AS1507 D a ta S he e t D u a l 2 5 6 - Ta p D i g i ta l P o t e n t i o m e t e r w i t h S P I I n t e r f a c e and High Endurance EEPROM 1 General Description 2 Key Features The AS1507 is a linear, dual 256-tap digital potentiometer specifically designed to replace discrete/mechanical potentiometers and is ideal for applications requiring a low-temperature-coefficient variable resistor. ! High Endurance: EEPROM up to 10M cycles ! High Reliability: EEPROM up to 150 years data retention @ 85°C The device is controlled via a 3-wire SPI-compatible interface and features an internal EEPROM for storing wiper positions. ! Wiper Position Retained in EEPROM and loaded at Power-Up ! 256 Tap Positions ! ±0.5LSB DNL in Voltage Divider Mode ! ±0.5LSB INL in Voltage Divider Mode ! End-to-End Resistance: 10/50/100kΩ ! Low End-to-End Resistance Temperature Coefficient: 90ppm/ºC Several device variants are available differentiated by end-to-end resistance as shown in Table 1 (see also Ordering Information on page 16). Table 1. Standard Products Model End-to-End Resistance (kΩ) AS1507-10 10 AS1507-50 50 ! Low-Power Standby Mode: 100nA AS1507-100 100 ! 5MHz SPI-Compatible Serial Interface ! Single-Supply Operation: +2.7 to +5.5V ! TQFN 3x3mm 16-pin Package The 3-wire SPI-compatible serial interface allows communication at data rates up to 5MHz. The internal EEPROM stores the last wiper position for initialization during power-up. 3 Applications The devices are available in an TQFN 3x3mm 16-pin package. The device is ideal for mechanical potentiometer replacement, low-drift programmable gain amplifiers, audio volume control, LCD contrast control, and low-drift programmable filters. Figure 1. Block Diagram 9 1 READY 15 VDD 8-Bit Latch 16 8 HIGH A 256-Position Decoder MUTE 25 WIPER 2 SCLK 3 SPI Interface SDIO 13 PowerOn Reset 16-Bit EEPROM 14 LOW A 12 HIGH B 4 CSN 256-Position Decoder 8-Bit Latch 25 8 WIPER 10 AS1507 7 11 LOW B GND www.austriamicrosystems.com Revision 1.00 1 - 17 AS1507 Data Sheet - P i n o u t 4 Pinout Pin Assignments 13 LOW A 14 WIPER A 15 HIGH A 16 MUTE Figure 2. Pin Assignments (Top View) VDD 1 12 HIGH B SCLK 2 11 WIPER B AS1507 NC 8 9 READY GND 7 CSN 4 NC 6 10 LOW B NC 5 SDIO 3 Pin Descriptions Table 2. Pin Descriptions Pin Number 1 2 3 4 5, 6, 8 7 9 10 11 12 13 14 15 16 N/A Pin Name VDD SCLK SDIO CSN NC GND READY Description 2.5 to 5.5V Supply Voltage. Bypass with a 0.1µF capacitor to GND. Serial Clock Input Serial Data Input Active-Low Chip Select Not Connected Ground EEPROM Ready. Active-Low indicates an ongoing write operation in the EEPROM. Low Terminal of Resistor B. The voltage at this pin can be greater than or less LOW B than the voltage at pin HIGH. Current can flow into or out of this pin. Wiper Terminal for Resistor B WIPER B High Terminal of Resistor B. The voltage at this pin can be greater than or less HIGH B than the voltage at pin LOW. Current can flow into or out of this pin. Low Terminal of Resistor A. The voltage at this pin can be greater than or less LOW A than the voltage at pin HIGH. Current can flow into or out of this pin. Wiper Terminal for Resistor A WIPER A High Terminal of Resistor A. The voltage at this pin can be greater than or less HIGH A than the voltage at pin LOW. Current can flow into or out of this pin. Mute. Both wiper registers are asynchronously set to zero. Data stored in the EEPROM is not affected. Active-High signal. Internal pull-down resistor. Can be left MUTE unconnected if not used. Exposed Pad The exposed pad is not internally connected. Connect to GND or leave floating. www.austriamicrosystems.com Revision 1.00 2 - 17 AS1507 Data Sheet - A b s o l u t e M a x i m u m R a t i n g s 5 Absolute Maximum Ratings Stresses beyond those listed in Table 3 may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Electrical Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 3. Absolute Maximum