Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - voltage regulator - special purpose TQFN 24 (4x4)

General Description

The MAX8710/MAX8711/MAX8712/MAX8761 offer com-

plete linear-regulator power-supply solutions for thin-film

transistor (TFT) liquid-crystal-display (LCD) panels used

in LCD monitors and LCD TVs. All four devices include a

high-performance AV

linear regulator, a positive

charge-pump regulator, a negative charge-pump regula-

tor, and built-in power-up sequence control. The

MAX8710/MAX8711/MAX8761 also include a high-cur-

rent operational amplifier. Additionally, the MAX8710/

MAX8761 provide logic-controlled high-voltage switches

to control the positive charge-pump output.

The linear regulator directly steps down the input voltage

to generate the supply voltage for the source-driver ICs

(AV

). The two built-in charge-pump regulators

are used to generate the TFT gate-on and gate-off sup-

plies. The high-current operational amplifier is typically

used to drive the LCD backplane (VCOM) and features

high output current (150mA), fast slew rate (12V/µs), and

wide bandwidth (12MHz). Its rail-to-rail inputs and output

maximize flexibility.

The MAX8710/MAX8761 are available in a 24-pin thin

QFN package, the MAX8711 is available in a 16-pin thin

QFN package, and the MAX8712 is available in a 12-pin

thin QFN package. All three packages are 4mm x 4mm

with a maximum thickness of 0.8mm for ultra-thin LCD

panel design. The MAX8710/MAX8711/MAX8712 oper-

ate over the -40°C to +100°C temperature range and the

MAX8761 operates over the -40°C to +85°C range.

Applications

LCD Monitor Panel Modules

LCD TV Panel Modules

Features

♦ High-Performance Linear Regulator

1.6% Output Accuracy

Works with Small Ceramic Output Capacitors

Fast Transient Response

Foldback Current Limit

♦ 50mA Negative Regulated Charge Pump

♦ 20mA Positive Regulated Charge Pump with

Adjustable Delay

♦ Built-In Power-Up Sequence

♦ High-Current Operational Amplifier

(MAX8710/MAX8711/MAX8761)

±150mA Output Short-Circuit Current

12V/µs Slew Rate

12MHz, -3dB Bandwidth

Rail-to-Rail Inputs/Output

♦ Dual-Mode™ High-Voltage Switches

(MAX8710/MAX8761)

♦ Thermal Protection

♦ Latched Fault Protection with Timer

MAX8710/MAX8711/MAX8712/MAX8761

Low-Cost, Linear-Regulator

LCD Panel Power Supplies

________________________________________________________________ Maxim Integrated Products 1

FBN

SUPCP

DRVN

DLP

POSB

SUPB

OUTB

NEGB

MODE

CTL

GND

INL

OUTL

FBL

SHDN

DRVP

FBP

SRC

GON

DRN

THR

REF

GOFF

CTL

VCOM

REF

VIN

MAX8710

MAX8761

Minimum Operating Circuit

SRC

FBN

DLP

MODE

FBL

CTL

OUTL

SUPCP

DRVN

DRVP

N.C.

131415161718

GND

OUTB

SUPB

THR

FBP

SHDN

654321

NEGB

INL

POSB

REF

DRN

GON

MAX8710

MAX8761

THIN QFN 4mm x 4mm

TOP VIEW

Pin Configurations

Ordering Information

PART TEMP RANGE PIN-PACKAGE

PKG

CODE

M A X8 7 1 0E TG+ -40°C to +100°C

24 Thin QFN

4mm x 4mm

T2444-4

M A X8 7 1 1E TE+ -40°C to +100°C

16 Thin QFN

4mm x 4mm

T2444-4

M A X8 7 1 2E TC+ -40°C to +100°C

12 Thin QFN

4mm x 4mm

T2444-4

M A X8 7 6 1E TG+ -40°C to +85°C

24 Thin QFN

4mm x 4mm

T2444-4

19-3174; Rev 1; 10/05

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.

Pin Configurations continued at end of data sheet.

EVALUATION KIT

AVAILABLE

Dual Mode is a trademark of Maxim Integrated Products, Inc.

+Denotes lead-free package.

