CAT521 Configured Digitally Programmable Potentiometer (DPP™): Programmable Voltage Applications FEATURES DESCRIPTION 8-bit DPP configured as a programmable voltage source in DAC-like applications Buffered wiper output Non-volatile NVRAM memory wiper storage Output voltage range includes both supply rails 1 LSB accuracy, high resolution Serial Microwire-like interface Single supply operation: 2.7V – 5.5V Setting read-back without effecting outputs The CAT521 is a 8-bit digitally-programmable potentiometer (DPP™) configured for programmable voltage and DAC-like applications. Intended for final calibration of products such as camcorders, fax machines and cellular telephones on automated high volume production lines, it is also well suited for self-calibrating systems and for applications where equipment which requires periodic adjustment is either difficult to access or in a hazardous environment. The programmable DPP has an output voltage range which includes both supply rails. The wiper is buffered by a rail to rail op amp. The wiper setting, stored in non-volatile NVRAM memory, is not lost when the device is powered down and is automatically reinstated when power is returned. The wiper can be dithered to test new output values without effecting the stored settings and stored settings can be read back without disturbing the DPP’s output. For Ordering Information details, see page 12. APPLICATIONS Automated product calibration Remote control adjustment of equipment Offset, gain and zero adjustments in selfcalibrating and adaptive control systems Tamper-proof calibrations DAC (with memory) substitute The CAT521 is controlled with a simple 3-wire, Microwire like serial interface. A Chip Select pin allows several devices to share a common serial interface. Communication back to the host controller is via a single serial data line thanks to the CAT521 Tri¯¯¯¯ output working in Stated Data Output pin. A RDY/BSY concert with an internal low voltage detector signals proper operation of the non-volatile NVRAM memory Erase/Write cycle. PIN CONFIGURATION PDIP 14-Lead (L) SOIC 14-Lead (W) VDD 1 14 VREFH CLK 2 13 NC RDY/¯¯¯¯ BSY 3 12 VOUT CS 4 CAT521 11 NC DI 5 10 NC DO 6 8 VREFL PROG 7 8 GND © Catalyst Semiconductor, Inc. Characteristics subject to change without notice The CAT521 is available in 0°C to 70°C commercial and -40°C to 85°C industrial operating temperature ranges. Both 14-pin plastic DIP and surface mount packages are available. 1 Doc. No. MD-2003 Rev. G CAT521 FUNCTIONAL DIAGRAM PROG DI CLK CS VREFH 1 14 3 7 PROGRAM CONTROL 5 2 SERIAL CONTROL 4 WIPER CONTROL REGISTERS AND NVRAM RDY/BSY VDD 24kΩ 24kΩ 24kΩ 24kΩ + 12 VOUT – SERIAL DATA OUTPUT REGISTER 6 DO CAT521 9 8 GND Doc. No. MD-2003 Rev. G VREFL 2 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT521 ABSOLUTE MAXIMUM RATINGS Parameters Ratings Supply Voltage* VDD to GND Inputs CLK to GND CS to GND DI to GND ¯¯¯¯ to GND RDY/BSY PROG to GND VREFH to GND VREFL to GND Units -0.5 to +7 -0.5 to VDD +0.5 -0.5 to VDD +0.5 -0.5 to VDD +0.5 -0.5 to VDD +0.5 -0.5 to VDD +0.5 -0.5 to VDD +0.5 -0.5 to VDD +0.5 V V V V V V V V Parameters Outputs D0 to GND VOUT 1– 4 to GND Operating Ambient Temperature Commercial (‘C’ or Blank suffix) Industrial (‘I’ suffix) Junction Temperature Storage Temperature Lead Soldering (10 sec max) Ratings Units -0.5 to VDD +0.5 V -0.5 to VDD +0.5 V 0 to +70 °C -40 to +85 +150 -65 to +150 +300 °C °C °C °C RELIABILITY CHARACTERISTICS Symbol Parameter Test Method Min VZAP(2) ILTH(2)(3) Max Units ESD Susceptibility MIL-STD-883, Test Method 3015 2000 V Latch-Up JEDEC Standard 17 100 mA POWER SUPPLY Symbol Parameter Conditions IDD1 Supply Current (Read) IDD2 Supply Current (Write) VDD Min Typ Max Units Normal Operating — 400 600 µA Programming, VDD = 5V — 1600 2500 µA VDD = 3V — 1000 1600 µA 2.7 — 5.5 V Min Typ Max Units Operating Voltage Range LOGIC INPUTS Symbol Parameter Conditions IIH Input Leakage Current VIN = VDD — — 10 µA IIL Input Leakage Current VIN = 0V — — -10 µA VIH High Level Input Voltage 2 — VDD V VIL Low Level Input Voltage 0 — 0.8 V LOGIC OUTPUTS Symbol Parameter Conditions