Ratings Parameter Min Max Units VDD to GND -0.3 +7.0 V All Other Pins to GND -0.3 VDD + 0.3 V AS1507-10 +1 AS1507-50 +1 AS1507-100 +1 Maximum Continuous Current into Pins HIGH, WIPER, and LOW Electrostatic Discharge 1 Latch-Up mA 1 -100 Thermal Resistance ΘJA 100 48 kV HBM MIL-Std. 883E 3015.7 methods mA JEDEC 78 ºC/W on PCB Operating Temperature Range -40 +85 ºC Storage Temperature Range -60 +150 ºC +150 ºC Junction Temperature Package Body Temperature Comments +260 ºC The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD-020C “Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). 1. The maximum rating voltage must not be exceeded during Latch-up test of the device. www.austriamicrosystems.com Revision 1.00 3 - 17 AS1507 Data Sheet - E l e c t r i c a l C h a r a c t e r i s t i c s 6 Electrical Characteristics VDD = +2.7 to +5.5V, HIGH = VDD, LOW = GND, TAMB = -40 to +85ºC. Typ values are at VDD = +5.0V, TAMB = +25ºC (unless otherwise specified). Table 4. Electrical Characteristics Symbol Power Supply VDD IDD Parameter Condition Min Typ Max Unit 0.1 5.5 0.5 V µA 110 200 µA ±0.5 ±0.25 ±1 ±0.5 LSB AS1507-10 AS1507-50 & -100 ±0.5 ±0.25 ±1 ±0.5 LSB TAMB = 0 to +85ºC 90 AS1507-10 AS1507-50 AS1507-100 AS1507-10 AS1507-50 AS1507-100 2.5 1.5 1.5 1 0.1 0.1 4 2.5 2.5 2 0.7 0.7 AS1507-10 AS1507-50 & -100 @ 3V AS1507-50 & -100 @ 5V AS1507-10 AS1507-50 & -100 ±1 ±0.6 ±0.5 ±0.5 ±0.5 ±2 ±1.5 ±1 ±1 ±1 VDD = 3V VDD = 5V 200 120 15 10 50 100 2.70 Standby Current Digital Inputs = VDD or GND, TAMB = +25ºC Operating Current 1 IOP Includes Non-Volatile Write to Memory (CMOS write) DC Performance (Voltage Divider Mode) N Resolution AS1507-10 2 INL Integral Linearity AS1507-50 & -100 DNL Differential Non-Linearity TCR End-to-End Resistance Temperature Coefficient 2 Full Scale Error Zero Scale Error 256 Taps ppm/ºC LSB LSB DC Performance (Variable Resistor Mode) INL DNL Integral Linearity 3 Differential Non-Linearity LSB LSB DC Performance (Resistor Characteristics) 4 RW Wiper Resistance CW Wiper Capacitance REE AS1507-10 AS1507-50 AS1507-100 End-to-End Resistance Inputs and Outputs WIPER Voltage Range HIGH Voltage Range LOW Voltage Range VIH Digital Input High Voltage VIL Digital Input Low Voltage ILEAK CIN ICONT GND0.3 5 5 VDD = 3V VDD = 5V VDD = 3V VDD = 5V Digital Input Leakage Current Digital Input Capacitance Continuous DAC current www.austriamicrosystems.com 7.5 37.5 75 Ω pF 12.5 62.5 125 kΩ VDD+ 0.3 V 2.1 2.4 V 200 5 0.6 0.8 500 1000 Revision 1.00 V nA pF µA 4 - 17 AS1507 Data Sheet - E l e c t r i c a l C h a r a c t e r i s t i c s Table 4. Electrical Characteristics (Continued) Symbol Parameter Condition Min Typ Max Unit Dynamic Characteristics Wiper -3dB Bandwidth tS 6 7 Wiper Settling Time AS1507-10 AS1507-50 AS1507-100 AS1507-10 AS1507-50 AS1507-100 1200 220 120 1100 1600 2200 TAMB = +85ºC 150 Years TAMB = +25ºC TAMB = +85ºC 10M 1M Write Cycles kHz ns Non-Volatile Memory Reliability Data Retention Endurance tBUSY 8 8 Write Non-Volatile Register Busy Time 20 ms 1. The programming current operates only during power-up and non-volatile memory writes. 2. DNL and INL are measured with the potentiometer configured as a voltage-divider with HIGH = VDD and LOW = GND. The wiper terminal is unloaded and measured with a high-input-impedance voltmeter. 3. DNL and INL are measured with the potentiometer configured as a variable resistor. HIGH is unconnected and LOW = GND. For the 5V condition, the wiper terminal is driven with a source current of 400µA @ 10kΩ, 80µA @ 50kΩ, 40µA @ 100kΩ. In 3V conditions, the wiper terminal is driven with a source current of 200µA @ 10kΩ, 40µA @ 50kΩ, 20µA @ 100kΩ. 4. The wiper resistance is measured using the source currents given in Note 3. The number is the worst case resistance over TAP positions. 5. The device draws higher supply current when the digital inputs are driven with voltages between (VDD - 0.5V) and (GND + 0.5V). 