MAX8758 Datasheet, PDF (1/20 Pages) Maxim Integrated Products – Step-Up Regulator with Switch Control and Operational Amplifier for TFT LCD

19-3699; Rev 1; 9/05
Step-Up Regulator with Switch Control and
Operational Amplifier for TFT LCD
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
Ordering Information
PART
MAX8758ETG
MAX8758ETG+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
24 Thin QFN-EP*
4mm x 4mm
24 Thin QFN-EP*
4mm x 4mm
*EP = Exposed pad.
+Denotes lead-free package.
Pin Configuration appears at end of data sheet.
DualMode is a trademark of Maxim Integrated Products, Inc.
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
Simplified Operating Circuit
VGOFF
VIN
LX
IN
FB
FREQ
GND
SHDN
COMP
LDO
MAX8758
PGND
OUT
SUPB
SS
MODE
FROM TCON CTL
DRN
VGON
GON
POSB
NEGB
OUTB
THR
DLP
SRC
VMAIN
TO VCOM
BACKPLANE
________________________________________________________________ Maxim Integrated Products 1
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.