DS1809-100

DS1809 Dallastat FEATURES        PIN ASSIGNMENT 64-Position Linear Taper Two Nonvolatile Wiper Storage Options Operates from +4.5V to +5.5V Supplies Operating Temperature Range: - Industrial: -40°C to +85°C Electronic Interface Provides Either Digital or Pushbutton Control Low-Cost Alternative to Mechanical Solutions Standard Resistance Values - DS1809-010 10kΩ - DS1809-050 50kΩ - DS1809-100 100kΩ RH 1 8 VCC UC 2 7 DC STR 3 6 RW RL 4 5 GND PDIP (300 mils) SO (150 mils) μSOP (118 mils) PIN DESCRIPTION VCC RH RL RW UC DC STR GND - Supply Voltage High End of Resistor Low End of Resistor Wiper Terminal Up Control Input Down Control Input Storage Enable Input Ground DESCRIPTION The DS1809 Dallastat is a nonvolatile digitally controlled potentiometer that provides 64 uniform wiper positions over the entire resistor range; including the high-end and low-end terminals of the device. The DS1809 is a low-power device capable of operating from power supplies of +4.5V to +5.5V. The device is ideal for low-power, portable, or battery powered applications. Wiper position is maintained in the absence of power. This is accomplished via the use of an EEPROM cell array. The device provides for two storage methods, which include an autostore capability and a command-initiated storage function. The EEPROM cell array is specified to accept greater than 50k writes. Storage of the wiper position is discussed in the Wiper Storage section of this data sheet. Wiper positioning is controlled via a dual pushbutton (or contact closure) interface. For simple pushbutton-controlled applications or CPU-generated control signals, external debounce circuitry is not needed. The control interface will support both repetitive pulse inputs and continuous pulse (“push-andhold”) inputs. Repetitive pulse and continuous pulse control as well as timing diagrams are discussed in the Operation. The DS1809 is available in standard 10 kΩ, 50 kΩ, and 100 kΩ resistor versions. The DS1809 is provided as an industrial temperature grade part only. Available packaging for the DS1809 include an 8lead (300-mil) PDIP, an 8-lead (150-mil) SO, and an 8-lead (118-mil) µSOP. 1 of 10 19-7387; Rev 4/14 DS1809 BLOCK DIAGRAM Figure 1 OPERATION The DS1809 Dallastat is a digitally controlled, nonvolatile potentiometer. A block diagram of the DS1809 is shown in Figure 1. The DS1809 is a linear potentiometer providing 64-uniform wiper positions over the entire resistor range including the end-terminals. All three potentiometer terminals of the device are accessible. These terminals include RH, RL, and RW. RH and RL are the end-terminals of the potentiometer. These terminals will have a constant resistance between them as defined by the potentiometer value chosen: 10kΩ, 50kΩ, or the 100kΩ version. Functionally, RH and RL are interchangeable. The wiper terminal, RW, is the multiplexed terminal and can be set to one of the 64 total positions that exist on the resistor ladder including the RH and RL terminals. Control of the wiper (RW) position setting is accomplished via the two inputs UC and DC. The UC and DC control inputs, when active, determine the direction on the resistor array that the wiper position will move. The UC (up control) control input is used to move the wiper position towards the RH terminal. The DC (down control) control input is used to move wiper position towards the RL terminal. The control inputs UC and DC are active low inputs that interpret input pulse widths as the means of controlling wiper movement. Internally, these inputs are pulled up to VCC via a 100kΩ resistance. A transition from a high-to-low on these inputs is considered the beginning of pulse input activity. A single pulse on the UC or DC input is defined as being greater than 1 millisecond but lasting no longer that ½ second. This type pulse input will cause the wiper position of the Dallastat to move one position. Multiple pulse inputs (repetitive pulse inputs) can be used to step through each wiper position of the device. The requirement for a repetitive pulse train on the UC or DC inputs is that pulses must be separated by a minimum high time of 1ms. If this is not the case the Dallastat will ignore that pulse