FLAT PANEL DISPLAY BUFFERING

Three features of the LM6132/34 make it a superb choice for

TFT LCD applications. First, its low current draw (360 µA per

applications such as in laptop computers. Second, since the

device operates down to 2.7V, it is a natural choice for next

generation 3V TFT panels. Last, but not least, the large ca-

pacitive drive capability of the LM6132 comes in very handy

in driving highly capacitive loads that are characteristic of

LCD display drivers.

The large capacitive drive capability of the LM6132/34 al-

lows it to be used as buffers for the gamma correction refer-

ence voltage inputs of resistor-DAC type column (Source)

drivers in TFT LCD panels. This amplifier is also useful for

buffering only the center reference voltage input of

Capacitor-DAC type column (Source) drivers such as the

LMC750X series.

Since for VGA and SVGA displays, the buffered voltages

must settle within approximately 4 µs, the well known tech-

nique of using a small isolation resistor in series with the am-

plifier’s output very effectively dampens the ringing at the

output.

With its wide supply voltage range of 2.7V to 24V), the

LM6132/34 can be used for a diverse range of applications.

The system designer is thus able to choose a single device

type that serves many sub-circuits in the system, eliminating

the need to specify multiple devices in the bill of materials.

Along with its sister parts, the LM6142 and LM6152 that

have the same wide supply voltage capability, choice of the

LM6132 in a design eliminates the need to search for mul-

tiple sources for new designs.

DS012349-44

FIGURE 7.

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