6. Wiper at midscale with a 10pF load (DC measurement) VDD = 5V, LOW = GND. An AC source (5V peak to peak sinus signal) is applied to HIGH and the WIPER output is measured. A 3dB bandwidth occurs when the AC WIPER/HIGH value is 3dB lower than the DC WIPER/HIGH value. 7. Wiper-settling time is the worst-case 0 to 50% rise-time measured between successive wiper positions. HIGH = VDD, LOW = GND; WIPER is unloaded and measured with a 10pF load. 8. This parameter is not tested but ensured by characterization. Timing Characteristics VDD = +2.7 to +5.5V, HIGH = VDD, LOW = GND, TAMB = -40 to +85ºC. Typ values are at VDD = +5.0V, TAMB = +25ºC (unless otherwise specified). See Figure 20 on page 9. Digital timing data is guaranteed by design and characterization, and is not production tested. Table 5. Timing Characteristics Symbol fSCLK tCP tCH tCL80 tCSS tCSH tDS tDH tCS0 tCS1 tCSW tBUSY Parameter SCLK Frequency SCLK Clock Period SCLK Pulse-Width High SCLK Pulse-Width Low CSN-Fall to SCLK Rise Setup SCLK-Rise to CSN-Rise Hold SDIO to SCLK Setup SDIO Hold after SCLK SCLK-Rise to CSN-Fall Delay CSN-Rise to SCLK-Rise Hold CSN Pulse-Width High Write Non-Volatile Register Busy Time www.austriamicrosystems.com Condition Min Typ Max 5 200 40 40 40 40 10 0 40 40 200 20 Revision 1.00 Unit MHz ns ns ns ns ns ns ns ns ns ns ms 5 - 17 AS1507 Data Sheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s 7 Typical Operating Characteristics VDD = 5V (unless otherwise specified). Figure 4. INL vs. TAP Position 10kΩ, Divider Mode 1 1 0.8 0.8 0.6 0.6 0.4 0.4 INL (LSB) . DNL (LSB) . Figure 3. DNL vs. TAP Position 10kΩ, Divider Mode 0.2 0 -0.2 0.2 0 -0.2 -0.4 -0.4 -0.6 -0.6 -0.8 -0.8 -1 -1 0 32 64 0 96 128 160 192 224 256 32 64 Figure 6. INL vs. TAP Position 50kΩ, Divider Mode 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 INL (LSB) . DNL (LSB) . Figure 5. DNL vs. TAP Position 50kΩ, Divider Mode 0.1 0 -0.1 0.1 0 -0.1 -0.2 -0.2 -0.3 -0.3 -0.4 -0.4 -0.5 -0.5 0 32 64 96 128 160 192 224 256 0 32 64 Tap Position Figure 8. INL vs. TAP Position 100kΩ, Divider Mode 0.5 0.4 0.4 0.3 0.3 0.2 0.2 INL (LSB) . 0.5 0.1 0 -0.1 0.1 0 -0.1 -0.2 -0.2 -0.3 -0.3 -0.4 -0.4 -0.5 96 128 160 192 224 256 Tap Position Figure 7. DNL vs. TAP Position 100kΩ, Divider Mode DNL (LSB) . 96 128 160 192 224 256 Tap Position Tap Position -0.5 0 32 64 96 128 160 192 224 256 0 Tap Position www.austriamicrosystems.com 32 64 96 128 160 192 224 256 Tap Position Revision 1.00 6 - 17 AS1507 Data Sheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s Figure 10. INL vs. TAP Position 10kΩ, Varistor Mode 1 2 0.8 1.6 0.6 1.2 0.4 0.8 INL (LSB) . DNL (LSB) . Figure 9. DNL vs. TAP Position 10kΩ, Varistor Mode 0.2 0 -0.2 0.4 0 -0.4 -0.4 -0.8 -0.6 -1.2 -0.8 -1.6 -1 -2 0 32 64 96 128 160 192 224 256 0 32 64 Tap Position Figure 12. INL vs. TAP Position 50kΩ, Varistor Mode 1 1 0.8 0.8 0.6 0.6 0.4 0.4 INL (LSB) . DNL (LSB) . Figure 11. DNL vs. TAP Position 50kΩ, Varistor Mode 0.2 0 -0.2 0.2 0 -0.2 -0.4 -0.4 -0.6 -0.6 -0.8 -0.8 -1 -1 0 32 64 96 128 160 192 224 256 0 32 64 Tap Position Figure 14. INL vs. TAP Position 100kΩ, Varistor 1 0.8 0.8 0.6 0.6 0.4 0.4 INL (LSB) . 1 0.2 0 -0.2 96 128 160 192 224 256 Tap Position Figure 13. DNL vs. TAP Position 100kΩ, Varistor Mode Mode DNL (LSB) . 96 128 160 192 224 256 Tap Position 0.2 0 -0.2 -0.4 -0.4 -0.6 -0.6 -0.8 -0.8 -1 -1 0 32 64 0 96 128 160 192 224 256 www.austriamicrosystems.com 32 64 96 128 160 192 224 256 Tap Position Tap Position Revision 1.00 7 - 17 AS1507 Data Sheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s Figure 15. Wiper Resistance vs. TAP; 5V Figure 16. Wiper Resistance vs. TAP; 3V 120 180 160 . 80 Resistance (Ω ) Resistance (Ω) . 100 60 40 140 120 100 80 60 40 20 20 0 0 0 32 64 96 128 160 192 224 256 0 32 64 Tap Position 96 128 160 192 224 256 Tap Position Figure 17. DAC Resistor vs. Temperature Figure 18. Gain vs. Bandwidth 0 118 117 Gain (dB) . Resistance (kΩ) . 