Single, Low Voltage Digitally Controlled Potentiometer (XDCP™) ISL23415 Features The ISL23415 is a volatile, low voltage, low noise, low power, SPI™ bus, 256 taps, single digitally controlled potentiometer (DCP), which integrates DCP core, wiper switches and control logic on a monolithic CMOS integrated circuit. • 256 resistor taps The digitally controlled potentiometer is implemented with a combination of resistor elements and CMOS switches. The position of the wipers are controlled by the user through the SPI bus interface. The potentiometer has an associated volatile Wiper Register (WR) that can be directly written to and read by the user. The contents of the WR controls the position of the wiper. When powered on, the ISL23415’s wiper will always commence at mid-scale (128 tap position). The low voltage, low power consumption, and small package of the ISL23415 make it an ideal choice for use in battery operated equipment. In addition, the ISL23415 has a VLOGIC pin allowing down to 1.2V bus operation, independent from the VCC value. This allows for low logic levels to be connected directly to the ISL23415 without passing through a voltage level shifter. The DCP can be used as a three-terminal potentiometer or as a two-terminal variable resistor in a wide variety of applications including control, parameter adjustments, and signal processing. • SPI serial interface - No additional level translator for low bus supply - Daisy Chaining of multiple DCP • Power supply - VCC = 1.7V to 5.5V analog power supply - VLOGIC = 1.2V to 5.5V SPI bus/logic power supply • Wiper resistance: 70Ω typical @ VCC = 3.3V • Shutdown Mode - forces the DCP into an end-to-end open circuit and RW is shorted to RL internally • Power-on preset to mid-scale (128 tap position) • Shutdown and standby current <2.8µA max • DCP terminal voltage from 0V to VCC • 10kΩ, 50kΩ or 100kΩ total resistance • Extended industrial temperature range: -40°C to +125°C • 10 Ld MSOP or 10 Ld µTQFN packages • Pb-free (RoHS compliant) Applications • Power supply margining • RF power amplifier bias compensation • LCD bias compensation • Gain adjustment in battery powered instruments • Portable medical equipment calibration 10000 RESISTANCE (Ω) 8000 6000 4000 2000 0 0 50 100 150 200 250 TAP POSITION (DECIMAL) FIGURE 1. FORWARD AND BACKWARD RESISTANCE vs TAP POSITION, 10k August 16, 2011 FN7780.1 1 FIGURE 2. VREF ADJUSTMENT CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas Inc. 2010, 2011. All Rights Reserved Intersil (and design) and XDCP are trademarks owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. ISL23415 Block Diagram VCC VLOGIC SCK SDI I/O BLOCK LEVEL SHIFTER SDO CS RH POWER-UP INTERFACE, CONTROL AND STATUS LOGIC WR VOLATILE REGISTER AND WIPER CONTROL CIRCUITRY RL RW GND Pin Configurations Pin Descriptions ISL23415 (10 LD MSOP) TOP VIEW O 10 GND 2 9 VCC SDO 3 8 RH SDI 4 7 RW CS 5 6 RL VLOGIC 1 SCK O 10 VLOGIC ISL23415 (10 LD µTQFN) TOP VIEW 1 9 GND SDO 2 8 VCC SDI 3 7 RH CS 4 6 RW µTQFN SYMBOL DESCRIPTION 1 10 VLOGIC 2 1 SCK Logic Pin - Serial bus clock input 3 2 SDO Logic Pin - Serial bus data output (configurable) 4 3 SDI Logic Pin - Serial bus data input 5 4 CS Logic Pin - Active low Chip Select 6 5 RL DCP “low” terminal 7 6 RW DCP wiper terminal 8 7 RH DCP “high” terminal 9 8 VCC Analog power supply. Range 1.7V to 5.5V 10 9 GND Ground pin SPI bus/logic supply. Range 1.2V to 5.5V RL 5 SCK MSOP 2 FN7780.1 August 16, 2011 ISL23415 Ordering Information PART NUMBER (Note 5) PART MARKING ISL23415TFUZ (Notes 1, 3) 3415T RESISTANCE OPTION (kΩ) TEMP. RANGE (°C) 100 -40 to +125 PACKAGE (Pb-free) 10 Ld MSOP PKG. DWG. # M10.118 ISL23415UFUZ (Notes 1, 3) 3415U 50 -40 to +125 10 Ld MSOP M10.118 ISL23415WFUZ (Notes 1, 3) 3415W 10 -40 to +125 10 Ld MSOP M10.118 ISL23415TFRUZ-T7A (Notes 2, 4) HE 100 -40 to +125 10 Ld µTQFN 2.1x1.6 L10.2.1x1.6A ISL23415TFRUZ-TK (Notes 2, 4) HE 100 -40 to +125 10 Ld µTQFN 2.1x1.6 L10.2.1x1.6A ISL23415UFRUZ-T7A (Notes 2, 4) HD 50 -40 to +125 10 Ld µTQFN 2.1x1.6 L10.2.1x1.6A ISL23415UFRUZ-TK (Notes 2, 4) HD 50 -40 to +125 10 Ld µTQFN 2.1x1.6 L10.2.1x1.6A ISL23415WFRUZ-T7A (Notes 2, 4) HC 10 -40 to +125 10 Ld µTQFN 2.1x1.6 L10.2.1x1.6A ISL23415WFRUZ-TK (Notes 2, 4) HC 10 -40 to +125 10 Ld µTQFN 2.1x1.6 L10.2.1x1.6A NOTES: 1. Add “-TK” or “-T7A” suffix for Tape and Reel option. Please refer to TB347 for details on reel specifications. 2. Please refer to TB347 for details on reel specifications. 3. