LM8342SDX/NOPB National Semiconductor, LM8342SDX/NOPB Datasheet

IC PROG TFT CALIBRATOR 10-LLP

LM8342SDX/NOPB

Manufacturer Part Number
LM8342SDX/NOPB
Description
IC PROG TFT CALIBRATOR 10-LLP
Manufacturer
National Semiconductor
Datasheet

Specifications of LM8342SDX/NOPB

Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
LM8342SDX
© 2008 National Semiconductor Corporation
LM8342
Programmable TFT V
Memory
General Description
The LM8342 is an integrated combination of a non-volatile
register (7 bits EEPROM) and a DAC controlled current
source. Using the LM8342, the V
simplified by elimination of the potentiometer adjustment task.
This adjustment task is currently performed at the factory us-
ing a trimmer adjustment tool and visual inspection.
The V
tion, using the I
can physically view the screen head-on (frontal viewing) when
performing this step, easing manufacturing especially for
large TFT panels.
The V
and R2) and is buffered by the actual V
trolling the level of I
current level at the output of the LM8342 is a fraction (1/128
to 128/128) of a maximum current which is set by R
an analog reference (AV
by the 7-bit DAC. As a result, the output current of the LM8342
has a good temperature stability yielding a very stable V
adjustment. Controlling the DAC setting of the LM8342 is
done via its I
is stored in a volatile register. Using a “Write to EE” command
the data can be stored permanently in the embedded EEP-
ROM. At power on of the device, the EEPROM data is copied
to the volatile register, setting the DAC. At any time, the data
in the EEPROM can be changed again via the I
interface.
Typical Application
COM
COM
adjustment can be done electronically in produc-
level is typically at half AV
2
C compatible interface. The actual DAC setting
2
C compatible interface. The factory operator
OUT
, the V
DD
). The actual fraction is determined
COM
COM
level can be tuned. The
calibration procedure is
DD
201392
COM
(determined by R1
driver. By con-
COM
2
C compatible
SET
Calibrator with Non-Volatile
and
COM
Features
Applications
I
current
Guaranteed monotonic DAC
Non-volatile memory to hold the setting
EEPROM in system programmable
No external programming voltage required
Maximum interface bus speed is 400 kHz
LLP-10 Package
TFT panel factory calibration
Digital potentiometer
Programmable current sink
2
C compatible programmable DAC to set the output
20139201
www.national.com
May 13, 2008

Related parts for LM8342SDX/NOPB

LM8342SDX/NOPB Summary of contents

Page 1

... EEP- ROM. At power on of the device, the EEPROM data is copied to the volatile register, setting the DAC. At any time, the data in the EEPROM can be changed again via the I interface. Typical Application © 2008 National Semiconductor Corporation Calibrator with Non-Volatile COM Features ■ I ...

Page 2

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ESD Tolerance (Note 2) Human Body Model Machine Model Supply and Reference Voltage Storage Temperature Range Electrical Characteristics Unless otherwise specified, all limits are guaranteed for T Boldface limits apply at the temperature extremes ...

Page 3

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and test conditions, ...

Page 4

Ordering Information Package Part Number LM8342SD 10-Pin LLP LM8342SDX Block Diagram Typical Performance Characteristics 25° 3V 15V vs www.national.com Package Marking L8342 = 1/2 AV and ...

Page 5

AV Startup (Full Scale) DD 20139220 I vs. R OUT SET 20139216 I Current Step Negative (Full Scale) OUT 20139207 V Startup (Full Scale vs. R OUT SET I Current Step Positive (Full Scale) OUT 5 20139219 20139215 ...

Page 6

I vs. V OUT Gain & Offset Change vs Error vs. V OUT www.national.com OUT 20139217 OUT 20139222 DD 20139210 6 I Error vs. V OUT OUT Differential Non-Linearity Error vs. DAC (V = 18V) OUT I Error ...

Page 7

I Error vs. Temperature OUT 20139213 Integral Non-Linearity Error vs. DAC 20139212 R vs. SCL-S Voltage ON 20139225 Total Unadjusted Error vs. DAC Differential Non-Linearity Error vs. DAC 7 20139209 20139211 www.national.com ...

Page 8

Application Section INTRODUCTION The LM8342 is an integrated combination of a digitally con- trolled current sink and a non-volatile register (7 bits EEP- ROM). Programming the register can be done using the I compatible interface. The LM8342 replaces the potentiometer ...

Page 9

Figure 3 shows a block diagram of a TFT panel. The V buffer supplies a common voltage (V COM TFT panel. In general voltage that is in the COM middle of the gamma voltage range. Screen ...

Page 10

The maximum output current of the LM8342 can be defined using an external resistor R in combination with an analog SET reference voltage AV . This maximum current can be cal- DD culated using Equation 1. The operating range for ...

Page 11

The timing diagram shows the major aspect of the communi- cation protocol and represents a typical data stream. In case a master wants to setup a data transfer, it tests if “the bus is busy.” not busy, ...

Page 12

TABLE 3. P-bit Truth Table Operation P-bit Read 1 Read 0 (don’t turn off the device) Write 1 Write 0 The LM8342 can be used compatible systems with clock speeds 400 kbps (Fast ...

Page 13

The voltage level of the V driver, for a general setting of COM (DAC ) , is calculated using Equation 4. 10 For calibrating the V level (see Figure 8) the tuning range COM of the design needs to be ...

Page 14

TABLE 4. Overview Resistor Values for Different R Settings 15V (V Level = 7 COM kΩ SET ΔV Δ COM (Ω) (Ω) (V) ±0.5 25k 28.6k ±0.5 ±1 ...

Page 15

Physical Dimensions inches (millimeters) unless otherwise noted 10-Pin LLP NS Package Number SDA10A 15 www.national.com ...

Page 16

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