Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsData collecting ICsData acquisition IC - Digital potentiometer logarithmic Non-permanent PDIP 20

1 of 17 051401

FEATURES

§ Ultra-low power consumption

§ Operates from 3V or 5V supplies

§ Two digitally controlled, 65-position

potentiometers including mute

§ Logarithmic resistive characteristics (1 dB

per step)

§ Zero-crossing detection eliminates noise

caused by wiper movement

§ Digital or mechanical pushbutton wiper

control

§ Serial port provides means for setting and

reading both potentiometers wipers

§ 20-pin SOIC and 20-pin TSSOP for surface

mount applications

§ Operating Temperature Range:

-40°C to +85°C

§ Software and hardware mute

§ Resistance Available: 45 kΩ

PIN ASSIGNMENT

PIN DESCRIPTION

L0, L1 - Low End of Resistor

H0, H1 - High End of Resistor

W1,W2 - Wiper End of Resistor

- 3V/5V Power Supply Input

RST - Serial Port Reset Input

D - Serial Port Data Input

CLK - Serial Port Clock Input

MODE - Mode Select Input

UC0, UC1 - Up Control Pushbutton Inputs

DC0, DC1 - Down Control Pushbutton

Inputs

VU, VD - Volume-Up/Volume-Down

Inputs

B0, B1 - Balance Pot-0, Pot-1 Inputs

GND - Digital Ground

MUTE - Mute

AGND - Analog Ground

ZCEN - Zero-Crossing Detect Input

OUT

- Cascade Output

DS1802

Dual Audio Taper Potentiometer

With Pushbutton Control

www.dalsemi.com

GND 1 20 VCC

COUT 2 19 VU (UC1)

CLK 3 18 VD (DC1)

D 4 17 B0 (UC0)

RST 5 16 B1 (DC0)

ZCEN 6 15 MUTE

MODE 7 14 AGND

W0 8 13 H1

L0 9 12 L1

H0 10 11 W1

20-Pin DIP (300-mil)

20-Pin SOIC (300-mil)

20-Pin TSSOP (173-mil)

See Mech. Drawings Section

Summary of content (17 pages)