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 4. These Intersil Pb-free plastic packaged products employ special Pb-free material sets; molding compounds/die attach materials and NiPdAu plate - e4 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 5. For Moisture Sensitivity Level (MSL), please see device information page for ISL23415. For more information on MSL please see techbrief TB363. 3 FN7780.1 August 16, 2011 ISL23415 Absolute Maximum Ratings Thermal Information Supply Voltage Range VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.0V VLOGIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.0V Voltage on any DCP Terminal Pin . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.0V Voltage on any Digital Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.0V Wiper Current IW (10s). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±6mA ESD Rating Human Body Model (Tested per JESD22-A114E) . . . . . . . . . . . . . . .6.5kV CDM Model (Tested per JESD22-A114E) . . . . . . . . . . . . . . . . . . . . . . . 1kV Machine Model (Tested per JESD22-A115-A) . . . . . . . . . . . . . . . . . . 200V Latch Up (Tested per JESD-78B; Class 2, Level A) . . . . . . . . . . 100mA @ +125°C Thermal Resistance (Typical) θJA (°C/W) θJC (°C/W) 10 Ld MSOP Package (Note 6, 7). . . . . . . . 170 70 10 Ld µTQFN Package (Note 6, 7) . . . . . . . 145 90 Maximum Junction Temperature (Plastic Package) . . . . . . . . . . . .+150°C Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp Recommended Operating Conditions Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +125°C VCC Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7V to 5.5V VLOGIC Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2V to 5.5V DCP Terminal Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0 to VCC Max Wiper Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±3mA CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. NOTES: 6. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details. 7. For θJC, the “case temp” location is the center top of the package. Analog Specifications SYMBOL RTOTAL VCC = 2.7V to 5.5V, VLOGIC = 1.2V to 5.5V over recommended operating conditions unless otherwise stated. Boldface limits apply over the operating temperature range, -40°C to +125°C. PARAMETER RH to RL Resistance TEST CONDITIONS VRH, VRL RW TYP (Note 8) MAX (Note 20) UNITS W option 10 kΩ U option 50 kΩ T option 100 kΩ RH to RL Resistance Tolerance End-to-End Temperature Coefficient MIN (Note 20) -20 ±2 +20 % W option 175 ppm/°C U option 85 ppm/°C T option 70 ppm/°C DCP Terminal Voltage VRH or VRL to GND Wiper Resistance RH - floating, VRL = 0V, force IW current to the wiper, IW = (VCC - VRL)/RTOTAL, VCC = 2.7V to 5.5V 70 VCC = 1.7V 580 Ω See “DCP Macro Model” on page 8. 32 pF CH/CL/CW Terminal Capacitance 0 VCC V 200 Ω ILkgDCP Leakage on DCP Pins Voltage at pin from GND to VCC Noise Resistor Noise Density Wiper at middle point, W option 16 nV/√Hz Wiper at middle point, U option 49 nV/√Hz Wiper at middle point, T option 61 nV/√Hz Digital Feedthrough from Bus to Wiper Wiper at middle point -65 dB Power Supply Reject Ratio Wiper output change if VCC change ±10%; wiper at middle point -75 dB Feed Thru PSRR 4 -0.4 <0.1 0.4 µA FN7780.1 August 16, 2011 ISL23415 Analog Specifications SYMBOL VCC = 2.7V to 5.5V, VLOGIC = 1.2V to 5.5V over recommended operating conditions unless otherwise stated. Boldface limits apply over the operating temperature range, -40°C to +125°C. (Continued) MIN (Note 20) TYP (Note 8) MAX (Note 20) W option -1.0 ±0.5 +1.0 LSB (Note 9) U, T option -0.5 ±0.15 +0.5 LSB (Note 9) -1 ±0.4 +1 LSB (Note 9) U, T option -0.4 ±0.1 +0.4 LSB (Note 9) W option -3.5 -2 0 LSB (Note 9) U, T option -2 -0.5 0 LSB (Note 9) W option 0 2 3.5 LSB (Note 9) U, T option 0 0.4 2 LSB (Note 9) PARAMETER TEST CONDITIONS UNITS VOLTAGE DIVIDER MODE (0V @ RL; VCC @ RH; measured at RW, unloaded) INL (Note 13) DNL (Note 12) FSerror (Note 11) ZSerror (Note 10) TCV (Note 14) fcutoff Integral Non-linearity, Guaranteed Monotonic Differential Non-linearity, Guaranteed Monotonic Full-scale Error Zero-scale Error Ratiometric Temperature Coefficient W option W option, Wiper Register set to 80 hex 8 ppm/°C U option, Wiper Register set to 80 hex 4 ppm/°C T option, Wiper Register set to 80 hex 2.3 ppm/°C Large Signal Wiper Settling Time From code 0 to FF hex 300 ns -3dB Cutoff Frequency Wiper at middle point W option 1200 kHz Wiper at middle point U option 250 kHz Wiper at middle point T option 120 kHz RHEOSTAT MODE (Measurements between RW and RL pins with RH not connected, or between RW and RH with RL not connected) RINL (Note 18) Integral