100kΩ -3 116 115 114 113 50kΩ 10kΩ -6 -9 112 111 -12 110 25 35 45 55 65 75 1 85 10 100 1000 10000 Frequency (kHz) Temperature (°C) Figure 19. EEPROM Data Retention vs. Temperature Data Retension (years) . 10000 1000 100 10 25 45 65 85 105 125 Temperature (°C) www.austriamicrosystems.com Revision 1.00 8 - 17 AS1507 Data Sheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description The AS1507 contains two resistor arrays with 255 resistive elements each (tap points), and has a total end-to-end resistance of 10, 50, or 100kΩ (see Ordering Information on page 16). The device provides high, low, and wiper terminals for a standard voltage-divider configuration. Pins HIGH, LOW, and WIPER can be connected in any configuration as long as their voltages fall between GND and VDD. A 3-wire, SPI-compatible serial interface controls movement of the wiper among the 256 tap points. The EEPROM stores the wiper position and recalls the stored wiper position upon power-up. The EEPROM typically holds wiper data for 150 years and up to 10M wiper store cycles. Analog Circuit The 256 tap points are accessible to the wiper along the resistor string between pins HIGH and LOW (similar to the end terminals of a mechanical potentiometer). The wiper tap point is selected by programming 8 data bits and a control byte via the 3-wire serial interface (see Programming the Device on page 10). Note: Integrated power-on reset circuitry loads the wiper position from the EEPROM at power-up. Digital Interface The AS1507 uses an SPI-compatible 3-wire interface for command settings of the device consisting of two input signals (chip-select - CSN, and data clock - SCLK) and one bi-directional data pin (SDIO). Driving CSN low enables serial interface and the command/data are passed into the device synchronously by each SCLK rising edge. There are 16-bit commands for write data into the wiper register or the non-volatile memory, and 8-bit commands for transferring data between wiper register and non-volatile memory and to read the data stored in the wiper register or non-volatile memory. The 8-bit commands can be implemented in 16-bit command structure alternatively. In this case the first 8 bits shifted through the SPI interface are not significant. The data byte passed at writing commands represents the position of the wiper. After loading the 8- or 16-bit command while CSN is low, the loaded command is executed at the next rising edge of CSN, simultaneously the serial interface is disabled. The CSN signal must be low during the whole serial input stream through the SPI, otherwise data on the SPI interface are corrupted. Note: If the data-in stream does not exactly contain 8 or 16 digits, no command is executed at the rising edge of CSN. Figure 20. Serial Data Timing ... CSN tCSW tCS0 tCL tCSS tCS1 tCH tCP tCSH ... SCLK tDS tDH ... SDIO Standby Mode Low-power standby mode is enabled at CSN high. After a read access standby mode is entered 2 cycles of SCLK after issuing the last bit of the data wiper or non-volatile register. If the digital inputs are stable VDD or GND there is only leakage power dissipation of the device. This power dissipation is defined with 0.1uA (typ) at 25ºC. www.austriamicrosystems.com Revision 1.00 9 - 17 AS1507 Data Sheet - D e t a i l e d D e s c r i p t i o n EEPROM (Non-Volatile Register) There is an internal EEPROM register implemented to retain the wiper position after power down. During an ongoing write cycle of the non-volatile register (tBUSY time) the system must not be powered down. A write cycle on the EEPROM is indicated by the READY signal. Data retention defines the ability of an EEPROM to retain data over time. The qualification has been done according to JEDEC Retention Lifetime Specification (A117). The EEPROM is cycled to the specified endurance limit before the data retention test is done. Based on activation