Rainbow Electronics MAX1531 - Manual (Page 16)

MAX1530/MAX1531
Multiple-Output Power-Supply Controllers for
LCD Monitors
16 ______________________________________________________________________________________
Standard Application Circuit
The standard application circuit (Figure 1) of the
MAX1531 is a complete power-supply system for TFT
LCD monitors. 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 applica-
tion 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 pro-
vide 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 excel-
lent load- and line-transient response. The use of syn-
chronous rectification 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
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 l ow - satur ati on P N P b i p ol ar tr ansi stor s
( S O T- 223)
Fai r chi l d N Z T660A
Q2, Q3*
200mA, 40V PNP bipolar transistors (SOT23)
Fairchild MMBT3906
Q5*, Q6*
200m A, 40V N P N b i p ol ar tr ansi stor s ( S OT23)
Fai r chi l d M M BT3904
Table 1. Selected Component List
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
Table 2. Component Suppliers
*For MAX1531 only.