Non-linearity, Guaranteed Monotonic W option; VCC = 2.7V to 5.5V -2.0 W option; VCC = 1.7V U, T option; VCC = 2.7V to 5.5V Differential Non-linearity, Guaranteed Monotonic W option; VCC = 2.7V to 5.5V -1.0 U, T option; VCC = 1.7V 5 ±0.3 -1 ±0.4 +1.0 ±0.15 ±0.35 MI (Note 15) MI (Note 15) +1 ±0.6 -0.5 MI (Note 15) MI (Note 15) 2.1 W option; VCC = 1.7V U, T option; VCC = 2.7V to 5.5V +2.0 10.5 U, T option; VCC = 1.7V RDNL (Note 17) ±1 MI (Note 15) MI (Note 15) +0.5 MI (Note 15) MI (Note 15) FN7780.1 August 16, 2011 ISL23415 Analog Specifications VCC = 2.7V to 5.5V, VLOGIC = 1.2V to 5.5V over recommended operating conditions unless otherwise stated. Boldface limits apply over the operating temperature range, -40°C to +125°C. (Continued) SYMBOL PARAMETER TEST CONDITIONS Roffset (Note 16) Offset, Wiper at 0 Position W option; VCC = 2.7V to 5.5V MIN (Note 20) TYP (Note 8) MAX (Note 20) 0 3 5.5 W option; VCC = 1.7V U, T option; VCC = 2.7V to 5.5V TCR (Note 19) Resistance Temperature Coefficient Operating Specifications SYMBOL ILOGIC ICC ILOGIC SB ICC SB VLOGIC Supply Current (Write/Read) VCC Supply Current (Write/Read) VCC Standby Current ILOGIC SHDN VLOGIC Shutdown Current ICC SHDN VCC Shutdown Current 6.3 0 MI (Note 15) 0.5 2 1.1 MI (Note 15) W option; Wiper register set between 32 hex and FF hex 220 ppm/°C U option; Wiper register set between 32 hex and FF hex 100 ppm/°C T option; Wiper register set between 32 hex and FF hex 75 ppm/°C MAX (Note 20) UNITS VLOGIC = 5.5V, VCC = 5.5V, fSCK = 5MHz (for SPI active read and write) 1.5 mA VLOGIC = 1.2V, VCC = 1.7V, fSCK = 1MHz (for SPI active read and write) 30 µA VLOGIC = 5.5V, VCC = 5.5V 100 µA VLOGIC = 1.2V, VCC = 1.7V 10 µA VLOGIC = 5.5V, VCC = 5.5V, SPI interface in standby 1.3 µA VLOGIC = 1.2V, VCC = 1.7V, SPI interface in standby 0.4 µA VLOGIC = 5.5V, VCC = 5.5V, SPI interface in standby 1.5 µA VLOGIC = 1.2V, VCC = 1.7V, SPI interface in standby 1 µA VLOGIC = 5.5V, VCC = 5.5V, SPI interface in standby 1.3 µA VLOGIC = 1.2V, VCC = 1.7V, SPI interface in standby 0.4 µA VLOGIC = VCC = 5.5V, SPI interface in standby 1.5 µA 1 µA 0.4 µA TEST CONDITIONS Leakage Current, at Pins CS, SDO, SDI, SCK Voltage at pin from GND to VLOGIC 6 MI (Note 15) U, T option; VCC = 1.7V MIN (Note 20) TYP (Note 8) VLOGIC = 1.2V, VCC = 1.7V, SPI interface in standby ILkgDig MI (Note 15) VCC = 2.7V to 5.5V, VLOGIC = 1.2V to 5.5V over recommended operating conditions unless otherwise stated. Boldface limits apply over the operating temperature range, -40°C to +125°C. PARAMETER VLOGIC Standby Current UNITS -0.4 <0.1 FN7780.1 August 16, 2011 ISL23415 Operating Specifications SYMBOL tDCP tShdnRec VCC = 2.7V to 5.5V, VLOGIC = 1.2V to 5.5V over recommended operating conditions unless otherwise stated. Boldface limits apply over the operating temperature range, -40°C to +125°C. (Continued) PARAMETER TEST CONDITIONS Wiper Response Time DCP Recall Time From Shutdown Mode VCC, VLOGIC VCC, VLOGIC Ramp Rate Ramp Serial Interface Specification SYMBOL MIN (Note 20) TYP (Note 8) MAX (Note 20) UNITS W option; CS rising edge to wiper new position, from 10% to 90% of final value. 0.4 µs U option; CS rising edge to wiper new position, from 10% to 90% of final value. 1.5 µs T option; CS rising edge to wiper new position, from 10% to 90% of final value. 3.5 µs CS rising edge to wiper recalled position and RH connection 1.5 µs Ramp monotonic at any level 0.01 50 V/ms For SCK, SDI, SDO, CS Unless Otherwise Noted. PARAMETER TEST CONDITIONS MIN (Note 20) TYP (Note 8) MAX (Note 20) UNITS VIL Input LOW Voltage -0.3 0.3 x VLOGIC V VIH Input HIGH Voltage 0.7 x VLOGIC VLOGIC+ 0.3 V Hysteresis VOL SDI and SCK Input Buffer Hysteresis SDO Output Buffer LOW Voltage VLOGIC > 2V 0.05 x VLOGIC VLOGIC < 2V 0.1 x VLOGIC IOL = 3mA, VLOGIC > 2V V 0 0.4 IOL = 1.5mA, VLOGIC < 2V Rpu (Note 19) SDO Pull-up Resistor Off-chip Maximum is determined by tRO and tFO with maximum bus load Cb = 30pF, fSCK = 5MHz V 0.2 x VLOGIC V 1.5 kΩ Cpin SCK, SDO, SDI, CS Pin Capacitance 10 fSCK SCK Frequency VLOGIC = 1.7V to 5.5V tCYC SPI Clock Cycle Time VLOGIC ≥ 1.7V 200 ns tWH SPI Clock High Time VLOGIC ≥ 1.7V 100 ns tWL SPI Clock Low Time VLOGIC ≥ 1.7V 100 ns tLEAD Lead Time VLOGIC ≥ 1.7V 250 ns tLAG Lag Time VLOGIC ≥ 1.7V 250 ns tSU SDI, SCK and CS Input Setup Time VLOGIC ≥ 1.7V 50 ns tH SDI, SCK and CS Input Hold Time VLOGIC ≥ 1.7V 50 ns tRI SDI, SCK and CS Input Rise Time VLOGIC ≥ 1.7V 10 tFI SDI, SCK and CS Input Fall Time VLOGIC ≥ 1.7V 10 20 ns 100 ns VLOGIC = 1.2V to 1.6V pF 5 MHz 1 MHz ns tDIS SDO Output Disable Time VLOGIC ≥ 1.7V 0 tSO SDO Output Setup Time VLOGIC ≥ 1.7V 50 ns tV SDO Output Valid Time VLOGIC ≥ 1.7V 150 ns tHO SDO Output Hold Time VLOGIC ≥ 1.7V 0 tRO SDO Output Rise Time Rpu = 1.5k, Cbus = 30pF 60 ns tFO SDO Output Fall Time Rpu = 1.5k, Cbus = 30pF 60 ns 7 ns FN7780.1 August 16, 2011 ISL23415 Serial Interface Specification SYMBOL tCS For SCK, SDI, SDO, CS Unless Otherwise Noted. (Continued) PARAMETER MIN (Note 20) TEST CONDITIONS CS Deselect Time TYP (Note 8) MAX (Note 20) 2 UNITS µs NOTES: 8. Typical values are for TA = +25°C and 3.3V supply voltages. 