energy of 0.6eV the data retention time derates over temperature as shown in Figure 19 on page 8. For the non-volatile register 1M endurance cycles and a data retention of 150 years are typical at 85 ºC. The non-volatile register is factory trimmed to mid-scale. Power-Up The AS1507 contains an integrated power-up circuit. At power up, the data are transferred from the non-volatile memory to the wiper register. The wiper register moves to the stored position. This data transfer takes 5µs after the supply has reached the POR trigger level. Programming the Device Write commands (see Table 6) require 16 clock cycles (see Figure 22 on page 12) to clock in the command and data. Copy and Read commands (see Table 6) can use 8 clock cycles to clock in the command (see Figure 21 on page 12) or 16 clock cycles. At 16 clock cycle commands the 8 data bits (D7:D0) are insignificant. Table 6. Command/Data Word Format Command Write Wiper Register A 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 C7 C6 C5 C4 C3 C2 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0 0 0 0 0 0 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0 Write Wiper Register B 0 0 0 0 0 0 1 0 D7 D6 D5 D4 D3 D2 D1 D0 Write both Wiper Registers 0 0 0 0 0 0 1 1 D7 D6 D5 D4 D3 D2 D1 D0 Write to Non-Volatile Register A 0 0 0 1 0 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0 Write to Non-Volatile Register B 0 0 0 1 0 0 1 0 D7 D6 D5 D4 D3 D2 D1 D0 Write to both Non-Volatile Registers 0 0 0 1 0 0 1 1 D7 D6 D5 D4 D3 D2 D1 D0 Copy Wiper Register A to NonVolatile Register 0 0 1 0 0 0 0 1 - - - - - - - - Copy Wiper Register B to NonVolatile Register 0 0 1 0 0 0 1 0 - - - - - - - - Copy Both Wiper Registers to Non-Volatile Registers 0 0 1 0 0 0 1 1 - - - - - - - - Copy Non-Volatile Register A to Wiper Register 0 0 1 1 0 0 0 1 - - - - - - - - Copy Non-Volatile Register B to Wiper Register 0 0 1 1 0 0 1 0 - - - - - - - - Copy Both Non-Volatile Registers to Wiper Registers 0 0 1 1 0 0 1 1 - - - - - - - - www.austriamicrosystems.com Revision 1.00 10 - 17 AS1507 Data Sheet - D e t a i l e d D e s c r i p t i o n Commands Write Wiper Register This is a 16-bit command (see Figure 22 on page 12). The first byte represents the command word starting with the MSB bit of the command, the second byte represents the data written to the wiper register (starting with the MSB). Data 0000 0000 the wiper moves the closest position to LOW, with data 1111 1111 the wiper moves to the closest position to HIGH. The wiper registers can be written independently in two write cycles with different data or in one write cycle with the same data. Note: At power-up the wiper position stored in the non-volatile memory are automatically loaded into the wiper register, the wiper moves to the related position. Write to Non-Volatile Register This is a 16-bit command (see Figure 22 on page 12). The first byte represents the command word starting with the MSB bit of the command, the second byte represents the data written to the non-volatile memory. The wiper position is not changed by this command, since the wiper register is not affected. The non-volatile registers can be written independently in two write cycles with different data or in one write cycle with the same data. There is a write non-volatile register time defined in the timing specification, which is required for storing the data in the non-volatile register. The READY pin indicates the write time with an active-low signal. During this time the device must not be powered down, otherwise the data stored in the non-volatile register is corrupted. Copy Wiper Register to Non-Volatile Register This command can be implemented as an 8- or 16-bit command. The data stored in the wiper register are transferred to the non-volatile memory, to keep the data during power-down. There is no automatic trigger of this command during power-down of the device. This