Rainbow Electronics MAX9552 User Manual

General Description

The MAX9550/MAX9551/MAX9552 provide a VCOM
source for TFT LCDs. The MAX9550/MAX9551/
MAX9552 source and sink a large current to quickly
restore the VCOM voltage, making it ideal for TFT LCDs.
The output settles to within 0.1% in less than 2µs. In
addition, the MAX9550/MAX9551/MAX9552 directly drive
the capacitive load in the VCOM layer of the TFT LCDs
without the need for a series resistor.

The MAX9550/MAX9551/MAX9552 feature single, dual,
and quad channel VCOM amplifiers, respectively. The
MAX9550/MAX9551/MAX9552 can drive up to 800mA of
peak current per channel and operate up to 20V. The
devices feature soft-start to reduce inrush current, output
short-circuit protection, and thermal shutdown.

The MAX9550 is available in a space-saving 5-pin thin
SOT23 package, and an 8-pin µMAX®package with an
exposed paddle. The MAX9551 is available in an 8-pin
µMAX package with an exposed paddle. The MAX9552
is available in a 14-pin TSSOP package. All devices are
specified over the -40°C to +85°C temperature range.

Applications

TFT-LCD Panels

Instrument Control Voltage Sources

Features

♦ Operates Up To 20V

♦ 800mA Peak Output Current

♦ Settles to Within 0.1% of V

OUT

in Less than 2µs

♦ Excellent Load Regulation

♦ Thermal-Shutdown Protection

♦ Short-Circuit Protection to Both Rails

♦ Soft-Start to Reduce Inrush Current

MAX9550/MAX9551/MAX9552

High-Current VCOM Drive Buffers

for TFT LCDs

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

MAX9550

16V

SUPPLY

IN+

OUT

1µF

TFT-LCD
CAPACITANCE

V

REF

V

DD

TFT LCD

IN-

GND

Typical Operating Circuit

19-3858; Rev 2; 9/06

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 Configuration appears at end of data sheet.

Note: All devices specified over the -40°C to +85°C operating

temperature range.

+Denotes lead-free package.
*EP = Exposed paddle.

PART

AMPS

PIN-PACKAGE

PKG

TOP

MARK

MAX9550EZK+T

1

ADSG

MAX9550EUA+

1 8 µMAX-EP*

AABA

MAX9551EUA+

2 8 µMAX-EP*

—

MAX9552EUD+

4

—

µMAX is a registered trademark of Maxim Integrated Products, Inc.

CODE

5 Thin SOT23-5 Z5-1

U8E-2

U8E-2

14 TSSOP-EP* U14E-3

MAX9550/MAX9551/MAX9552

High-Current VCOM Drive Buffers
for TFT LCDs

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= 16V, GND = 0V, V

CM

= V

OUT

= VDD/ 2, CL= 1µF, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at

T

A

= +25°C.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

Supply Voltage (VDDto GND) ................................-0.3V to +22V

Any Other Pin to GND ................................-0.3V to (V

DD

+ 0.3V)

IN+/IN- (current) ...............................................................±20mA

OUT, OUT_ (current)................................................................1A

Continuous Power Dissipation (T

A

= +70°C)

5-Pin Thin SOT23 (derate 9.5mW/°C above +70°C)....727mW

8-Pin µMAX (derate 10.3mW/°C above +70°C) ........824.7mW

14-Pin TSSOP (derate 20.8mW/°C above +70°C) .....1667mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER

CONDITIONS

TYP MAX

UNITS

DC CHARACTERISTICS

Supply Voltage Range V

DD

Inferred from PSRR test and transient
load test

720V

Quiescent Current I

CC

Per channel 2 4 mA

Low Output Voltage V

OL

IL = -4mA 0.04 0.1 V

High Output Voltage V

OH

IH = +4mA

V

Input Offset Voltage V

OS

+1 +10 mV

Input Bias Current I

B

0.01 1 µA

Input Resistance R

IN

1

MΩ

Common-Mode Input Voltage

CMVR Inferred from CMRR 2

V

Common-Mode Rejection Ratio CMRR 2V ≤ VIN ≤ (VDD - 2V) 80 96 dB

Power-Supply Rejection Ratio PSRR V

OUT

= 3.5V, VDD = 7V to 16V 80 96 dB

Continuous Output Current I

O

VDD = 7V, V

OUT

= 3.5V, guaranteed by

load, regulation test

55 mA

I

OUT

= 0mA to 50mA 6 13

Output Load Regulation LR1

I

OUT

= 0mA to -50mA 6 13

mV

6.5 15

Output Load Regulation LR2

V

DD

= 7V,

V

OUT

= 3.5V

6.5 15

mV

Thermal Shutdown +160 °C

Thermal Hysteresis 15 °C

SYMBOL

MIN

VDD - 0. 0 4 V

-10

I

= 0mA to -55mA

OUT

I

= 0mA to 55mA

OUT

- 0.1

DD

VDD - 2

MAX9550/MAX9551/MAX9552

High-Current VCOM Drive Buffers

for TFT LCDs

_______________________________________________________________________________________ 3

Note 1: All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by design.

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 16V, GND = 0V, V

CM

= V

OUT

= VDD/ 2, CL= 1µF, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at

T

A

= +25°C.) (Note 1)

PARAMETER

CONDITIONS

TYP MAX

UNITS

AC CHARACTERISTICS

Settling Time t

S

Settling to 0.1% of V

OUT

, IL = 0 to 600mA,

C

L

= 1µF, RS = 2.2Ω, CS = 0.1µF

(Figure 1)

2.0 µs

Input Capacitance C

IN

1.5 pF

I

OUT

= ±50mA 13

Transconductance gm

I

OUT

= ±500mA 42

S

VDD = 7V, VIN = 1.5V
pulse for 100µs

±290

Transient Output Current

AV = 1

V

DD

= 16V, VIN = 1.5V

pulse for 100µs

±830

mA

Typical Operating Characteristics

(VDD= 16V, GND = 0V, V

CM

= V

OUT

= VDD/ 2, CL= 1µF, TA = +25°C, unless otherwise noted.)

INPUT OFFSET VOLTAGE DEVIATION

vs. SUPPLY VOLTAGE

VDD (V)

V

OS

(mV)

201510

-0.1

0

0.1

0.2

0.3

0.4

0.5

-0.2
525

MAX9550 toc01

TA = -40°C

TA = +25°C

TA = +85°C

INPUT OFFSET VOLTAGE DEVIATION

vs. TEMPERATURE

MAX9550 toc02

TEMPERATURE (°C)

V

OS

(mV)

7550250-25

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

-0.4

-50 100

TRANSCONDUCTANCE
vs. OUTPUT CURRENT

MAX9550 toc03

OUTPUT CURRENT (mA)

TRANSCONDUCTANCE (S)

4002000-200-400

10

20

30

40

50

60

0

-600 600

TA = -40°C

TA = +25°C

TA = +85°C

SYMBOL

I

OUTMAX

MIN

±200

±600

MAX9550/MAX9551/MAX9552

High-Current VCOM Drive Buffers
for TFT LCDs

4 _______________________________________________________________________________________

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX9550 toc04

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

201510

0.5

1.0

1.5

2.0

2.5

3.0

0

525

TA = +85°C

TA = -40°C

TA = +25°C

SUPPLY CURRENT

vs. TEMPERATURE

MAX9550 toc05

TEMPERATURE (°C)

SUPPLY CURRENT (mA)

7550-25 0 25

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0

-50 100

LOAD TRANSIENT (±600mA)

MAX9550 toc06

2µs/div

I

OUT

500mA/div

V

OUT

50mV/div

AC-COUPLED

RS = 2.2Ω, CL = 1µF, CS = 0.1µF

SHORT-CIRCUIT WAVEFORMS

MAX9550 toc07

5ms/div

V

CC

5V/div

V

OUT

5V/div

I

OUT

200mA/div

I

CC

200mA/div

STARTUP WAVEFORM

MAX9550 toc08

20µs/div

V

OUT

5V/div

IN

+

5V/div

V

CC

10V/div

I

OUT

200mA/div

Typical Operating Characteristics (continued)

(VDD= 16V, GND = 0V, V

CM

= V

OUT

= VDD/ 2, CL= 1µF, TA = +25°C, unless otherwise noted.)