9. LSB = [V(RW)255 – V(RW)0]/255. V(RW)255 and V(RW)0 are V(RW) for the DCP register set to FF hex and 00 hex respectively. LSB is the incremental voltage when changing from one tap to an adjacent tap. 10. ZS error = V(RW)0/LSB. 11. FS error = [V(RW)255 – VCC]/LSB. 12. DNL = [V(RW)i – V(RW)i-1]/LSB-1, for i = 1 to 255. i is the DCP register setting. 13. INL = [V(RW)i – i • LSB – V(RW)0]/LSB for i = 1 to 255 Max ( V ( RW ) i ) – Min ( V ( RW ) i ) 10 6 for i = 16 to 255 decimal, T = -40°C to +125°C. Max( ) is the maximum value of the wiper voltage TC V = ------------------------------------------------------------------------------ × --------------------V ( RWi ( +25°C ) ) +165°C and Min( ) is the minimum value of the wiper voltage over the temperature range. 14. 15. MI = |RW255 – RW0|/255. MI is a minimum increment. RW255 and RW0 are the measured resistances for the DCP register set to FF hex and 00 hex respectively. 16. Roffset = RW0/MI, when measuring between RW and RL. Roffset = RW255/MI, when measuring between RW and RH. 17. RDNL = (RWi – RWi-1)/MI -1, for i = 16 to 255. 18. RINL = [RWi – (MI • i) – RW0]/MI, for i = 16 to 255. 19. 6 [ Max ( Ri ) – Min ( Ri ) ] 10 for i = 16 to 255, T = -40°C to +125°C. Max( ) is the maximum value of the resistance and Min( ) is the TC R = ------------------------------------------------------- × --------------------Ri ( +25°C ) +165°C minimum value of the resistance over the temperature range. 20. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design. DCP Macro Model RTOTAL RH CL CH CW 32pF RL 32pF 32pF RW Timing Diagrams Input Timing tCS CS SCK tSU SDI tH MSB tLAG tCYC tLEAD tWL ... tWH ... tRI tFI LSB SDO 8 FN7780.1 August 16, 2011 ISL23415 Timing Diagrams (Continued) Output Timing CS SCK ... tSO tHO tDIS ... MSB SDO LSB tV ADDR SDI XDCP™ Timing (for All Load Instructions) CS tDCP SCK ... ... MSB SDI LSB VW SDO *When CS is HIGH SDO at Z or Hi-Z state 0.4 0.30 0.2 0.15 DNL (LSB) DNL (LSB) Typical Performance Curves 0 -0.2 0 -0.15 -0.4 0 50 100 150 200 TAP POSITION (DECIMAL) FIGURE 3. 10k DNL vs TAP POSITION, VCC = 5V 9 250 -0.30 0 50 100 150 200 250 TAP POSITION (DECIMAL) FIGURE 4. 50k DNL vs TAP POSITION, VCC = 5V FN7780.1 August 16, 2011 ISL23415 (Continued) 0.4 0.30 0.2 0.15 INL (LSB) INL (LSB) Typical Performance Curves 0 0 -0.15 -0.2 -0.30 -0.4 0 50 100 150 200 0 250 50 TAP POSITION (DECIMAL) 150 200 250 FIGURE 6. 50k INL vs TAP POSITION, VCC = 5V 0.4 0.30 0.2 0.15 RDNL (MI) RDNL (MI) FIGURE 5. 10k INL vs TAP POSITION, VCC = 5V 0 -0.2 -0.4 100 TAP POSITION (DECIMAL) 0 -0.15 0 50 100 150 200 -0.30 250 0 50 TAP POSITION (DECIMAL) FIGURE 7. 10k RDNL vs TAP POSITION, VCC = 5V 100 150 TAP POSITION (DECIMAL) 200 250 FIGURE 8. 50k RDNL vs TAP POSITION, VCC = 5V 0.6 0.30 0.4 0.15 RINL (MI) RINL (MI) 0.2 0 0 -0.2 -0.15 -0.4 -0.6 0 50 100 150 200 TAP POSITION (DECIMAL) FIGURE 9. 10k RINL vs TAP POSITION, VCC = 5V 10 250 -0.30 0 50 100 150 200 250 TAP POSITION (DECIMAL) FIGURE 10. 50k RINL vs TAP POSITION, VCC = 5V FN7780.1 August 16, 2011 ISL23415 Typical Performance Curves (Continued) 60 70 +125°C +125°C 50 WIPER RESISTANCE (Ω) WIPER RESISTANCE (Ω) 60 +25°C 50 40 30 20 -40°C 10 50 100 150 TAP POSITION (DECIMAL) 200 30 20 0 250 -40°C 0 100 150 200 250 FIGURE 12. 50k WIPER RESISTANCE vs TAP POSITION, VCC = 5V 300 70 250 60 50 TCv (ppm/°C) 200 150 100 40 30 20 50 0 15 50 TAP POSITION (DECIMAL) FIGURE 11. 10k WIPER RESISTANCE vs TAP POSITION, VCC = 5V TCv (ppm/°C) 40 10 0 0 +25°C 10 65 115 165 0 15 215 65 TAP POSITION (DECIMAL) 115 165 215 TAP POSITION (DECIMAL) FIGURE 13. 10k TCv vs TAP POSITION FIGURE 14. 50k TCv vs TAP POSITION 600 200 500 TCr (ppm/°C) TCr (ppm/°C) 150 400 300 200 100 50 100 0 15 65 115 165 TAP POSITION (DECIMAL) FIGURE 15. 10k TCr vs TAP POSITION 11 215 0 15 65 115 165 215 TAP POSITION (DECIMAL) FIGURE 16. 50k TCr vs TAP POSITION FN7780.1 August 16, 2011 ISL23415 Typical Performance Curves (Continued) 120 35 30 90 TCr (ppm/°C) TCv (ppm/°C) 25 20 15 10 60 30 5 0 15 65 115 165 215 0 15 65 TAP POSITION (DECIMAL) FIGURE 17. 