command must be triggered before powering down the device. There is a write non-volatile register time defined in the timing specification, which is required for storing the data in the non-volatile register. During this time the device must not be powered down, otherwise the data stored in the non-volatile register is corrupted. Copy Non-Volatile Register to Wiper Register This command can be implemented as an 8- or 16-bit command. The data stored in the non-volatile register are transferred to the wiper register, the wiper register moves to the stored position. This command is automatically executed during power up of the system. Read Non-Volatile Register The AS1507 features the capability to read the data from the non-volatile register via the SPI interface (see Figure 23 on page 12). This command can be implemented as an 8- or 16-bit command. The SDIO pin is a bi-directional pin. During the CSN low phase of the sequence the SDIO pin is used as input pin to set the command byte. After CSN rising edge the pin SDIO is set as output pin, the data stored in the non-volatile register are read serially, MSB first. The data propagation starts at the second rising edge of SCLK after the rising edge of CSN. CSN must be high during the read operation. With the next falling edge of CSN the SDIO pin is set to an input pin again. Read Wiper Register The AS1507 features the capability to read the data from the wiper register via the SPI interface (see Figure 23 on page 12). This command can be implemented as an 8- or 16-bit command. The SDIO pin is a bi-directional pin. During the CSN low phase of the sequence, the SDIO pin is used as input pin to set the command byte. After CSN rising edge the pin SDIO is set as output pin, the data stored in the wiper register are read serially, MSB first. The wiper position is unchanged. The data propagation starts at the second rising edge of SCLK after the rising edge of CSN. CSN must be high during the read operation. With the next falling edge of CSN the SDIO pin is set to an input pin again. Mute Command When a high signal is applied on the MUTE pin both wiper positions are set to zero permanently. While in mute operation SPI commands to wiper registers are not executed. Data stored in non-volatile registers are not affected by the mute command. The MUTE pin includes a pull-down resistor. If a mute function is not required the pin can be left unconnected. www.austriamicrosystems.com Revision 1.00 11 - 17 AS1507 Data Sheet - D e t a i l e d D e s c r i p t i o n Figure 21. 8-Bit Command Word CSN SCLK SDIO C7 C6 C5 C4 C3 C2 C1 C0 Figure 22. 16-Bit Command/Data Word CSN SCLK SDIO C7 C6 C5 C4 C3 C2 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0 Figure 23. 16-Bit Read Command CSN SCLK SDIO C7 C6 C5 C4 C3 C2 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0 Figure 24. 16-Bit EEPROM Write Command CSN SCLK SDIO 0 0 0 1 0 0 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0 tBUSY READY www.austriamicrosystems.com Revision 1.00 12 - 17 AS1507 Data Sheet - A p p l i c a t i o n I n f o r m a t i o n 9 Application Information The AS1507 is intended for circuits requiring digitally controlled adjustable resistance, such as LCD contrast control (where voltage biasing adjusts the display contrast), or programmable filters with adjustable gain and/or cutoff frequency. Programmable Filter Figure 25 shows the configuration for a 1st-order programmable filter. The DC gain of the filter is adjusted by R2 and can be calculated as: G = 1 + (R1/R2) (EQ 1) The cutoff frequency (fC) is adjusted by R3, and can be calculated as: fC = 1/(2π x R3 x C) (EQ 2) Figure 25. Programmable Filter Circuit CIN VIN + VOUT – R1 HIGHB HIGHA WIPERA R3 R2 AS1507 LOWA WIPERB LOWB Offset Voltage and Gain Adjustment Connect one potentiometer of the AS1507 to an op amp to nullify the offset voltage over the operating temperature range. Use