CAT5133ZI-10-GT3 Datasheet, PDF (3/10 Pages) ON Semiconductor – 16 Volt Digitally Programmable Potentiometer with 128 Taps and an Increment Decrement Interface

CAT5133
POWER-ON AND POTENTIOMETER CHARACTERISTICS
The CAT5133 is a 128-position, digital controlled
potentiometer. When applying power to the CAT5133,
V_CC must be supplied prior to or simultaneously with
V+. At the same time, the signals on R_H, R_W and R_L
terminals should not exceed V+. If V+ is applied before
V_CC, the electronic switches of the DPP are powered in
the absence of the switch control signals, that could
result in multiple switches being turned on. This
causes unexpected wiper settings and possible current
overload of the potentiometer.
When V_CC is applied, the device turns on at the mid-
point wiper location (64) until the wiper register can be
loaded with the nonvolatile memory location
previously stored in the device. After the nonvolatile
memory data is loaded into the wiper register the
wiper location will change to the previously stored
wiper position.
At power-down, it is recommended to turn-off first the
signals on R_H, R_W and R_L, followed by V+ and, after
that, V_CC, in order to avoid unexpected transitions of
the wiper and uncontrolled current overload of the
potentiometer.
The end-to-end nominal resistance of the potentio-
meter has 128 contact points linearly distributed
across the total resistor. Each of these contact points
is addressed by the 7 bit wiper register which is
decoded to select one of these 128 contact points.
Each contact point generates a linear resistive value
between the 0 position and the 127 position. These
values can be determined by dividing the end-to-end
value of the potentiometer by 127. The 10kΩ
potentiometer has a resistance of ~79Ω between each
wiper position. However in addition to the ~79Ω for
each resistive segment of the potentiometer, a wiper
resistance offset must be considered. Table 8 shows
the effect of this value and how it would appear on the
wiper terminal.
This offset will appear in each of the CAT5133 end-to-
end resistance values in the same way as the 10kΩ
example. However resistance between each wiper
position for the 50kΩ version will be ~395Ω and for
the100kΩ version will be ~790Ω.
Potentiometer Resistance and Wiper Resistance Offset Effects
Position
0
01
63
127
Typical R_W to R_L Resistance
for 10kΩ DPP
70Ω or
0Ω + 70Ω
149Ω or
79Ω + 70Ω
5,047Ω or 4,977Ω + 70Ω
10,070Ω or 10,000Ω + 70Ω
Position
00
64
126
127
Typical R_W to R_H Resistance
for 10kΩ DPP
10,070Ω or 10,000Ω + 70Ω
5,047Ω or 4,977Ω + 70Ω
149Ω or
79Ω + 70Ω
70Ω or
0Ω + 70Ω
ABSOLUTE MAXIMUM RATINGS⁽¹⁾
Parameters
Temperature Under Bias
Storage Temperature
Voltage on any U/D¯, I¯N¯C¯,& ¯C¯S¯ Pins with Respect to V_CC(2)
Voltage on R_H, R_L, & R_W Pins with Respect to V_CC
V_CC with Respect to Ground
V+ with respect to Ground
Wiper Current
Lead Soldering temperature (10 seconds)
Ratings
-55 to +125
-65 to +150
-0.3 to +V_CC+0.3
V+
-0.3 to +6.0
-0.3 to +16.5
±6
+300
Units
°C
°C
V
V
V
V
mA
°C
Notes:
(1) Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions outside of those listed in the operational sections of this
specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability.
(2) Latch-up protection is provided for stresses up to 100mA on the digital from -0.3V to V_CC +0.3V.
© 2008 SCILLC. All rights reserved.
3
Characteristics subject to change without notice
Doc. No. MD-2125 Rev. D