18-Channel Gamma Buffer
www.BDTIC.com/ADI
FEATURES
18 precision gamma reference outputs
Mask-programmable voltage regulator: 0.4% accuracy
Upper 9 buffers swing to VDD
Lower 9 buffers swing to GND
Single-supply operation: 7.5 V to 16.5 V
Gamma current drive: 15 mA per channel
Peak output current: 150 mA
Output voltage stable under load conditions
48-lead, Pb-free LQFP package
APPLICATIONS
LCD TV panels
LCD monitor panels
GENERAL DESCRIPTION
The ADD8709 is an 18-channel integrated gamma reference for
use in LCD TV and monitors panels. The output buffers feature
high current drive and low offset voltage to provide an accurate
and stable gamma curve. The top nine channels swing to V
and the lower nine channels swing to GND.
An on-board voltage regulator provides a fixed input for the
gamma buffers, isolating the gamma curve from supply ripple.
The ADD8709 is specified over the temperature range of
–40°C to +105°C and comes in a 48-lead, Pb-free, low-profile
quad flat package.
DD
V
REG OUT
with Regulator
FUNCTIONAL BLOCK DIAGRAM
V
GND
DD
700Ω*
FB
V
18
IN
17
V
IN
16
V
IN
15
V
IN
V
14
IN
V
13
IN
V
12
IN
V
11
IN
V
10
IN
V
9
IN
V
8
IN
V
7
IN
V
6
IN
V
5
IN
V
4
IN
V
3
IN
V
2
IN
V
1
IN
VOLTAGE
REGULATOR
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
700Ω*
ADD8709
VDDV
DD
GAMMA
BUFFERS
V
18
OUT
V
17
OUT
V
16
OUT
V
15
OUT
V
14
OUT
V
13
OUT
V
12
OUT
V
11
OUT
V
10
OUT
V
9
OUT
V
8
OUT
V
7
OUT
V
6
OUT
V
5
OUT
V
4
OUT
V
3
OUT
V
2
OUT
V
1
OUT
Rev. A
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.
Specifications subject to change without notice. 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 owners.
*ESD PROTECTION RESISTORS
GND GND
Figure 1. 48-Lead LQFP
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 www.analog.com
Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved.
04715-001
ADD8709
www.BDTIC.com/ADI
TABLE OF CONTENTS
Electrical Characteristics................................................................. 3
Absolute Maximum Ratings............................................................ 4
ESD Caution.................................................................................. 4
Pin Configuration and Function Descriptions............................. 5
Typical Performance Characteristics ............................................. 7
Application Notes ........................................................................... 10
Volt a ge R e gu l ator ....................................................................... 10
Maximum Power Dissipation ................................................... 10
Operating Temperature Range .................................................10
Typical Applications C i r c uit.......................................................... 12
Outline Dimensions ....................................................................... 13
Ordering Guide........................................................................... 13
REVISION HISTORY
10/04—Data Sheet Changed from Rev. 0 to Rev. A
Changes to Product Overview Section .......................................... 1
Changes to Figure 1.......................................................................... 1
Changes to Electrical Characteristics Section .............................. 3
Changes to Absolute Maximum Ratings Section......................... 4
Changes to Pin Configuration and Function Description.......... 5
Changes to Typical Performance Characteristics Section........... 7
Changes to Applications Notes Section....................................... 10
Changes to Figure 28, Typical Applications Circuit...................12
Changes to Ordering Guide.......................................................... 13
8/04—Revision 0: Initial Version
Rev. A | Page 2 of 16
ADD8709
www.BDTIC.com/ADI
ELECTRICAL CHARACTERISTICS
VDD = 16 V, TA @ 25°C, unless otherwise noted.
Table 1.
Parameter Symbol Conditions Min Typ Max Unit
BUFFER CHARACTERISTICS
OUTPUTS
Output Voltage Range (Ch18 to Ch10) V
Output Voltage Range (Ch9 to Ch1) V
Output vs. Load (Ch18, Ch17, Ch2, Ch1) ∆V
Output vs. Load (Ch16 to Ch3) ∆V
OUT
OUT
OUT
OUT
INPUTS
Offset Voltage V
OS
Offset Voltage Drift ∆VOS/∆T
Input Bias Current I
Input Voltage Range (Ch18 to Ch10) V
Input Voltage Range (Ch9 to Ch1) V
B
IN
IN
DYNAMIC PERFORMANCE
Slew Rate SR RL = 10 kΩ, CL = 200 pF 4 6 V/µs
Bandwidth BW –3 dB, RL = 10 kΩ, CL = 200 pF 4.5 MHz
Settling Time to 0.1% t
Phase Margin Ф
S
o
Power Supply Rejection Ratio PSRR VDD = 7 V to 17 V, −40°C ≤ TA ≤ +105°C 68 90 dB
VOLTAGE REGULATOR
Programmable Range V
Initial Regulator Accuracy V
Dropout Voltage V
REG OUT
ACC
DO
I
Line Regulation REG
Load Regulation REG
Maximum Load Current I
Feedback Reference Voltage V
Feedback Input Bias Current I
LINE
LOADIO
O
REF
BFB
POWER SUPPLY
Supply Voltage V
Supply Current I
S
SY
1
∆V
is the shift from the desired output voltage under the specified current load.