the second potentiometer in the feedback path to adjust the gain of the op amp (Figure 26). Figure 26. Offset Voltage and Gain Adjustment Circuit 5V + – HIGHA WIPERA LOWA www.austriamicrosystems.com HIGHB AS1507 WIPERB LOWB Revision 1.00 13 - 17 AS1507 Data Sheet - A p p l i c a t i o n I n f o r m a t i o n Positive LCD Bias Control The device can be used in applications where a voltage-divider or variable resistor is used to make an adjustable, positive LCD-bias voltage, such as for the AS1120 LCD Driver. The op amp provides buffering and gain to the resistordivider network made by the potentiometer (Figure 27) or to a fixed resistor and a variable resistor (Figure 28). Figure 27. Positive LCD Bias Control using a Voltage Divider 5V HIGH 30V AS1507 WIPER LOW + VOUT – Figure 28. Positive LCD Bias Control using a Variable Resistor 5V 30V + VOUT – HIGH AS1507 WIPER LOW Adjustable Voltage Reference Figure 29 shows the device used as the feedback resistor in an adjustable voltage-reference application. Output voltages of external voltage references, supervisory reset thresholds, or LED brightness control can be independently adjusted by changing the wiper position of the AS1507. Figure 29. Adjustable Voltage Reference Circuit – VOUT = 1.23V(50kΩ/R2(kΩ) 5V VIN VIN VOUTREF1 OUT HIGHA ADJ WIPERA HIGHB AS1507 ADJ LOWA www.austriamicrosystems.com VOUTREF OUT WIPERB AS1507 LOWB Revision 1.00 14 - 17 AS1507 Data Sheet - P a c k a g e D r a w i n g s a n d M a r k i n g s 10 Package Drawings and Markings The device is available in an TQFN 3x3mm 16-pin package. Figure 30. TQFN 3x3mm 16-pin Package Symbol A A1 L L1 K aaa bbb ccc ddd Min 0.70 0.00 0.30 0.03 0.20 Typ 0.75 0.02 0.40 0.10 0.10 0.10 0.05 Max 0.80 0.05 0.50 0.15 Notes 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 Symbol D BSC E BSC D2 E2 θ b e N ND Min 1.55 1.55 0º 0.18 Typ 3.00 3.00 1.70 1.70 0.25 0.5 16 4 Max 1.80 1.80 14º 0.30 Notes 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2, 5 1, 2 1, 2, 5 Notes: 1. 2. 3. 4. Dimensioning and tolerancing conform to ASME Y14.5M-1994. All dimensions are in millimeters, angle is in degrees. N is the total number of terminals. Terminal #1 identifier and terminal numbering convention shall conform to JESD 95-1 SPP-012. Details of terminal #1 identifier are optional, but must be located within the area indicated. The terminal #1 identifier may be either a mold, embedded metal or mark feature. 5. Dimension b applies to metallized terminal and is measured between 0.15 and 0.30mm from terminal tip. 6. ND refers to the maximum number of terminals on D side. 7. Unilateral coplanarity zone applies to the exposed heat sink slug as well as the terminals. www.austriamicrosystems.com Revision 1.00 15 - 17 AS1507 Data Sheet 11 Ordering Information The device is available as the standard products shown in Table 7. Table 7. Ordering Information Model Marking Description End-to-End Resistance Delivery Form Package AS1507-BTDT-10 ASPF Dual 256-Tap, Non-Volatile, SPI Digital Potentiometer 10kΩ Tape and Reel TQFN 3x3mm 16pin AS1507-BTDT-50 ASPE Dual 256-Tap, Non-Volatile, SPI Digital Potentiometer 50kΩ Tape and Reel TQFN 3x3mm 16pin AS1507-BTDT-100 ASPD Dual 256-Tap, Non-Volatile, SPI Digital Potentiometer 100kΩ Tape and Reel TQFN 3x3mm 16pin www.austriamicrosystems.com Revision 1.00 16 - 17 AS1507 Data Sheet - O r d e r i n g I n f o r m a t i o n Copyrights Copyright © 1997-2007, austriamicrosystems AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies. Disclaimer Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or lifesustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. Contact Information Headquarters austriamicrosystems AG A-8141 Schloss Premstaetten, Austria Tel: +43 (0) 3136 500 0 Fax: +43 (0) 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: http://www.austriamicrosystems.com/contact www.austriamicrosystems.com Revision 1.00 17 - 17