ds1666 Maxim Integrated Products, Inc., ds1666 Datasheet - Page 2

• Manufacturer Part Number: ds1666
• Description: Ds1666 ?5v Pseudo Log Audio Digital Potentiometer
• Manufacturer: Maxim Integrated Products, Inc.

The DS1666 is uniquely designed to provide a potentiometer that is pseudo-logarithmic rather than linear
across its entire range. The lower half of the potentiometer advances 1% of total resistance for each 3%
of scale advanced, providing for precise amplification of low volume signals. The upper half of the
potentiometer advances 2% of resistance for every 1% of scale advanced, providing for the lower
resolution gain required for high volume amplification.
GRAPH OF AUDIO TAPER Figure 1
OPERATION
The DS1666 has a total of 128 tap-points including the V
segments exist between the V
whose position is controlled via a 3-terminal control port. A block diagram of the DS1666 is shown in
Figure 2.
The 3-terminal port of the DS1666 provides an increment/ decrement interface which is activated via a
chip select input. This interface consists of the input signals
control a 7-bit up/down counter. The output of the 7-bit up/down counter controls a 1 of 128 decoder to
select wiper position. The timing diagram for the 3-terminal interface control is shown in Figure 4.
ANALOG CHARACTERISTICS
The DS1666 has a pseudo-logarithmic resistor array that resembles an audio taper potentiometer as
shown in Figure 1. Taps on the lower portion of the potentiometer increment 0.25% of the total
resistance and are specified to within ±0.5% of the expected value. Taps on the higher portion increment
1.5% of the total resistance and are specified to within ±2.0% of the expected value.
End-to-End Resistance Tolerance = ±20 %
Temperature Coefficient = 750 PPM/°C typical
L
and V
H
terminals. These tap-points are accessible to the V
2 of 9
L
and V
CS
,
H
INC
terminals. A total of 127 resistive
, and U/
D
. These input signals
W
102899
terminal