Datasheet MAX5160 (Maxim) - 6

Low-Power Digital Potentiometers Alternative Positive Adjustable Gain LCD Bias Control
Figure 5 shows how to use the MAX5161 to digitally Alternatively, use an op amp to provide buffering and adjust the gain of a noninverting op amp configuration. gain to the output of the MAX5160/MAX5161. Connect Connect the MAX5161 in series with a resistor to ground the MAX5160 to the positive input of a noninverting op to form the adjustable gain control of a noninverting amp (Figure 3) to select a portion of the input signal by amplifier. The MAX5160/MAX5161 have a low 5ppm/°C digitally controlling the wiper terminal. Figure 4 shows a ratiometric tempco that allows for a very stable adjust- similar circuit for the MAX5161. able gain configuration over temperature.
Serial Interface
Figure 6 is the serial-interface timing diagram. +5V +5V +5V +5V H MAX5161 H MAX5160 INC 30V
MAX5160/MAX5161
30V INC VDD U/D U/D W CS V VDD VOUT GND OUT GND L L GAIN 6 GAIN 6 Figure 3. MAX5160 Positive LCD Bias Control Figure 4. MAX5161 Positive LCD Bias Control VCC VCC VIN VIN VOUT VOUT +5V H INC W U/D L H MAX5161 VDD GND L MAX5160
a) b)
Figure 5. Adjustable Gain Circuit: a) MAX5161; b) MAX5160
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