Summary of content (25 pages)

PAGE 1
9-3174; Rev 1; 10/05 KIT ATION EVALU LE B A IL A AV Low-Cost, Linear-Regulator LCD Panel Power Supplies The MAX8710/MAX8711/MAX8712/MAX8761 offer complete linear-regulator power-supply solutions for thin-film transistor (TFT) liquid-crystal-display (LCD) panels used in LCD monitors and LCD TVs. All four devices include a high-performance AV DD linear regulator, a positive charge-pump regulator, a negative charge-pump regulator, and built-in power-up sequence control.
PAGE 2
MAX8710/MAX8711/MAX8712/MAX8761 Low-Cost, Linear-Regulator LCD Panel Power Supplies ABSOLUTE MAXIMUM RATINGS CTL, FBL, FBP, FBN, SHDN, REF, THR to GND........-0.3V to +6V MODE, DLP to GND ......................................-0.3V to VREF + 0.3V IN, INL to GND .........................................................-0.3V to +28V SUPCP, SUPB to GND.............................................-0.3V to +14V OUTL (MAX8710/MAX8761) ………………………-0.3V to +28V OUTL (MAX8711/MAX8712) ………………………-0.
PAGE 3
Low-Cost, Linear-Regulator LCD Panel Power Supplies (Circuit of Figure 1. VIN = VINL = VSUPCP = 12V, VOUTL = VSUPB = 10V, VSRC = 27V, TA = 0°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS 13.2 V OPERATIONAL AMPLIFIER (MAX8710/MAX8711/MAX8761) SUPB Supply Operating Range 4.5 SUPB Supply Current Buffer configuration, VPOSB = 4V, no load 0.7 1.
PAGE 4
MAX8710/MAX8711/MAX8712/MAX8761 Low-Cost, Linear-Regulator LCD Panel Power Supplies ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure 1. VIN = VINL = VSUPCP = 12V, VOUTL = VSUPB = 10V, VSRC = 27V, TA = 0°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.
PAGE 5
Low-Cost, Linear-Regulator LCD Panel Power Supplies (Circuit of Figure 1. VIN = VINL = VSUPCP = 12V, VOUTL = VSUPB = 10V, VSRC = 27V, TA = -40°C to +100°C (-40°C to 85°C for MAX8761), unless otherwise noted.) (Note 1) PARAMETER REF Output Voltage CONDITIONS -10µA < IREF < 1mA (excluding internal load) SUPCP Input Supply Range Charge-Pump Regulators Operating Frequency MIN MAX UNITS 4.9 TYP 5.1 V 2.7 13.
PAGE 6
ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure 1. VIN = VINL = VSUPCP = 12V, VOUTL = VSUPB = 10V, VSRC = 27V, TA = -40°C to +100°C, (-40°C to +85°C for MAX8761), unless otherwise noted.) (Note 1) PARAMETER CONDITIONS MIN TYP VFBN = 350mV DRVN n-Channel On-Resistance MAX 6 VFBN = 150mV 20 MAX8710/MAX8711/MAX8712 2.0 MAX8761 2.05 UNITS Ω kΩ SEQUENCE CONTROL SHDN Input Low Voltage 0.6 SHDN Input High Voltage DLP Capacitor Charge Current During startup, VDLP = 1.
PAGE 7
Low-Cost, Linear-Regulator LCD Panel Power Supplies MAX8761 LINEAR-REGULATOR LOAD REGULATION MAX8761 LINEAR-REGULATOR LOAD TRANSIENT RESPONSE MAX8710/11/12/61 toc05 0 VOUTL = 10V VINL = 12V -0.4 MAX8710/11/12/61 toc06 MAX8710/11/12/61 toc04 0.4 10V A A -0.8 B -1.2 B -1.6 0mA LOAD CURRENT (mA) -2.
PAGE 8
Typical Operating Characteristics (continued) (Circuit of Figure 1. VIN = VINL = VSUPCP = 12V, VOUTL = VSUPB = 10V, VSRC = 27V, TA = 0°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.) POSITIVE CHARGE-PUMP LINE REGULATION -0.4 -0.6 -0.8 -0.25 -0.50 -0.75 MAX8710/11/12/61 toc15 0 0.2 MAX8710/11/12 toc14 VGOFF = -5V INPUT = 12V OUTPUT-VOLTAGE ERROR (%) -0.2 0.
PAGE 9
