Rainbow Electronics MAX1531 - Manual

General Description
The MAX1530/MAX1531 multiple-output power-supply
controllers generate all the supply rails for thin-film tran-
sistor (TFT) liquid-crystal display (LCD) monitors. Both
devices include a high-efficiency, fixed-frequency,
step-down regulator. The low-cost, all N-channel, syn-
chronous topology enables operation with efficiency as
high as 93%. High-frequency operation allows the use
of small inductors and capacitors, resulting in a com-
pact solution. The MAX1530 includes three linear regu-
lator controllers and the MAX1531 includes five linear
regulator controllers for supplying logic and LCD bias
voltages. A programmable startup sequence enables
easy control of the regulators.
The MAX1530/MAX1531 include soft-start functions to
limit inrush current during startup. An internal step-
down converter current-limit function and a versatile
overcurrent shutdown protect the power supplies against
fault conditions. The MAX1530/MAX1531 use a current-
mode control architecture, providing fast load transient
response and easy compensation. An internal linear
regulator provides MOSFET gate drive and can be
used to power small external loads.
The MAX1530/MAX1531 can operate from inputs as
high as 28V and are well suited for LCD monitor and TV
applications running directly from AC/DC wall adapters.
Both devices are available in a small (5mm x 5mm),
ultra-thin (0.8mm), 32-pin QFN package and operate
over the -40°C to +85°C temperature range.
Applications
LCD Monitors and TVs
Automotive LCDs
Features
♦ 4.5V to 28V Input Voltage Range
♦ 250kHz/500kHz Current-Mode Step-Down Converter
Small Inductor/Capacitors
No Sense Resistor
♦ Three Positive Linear Regulator Controllers
One Positive and One Negative Additional
Controller (MAX1531)
Small Input and Output Capacitors
♦ Timed Reset Output
♦ Uncommitted Overcurrent Protection (MAX1531)
♦ Soft-Start for All Regulators
♦ Programmable Input Undervoltage Comparator
♦ Programmable Startup Sequencing
MAX1530/MAX1531
Multiple-Output Power-Supply Controllers for
LCD Monitors
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
RESET
V IN
V GON
25V
V GOFF
-9V
V IN = 12V
ONL2
V SOURCE
10V/500mA
V GAMMA
9.7V
V N
ONL5
ONL4
ONL3
SEQ
VL
RSTIN
V OUT
3.3V/1.5A
V LOGIC
2.5V/500mA
V OUT
V L
V L
V P
V N
V IN
V IN
V P
V L
DRV3
FBL3
FBL1
DRV1
BST
IN
DH
LX
DL
PGND
FB
COMP
FBL2
DRV2
FBL5
DRV5
DRV4
FBL4
CSH
CSL
FREQ
ILIM
VL
EN
AGND
MAX1530
Minimal Operating Circuit
19-2866; Rev 0; 5/03
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Pin Configuration appears at end of data sheet.
PART TEMP RANGE PIN-PACKAGE
MAX1530ETJ -40°C to +85°C 32 Thin QFN
MAX1531ETJ -40°C to +85°C 32 Thin QFN