Datasheet

Standard Application Circuit
The standard application circuit (Figure 1) of the MAX1531
is a complete power-supply system for TFT LCD moni-
tors. The circuit generates a 3.3V/1.5A main output, a
2.5V/500mA output for the timing controller and digital
sections of source/gate drive ICs, a 10V/500mA source
drive supply voltage, a 9.7V/50mA gamma reference, a
25V/20mA gate-on voltage, and a -10V/50mA gate-off
voltage. The input voltage is 12V ±10%. Table 1 lists the
selected components and Table 2 lists the component
suppliers. The standard application circuit (Figure 2) of
the MAX1530 is similar to the MAX1531 application circuit
except that gate-on and gate-off voltages are eliminated.
Detailed Description
The MAX1530/MAX1531 power-supply controllers provide
logic and bias power for LCD monitors. Figure 3 shows
the IC functional diagram. The main step-down controller
employs a current-mode PWM control method to ease
compensation requirements and provide excellent load-
and line-transient response. The use of synchronous rec-
tification yields excellent efficiency.
The MAX1530 includes three analog gain blocks to control
three auxiliary positive linear regulators, and the MAX1531
includes five analog gain blocks to control four positive and
one negative linear regulators. Use the positive gain blocks
to generate low-voltage rails directly from the input voltage
or the main step-down converter output, or higher voltages
using charge pumps attached to the switching node or
Table 1. Selected Component List
Table 2. Component Suppliers
*For MAX1531 only.
DESIGNATION DESCRIPTION
C3
4.7µF, 25V X7R ceramic capacitor
(1210) TDK C3225X7R1E475K
C7
22µF, 6.3V X7R ceramic capacitor
TDK C3216X7R0J226M
C9
10µF, 6.3V X5R ceramic capacitor
TDK C2012X5R0J106M
C12, C19*
0.47µF, 16V X7R ceramic capacitors
(0805) TDK C2012X7R1C474K
C13
4.7µF, 16V X7R ceramic capacitor
TDK C3216X7R1C475K
C21, C22
2.2µF, 25V X7R ceramic capacitors
(1206) TDK C3216X7R1C475M
D1, D6*
100mA, 30V Schottky diodes (SOD523)
Central Semiconductor CMOSH-3
D2
100mA, 75V, small-signal switching
diode, SOT23 Fairchild Semiconductor
MMBD4148
DESIGNATION DESCRIPTION
D3*, D4*, D5*
200mA, 25V dual Schottky diodes
(SOT23) Fairchild BAT54S
L1
10µH, 2.3A (DC) inductor
Sumida CDR7D28MN-100
N1
2.5A, 30V dual N-channel MOSFET
(6-pin Super SOT)
Fairchild FDC6561AN
Q1, Q4
3A, 60V low-saturation PNP bipolar
transistors
(SOT-223) Fairchild NZT660A
Q2, Q3*
200mA, 40V PNP bipolar transistors
(SOT23) Fairchild MMBT3906
Q5*, Q6*
200mA, 40V NPN bipolar transistors
(SOT23) Fairchild MMBT3904
SUPPLIER PHONE FAX WEBSITE
Central Semi 516-435-1110 516-435-1824 www.centralsemi.com
Fairchild 888-522-5372 972-910-8036 www.fairchildsemi.com
Sumida 847-956-0666 847-956-0702 www.sumida.com
TDK 847-803-6100 847-390-4405 www.components.tdk.com
MAX1530/MAX1531 Multiple-Output Power-Supply
Controllers for LCD Monitors
www.maximintegrated.com
Maxim Integrated │ 16