ADD8733 Datasheet, PDF (1/16 Pages) Analog Devices – Integrated TFT Panel Power Supply with Gate Modulation and VCOM

Preliminary Technical Data
Integrated TFT Panel Power Supply
with Gate Modulation and VCOM
ADD8733
FEATURES
Step-up switching regulator with 3 A switch current limit
8 V to 16.5 V input voltage range
Adjustable output voltage up to 20 V
1.2 A series switch for power sequencing
Overvoltage protection (OVP)
Step-down switching regulator with 3 A switch current limit
8 V to 16.5 V input voltage range
Adjustable output voltage down to 2.5 V
Gate pulse modulator circuitry
Independently adjustable delay and falling slope
Positive charge-pump regulator for VGH
Negative charge-pump regulator for VGL
Two VCOM amplifiers
General
Power supply sequencing
Thermal fault protection
650 kHz or 1.2 MHz PWM frequency
Soft start
Undervoltage lockout (UVLO)
48-lead RoHS compliant LFCSP
APPLICATIONS
TFT LCD panels for TVs and monitors
BLOCK DIAGRAM
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
ADD8733
STEP-UP SWITCHING REGULATOR
AND POWER SEQUENCING
STEP-DOWN SWITCHING REGULATOR
TWO VCOM AMPLIFIERS
GATE PULSE
MODULATION
X
VGH
REGULATOR
VGL
REGULATOR
X
X
UNDERVOLTAGE
X
X
LOCKOUT AND
X
THERMAL PROTECTION
X
X
CONTROL
Figure 1.
GENERAL DESCRIPTION
The ADD8733 is a 4-channel regulator with two VCOM
amplifiers and gate pulse modulation (GPM) that provides
all the necessary voltages for thin film transistor (TFT) liquid
crystal displays (LCD). Included is a step-up regulator, a step-
down regulator for digital logic, two VCOM amplifiers, two
charge-pump regulators for VGH and VGL, and an integrated
gate pulse modulator.
By offering a complete power integration solution optimized for
TFT LCD TVs and monitors, the ADD8733 helps to lower cost,
simplify board design, and increase performance over existing
solutions.
The ADD8733 is offered in a 48-lead RoHS compliant LFCSP
and is specified over the industrial temperature range of −40°C
to +85°C.
Rev. PrA
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