Rainbow Electronics MAX8758 - Manual

General Description
The MAX8758 includes a high-performance step-up regu-
lator, a high-speed operational amplifier, and a logic-
controlled, high-voltage switch-control block with pro-
grammable delay. The device is optimized for thin-film
transistor (TFT) liquid-crystal display (LCD) applications.
The step-up DC-DC regulator provides the regulated sup-
ply voltage for the panel source driver ICs. The converter
is a high-frequency (640kHz/1.2MHz), current-mode regu-
lator with an integrated 14V n-channel power MOSFET.
The high-switching frequency allows the use of ultra-small
inductors and ceramic capacitors. The current-mode con-
trol architecture provides fast transient response to pulsed
loads. The regulator achieves efficiencies over 85% by
bootstrapping the supply rail of the internal gate driver
from the step-up regulator output. The step-up regulator
features undervoltage lockout (UVLO), soft-start, and
internal current limit. The high-current operational amplifier
is designed to drive the LCD backplane (VCOM). The
amplifier features high output current (±150mA), fast slew
rate (7.5V/µs), wide bandwidth (12MHz), and rail-to-rail
inputs and outputs.
The MAX8758 is available in a 24-pin, 4mm x 4mm, thin
QFN package with a maximum thickness of 0.8mm for
ultra-thin LCD panels. The device operates over the
-40°C to +85°C temperature range.
Applications
Notebook Displays
LCD Monitors
Features
♦ 1.8V to 5.5V Input Voltage Range
♦ Input Undervoltage Lockout
♦ 0.5mA Quiescent Current
♦ 640kHz/1.2MHz Current-Mode Step-Up Regulator
Fast Transient Response
High-Accuracy Output Voltage (1.5%)
Built-In 14V, 2.5A, 115mΩ MOSFET
High Efficiency
Programmable Soft-Start
Current Limit with Lossless Sensing
Timer-Delay Fault Latch
♦ High-Speed Operational Amplifier
±150mA Output Current
7.5V/µs Slew Rate
12MHz, -3dB Bandwidth
Rail-to-Rail Inputs/Outputs
♦ Dual-Mode™, Logic-Controlled, High-Voltage
Switch with Programmable Delay
♦ Thermal-Overload Protection
♦ 24-Pin, 4mm x 4mm, Thin QFN Package
MAX8758
Step-Up Regulator with Switch Control and
Operational Amplifier for TFT LCD
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
V MAIN
TO VCOM
BACKPLANE
V GON
FROM TCON
V IN
V GOFF
IN
FREQ
SHDN
COMP
LDO
FB
LX
GND
PGND
OUT
SUPB
GON
DRN
CTL
MODE
SS POSB
NEGB
OUTB
THR
DLP
SRC
MAX8758
Simplified Operating Circuit
19-3699; Rev 0; 5/05
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.
PART TEMP RANGE PIN-PACKAGE
MAX8758ETG -40°C to +85°C
24 Thin QFN-EP*
4mm x 4mm
Pin Configuration appears at end of data sheet.
DualMode is a trademark of Maxim Integrated Products, Inc.
*EP = Exposed pad.