Analog Devices ADD8701 Datasheet

12-Channel Gamma Buffers

with VCOM Buffer

ADD8701

FEATURES
Single-Supply Operation: 7 V to 16 V
Dual-Supply Operation: 3.5 V to 8 V
Supply Current: 13 mA Max
Upper/Lower Buffers Swing to V

/GND

DD

Continuous Output Current: 10 mA
VCOM Peak Output Current: 250 mA
Offset Voltage: 15 mV Max
Slew Rate: 6 V/s
Fast Settling Time with Large C-Load

APPLICATIONS
TFT LCD Panels

GENERAL DESCRIPTION

The ADD8701 is a low cost, 12-channel buffer amplifier and
VCOM driver that operates from a single supply. The part is
designed for high resolution TFT LCD panels, and is built on
an advanced, high voltage, CBCMOS process.

The buffers have high slew rate, 10 mA continuous output current,
and high capacitive load drive capability. The VCOM buffer has
increased drive of 35 mA and can drive large capacitive loads. The
ADD8701 offers wide supply range and offset voltages below 15 mV.

FUNCTIONAL BLOCK DIAGRAM

OUT

VCOM

GND

V12

V11

V

VCOM IN

IN12

IN11

IN10

IN9

IN8

IN7

32

31

1

DD

2

3

4

5

6

7

8

9

10

IN6

IN5

V10V9V8

30

26

28

11

12

13

IN4

IN3

IN2

V7

27

26

25

24

GND

V

23

DD

22

V6

21

V5

V4

20

19

V3

18

V2

V1

17

14

15

16

DD

IN1

V

GND

The ADD8701 is specified over the –40ºC to +85ºC tempera­ture range and is available in a 32-lead lead frame chip scale
package (LFCSP).

All inputs and outputs incorporate internal ESD protection
circuits.

PAN E L
TIMING

CONTROLLER

TIMING AND CONTROL

SCAN DRIVER CONTROL

SCAN

DRIVERS

768

SOURCE DRIVER

NO. 1

384

R

G

B

SOURCE DRIVER

NO. 2

384

TFT COLOR PANEL

1024 ⴛ 768

Figure 1. Typical SVGA TFT-LCD Application

REV. 0

Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.

V

DD

V12

GAMMA

REFERENCE

VOLTAGES

RESISTOR

SOURCE DRIVER

NO. 8

384

ADD8701

VCOM OUT

V1

VCOM IN

LADDER

GND

V

DD

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2003 Analog Devices, Inc. All rights reserved.

ADD8701–SPECIFICATIONS

ELECTRICAL CHARACTERISTICS

(7 V ≤ VDD ≤ 16 V, TA = 25°C, unless otherwise specified.)

Parameter Symbol Condition Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage V

OS

415 mV

Offset Voltage Drift ∆VOS/∆T –40°C ≤ TA ≤ +85°C 5 µV/°C
Input Bias Current I

B

–40°C ≤ T

≤ +85°C 1.5 µA

A

Input Voltage Range –0.5 V
Input Impedance Z
Input Capacitance C

IN

IN

0.5 1.1 µA

+ 0.5 V

DD

400 kΩ
1pF

OUTPUT CHARACTERISTICS

Output Voltage High (V11, V12) V

Output Swing (V3 to V10) V
Output Swing (V3 to V10) V
Output Voltage Low (V1, V2) V