Min Typ Max Units VOH High Level Output Voltage IOH = -40µA VDD -0.3 — — V VIL Low Level Output Voltage IOL = 1 mA, VDD = +5V — — 0.4 V IOL = 0.4 mA, VDD = +3V — — 0.4 V 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) This parameter is tested initially and after a design or process change that affects the parameter. (3) Latch-up protection is provided for stresses up to 100mA on address and data pins from –1V to VCC + 1V. © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 3 Doc. No. MD-2003 Rev. G CAT521 POTENTIOMETER CHARACTERISTICS VDD = +2.7V to +5.5V, VREFH = VDD, VREFL = 0V, unless otherwise specified Symbol RPOT Parameter Conditions Potentiometer Resistance See note 3 Min Typ Max 24 RPOT to RPOT Match — Units kΩ ±0.5 Pot Resistance Tolerance ±1 % ±20 % Voltage on VREFH pin 2.7 VDD V Voltage on VREFL pin 0 VDD - 2.7 V Resolution 0.4 % INL Integral Linearity Error 0.5 1 LSB DNL Differential Linearity Error 0.25 0.5 LSB ROUT Buffer Output Resistance 10 Ω IOUT Buffer Output Current 3 mA TCRPOT TC of Pot Resistance 300 ppm/ºC CH/CL Potentiometer Capacitances 8/8 pF AC ELECTRICAL CHARACTERISTICS VDD = +2.7V to +5.5V, VREFH = VDD, VREFL = 0V, unless otherwise specified Symbol Parameter Conditions Min Typ Max Units Digital tCSMIN Minimum CS Low Time 150 — — ns tCSS CS Setup Time 100 — — ns tCSH CS Hold Time 0 — — ns tDIS DI Setup Time 50 — — ns 50 — — ns CL = 100pF (1) tDIH DI Hold Time tDO1 Output Delay to 1 — — 150 ns tDO0 Output Delay to 0 — — 150 ns tHZ Output Delay to High-Z — 400 — ns tLZ Output Delay to Low-Z — 400 — ns tBUSY Erase/Write Cycle Time — 4 5 ms tPS PROG Setup Time 150 — — ns tPROG Minimum Pulse Width 700 — — ns tCLKH Minimum CLK High Time 500 — — ns tCLKL Minimum CLK Low Time 300 — — ns fC Clock Frequency DC — 1 MHz CLOAD = 10pF, VDD = +5V — 3 10 µs CLOAD = 10pF, VDD = +3V — 6 10 µs Analog tDS DPP Settling Time to 1 LSB Notes: (1) All timing measurements are defined at the point of signal crossing VDD / 2. (2) These parameters are periodically sampled and are not 100% tested. (3) The 24kΩ +20% resistors are configured as 4 resistors in parallel which would provide a measured value between VREFH and VREFL of 6kΩ +20%. The individual 24kΩ resistors are not measurable but guaranteed by design and verification of the 6kΩ +20% value. Doc. No. MD-2003 Rev. G 4 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT521 A.C. TIMING DIAGRAM to 1 2 3 4 5 tCLK H CLK tCSS tCLK L t CSH CS tCSMIN tDIS DI tDIH t DO0 tLZ DO tHZ tDO1 PROG t PS tPROG RDY/BSY tBUSY to © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 1 2 3 5 4 5 Doc. No. MD-2003 Rev. G CAT521 PIN DESCRIPTION Pin Name 1 VDD Power supply positive 2 CLK Clock input pin 3 ¯¯¯¯ RDY/BSY 4 CS Chip select 5 DI Serial data input pin 6 DO Serial data output pin 7 PROG 8 GND Power supply ground 9 VREFL Minimum DAC output voltage 10 NC No Connect 11 NC No Connect 12 VOUT DPP output 13 NC No Connect 14 VREFH DPP addressing is as follows: Function Ready/Busy output A0 A1 VOUT 1 0 EEPROM Programming Enable Input Maximum DPP 1 output voltage because the DO pin is Tri-Stated and returns to a high impedance when not in use. DEVICE OPERATION The CAT521 is a single 8-bit configured digitally programmable potentiometer (DPP™) whose output can be programmed to any one of 256 individual voltage steps. Once programmed, the output setting is retained in non-volatile memory and will not be lost when power is removed from the chip. Upon power up the DPP returns to the setting stored in non-volatile memory. The DPP can be written to and read from without effecting the output voltage during the read or write cycle. The output can also be adjusted without altering the stored output setting, which is useful for testing new output settings before storing them in memory. CHIP SELECT Chip Select (CS) enables and disables the CAT521’s read and write operations. When CS is high data may be read to or from the chip, and the Data Output (DO) pin is active. Data loaded into the DPP control register will remain in effect until CS goes low. Bringing CS to a logic low returns all DPP outputs to the settings stored