1
EN2
DLY1
DLY2
RESET
DEL
DRVN
DRVP
GPGD
NTC
SET
COMP3
FB3
LX3
HVS
IN3
RHVS
COMP1
FB1
GND1
GND1
LX1
LX1
FBN SS FBP
IN
12V
22
µF
16V