Continuous Output Current I
Peak Output Current I

OUT

OUT

OUT

OUT

OUT

PK

IL = 100 µA 15.995 V

= 16 V, IL = 5 mA 15.85 15.9 V

V

DD

–40°C ≤ T
V

DD

–40°C ≤ T

≤ +85°C 15.75 V

A

= 7 V, IL = 5 mA 6.75 6.85 V

≤ +85°C 6.65 V

A

IL = 5 mA, VDD = 16 V 14.6 V
IL = 5 mA, VDD = 7 V 5.6 V
IL = 100 µA 5 mV

= 16 V, IL = 5 mA 85 150 mV

V

DD

–40°C ≤ T
V

DD

–40°C ≤ T

≤ +85°C 250 mV

A

= 7 V, IL = 5 mA 140 300 mV

≤ +85°C 400 mV

A

10 mA

VDD = 16 V 150 mA

VCOM CHARACTERISTICS

Continuous Output Current I
Peak Output Current I

OUT

PK

VDD = 16 V 250 mA

35 mA

TRANSFER CHARACTERISTICS

Gain A

VCL

Gain Linearity NL R

RL = 2 kΩ 0.995 0.9985 1.005 V/V
–40°C ≤ T

= 10 kΩ

L

VO = 0.5 to (V

≤ +85°C 0.995 0.9980 1.005 V/V

A

– 0.5 V) 0.01 %

DD

SUPPLY CHARACTERISTICS

Supply Voltage V

DD

Power Supply Rejection Ratio PSRR V

Supply Current I

SYS

= 6 V to 17 V

DD

–40°C ≤ T

≤ +85°C 70 90 dB

A

No Load 10 13 mA

716V

–40°C ≤ TA ≤ +85°C 15 mA

DYNAMIC PERFORMANCE

Slew Rate SR RL = 10 kΩ, CL = 200 pF 4 6 V/µs
Bandwidth BW –3 dB, R
Settling Time to 0.1% (Buffers) t
Settling Time to 0.1% (VCOM) t

S

S

Phase Margin fo R

1 V, RL = 10 kΩ, CL = 200 pF 1.1 µs
1 V, RL = 10 kΩ, CL = 200 pF 0.7 µs

L

= 10 kΩ, CL = 200 pF 4.5 MHz

L

= 10 kΩ, CL = 200 pF 55 Degrees

Channel Separation 75 dB

NOISE PERFORMANCE

Voltage Noise Density e

Current Noise Density i

Specifications subject to change without notice.

n

e

n

n

f = 1 kHz 26 nV/√Hz
f = 10 kHz 25 nV/√Hz
f = 10 kHz 0.8 pA/√Hz

REV. 0–2–

ADD8701

ABSOLUTE MAXIMUM RATINGS*

Supply Voltage (VDD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 V

Input Voltage . . . . . . . . . . . . . . . . . . . . . –0.5 V to V

+ 0.5 V

DD

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

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

Junction Temperature Range . . . . . . . . . . . . . –65°C to +150°C

Lead Temperature Range (Soldering, 60 sec) . . . . . . . . 300°C

ESD Tolerance (HBM) . . . . . . . . . . . . . . . . . . . . . . . ±1,000 V

*Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.

Package Type 

1

JA



2

JB

Unit

32-Lead LFCSP (CP) 35 13 °C/W

NOTES

1

θJA is specified for worst-case conditions, i.e., θ

in circuit board for surface-mount packages.

2

ψJB is applied for calculating the junction temperature by reference to the board

is specified for device soldered

JA

temperature.

ORDERING GUIDE

Model Temperature Package Package

Range Description Option

ADD8701ACP –40°C to +85°C 32-Lead LFCSP CP-32

PIN CONFIGURATION

32 VCOM OUT

31 GND

30 V12

29 V11

28 V10

27 V9

26 V8

25 V7

V

DD

VCOM IN 2

IN12 3
IN11 4
IN10 5

IN9 6
IN8 7
IN7 8

1

PIN 1
INDICATOR

ADD8701

TOP VIEW

IN6 9

IN5 10

IN4 11

IN3 12

IN2 13

24 GND
23 V

DD

22 V6
21 V5
20 V4
19 V3
18 V2
17 V1

15

DD

IN1 14

V

GND 16

PIN FUNCTION DESCRIPTION

Pin No. Mnemonic Description

1, 15, 23 V

DD

Power (+)

2 VCOM IN VCOM Buffer Input

3–14 IN12–IN1 Gamma Buffer Inputs

16, 24, 31 GND Power (–)

17–22, 25–30 V1–V12 Gamma Buffer Outputs

32 VCOM OUT VCOM Buffer Output

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although the
ADD8701 features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended
to avoid performance degradation or loss of functionality.

REV. 0

–3–