input. A continuous pulse input (“push and hold”) is defined as lasting longer that one-half second. A continuous pulse input will cause the wiper position to move one position every 100 milliseconds following the initial one-half-second hold time. The total time to transcend the entire potentiometer given a continuous pulse input is provided by the equation: 2 of 10 DS1809 1/2(second) + 62 x 100ms = 6.7 (seconds) If the wiper position of the DS1809 is incremented to an end-position, it will stay at that position until the device receives an opposite direction input pulse command over the UC or DC inputs. For example, if the wiper position is incremented to the RH terminal using the UC input control, it will stay at that position until UC is first deactivated, and then the DC input is activated to move the wiper position towards the RL terminal. The UC and DC control inputs are designed to support simple pushbutton inputs or CPU generated inputs. Figure 2 illustrates the requirements for pushbutton generated controls. For manual pushbutton controls, all that is required are the desired pushbuttons to implement contact closure. No external debounce or timing circuitry is needed to support the pushbutton operation. Applications using CPU generated controls must power the UC and DC control pins in a high state to avoid any inadvertent wiper position movement. To help prevent inadvertent wiper position movement during a power-up, the DS1809 locks out the control port inputs for a minimum time of 10 ms. WIPER STORAGE As stated earlier, the DS1809 provides for two methods of nonvolatile wiper storage using internal EEPROM memory cells. These two methods include an autostore configuration and a command initiated storage operation, both of which utilize the STR input pin. The EEPROM cell array of the DS1809 is designed to accept greater than 50k writes. AUTOSTORAGE The autostore configuration is designed to provide wiper position storage as the part powers down; writing the current wiper position into memory. The configuration for initiating the automatic storage capability of the DS1809 is shown in Figure 3. As shown in this configuration, two external devices are required to insure proper wiper storage. This includes a Schottky diode and a 10-uf capacitor. The automatic store configuration will cause the DS1809 to initiate storage of wiper position when power (VCC) to the device is removed. The 10-uF capacitor and Schottky diode are used to provide supplemental power for wiper storage. COMMAND-INITIATED WIPER STORAGE The DS1809 will also support a command-initiated wiper storage operation during powered conditions. For command initiated storage the STR pin should be held in a low state on power-up; otherwise the part will assume an autostore configuration. As shown in Figure 5, a low-to-high pulse lasting at least 1 µs on the STR input will cause the DS1809 to initiate the storage of the current wiper position into EEPROM when VCC is present. 3 of 10 DS1809 PUSHBUTTON CONFIGURATION Figure 2 It is assumed that the STR input will be controlled by either external logic or CPU driven. No external capacitors or diodes are needed for the command-initiated storage operation. The STR input will take precedence over the pushbutton inputs UC and DC. AUTOSTORE CONFIGURATION Figure 3 4 of 10 DS1809 PUSHBUTTON TIMING DIAGRAMS Figure 4 If during any pushbutton activity the STR input is activated, pushbutton operation will be suspended until the storage of EEPROM has been completed. Once complete, pushbutton inputs, if still active, will resume from the point of suspension. Command initiated storage operations will require a minimum of 4 ms to complete the storage operation. This 4ms is measured from the rise of STR input (see Figure 5). For applications not requiring or using the nonvolatile memory feature of the DS1809, it is recommended that the STR input be connected to GND. COMMAND INITIATED WIPER STORAGE - Figure 5 5 of 10 DS1809 ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground Operating Temperature Range Storage Temperature Range Soldering Temperature -1.0V to +7.0V -40°C to +85°C; industrial -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. RECOMMENDED