19-0793; Rev 3; 3/11
KIT
ATION
EVALU
BLE
AVAILA
TFT-LCD DC-DC Converter with
Operational Amplifiers
General Description
Features
o
2.5V to 5.5V Input Supply Range
o
1.2MHz Current-Mode Step-Up Regulator
Fast Transient Response to Pulsed Load
High-Accuracy Output Voltage (1%)
Built-In 20V, 3A, 0.16Ω n-Channel MOSFET
High Efficiency (85%)
o
Linear-Regulator Controllers for V
GON
and V
GOFF
o
High-Performance Operational Amplifiers
±130mA Output Short-Circuit Current
45V/µs Slew Rate
20MHz, -3dB Bandwidth
Rail-to-Rail Inputs/Outputs
o
Logic-Controlled, High-Voltage Switch with
Adjustable Delay
o
Timer-Delay Fault Latch for All Regulator Outputs
o
Thermal-Overload Protection
o
0.6mA Quiescent Current
MAX8795A
The MAX8795A includes a high-performance step-up
regulator, two linear-regulator controllers, and five high-
current operational amplifiers for active-matrix, thin-film
transistor (TFT), liquid-crystal displays (LCDs). Also
included is a logic-controlled, high-voltage switch with
adjustable delay.
The step-up DC-DC converter provides the regulated
supply voltage for the panel source driver ICs. The con-
verter is a high-frequency (1.2MHz) current-mode regu-
lator with an integrated 20V n-channel MOSFET that
allows the use of ultra-small inductors and ceramic
capacitors. It provides fast transient response to pulsed
loads while achieving efficiencies over 85%.
The gate-on and gate-off linear-regulator controllers
provide regulated TFT gate-on and gate-off supplies
using external charge pumps attached to the switching
node. The MAX8795A includes five high-performance
operational amplifiers. These amplifiers are designed to
drive the LCD backplane (VCOM) and/or the gamma-
correction divider string. The device features high out-
put current (±130mA), fast slew rate (45V/µs), wide
bandwidth (20MHz), and rail-to-rail inputs and outputs.
The MAX8795A is available in a lead-free, 32-pin, thin
QFN package with a maximum thickness of 0.8mm for
ultra-thin LCD panels, as well as in a 32-pin LQFP
package with 0.8mm pin pitch.
Minimal Operating Circuit
V
CN
V
CP
V
IN
LX
IN
STEP-UP
CONTROLLER
PGND
AGND
FB
V
MAIN
Applications
Notebook Computer Displays
LCD Monitor Panels
Automotive Displays
COMP
V
CP
MAX8795A
DRVP
GATE-ON
CONTROLLER
FBP
V
GON
SRC
DEL
COM
SWITCH
CONTROL
CTL
V
CN
DRN
Ordering Information
PART
MAX8795AETJ+
MAX8795AGCJ+
MAX8795AGTJ+
MAX8795AGTJ/V+
TEMP RANGE
-40°C to +85°C
-40°C to +105°C
-40°C to +105°C
-40°C to +85°C
PIN-PACKAGE
32 Thin QFN
32 LQFP
32 TQFN
32 TQFN
DRVN
GATE-OFF
CONTROLLER
V
GOFF
SUP
NEG1
FBN
OUT1
OP1
REF
NEG4
POS1
NEG2
REF
+Denotes
a lead(Pb)-free/RoHS-compliant package.
/V Denotes an automotive-qualified part.
OUT2
OP2
OP4
OUT4
POS2
POS4
NEG5
OUT3
OP3
OP5
OUT5
POS3
EP
BGND
POS5
Pin Configurations appear at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