OUT
IL = 100 µA 1.4 V
IL = 100 µA 0
1
IL = 20 mA 15 mV
1
IL = 5 mA 5 mV
DD
V
DD
− 1.4
V
V
5 15 mV
−40°C ≤ TA ≤ +105°C
20 µV/°C
−40°C ≤ TA ≤ +105°C 0.5 1.5 µA
1.4 V
0
DD
VDD − 1.4
V
V
1 V step, RL = 10 kΩ, CL = 200 pF 1.1 µs
RL = 10 kΩ, CL = 200 pF 55 Degrees
5
No load; V
= 14.4 V 0.4 1.5 %
REG OUT
VDD − 0.6
V
IL = 100 µA 100 150 mV
= 5 mA 310 350 mV
L
VIN = 8.5 V to 16.5 V, V
= 8 V 0.01 0.20 %/V
OUT
= 100 µA to 10 mA 0.02 0.10 %/mA
−40°C ≤ TA ≤ +105°C 5 mA
1.2 V
−40°C ≤ TA ≤ +105°C −150 10 150 nA
7.5 16.5 V
No load, −40°C ≤ TA ≤ +105°C 10.5 17 mA
Rev. A | Page 3 of 16
ADD8709
www.BDTIC.com/ADI
ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter Rating
Supply Voltage (VDD) 18 V
Input Voltage –0.5 V to V
Storage Temperature Range –65°C to +150°C
Operating Temperature Range
Junction Temperature Range –65°C to +150°C
Lead Temperature Range (Soldering, 60 sec) 300°C
ESD Tolerance (HBM) ±2000 V
ESD Tolerance (MM) ±150 V
Table 3. Package Characteristics
Package Type θ
LQFP (ST) 74.57 °C/W
1
See section. Application Notes
1
JA
−40°C to +105°C
Unit
DD
Stresses above those listed under Absolute Maximum Ratings
may cause permanent 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.
ESD 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 this product 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. A | Page 4 of 16
ADD8709
www.BDTIC.com/ADI
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
18
17
16
15
14
48 47 46 45 44 43 42 41 40 39 38 37
1
REG
FB
GND
2
3
V
DD
V
REG OUT
VIN18
V
IN
V
IN
V
IN
V
IN
V
IN
V
IN
V
IN
4
5
17
6
16
7
15
8
14
9
13
10
12
11
11
12
13 14 15 16 17 18 19 20 21 22 23 24
Figure 2. 48-Lead Low-Profile Quad Flat Package (ST-48)
Table 4. Pin Function Descriptions
Pin No. Name Description
1 REG
FB
Regulator feedback. Compares a percentage of the regulator output to the internal 1.2 V voltage
reference.
2 GND Ground. Normally 0 V.
3 V
DD
4 REG
OUT
Supply voltage. Normally 16 V.
Regulator output voltage. Provides a regulated output voltage for use as a reference for the gamma
resistors.
5 VIN18
6 VIN17
7 VIN16
8 VIN15
9 VIN14
10 VIN13
11 VIN12
12 VIN11
13 VIN10
14 VIN9
Buffer inputs. An external resistor calculator is available upon request from your local sales office.
15 VIN8
16 VIN7
17 VIN6
18 VIN5
19 VIN4
20 VIN3
21 VIN2
22 VIN1
23 GND Ground. Normally 0 V.
24 V
25 V
26 V
DD
OUT
OUT
1
2
Supply voltage. Normally 16 V.
Buffer outputs. These buffers can swing to ground.
VDDGND
9
10
IN
IN
V
V
8
V
OUT
IN
OUT
OUT
V
V
ADD8709
TOP VIEW
(Not to Scale)
7
6
IN
IN
V
V
V
5
V
OUT
IN
V
4
V
OUT
IN
13
V
3
V
OUT
IN
12
11
DD
OUT
OUT
GND
V
V
2
IN
V
V
36
V
10
OUT
9
35
V
OUT
8
34
V
OUT
7
33
V
OUT
32
V
DD
GND
31
6
V
30
OUT
5
V
29
OUT
4
V
28
OUT
3
V
27
OUT
2
V
26
OUT
1
V
25
OUT
1
DD
IN
V
V
GND
04715-002
Rev. A | Page 5 of 16