MAX8795A_12 Datasheet, PDF (1/31 Pages) Maxim Integrated Products – TFT-LCD DC-DC Converter with Operational Amplifiers

19-0793; Rev 5; 5/12
EVAALVUAAILTAIOBNLEKIT
TFT-LCD DC-DC Converter with
Operational Amplifiers
General Description
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.
Applications
Notebook Computer Displays
LCD Monitor Panels
Automotive Displays
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX8795AETJ+
-40°C to +85°C
32 Thin QFN
MAX8795AGCJ+
-40°C to +105°C
32 LQFP
MAX8795AGCJ/V+ -40°C to +105°C
32 LQFP
MAX8795AGTJ+
-40°C to +105°C
32 TQFN
MAX8795AGTJ/V+ -40°C to +105°C
32 TQFN
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive-qualified part.
Pin Configurations appear at end of data sheet.
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
Minimal Operating Circuit
VCN
VCP
VIN
IN
STEP-UP
CONTROLLER
LX
FB
COMP
PGND
AGND
MAX8795A
DRVP
GATE-ON
CONTROLLER
FBP
SRC
COM
SWITCH
CONTROL
DRN
SUP
NEG1
OUT1 _OP1
POS1
NEG2
GATE-OFF
CONTROLLER
REF
DEL
CTL
DRVN
FBN
REF
NEG4
OUT2 _OP2
POS2
OP4 ^OUT4
POS4
NEG5
OUT3
OP3
POS3
OUT5
OP5
EP
BGND
POS5
VMAIN
VCP
VGON
VCN
VGOFF
________________________________________________________________ Maxim Integrated Products 1
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or visit Maxim’s website at www.maxim-ic.com.