in nonvolatile memory and switches DO to its high impedance Tri-State mode. Because CS functions like a reset the CS pin has been desensitized with a 30ns to 90ns filter circuit to prevent noise spikes from causing unwanted resets and the loss of volatile data. DIGITAL INTERFACE The CAT521 employs a 3 wire, Microwire-like serial control interface consisting of Clock (CLK), Chip Select (CS) and Data In (DI) inputs. For all operations, address and data are shifted in LSB first. In addition, all digital data must be preceded by a logic “1” as a start bit. The DPP address and data are clocked into the DI pin on the clock’s rising edge. When sending multiple blocks of information a minimum of two clock cycles is required between the last block sent and the next start bit. CLOCK The CAT521 clock controls both data flow in and out of the device and non-volatile memory cell programming. Serial data is shifted into the DI pin and out of the DO pin on the clock’s rising edge. While it is not necessary for the clock to be running between data transfers, the clock must be operating in order to write to non-volatile memory, even though the data being saved may already be resident in the DPP wiper control register. Multiple devices may share a common input data line by selectively activating the CS control of the desired IC. Data Outputs (DO) can also share a common line Doc. No. MD-2003 Rev. G DPP OUTPUT No clock is necessary upon system power-up. The CAT521 internal power-on reset circuitry loads data 6 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT521 from non-volatile memory to the DPP without using the external clock. command indicating a failure to record the desired data in non-volatile memory. As data transfers are edge triggered clean clock transitions are necessary to avoid falsely clocking data into the control register. Standard CMOS and TTL logic families work well in this regard and it is recommended that any mechanical switches used for breadboarding or device evaluation purposes be debounced by a flip-flop or other suitable debouncing circuit. DATA OUTPUT Data is output serially by the CAT521, LSB first, via the Data Out (DO) pin following the reception of a start bit and two address bits by the Data Input (DI). DO becomes active whenever CS goes high and resumes its high impedance Tri-State mode when CS returns low. Tri-Stating the DO pin allows several 521s to share a single serial data line and simplifies interfacing multiple 521s to a microprocessor. VREF VREF, the voltage applied between pins VREFH & VREFL, sets the DPP’s Zero to Full Scale output range where VREFL = Zero and VREFH = Full Scale. VREF can span the full power supply range or just a fraction of it. In typical applications VREFH & VREFL are connected across the power supply rails. When using less than the full supply voltage be mindfull of the limits placed on VREFH and VREFL as specified in the References section of DC Electrical Characteristics. WRITING TO MEMORY Programming the CAT521’s non-volatile memory is accomplished through the control signals: Chip Select (CS) and Program (PROG). With CS high, a start bit followed by a two bit DPP address and eight data bits are clocked into the DPP wiper control register via the DI pin. Data enters on the clock’s rising edge. The DPP output changes to its new setting on the clock cycle following D7, the last data bit. ¯¯¯¯¯ READY/BUSY When saving data to non-volatile memory, the ¯¯¯¯) signals the start and Ready/Busy ouput (RDY/BSY duration of the erase/write cycle. Upon receiving a ¯¯¯¯ command to store data (PROG goes high) RDY/BSY goes low and remains low until the programming cycle is complete. During this time the CAT521 will ignore any data appearing at DI and no data will be output on DO. Programming is accomplished by bringing PROG high sometime after the start bit and at least 150ns prior to the rising edge of the clock cycle immediately following the D7 bit. Two clock cycles after the D7 bit the DPP wiper control register will be ready to receive the next set of address and data bits. The clock must be kept running throughout