Low-Cost, Linear-Regulator LCD Panel Power Supplies MAX8710/MAX8711/MAX8761 SUPB SUPPLY CURRENT vs. SUPB VOLTAGE REFERENCE vs. TEMPERATURE -0.2 -0.4 MAX8710/11/12/61 toc21 0 MAX8710/11/12/61 toc22 1.0 SUPB SUPPLY CURRENT (mA) MAX8710/11/12/91 toc20 REF VOLTAGE ERROR (%) 0.2 MAX8710/MAX8711/MAX8761 OPERATIONALAMPLIFIER SMALL-SIGNAL STEP RESPONSE (BUFFER CONFIGURATION) 0.8 A 0V 0.6 0.4 B 0V 0.2 BUFFER CONFIGURATION VOUTB = 0.5 x VPOSB -0.
PAGE 10
MAX8710/MAX8711/MAX8712/MAX8761 Low-Cost, Linear-Regulator LCD Panel Power Supplies Pin Description PIN NAME FUNCTION — GON Internal High-Voltage MOSFET Switch Common Terminal. GON is the output of the high-voltage switch-control block. GON is internally pulled to GND by a 1kΩ resistor in shutdown for the MAX8710. GON is not pulled to GND for the MAX8761. — — DRN Switch Input. Drain of the internal high-voltage back-to-back p-channel MOSFETs connected to GON. 3 1 1 REF Reference Output.
PAGE 11
Low-Cost, Linear-Regulator LCD Panel Power Supplies PIN NAME FUNCTION MAX8710/ MAX8761 MAX8711 MAX8712 18 13 9 SHDN Active-Low Shutdown Control Input. Pull SHDN low to turn off all sections of the device except REF. Pull SHDN high to enable the device. Cycle SHDN to reset the device after a fault. 19 — — CTL High-Voltage Switch-Control Block Timing Control Input. See the Switch Control (MAX8710/MAX8761) section for details. 20 14 10 FBL Linear-Regulator Feedback Input.
PAGE 12
MAX8710/MAX8711/MAX8712/MAX8761 Low-Cost, Linear-Regulator LCD Panel Power Supplies IN 10.8V TO 13.2V GND 10µF 0.1µF GND IN N.C. INL OUTL C1 4.7µF/10µF 47pF/22pF (MAX8710/MAX8761) (MAX8710/MAX8761) AVDD SUPB 0.1µF AVDD 10V 300mA/500mA (MAX8710/MAX8761) FBL 120kΩ POSB 100kΩ R1 100kΩ 1% R2 33.2kΩ 1% MAX8710 MAX8761 IN SUPCP 0.1µF NEGB 0.1µF OUTB OUTB DRVP 0.1µF 0.22µF MMBD4148SE (FAIRCHILD) DRVN 1µF R5 110kΩ 1% VP 27V/20mA FBP FBN R4 33.2kΩ 1% R6 100kΩ 1% 0.
PAGE 13
Low-Cost, Linear-Regulator LCD Panel Power Supplies 10µF 0.1µF GND IN INL OUTL C1 47pF AVDD 4.7µF SUPB 120kΩ MAX8710/MAX8711/MAX8712/MAX8761 IN 10.8V TO 13.2V GND 0.1µF AVDD 10V/300mA FBL POSB R1 100kΩ 1% R2 33.2kΩ 1% MAX8711 100kΩ NEGB OUTB OUTB MMBD4148SE (FAIRCHILD) DRVP 0.22µF 0.1µF DRVN 1µF GOFF -5V/50mA MMBD4148 0.1µF 0.1µF 2x MMBD4148SE (FAIRCHILD) R5 110kΩ 1% 1µF FBN R4 33.2kΩ 1% REF GON 27V/20mA FBP R6 100kΩ 1% REF 5V/1mA 1µF R3 325kΩ 1% DLP 0.1µF 0.
PAGE 14
MAX8710/MAX8711/MAX8712/MAX8761 Low-Cost, Linear-Regulator LCD Panel Power Supplies IN 10.8V TO 13.2V GND 10µF 0.1µF GND IN INL OUTL MMBD4148SE (FAIRCHILD) C1 47pF 0.22µF DRVN 1µF GOFF -5V/50mA R6 100kΩ 1% MAX8712 0.47µF R1 100kΩ 1% R2 33.2kΩ 1% MMBD4148 REF REF 5V/1mA AVDD 10V/300mA FBL R5 110kΩ 1% FBN 4.7µF 0.1µF DRVP 0.1µF 0.1µF DLP 1µF 2x MMBD4148SE (FAIRCHILD) 0.1µF 1µF SHDN SHDN GON 27V/20mA FBP R4 33.2kΩ 1% R3 325kΩ 1% Figure 3.
PAGE 15
Low-Cost, Linear-Regulator LCD Panel Power Supplies MAX8710/MAX8711/MAX8712/MAX8761 IN IN GND REF REF REF MAX8710 MAX8761 INL LINEAR REG OUTL AVDD FBL FBN VIN SUPCP OSC SHDN DRVN VGOFF DLP DRVP SEQ POSB AVDD AVDD VP SUPB FBP OUTB VCOM NEGB MODE SRC SWITCH CONTROL CTL GON VGON CTL REF DRN THR Figure 4.
PAGE 16
MAX8710/MAX8711/MAX8712/MAX8761 Low-Cost, Linear-Regulator LCD Panel Power Supplies The linear regulator is enabled whenever REF is in regulation and SHDN is logic high. Each time it is enabled, the linear regulator goes through a soft-start routine by ramping up its internal reference voltage from 0 to 2.5V in 128 steps. The soft-start period is 2.73ms (typ), and FBL fault detection is disabled during this period. This soft-start feature effectively limits the inrush current during startup.
