MAX8752ETA+T Maxim Integrated Products, MAX8752ETA+T Datasheet

IC DC-DC CONV TFT LCD 8-TDFN

MAX8752ETA+T

Manufacturer Part Number
MAX8752ETA+T
Description
IC DC-DC CONV TFT LCD 8-TDFN
Manufacturer
Maxim Integrated Products
Datasheet

Specifications of MAX8752ETA+T

Applications
Converter, TFT, LCD
Voltage - Input
1.8 ~ 5.5 V
Number Of Outputs
1
Voltage - Output
1.8 ~ 13 V
Operating Temperature
0°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
8-TDFN Exposed Pad
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX8752 is a high-performance, step-up DC-DC
converter that provides a regulated supply voltage for
active-matrix thin-film transistor (TFT) liquid-crystal dis-
plays (LCDs). The MAX8752 incorporates current-mode,
fixed-frequency, pulse-width modulation (PWM) circuitry
with a built-in n-channel power MOSFET to achieve high
efficiency and fast transient response. The input supply
voltage of the MAX8752 is from 1.8V to 5.5V.
The MAX8752 operates with a switching frequency of
1.2MHz, allowing the use of ultrasmall inductors and low-
ESR ceramic capacitors. The current-mode architecture
provides fast transient response to the pulsed loads typi-
cal of LCD source-driver applications. A compensation
pin (COMP) gives users flexibility in adjusting loop
dynamics. The 14V internal MOSFET can generate output
voltages up to 13V. The internal digital soft-start and cur-
rent limit effectively control inrush and fault currents.
The MAX8752 is available in a 3mm x 3mm 8-pin TDFN
package with a maximum height of 8mm.
19-3793; Rev 0; 8/05
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.
+1.8V TO +5.5V
Notebook Computer Displays
LCD Monitor Panels
Automotive Displays
V
IN
Typical Operating Circuit
________________________________________________________________ Maxim Integrated Products
IN
COMP
LDO
General Description
MAX8752
SHDN
IN
LX
GND
SUP
FB
TFT LCD Step-Up DC-DC Converter
Applications
V
MAIN
♦ 1.8V to 5.5V Input Supply Range
♦ Built-In 14V, 2.2A, 0.2Ω n-Channel MOSFET
♦ High Efficiency (> 85%)
♦ Fast Transient Response to Pulsed Load
♦ High-Accuracy Output Voltage (1.5%)
♦ Internal Digital Soft-Start
♦ Input Supply Undervoltage Lockout
♦ 1.2MHz Switching Frequency
♦ 0.1µA Shutdown Current
♦ Small 8-Pin TDFN Package
MAX8752ETA
PART
TOP VIEW
-40°C to +85°C
RANGE
TEMP
Ordering Information
3mm x 3mm
MAX8752
TDFN
Pin Configuration
8 TDFN
3mm x 3mm
PACKAGE
PIN-
Features
T833-2
CODE
PKG
1

Related parts for MAX8752ETA+T

MAX8752ETA+T Summary of contents

Page 1

... COMP LDO SUP SHDN IN ________________________________________________________________ Maxim Integrated Products 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. ♦ 1.8V to 5.5V Input Supply Range ♦ Built-In 14V, 2.2A, 0.2Ω n-Channel MOSFET ♦ High Efficiency (> 85%) ♦ ...

Page 2

TFT LCD Step-Up DC-DC Converter ABSOLUTE MAXIMUM RATINGS LX, SUP to GND .....................................................-0.3V to +14V SHDN, LDO to GND............................................-0.3V to +6V IN GND ...................................................-0. COMP to GND ..........................................-0. Switch Maximum Continuous RMS Current ...

Page 3

TFT LCD Step-Up DC-DC Converter ELECTRICAL CHARACTERISTICS (continued 2.5V 0°C to +85°C. Typical values are at T SHDN IN A PARAMETER n-CHANNEL MOSFET Current Limit V FB On-Resistance Leakage Current V LX Current-Sense Transresistance ...

Page 4

TFT LCD Step-Up DC-DC Converter ELECTRICAL CHARACTERISTICS (continued 2.5V -40°C to +85°C. unless otherwise noted.) SHDN IN A PARAMETER CONTROL INPUTS SHDN Input Low Voltage SHDN Input High Voltage Note 1: Step-up regulator inhibited ...

Page 5

Figure 2.5V MAIN SOFT-START (HEAVY LOAD) MAX8752 toc07 INDUCTOR CURRENT 1A/div 0A V MAIN 5V/div 0V 2ms/div SWITCHING WAVEFORMS MAX8752 toc10 LX 5V/div 0V INDUCTOR CURRENT 500mA/div I = 300mA LOAD 0A 1μs/div ...

Page 6

TFT LCD Step-Up DC-DC Converter PIN NAME Compensation Pin for Error Amplifier. Connect a series resistance and capacitor from COMP to GND. 1 COMP See the Loop Compensation section for component selection guidelines. Feedback Pin. The FB regulation voltage is ...

Page 7

TFT LCD Step-Up DC-DC Converter CLOCK LOGIC AND DRIVER CURRENT LIMIT STARTUP IN OSC SOFT- START SLOPE COMP ∑ OSCILLATOR PWM COMPARATOR SHDN LINEAR SUP REGULATOR AND MAX8752 LDO BOOTSTRAP Figure 2. MAX8752 Functional Diagram Detailed Description The MAX8752 is ...

Page 8

TFT LCD Step-Up DC-DC Converter is the current limit calculated above, η is the where I LIM regulator efficiency (85% nominal), and D is the duty cycle. The duty cycle when operating at the current limit is: − ...

Page 9

TFT LCD Step-Up DC-DC Converter The maximum output current, input voltage, output volt- age, and switching frequency determine the inductor value. Very high inductance values minimize the cur- rent ripple and therefore reduce the peak current, which decreases core losses ...

Page 10

TFT LCD Step-Up DC-DC Converter Choosing an LIR of 0.5 and estimating efficiency of 80% at this operating point: 2 ⎛ ⎞ ⎛ ⎞ − ⎜ ⎟ ⎜ ...

Page 11

TFT LCD Step-Up DC-DC Converter Loop Compensation The voltage-feedback loop needs proper compensa- tion to prevent excessive output ripple and poor effi- ciency caused by instability. This is done by connecting a resistor (R ) and capacitor (C COMP in ...

Page 12

... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products A2 ...

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