19-4820; Rev 0; 7/09
Multi-Output Power Supply with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
General Description
Features
S 8.0V to 16.5V IN Supply-Voltage Range
The MAX17114 generates all the supply rails for thin-film
transistor liquid-crystal display (TFT LCD) TV panels
operating from a regulated 12V input. It includes a step-
down and a step-up regulator, a positive and a negative
charge pump, an operational amplifier, a high-accuracy,
high-voltage gamma reference, and a high-voltage
switch control block. The MAX17114 can operate from
input voltages from 8V to 16.5V and is optimized for an
LCD TV panel running directly from 12V supplies.
S Selectable Frequency (500kHz/750kHz)
S Current-Mode Step-Up Regulator
Fast Load-Transient Response
High-Accuracy Output Voltage (1.0%)
Built-In 20V, 3.5A, 100mI MOSFET
High Efficiency
Adjustable Soft-Start
Adjustable Current Limit
The step-up and step-down switching regulators feature
internal power MOSFETs and high-frequency opera-
tion allowing the use of small inductors and capacitors,
resulting in a compact solution. The step-up regulator
provides TFT source driver supply voltage, while the
step-down regulator provides the system with logic sup-
ply voltage. Both regulators use fixed-frequency current-
mode control architectures, providing fast load-transient
response and easy compensation. A current-limit func-
tion for internal switches and output-fault shutdown pro-
tects the step-up and step-down power supplies against
fault conditions. The MAX17114 provides soft-start func-
tions to limit inrush current during startup. In addition,
the MAX17114 integrates a control block that can drive
an external p-channel MOSFET to sequence power to
source drivers.
Low Duty-Cycle Operation (13.2V - 13.5V AVDD)
IN
S Current-Mode Step-Down Regulator
Fast Load-Transient Response
Built-In 20V, 3.2A, 120mI MOSFET
High Efficiency
3ms Internal Soft-Start
S Adjustable Positive Charge-Pump Regulator
S Adjustable Negative Charge-Pump Regulator
S Integrated High-Voltage Switch with Adjustable
Turn-On Delay
S High-Speed Operational Amplifier
200mA Short-Circuit Current
45V/µs Slew Rate
S High-Accuracy Reference for Gamma Buffer
0.5% Feedback Voltage
The positive and negative charge-pump regulators pro-
vide TFT gate-driver supply voltages. Both output volt-
ages can be adjusted with external resistive voltage-
dividers. A logic-controlled, high-voltage switch block
allows the manipulation of the positive gate-driver supply.
Up to 30mA Load Current
Low-Dropout Voltage 0.5V at 60mA
S External p-Channel Gate Control for AVDD
Sequencing
The MAX17114 includes one high-current operational
amplifier designed to drive the LCD backplane (VCOM).
The amplifier features high output current (Q200mA), fast
slew rate (45V/Fs), wide bandwidth (20MHz), and rail-to-
rail outputs.
S XAO Comparator
S Input Undervoltage-Lockout and Thermal-
Overload Protection
S 48-Pin, 7mm x 7mm, Thin QFN Package
Also featured in the MAX17114 is a high-accuracy, high-
voltage adjustable reference for gamma correction.
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
The MAX17114 is available in a small (7mm x 7mm),
ultra-thin (0.8mm), 48-pin, TQFN-EP package and oper-
ates over the -40NC to +85NC temperature range.
MAX17114ETM+
-40NC to +85NC
48 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Applications
Pin Configuration and Simplified Operating Circuit appear
at end of data sheet.
LCD TV Panels
_______________________________________________________________ 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.