PAGE 17
Low-Cost, Linear-Regulator LCD Panel Power Supplies Negative Charge-Pump Regulator The negative charge-pump regulator is typically used to generate the negative supply rail for the TFT LCD gatedriver ICs. The output voltage is set with an external resistive voltage-divider from its output to REF with the midpoint connected to FBN. The number of charge-pump stages and the setting of the feedback divider determine the output of the negative charge-pump regulator.
PAGE 18
MAX8710/MAX8711/MAX8712/MAX8761 Low-Cost, Linear-Regulator LCD Panel Power Supplies Power-Up Sequence and Shutdown Control Thermal-Overload Protection When the MAX8710/MAX8711/MAX8712/MAX8761 are powered up, REF rises with the voltage on IN. After REF reaches regulation and if SHDN is logic high, the linear regulator, operational amplifier, and negative chargepump regulator are enabled and begin their respective soft-start routines.
PAGE 19
Low-Cost, Linear-Regulator LCD Panel Power Supplies MAX8710/MAX8711/MAX8712/MAX8761 REF MAX8710 5µA DLP Q4 FAULT SHDN REF OK SRC 0.5 x VREF Q1 GON 9R 1kΩ Q3 REF 50µA R R Q2 DRN THR 4R MODE 1kΩ 5R Q5 CTL Figure 6.
PAGE 20
MAX8710/MAX8711/MAX8712/MAX8761 Low-Cost, Linear-Regulator LCD Panel Power Supplies FAULT REF OK SRC MAX8761 Q1 GON REF 50µA 9R R R Q2 4R DRN THR MODE 1kΩ 5R Q5 CTL Figure 7.
PAGE 21
Low-Cost, Linear-Regulator LCD Panel Power Supplies Linear Regulator Output-Voltage Selection Adjust the linear-regulator output voltage by connecting a resistive voltage-divider from the linear-regulator output AVDD to GND with the center tap connected to FBL (Figure 1). Select the lower resistor of divider R2 in the 10kΩ to 50kΩ range. Calculate upper resistor R1 with the following equation: ⎛V ⎞ R1 = R2 × ⎜ AVDD − 1⎟ ⎝ VFBL ⎠ where VFBL = 2.5V (typ) is the regulation point of the linear regulator.
PAGE 22
MAX8710/MAX8711/MAX8712/MAX8761 Low-Cost, Linear-Regulator LCD Panel Power Supplies ƒU 1 ƒ ZERO = = 2πR1C1 VOUTL / VFBL where R1 is the upper resistor of the feedback divider and fu is the unity gain frequency. The unity gain frequency (f u) for the MAX8710/MAX8711/MAX8712 is approximately 80kHz; for MAX8761, fu is approximately 160kHz. The value of R1 was calculated in the OutputVoltage Selection section to set VOUTL.
PAGE 23
Low-Cost, Linear-Regulator LCD Panel Power Supplies COUT _ CP ≥ VIN = 19V 51Ω INL ILOAD _ CP LINEAR REGULATOR 2 fOSC VRIPPLE _ CP 140kΩ 4.7µF 20kΩ Figure 8. High-Power Linear Regulator REF 0.47µF MAX8710 VDD External Transistor for Higher Current or Power Dissipation The solution for such applications is to connect an external pnp transistor with the internal pnp transistor in a Darlington configuration as shown in Figure 8.
PAGE 24
5) Minimize the size of the switching nodes (DRVP and DRVN). Keep the switching nodes away from feedback nodes (FBL, FBP, and FBN) and the analog ground. Use DC traces as a shield if necessary. Refer to the MAX8710 evaluation kit for an example of proper board layout.
PAGE 25
Low-Cost, Linear-Regulator LCD Panel Power Supplies 24L QFN THIN.EPS PACKAGE OUTLINE, 12, 16, 20, 24, 28L THIN QFN, 4x4x0.8mm 21-0139 E 1 2 PACKAGE OUTLINE, 12, 16, 20, 24, 28L THIN QFN, 4x4x0.8mm 21-0139 E 2 2 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.