100k TCv vs TAP POSITION 115 165 TAP POSITION (DECIMAL) 215 FIGURE 18. 100k TCr vs TAP POSITION SCK CLOCK RW PIN 10mV/DIV 1µs/DIV 20mV/DIV 5µs/DIV FIGURE 19. WIPER DIGITAL FEEDTHROUGH FIGURE 20. WIPER TRANSITION GLITCH 1V/DIV 0.1s/DIV 1V/DIV 1µs/DIV VRW CS RISING EDGE FIGURE 21. WIPER LARGE SIGNAL SETTLING TIME 12 FIGURE 22. POWER-ON START-UP IN VOLTAGE DIVIDER MODE FN7780.1 August 16, 2011 ISL23415 Typical Performance Curves (Continued) 1.2 STANDBY CURRENT ICC (µA) CH1: 0.5V/DIV, 0.2µs/DIV RH PIN CH2: 0.2V/DIV, 0.2µs/DIV RW PIN RTOTAL = 10k -3dB FREQUENCY = 1.4MHz AT MIDDLE TAP 1.0 0.8 VCC = 5.5V, VLOGIC = 5.5V 0.6 0.4 VCC = 1.7V, VLOGIC = 1.2V 0.2 0 -40 -15 10 35 60 85 110 TEMPERATURE (°C) FIGURE 23. 10k -3dB CUT OFF FREQUENCY FIGURE 24. STANDBY CURRENT vs TEMPERATURE Functional Pin Description Potentiometers Pins RH AND RL The high (RH) and low (RL) terminals of the ISL23415 are equivalent to the fixed terminals of a mechanical potentiometer. The RH and RL are referenced to the relative position of the wiper and not the voltage potential on the terminals. With the WR register set to 255 decimal, the wiper will be closest to RH, and with the WR register set to 0, the wiper is closest to RL. RW The RW is the wiper terminal, and it is equivalent to the moveable terminal of a mechanical potentiometer. The position of the wiper within the array is determined by the WR register. Power Pins VCC Power terminal for the potentiometer section analog power source. Can be any value needed to support voltage range of DCP pins, from 1.7V to 5.5V, independent of the VLOGIC voltage. Bus Interface Pins SERIAL CLOCK (SCL) This input is the serial clock of the SPI serial interface. SERIAL DATA INPUT (SDI) The SDI is a serial data input pin for SPI interface. It receives operation code, wiper address and data from the SPI remote host device. The data bits are shifted in at the rising edge of the serial clock SCK, while the CS input is low. SERIAL DATA OUTPUT (SDO) The SDO is a serial data output pin. During a read cycle, the data bits are shifted out on the falling edge of the serial clock SCK and will be available to the master on the following rising edge of SCK. 13 The output type is configured through ACR[1] bit for Push-Pull or Open Drain operation. Default setting for this pin is Push-Pull. An external pull-up resistor is required for Open Drain output operation. When CS is HIGH, the SDO pin is in tri-state (Z) or high-tri-state (Hi-Z) depends on the selected configuration. CHIP SELECT (CS) CS LOW enables the ISL23415, placing it in the active power mode. A HIGH to LOW transition on CS is required prior to the start of any operation after power-up. When CS is HIGH, the ISL23415 is deselected and the SDO pin is at high impedance, and the device will be in the standby state. VLOGIC Digital power source for the logic control section. It supplies an internal level translator for 1.2V to 5.5V serial bus operation. Use the same supply as the I2C logic source. Principles of Operation The ISL23415 is an integrated circuit incorporating one DCP with its associated registers and an SPI serial interface providing direct communication between a host and the potentiometer. The resistor array is comprised of individual resistors connected in series. At either end of the array and between each resistor is an electronic switch that transfers the potential at that point to the wiper. The electronic switches on the device operate in a “make before break” mode when the wiper changes tap positions. Voltage at any DCP pins, RH, RL or RW, should not exceed VCC level at any conditions during power-up and normal operation. The VLOGIC pin needs to be connected to the SPI bus supply which allows reliable communication with the wide range of microcontrollers and independent of the VCC level. This is extremely important in systems where the digital supply has lower levels than the analog supply. FN7780.1 August 16, 2011 ISL23415 DCP Description While the ISL23415 is being powered up, the WR is reset to 80h (128 decimal), which locates RW roughly at the center between RL and RH. The WR can be read or written to directly using the SPI serial interface as described in the following sections. Memory Description The ISL23415 contains two volatile 8-bit registers: the Wiper Register (WR) and the Access Control Register (ACR). Memory map of ISL23415 is in Table 1. The Wiper Register WR at address 0 contains current wiper position of the DCP. The Access Control Register (ACR) at address 10h contains