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AS1507

Data Sheet - A p p l i c a t i o n I n f o r m a t i o n

Positive LCD Bias Control

The device can be used in applications where a voltage-divider or variable resistor is used to make an adjustable, pos-

itive LCD-bias voltage, such as for the AS1120 LCD Driver. The op amp provides buffering and gain to the resistor-

divider network made by the potentiometer (Figure 27) or to a fixed resistor and a variable resistor (Figure 28).

Figure 27. Positive LCD Bias Control using a Voltage Divider

Figure 28. Positive LCD Bias Control using a Variable Resistor

Adjustable Voltage Reference

Figure 29 shows the device used as the feedback resistor in an adjustable voltage-reference application. Output volt-

ages of external voltage references, supervisory reset thresholds, or LED brightness control can be independently

adjusted by changing the wiper position of the AS1507.

+

–

5V

HIGH

WIPER

LOW

30V

AS1507

+

–

5V

HIGH

WIPER

LOW

30V

AS1507

5V

HIGHA

WIPERA

LOWA

OUT

ADJ

AS1507

HIGHB

WIPERB

LOWB

OUT

ADJ

AS1507