DC OPERATING CONDITIONS (TA = -40°C to +85°C, unless otherwise noted.) PARAMETER SYMBOL MIN Supply Voltage VCC Resistor Inputs GND TYP MAX UNITS NOTES +4.5 5.5 V 1 RL,RH,RW GND-0.5 VCC+0.5 V 2 GND GND GND 1 DC ELECTRICAL CONDITIONS (TA = -40°C to +85°C, unless otherwise noted.) PARAMETER Supply Current Active SYMBOL MIN ICC TYP MAX UNITS NOTES 500 1000 μA 5 25 μA 6 Standby Current ISTBY Logic Input High VIH +2.0 VCC+0.5 V 6,11 Logic Input Low VIL -0.5 +0.8 +0.6 V 6,11 Input Leakage IIL -1 +1 μA 3 RWIPER 400 Ω Wiper Current IW 1 mA Storage Pin Current (STR) ISP 8 μA 12,18 ms 19 Wiper resistance Wiper Storage Time tWST 5 4 6 of 10 DS1809 AC ELECTRICAL CONDITIONS PARAMETER SYMBOL MIN Single Input Pulse Width tPW Repetitive Pulse High Time TYP MAX UNITS NOTES 1 DC ms 4,5,7,9 tHPW 1 DC ms 4,5,7,8,9 Continuous Pulse tCCP 1 DC ms 4,5,7,8,9 Storage Control Pulse tSTR 1 μs 10,12 Capacitance CIN pF 10 5 10 ANALOG RESISTOR CHARACTERISTICS ELECTRICAL CONDITIONS PARAMETER SYMBOL MIN TYP MAX UNITS NOTES End-to-End Resistor Tolerance -20 +20 % 14 Absolute Linearity -0.6 +0.6 LSB 15 Relative Linearity -0.25 +0.25 LSB 16 MHz 17 ppm/ºC 14 -3 dB Cutoff Frequency fCUTOFF Temperature Coefficient 750 NOTES: 1. All voltages are referenced with respect to ground. 2. Voltages across the potentiometer terminals (RL, RW, RH) cannot exceed VCC or go below ground by 0.5V. 3. Inputs UC and DC are internally pulled up with resistance of 100kΩ. 4. UC and DC inputs are internally pulled up to VCC via a 100kΩ resistor. 5. Active current is specified when the inputs UC or DC are active. 6. Standby current is the current consumed when the UC, DC, and STR inputs are inactive. 7. Input pulse width is the minimum time required for an input to cause an increment or decrement. 8. Repetitive pulse inputs on UC or DC will be recognized as long as they are within 500ms of each other. Pulses occurring faster than 1 ms apart may not be recognized as individual and separate pulses. 9. Input pulse timing has tolerances to ±10%. 10. Capacitance values apply at 25°C. 11. For VCC = 5V±10%, maximum VIL = +0.8V. Input logic levels are referenced to ground. 12. If not used STR should be connected to ground. 13. The DS1809 is offered in three values: 10kΩ, 50kΩ, and 100kΩ. 7 of 10 DS1809 14. Valid at +25°C only. 15. Absolute linearity is used to compare measured wiper voltage versus expected wiper voltage as determined by wiper position. The DS1809 is specified to provide a absolute linearity of ±0.60 LSB. 16. Relative linearity is used to determine the change in voltage between successive tap positions. The DS1809 is specified to provide a relative linearity specification of ±0.25 LSB. 17. -3 dB cutoff frequency characteristics for the DS1809 depend on the potentiometer’s total resistance. DS1809-010: 1MHz; DS1809-050: 200kHz; and the DS1809-100: 100kHz. 18. Current leakage on the input control storage pin will require a typical 5µA and maximum 8µA to implement the auto-storage feature. 19. A minimum time of 4ms between 2.2V and 1.7V is required on the input to the STR terminal when using the part in the auto-storage configuration. The 2.2V to 1.7V range is a worst case condition for meeting the power-down storage requirements of the part. 8 of 10 DS1809 ORDERING INFORMATION PART DS1809-010+ DS1809-050+ DS1809-100+ DS1809U-010+T DS1809U-050+T DS1809U-100+T DS1809Z-010+ DS1809Z-050+ DS1809Z-100+ TEMP RANGE -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C VERSION (kΩ) 10 50 100 10 50 100 10 50 100 PIN-PACKAGE TOP MARK 8 PDIP 8 PDIP 8 PDIP 8 µSOP 8 µSOP 8 µSOP 8 SO 8 SO 8 SO DS1809-010 DS1809-050 DS1809-100 1809 X 1809 L 1809 C DS1809 X DS1809 L DS1809 C +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel PACKAGE INFORMATION For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. PDIP µSOP SO P8+1 U8+1 S8+5 21-0043 21-0036 21-0041 — 90-0092 90-0096 9 of 10 DS1809 REVISION HISTORY REVISION DATE 4/14 DESCRIPTION Added lead(Pb)-free parts and top mark information to the Ordering Information table; added the Package Information table PAGES CHANGED 9 . 10 of 10 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. 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