LMC6009 Datasheet, PDF (5/7 Pages) National Semiconductor (TI) – 9 Channel Buffer Amplifier for TFT-LCD

Block Diagram
FIGURE 6. Block Diagram of LMC6009
DS012533-8
Applications
The LMC6009 is useful for buffering the nine reference volt-
ages for gamma correction in a TFT-LCD as shown in
Figure 7. The A/B channel inputs allow the user to alternate
two sets of gamma references to compensate for asymmetri-
cal Gamma characteristic during Row Inversion. The
LMC6009 eliminates the need for nine external switches or
an 18-to-9 multiplexer.
Since the buffers in the LMC6009 draw extremely low bias
current (1.5 µA max), large resistance values can be used in
the reference voltage string. This allows the power dissipa-
tion in the gamma reference circuit to be minimized. The
nine buffers are guaranteed to deliver 80 mA to the load, al-
lowing the pixel voltages of the TFT-LCD to settle very
quickly.
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