the programming cycle. Internal control circuitry takes care of generating and ramping up the programming voltage for data transfer to the non-volatile memory cells. The CAT521 nonvolatile memory cells will endure over 1,000,000 write cycles and will retain data for a minimum of 100 years without being refreshed. ¯¯¯¯ is internally ANDed with a low voltage RDY/BSY detector circuit monitoring VDD. If VDD is below the minimum value required for EEPROM programming, ¯¯¯¯ will remain high following the program RDY/BSY Figure 1. Writing to Memory to 1 2 3 4 5 6 A0 A1 D0 D1 7 8 9 10 11 12 N N+1 N+2 CS NEW DPP DATA DI 1 D2 D3 D4 D5 D6 D7 D6 D7 CURRENT DPP DATA DO D0 D1 D2 D3 D4 D5 PROG RDY/BSY DPP OUTPUT © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CURRENT DPP VALUE NEW DPP VALUE NEW DPP VALUE NON-VOL ATILE VOLATILE NON-VOL ATILE 7 Doc. No. MD-2003 Rev. G CAT521 READING DATA Each time data is transferred into the DPP wiper control register currently held data is shifted out via the D0 pin, thus in every data transaction a read cycle occurs. Note, however, that the reading process is destructive. Data must be removed from the register in order to be read. Figure 2 depicts a Read Only cycle in which no change occurs in the DPP’s output. This feature allows µPs to poll DPPs for their current setting without disturbing the output voltage but it assumes that the setting being read is also stored in non-volatile memory so that it can be restored at the end of the read cycle. In Figure 2 CS returns low th before the 13 clock cycle completes. In doing so the non-volatile memory's setting is reloaded into the DPP wiper control register. Since this value is the same as that which had been there previously no change in the DPP’s output is noticed. Had the value held in the control register been different from that stored in nonvolatile memory then a change would occur at the read cycle’s conclusion. TEMPORARILY CHANGE OUTPUT The CAT521 allows temporary changes in the DPP’s output to be made without disturbing the settings retained in non-volatile memory. This feature is particularly useful when testing for a new output setting and allows for user adjustment of preset or default values without losing the original factory settings. Figure 2. Reading from Memory Figure 3. Temporary Change in Output Figure 3 shows the control and data signals needed to effect a temporary output change. DPP settings may be changed as many times as required. The temporary setting remains in effect long as CS remains high. When CS returns low the DPP will return to the output value stored in non-volatile memory. When it is desired to save a new setting acquired using this feature, the new value must be reloaded into the DPP wiper control register prior to programming. This is because the CAT521’s internal control circuitry discards from the programming register the new data two clock cycles after receiving it if no PROG signal is received. to to 1 2 3 4 5 6 7 8 9 10 11 1 2 3 4 5 6 A0 A1 D0 D1 D0 D1 7 8 9 10 11 12 N N+1 N+2 12 CS CS NEW DPP DATA DI 1 A0 DI A1 1 D0 D1 D2 D3 D4 D5 D3 D4 D5 D6 D7 D6 D7 CURRENT DPP DATA CURRENT DPP DATA DO D2 D6 DO D7 D2 D3 D4 D5 PROG PROG RDY/BSY RDY/BSY DPP OUTPUT DPP OUTPUT CURRENT DPP VALUE NON-VOL ATILE Doc. No. MD-2003 Rev. G 8 CURRENT DPP VALUE NEW DPP VALUE CURRENT DPP VALUE NON-VOL ATILE VOLATILE NON-VOL ATILE © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT521 APPLICATION CIRCUITS +5V VI RI DPP INPUT RF DPP OUTPUT VDPP = +15V VREFH VDD CONTROL & DATA OP 07 -15V VREFL VOUT = LSB VOUT + CAT521 GND MSB – VDPP ( RI + RF ) - VI R F RI For R I = RF VOUT = 2VDPP - VI 1111 1111 1000 0000 0111 1111 0000 0001 0000 0000 ANALOG OUTPUT CODE V - VZERO + VZERO 255 FS VFS = 0.99VREF VREF = 5V VZERO = 0.01VREF RI = RF 255 × 0.98VREF + 0.01VREF = 0.990 VREF 255 128 × 0.98VREF + 0.01VREF = 0.502VREF 255 127 × 0.98VREF + 0.01VREF = 0.498 VREF 255 1 × 0.98VREF + 0.01VREF = 0.014 VREF 255 0 × 0.98VREF + 0.01VREF = 0.010 VREF 255 VOUT = +4.90V VOUT = +0.02V VOUT = -0 .02V VOUT = -4.86V VOUT = -4.90V Bipolar DPP Output V+ +5V RI I > 2mA RF +15V VDD CONTROL & DATA – VREFH + CAT521 GND VREF = 5.00V VOUT VDD OP 07 CONTROL & DATA -15V VREFL VREFH VREFL GND R VOUT = (1 + F ) VDPP RI Amplified DPP Output LT 1029 CAT521 Digitally Trimmed Voltage Reference 28 - 32V 15kΩ 10µF 10kΩ 1N5231B VDD CONTROL & DATA VREFH 5.1V CAT521 + MPT3055EL GND VREFL – LM 324 OUTPUT 1.00kΩ 4.02kΩ 10µF 35V 0 - 25V @ 1A Digitally Controlled Voltage Reference © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 9 Doc. No. MD-2003 Rev. G CAT521 PACKAGE OUTLINE DRAWING PDIP 14-Lead (L) (1)(2) SYMBOL MIN A 3.56 5.33 A1 0.38 2.92 3.30 4.95 b 0.36 0.45 0.55 b1 1.15 1.52 1.77 c 0.21 0.26 0.35 D 18.67 19.05 19.68 E 7.62 7.87 8.25 E1 6.10 6.35 7.11 e TOP VIEW MAX A2 E1 D NOM 2.54 BSC eB 7.88 L 2.99 10.92 3.30 3.81 E A2 A c A1 e L b b1 eB SIDE VIEW END VIEW For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/tapeandreel.pdf. Notes: (1) All dimensions are in millimeters. Angles in degrees. (2) Complies with JEDEC MS-001. Doc. No. MD-2003 Rev. G 10 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT521 SOIC 14-Lead (W) (1)(2) SYMBOL E1 MIN NOM MAX A 1.35 1.75 A1 0.10 0.25 b 0.33 0.51 c 0.19 D 8.55 E E1 E 0.25 8.65 8.75 5.80 6.00 6.20 3.80 3.90 4.00 e 1.27 BSC h 0.25 0.50 L 0.40 1.27 θ 0º 8º PIN#1 IDENTIFICATION TOP VIEW h D θ A e b c L A1 SIDE VIEW END VIEW For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/tapeandreel.pdf. Notes: (1) All dimensions are in millimeters. Angles in degrees. (2) Complies with JEDEC MS-012. © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 11 Doc. No. MD-2003 Rev. G CAT521 EXAMPLE OF ORDERING INFORMATION Prefix CAT Device # Suffix 521 W Optional Company ID I Temperature Range I = Industrial (-40ºC to 85ºC) Product Number 521 - T2 Tape & Reel T2: 2000/Reel Package L: PDIP W: SOIC Notes: (1) (2) (3) All packages are RoHS compliant (Lead-free, Halogen-free). Standard lead finish is Matte-Tin. The device used in the above example is a CAT521WI-T2 (SOIC, Industrial Temperature, Tape & Reel). ORDERING INFORMATION CAT521WI CAT521LI Doc. No. MD-2003 Rev. G 12 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice REVISION HISTORY Date 3/16/2004 Rev. E Reason Updated Potentiometer Characteristics 07/12/2004 F Updated Functional Diagram Updated Potentiometer Characteristics Added Note 3 under Potentiometer/AC Characteristics tables 07/26/2007 G Updated Ordering Information Added MD- to document number Add Package Outline Drawings Copyrights, Trademarks and Patents © Catalyst Semiconductor, Inc. Trademarks and registered trademarks of Catalyst Semiconductor include each of the following: Beyond Memory™, DPP™, EZDim™, LDD™, MiniPot™, and Quad-Mode™ Catalyst Semiconductor has been issued U.S. and foreign patents and has patent applications pending that protect its products. CATALYST SEMICONDUCTOR MAKES NO WARRANTY, REPRESENTATION OR GUARANTEE, EXPRESS OR IMPLIED, REGARDING THE SUITABILITY OF ITS PRODUCTS FOR ANY PARTICULAR PURPOSE, NOR THAT THE USE OF ITS PRODUCTS WILL NOT INFRINGE ITS INTELLECTUAL PROPERTY RIGHTS OR THE RIGHTS OF THIRD PARTIES WITH RESPECT TO ANY PARTICULAR USE OR APPLICATION AND SPECIFICALLY DISCLAIMS ANY AND ALL LIABILITY ARISING OUT OF ANY SUCH USE OR APPLICATION, INCLUDING BUT NOT LIMITED TO, CONSEQUENTIAL OR INCIDENTAL DAMAGES. Catalyst Semiconductor products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Catalyst Semiconductor product could create a situation where personal injury or death may occur. Catalyst Semiconductor reserves the right to make changes to or discontinue any product or service described herein without notice. Products with data sheets labeled "Advance Information" or "Preliminary" and other products described herein may not be in production or offered for sale. Catalyst Semiconductor advises customers to obtain the current version of the relevant product information before placing orders. Circuit diagrams illustrate typical semiconductor applications and may not be complete. Catalyst Semiconductor, Inc. Corporate Headquarters 2975 Stender Way Santa Clara, CA 95054 Phone: 408.542.1000 Fax: 408.542.1200 www.catsemi.com Document No: MD-2003 Revision: G Issue date: 07/26/07