information and control bits described in Table 2. TABLE 1. MEMORY MAP ADDRESS (hex) VOLATILE DEFAULT SETTING (hex) 10 ACR 40 0 WR 80 TABLE 2. ACCESS CONTROL REGISTER (ACR) BIT # 7 6 5 4 3 2 1 0 NAME 0 SHDN 0 0 0 0 SDO 0 The SDO bit (ACR[1]) configures type of SDO output pin. The default value of SDO bit is 0 for Push-Pull output. The SDO pin can be configured as Open Drain output for some applications. In this case, an external pull-up resistor is required, reference the “Serial Interface Specification” on page 7. RH RW 2kΩ RL FIGURE 25. DCP CONNECTION IN SHUTDOWN MODE When the device enters shutdown, all current DCP WR settings are maintained. When the device exits shutdown, the wipers will return to the previous WR settings after a short settling time (see Figure 26). WIPER VOLTAGE, VRW (V) Each DCP is implemented with a combination of resistor elements and CMOS switches. The physical ends of DCP are equivalent to the fixed terminals of a mechanical potentiometer (RH and RL pins). The RW pin of the DCP is connected to intermediate nodes, and is equivalent to the wiper terminal of a mechanical potentiometer. The position of the wiper terminal within the DCP is controlled by the 8-bit volatile Wiper Register (WR). When the WR of a DCP contains all zeroes (WR[7:0] = 00h), its wiper terminal (RW) is closest to its “Low” terminal (RL). When the WR register of a DCP contains all ones (WR[7:0] = FFh), its wiper terminal (RW) is closest to its “High” terminal (RH). As the value of the WR increases from all zeroes (0) to all ones (255 decimal), the wiper moves monotonically from the position closest to RL to the position closest to RH. At the same time, the resistance between RW and RL increases monotonically, while the resistance between RH and RW decreases monotonically. POWER-UP MID SCALE = 80H USER PROGRAMMED SHDN ACTIVATED AFTER SHDN SHDN RELEASED WIPER RESTORE TO THE ORIGINAL POSITION SHDN MODE 0 TIME (s) FIGURE 26. SHUTDOWN MODE WIPER RESPONSE SPI Serial Interface The ISL23415 supports an SPI serial protocol, mode 0. The device is accessed via the SDI input and SDO output with data clocked in on the rising edge of SCK, and clocked out on the falling edge of SCK. CS must be LOW during communication with the ISL23415. The SCK and CS lines are controlled by the host or master. The ISL23415 operates only as a slave device. All communication over the SPI interface is conducted by sending the MSB of each byte of data first. Protocol Conventions The SPI protocol contains Instruction Byte followed by one or more Data Bytes. A valid Instruction Byte contains instruction as the three MSBs, with the following five register address bits (see Table 3). The next byte sent to the ISL23415 is the Data Byte. Shutdown Function The SHDN bit (ACR[6]) disables or enables shutdown mode for all DCP channels simultaneously. When this bit is 0, i.e., each DCP is forced to end-to-end open circuit and each RW shorted to RL through a 2kΩ serial resistor, as shown in Figure 25. Default value of the SHDN bit is 1. TABLE 3. INSTRUCTION BYTE FORMAT BIT # 7 6 5 4 3 2 1 0 I2 I1 I0 R4 R3 R2 R1 R0 Table 4 contains a valid instruction set for ISL23415. If the [R4:R0] bits are zero or one, then the read or write is to the WRi register. If the [R4:R0] are 10000, then the operation is to the ACR. 14 FN7780.1 August 16, 2011 ISL23415 TABLE 4. INSTRUCTION SET INSTRUCTION SET I2 I1 I0 R4 R3 R2 R1 R0 OPERATION 0 0 0 X X X X X NOP 0 0 1 X X X X X ACR READ 0 1 1 X X X X X ACR WRTE 1 0 0 R4 R3 R2 R1 R0 WRi or ACR READ 1 1 0 R4 R3 R2 R1 R0 WRi or ACR WRTE Where X means “do not care”. CS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 SCK WR INSTRUCTION SDI DATA BYTE ADDR SDO FIGURE 27. TWO BYTE WRITE SEQUENCE CS 1 8 16 24 32 SCK SDI RD NOP ADDR RD SDO ADDR READ DATA FIGURE 28. FOUR BYTE READ SEQUENCE Write Operation Read Operation A write operation to the ISL23415 is a two or more bytes operation. It requires first, the CS transition from HIGH-to-LOW. Then the host sends a valid Instruction Byte, followed by one or more Data Bytes to the SDI pin. The host terminates the write operation by pulling the CS pin from LOW-to-HIGH. Instruction is executed on the rising edge of CS (see Figure 27). A Read operation to the ISL23415 is a four byte operation. It requires first, the CS transition from HIGH-to-LOW. Then the host sends a valid Instruction Byte, followed by a “dummy” Data Byte, NOP Instruction Byte and another “dummy” Data Byte to SDI pin. The SPI host receives the Instruction Byte (instruction code + register address) and requested Data Byte from SDO pin on the rising edge of SCK during third and fourth bytes, respectively. The host terminates the read by pulling the CS pin from LOW-to-HIGH (see Figure 28). 