Datasheet

Step-Up, Step-Down Regulator, Gate-On Charge Pump,
and Boost-Buck Regulator for TV TFT LCD Display
MAX17122
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Detailed Description
The MAX17122 is a multiple-output power supply
designed primarily for TFT LCD TV panels. It contains
a step-down switching regulator to generate the supply
for system logic, a step-up switching regulator to gener-
ate the supply for source-driver ICs, a linear-controlled
positive charge-pump regulator to generate the supply
for TFT positive gate drivers, a boost-buck regulator, and
a negative linear regulator to generate the supply for TFT
negative gate drivers.
Each switching regulator features adjustable output volt-
age, digital soft-start, and timer-delayed fault protection.
They all use fixed-frequency (750kHz) current-mode
control architectures. The step-up regulator switches
in-phase with a boost-buck regulator while 180N out-of-
phase with a step-down regulator to minimize the input
ripple and noise coupling.
The boost-buck regulator also features a temperature-com-
pensated output so it can vary according to the tempera-
ture sensed by an external NTC thermistor. The step-down
regulator also features an adjustable-delay, open-drain,
power-good output. A simple untimed output monitors the
positive charge-pump linear regulator’s feedback.
Table 1. Component List
Table 2. Component Suppliers
DESIGNATION DESCRIPTION
C1, C7
22FF Q20%, 16V X5R ceramic capaci-
tors (1206)
Murata GRM31CR61C226M
Taiyo Yuden EMK316BJ226M
C2, C3
22FF Q20%, 25V X5R ceramic capaci-
tors (1210)
Murata GRM32ER61E226K
Murata GRM32ER61E226M
C4
1FF Q10%, 50V X7R ceramic capacitor
(1206)
Murata GRM31MR71H105KA
TDK C3216X7R1H105K
C5
22FF Q20%, 6.3V X5R ceramic capacitor
(0805)
Murata GRM21BR60J226M
TDK C2012X5R0J226K
C6
2.2FF Q10%, 16V X5R ceramic capacitor
(0603)
Murata GRM188R61C225K
TDK C1608Y5V1C225ZT
D1, D2
Schottky diodes 30V, 3A (M Flat)
Toshiba CMS02
DESIGNATION DESCRIPTION
D3
Schottky diode 50V, 1A (SMA)
Fairchild SS15
Diodes Inc. B150
D4
Small-signal diode (SOT23)
Fairchild BAT54S
Diodes Inc. BAT54S
L1, L2
Inductors, 4.7FH, 3.5A
TOKO FDV0620-4R7M
Sumida CDRH6D26HPNP-4R7P
NEC MPLC0730L4R7
L3
Inductor, 22FH, 1.6A
Sumida CDRH8D28NP-220N
N1
High-gain, 25V npn transistor (DPAK)
Fairchild KSH200
ON Semi MJD200
P1
High gain, -25V pnp transistor (DPAK)
Fairchild KSH210
ON Semi MJD210
Q1
-30V, 0.056I p-channel MOSFET (6-pin
SC70 PowerPAK)
Vishay SiA421DJ
SUPPLIER PHONE FAX WEBSITE
Diodes Incorporated 805-446-4800 805-446-4850 www.diodes.com
Fairchild Semiconductor 408-822-2000 408-822-2102 www.fairchildsemi.com
Murata Electronics North America, Inc. 770-436-1300 770-436-3030 www.murata-northamerica.com
ON Semiconductor 888-743-7826 — www.onsemi.com
Sumida Corp. 847-545-6700 847-545-6720 www.sumida.com
TDK Corp. 847-803-6100 847-390-4405 www.component.tdk.com
Toshiba America Electronic Components, Inc. 949-455-2000 949-859-3963 www.toshiba.com/taec