CAT5133ZI-10-GT3 ON Semiconductor

CAT5133 16 Volt Digital Potentiometer (POT) with 128 Taps and an Increment Decrement Interface Description CAT5133 V V+ CC UP/DOWN (U/D) 127 R H Increment Control Logic and Address Decode (INC) Device Select (CS) 128 Tap Position Decode Control 7 Bit 7Bit Wiper Nonvolatile Control Memory Register Register (WCR) (DR) 0 R L R W Figure 1. Block Diagram Table 1. PIN DESCRIPTIONS Pin Name Function 1 U/D Up/Down Data Input Determines the direction of movement of the wiper 2 GND Ground 3 V Logic Supply Voltage (2.7 V to 5.5 V) CC 4 CS Chip Select The chip is selected when the input is low. 5 N/C No Connect 6 R High Reference Terminal for the Potentiometer H 7 R Wiper Terminal for the Potentiometer W 8 R Low Reference Terminal for the Potentiometer L 9 V Analog Bias Voltage Input (+8.0 V to +16.0 V) + 10 INC Increment Input Moves the wiper in the direction determined by the Up/Down input on each negative edge Device Operation The CAT5133 operates like a digitally controlled (depending on the state of the U/D input and 7-bit counter). potentiometer with R and R equivalent to the high and low The wiper, when at either fixed terminal, acts like its H L terminals and R equivalent to the mechanical mechanical equivalent and does not move beyond the last W potentiometers wiper. There are 128 available tap positions position. The value of the counter is stored in nonvolatile including the resistor end points, R and R . There are 127 memory whenever CS transitions HIGH while the INC input H L resistor elements connected in series between the R and R is also HIGH. When the CAT5133 is powered-down the last H L terminals. The wiper terminal is connected to one of the 128 stored wiper counter position is maintained in the taps and controlled by three inputs, INC, U/D and CS. These nonvolatile memory. When power is restored, the contents inputs control a 7-bit up/down counter whose output is of the memory are recalled and the counter is set to the value decoded to select the wiper position. The selected wiper stored. position can be stored in nonvolatile memory using the INC With INC set low, the CAT5133 may be de-selected and and CS inputs. powered down without storing the current wiper position in With CS set LOW the CAT5133 is selected and will nonvolatile memory. This allows the system to always respond to the U/D and INC inputs. HIGH to LOW power up to a preset value stored in nonvolatile memory. transitions on INC will increment or decrement the wiper