15 FN7780.1 August 16, 2011 ISL23415 Applications Information The first part starts by HIGH-to-LOW transition on CS line, followed by N two bytes read instruction on SDI line with reversed chain access sequence: the instruction byte + dummy data byte for the last DCP in chain is going first, followed by LOW-to-HIGH transition on CS line. The read instructions are executed during second part of read sequence. It also starts by HIGH-to-LOW transition on CS line, followed by N number of two bytes NOP instructions on SDI line and LOW-to-HIGH transition of CS. The data is read on every even byte during second part of read sequence while every odd byte contains code 111b followed by address from which the data is being read. Communicating with ISL23415 Communication with ISL23415 proceeds using SPI interface through the ACR (address 10000b) and WR (addresses 00000b) registers. The wiper of the potentiometer is controlled by the WR register. Writes and reads can be made directly to these register to control and monitor the wiper position. Daisy Chain Configuration Wiper Transition When application needs more than one ISL23415, it can communicate with all of them without additional CS lines by daisy chaining the DCPs as shown on Figure 29. In Daisy Chain configuration, the SDO pin of the previous chip is connected to the SDI pin of the following chip, and each CS and SCK pins are connected to the corresponding microcontroller pins in parallel, like regular SPI interface implementation. The Daisy Chain configuration can also be used for simultaneous setting of multiple DCPs. Note, the number of daisy chained DCPs is limited only by the driving capabilities of SCK and CS pins of microcontroller; for larger number of SPI devices buffering of SCK and CS lines is required. When stepping up through each tap in voltage divider mode, some tap transition points can result in noticeable voltage transients, or overshoot/undershoot, resulting from the sudden transition from a very low impedance “make” to a much higher impedance “break within a short period of time (<1µs). There are several code transitions such as 0Fh to 10h, 1Fh to 20h,..., EFh to FFh, which have higher transient glitch. Note, that all switching transients will settle well within the settling time as stated in the datasheet. A small capacitor can be added externally to reduce the amplitude of these voltage transients, but that will also reduce the useful bandwidth of the circuit, thus may not be a good solution for some applications. It may be a good idea, in that case, to use fast amplifiers in a signal chain for fast recovery. Daisy Chain Write Operation The write operation starts by HIGH-to-LOW transition on CS line, followed by N number of two bytes write instructions on SDI line with reversed chain access sequence: the instruction byte + data byte for the last DCP in chain is going first, as shown in Figure 30, where N is a number of DCPs in chain. The serial data is going through DCPs from DCP0 to DCP(N-1) as follow: DCP0 --> DCP1 --> DCP2 --> ... --> DCP(N-1). The write instruction is executed on the rising edge of CS for all N DCPs simultaneously. VLOGIC Requirements It is recommended to keep VLOGIC powered all the time during normal operation. In a case where turning VLOGIC OFF is necessary, it is recommended to ground the VLOGIC pin of the ISL23415. Grounding the VLOGIC pin or both VLOGIC and VCC does not affect other devices on the same bus. It is good practice to put a 1µF capacitor in parallel with 0.1µF decoupling capacitor close to the VLOGIC pin. Daisy Chain Read Operation The read operation consists of two parts: first, send the read instructions (N two bytes operation) with valid address; second, read the requested data while sending NOP instructions (N two bytes operation) as shown in Figures 31 and 32. VCC Requirements and Placement It is recommended to put a 1µF capacitor in parallel with 0.1µF decoupling capacitor close to the VCC pin. N DCP IN A CHAIN CS SCK DCP0 MOSI MISO µC DCP1 DCP2 CS CS CS SCK SCK SCK SDI SDO SDI SDO SDI DCP(N-1) CS SCK SDO SDI SDO FIGURE 29. DAISY CHAIN CONFIGURATION 16 FN7780.1 August 16, 2011 ISL23415 CS SCK 16 CLKLS WR SDI 16 CLKS 16 CLKS D C P2 SDO 0 WR D C P1 WR D C P0 WR D C P2 WR D C P1 WR D C P2 SDO 1 SDO 2 FIGURE 30. DAISY CHAIN WRITE SEQUENCE OF N = 3 DCP CS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 SCK SDI INSTRUCTION ADDR DATA IN SDO DATA OUT FIGURE 31. TWO BYTE READ INSTRUCTION CS SCK 16 CLKS SDI RD DCP2 16 CLKS RD DCP1 SDO 16 CLKS 16 CLKS 16 CLKS 16 CLKS RD DCP0 NOP NOP NOP DCP2 OUT DCP1 OUT DCP0 OUT FIGURE 32. DAISY CHAIN READ SEQUENCE OF N = 3 DCP 17 FN7780.1 August 16, 2011 ISL23415 Revision History The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make sure you have the latest Rev. DATE REVISION CHANGE 12/15/10 FN7780.0 Initial Release. 