PAGE 1
DS1802 Dual Audio Taper Potentiometer With Pushbutton Control www.dalsemi.
PAGE 2
DS1802 DESCRIPTION The DS1802 is a dual audio taper-potentiometer having logarithmic resistive characteristics over the device range. Each potentiometer provides 65 wiper positions with a 1 dB increment per step and device mute. The DS1802 has two methods of device control, which include contact closure (pushbutton) inputs and a 3-wire serial interface for wiper positioning. The pushbutton control inputs provide a simple interface for device control without the need for a CPU.
PAGE 3
DS1802 DS1802 BLOCK DIAGRAM Figure 1 CONTACT CLOSURE INTERFACE CONTROL The DS1802 can be configured to operate from contact closure inputs sometimes referred to as pushbutton control. There exists a total of four physical contact closure terminals on the device package. When combined with the MODE input, these contact closure inputs provide a total of eight different contact closure functions. These eight contact closure functions are listed in Table 2.
PAGE 4
DS1802 Independent mode control allows the user to independently control each potentiometer's wiper position. For independent mode control, the MODE input should be in a high state. For stereo mode control, the MODE input should be in a low state. The input should always be tied to a well-defined logic state. The contact closure inputs which affect independent mode control include UC0, UC1, DC0, and DC1.
PAGE 5
DS1802 SINGLE PUSHBUTTON CONFIGURATION Figure 2(a) DUAL PUSHBUTTON CONFIGURATION Figure 2(b) Contact closure is defined as the transition from a high level to a low level on the contact closure input terminals. The DS1802 interprets input pulse widths as the means of controlling wiper movement. A single pulse input over the UCx or DCx input terminals will cause the wiper to move one position. A transition from high to low on these inputs is considered the beginning of pulse activity or contact closure.
PAGE 6
DS1802 Pulse inputs lasting longer than 1 second will cause the wiper to move one position every 100 ms following the initial 1 second hold time. The total time to transcend the entire potentiometer using a continuous input pulse is given by the formula below: 1 (second) + 63 X 100 ms =7.3 (seconds) Single Contact Closure Single contact closure operation allows the user to control wiper movement in either direction from a single pushbutton input.
PAGE 7
DS1802 DS1802 BALANCING EXAMPLE Figure 3 CONTACT CLOSURE TIMING (UC, DC) Figure 4 Dual Contact Closure In dual pushbutton mode, each direction is controlled by the respective cont rol inputs. No wait states are required to change wiper direction, balance, or volume in dual pushbutton mode. Additionally, in dual pushbutton mode as the wiper position reaches the end of the potentiometer, the direction of wiper movement will not change.
PAGE 8
DS1802 All contact closure control inputs, UC0, UC1, DC0, DC1, VU, VD, B0 and B1 are internally pulled up by a 50 kO resistance. The UC0, UC1, DC0 DC1, VU, VD, B0, and B1 inputs are internally debounced and require no external components for input signal conditioning. 3-WIRE SERIAL INTERFACE CONTROL One method of communication and control of the DS1802 is accomplished through a 3-wire serial port interface that drives an internal control logic unit.
PAGE 9
DS1802 16-BIT I/O SHIFT REGISTER Figure 5 TIMING DIAGRAMS Figure 6 9 of 17
PAGE 10
DS1802 CASCADE OPERATION A feature of the DS1802 is the ability to control multiple devices from a single processor. Multiple DS1802s can be linked or daisy-chained as shown in Figure 7. As a bit is entered in to the I/O shift registeroftheDS1802 it will appear at the COUT out put after a maximum delay of 50 nanoseconds. The COUT output of the DS1802 can be used to drive the D input of another DS1802.
PAGE 11
DS1802 time window. Subsequent changes when operating with continuous input pulse occur on 100 ms time intervals and are dependent on zero-crossing or 50 ms timeouts. MUTE CONTROL The DS1802 provides a mute control feature which can be accessed by the user through hardware or software. Hardware control of the device is achieved through the MUTE input pin. This pin is internally pulled up through a 50 kΩ resistor.
PAGE 12
DS1802 TYPICAL SUPPLY CURRENT VS.
PAGE 13
DS1802 ABSOLUTE MAXIMUM RATINGS* Voltage on Any Pin Relative to Ground Operating Temperature Storage Temperature Soldering Temperature -0.7V to +7.0V -40° to +85°C -55°C to +125°C See J-STD-020A Specification * This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.
PAGE 14
DS1802 ANALOG RESISTOR CHARACTERISTICS PARAMETER SYMBOL MAX UNITS NOTES +20 +1 % dB 17 Absolute Tolerance -20 -1 Inter-channel Matching -0.5 +0.5 dB 6 Tap-to-Tap Tolerance -0.25 +0.25 dB 7,16 End to End Resistor Tolerance -3 dB Cutoff Frequency MIN (-40°C to +85°C;V CC=2.7V to 5.
PAGE 15
DS1802 AC ELECTRICAL CHARACTERISTICS PARAMETER (-40°C to +85°C; VCC=2.7V to 5.
PAGE 16
DS1802 7. Tap-to-tap tolerance is used to determine the change in voltage between successive tap positions. The DS1802 is specified for ±0.25 dB tap-to-tap tolerance. 8. Typical values are for tA =25°C and no minal supply voltage. 9. Power-up time is the time for all pushbutton inputs to be stable and active once power has reached a valid level, 2.7V min. 10. See Figure 6. 11. Absolute tolerance is used to determine measured wiper voltage vs. expected wiper voltage as determined by wiper position.
PAGE 17
DS1802 INTERNAL GROUND CONNECTIONS Figure 10 NOTE: GND and AGND must be tied to the same voltage level.