7/28/11 FN7780.1 Added “Shutdown Function” section and revised “VLOGIC Standby Current”and “VCC Shutdown Current” limits on page 6. On page 7, split “Wiper Response Time” up into 3 separate conditions for each option (W, U, T). Products Intersil Corporation is a leader in the design and manufacture of high-performance analog semiconductors. The Company's products address some of the industry's fastest growing markets, such as, flat panel displays, cell phones, handheld products, and notebooks. Intersil's product families address power management and analog signal processing functions. Go to www.intersil.com/products for a complete list of Intersil product families. 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For information regarding Intersil Corporation and its products, see www.intersil.com 18 FN7780.1 August 16, 2011 ISL23415 Mini Small Outline Plastic Packages (MSOP) N M10.118 (JEDEC MO-187BA) 10 LEAD MINI SMALL OUTLINE PLASTIC PACKAGE E1 INCHES E -B- INDEX AREA 1 2 0.20 (0.008) A B C TOP VIEW 4X θ 0.25 (0.010) R1 R GAUGE PLANE A SEATING PLANE -C- A2 A1 b -He D 0.10 (0.004) 4X θ L SEATING PLANE C 0.20 (0.008) MIN MAX MIN MAX NOTES A 0.037 0.043 0.94 1.10 - A1 0.002 0.006 0.05 0.15 - A2 0.030 0.037 0.75 0.95 - b 0.007 0.011 0.18 0.27 9 c 0.004 0.008 0.09 0.20 - D 0.116 0.120 2.95 3.05 3 E1 0.116 0.120 2.95 3.05 4 0.020 BSC C a CL E1 0.20 (0.008) C D -B- - 0.187 0.199 4.75 5.05 - L 0.016 0.028 0.40 0.70 6 0.037 REF N C 0.50 BSC E L1 -A- SIDE VIEW SYMBOL e L1 MILLIMETERS 0.95 REF 10 R 0.003 R1 - 10 - 0.07 0.003 - θ 5o 15o α 0o 6o 7 - - 0.07 - - 5o 15o - 0o 6o Rev. 0 12/02 END VIEW NOTES: 1. These package dimensions are within allowable dimensions of JEDEC MO-187BA. 2. Dimensioning and tolerancing per ANSI Y14.5M-1994. 3. Dimension “D” does not include mold flash, protrusions or gate burrs and are measured at Datum Plane. Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006 inch) per side. 4. Dimension “E1” does not include interlead flash or protrusions and are measured at Datum Plane. - H - Interlead flash and protrusions shall not exceed 0.15mm (0.006 inch) per side. 5. Formed leads shall be planar with respect to one another within 0.10mm (.004) at seating Plane. 6. “L” is the length of terminal for soldering to a substrate. 7. “N” is the number of terminal positions. 8. Terminal numbers are shown for reference only. 9. Dimension “b” does not include dambar protrusion. Allowable dambar protrusion shall be 0.08mm (0.003 inch) total in excess of “b” dimension at maximum material condition. Minimum space between protrusion and adjacent lead is 0.07mm (0.0027 inch). 10. Datums -A -H- . and - B - to be determined at Datum plane 11. Controlling dimension: MILLIMETER. Converted inch dimensions are for reference only 19 FN7780.1 August 16, 2011 ISL23415 Package Outline Drawing L10.2.1x1.6A 10 LEAD ULTRA THIN QUAD FLAT NO-LEAD PLASTIC PACKAGE Rev 5, 3/10 8. PIN 1 INDEX AREA 2.10 A B PIN #1 ID 1 0.05 MIN. 1 8. 4 4X 0.20 MIN. 1.60 0.10 MIN. 10 5 0.80 10X 0.40 0.10 6 9 2X 6X 0.50 10 X 0.20 4 TOP VIEW 0.10 M C A B M C BOTTOM VIEW (10 X 0.20) SEE DETAIL "X" (0.05 MIN) PACKAGE OUTLINE 1 MAX. 0.55 0.10 C (10X 0.60) C (0.10 MIN.) (2.00) SEATING PLANE 0.08 C SIDE VIEW (0.80) (1.30) C 0 . 125 REF (6X 0.50 ) (2.50) 0-0.05 TYPICAL RECOMMENDED LAND PATTERN DETAIL "X" NOTES: 20 1. Dimensioning and tolerancing conform to ASME Y14.5M-1994. 2. All Dimensions are in millimeters. Angles are in degrees. Dimensions in ( ) for Reference Only. 3. Unless otherwise specified, tolerance : Decimal ± 0.05 4. Lead width dimension applies to the metallized terminal and is measured between 0.15mm and 0.30mm from the terminal tip. 5. Maximum package warpage is 0.05mm. 6. Maximum allowable burrs is 0.076mm in all directions. 7. Same as JEDEC MO-255UABD except: No lead-pull-back, MIN. Package thickness = 0.45 not 0.50mm Lead Length dim. = 0.45mm max. not 0.42mm. 8. The configuration of the pin #1 identifier is optional, but must be located within the zone indicated. The pin #1 identifier may be either a mold or mark feature. FN7780.1 August 16, 2011