ISL21009_09

® ISL21009 Data Sheet September 16, 2009 FN6327.7 High Voltage Input Precision, Low Noise FGA™ Voltage References The ISL21009 FGA™ voltage references are extremely low power, high precision, and low noise voltage references fabricated on Intersil’s proprietary Floating Gate Analog technology. The ISL21009 features very low noise (4.5µVP-P for 0.1Hz to 10Hz), low operating current (180µA, Max), and 3ppm/°C of temperature drift. In addition, the ISL21009 family features guaranteed initial accuracy as low as ±0.5mV. This combination of high initial accuracy, low power and low output noise performance of the ISL21009 enables versatile high performance control and data acquisition applications with low power consumption. Features • Output Voltages . . . . . . . .1.250V, 2.500V, 4.096V, 5.000V • Initial Accuracy . . . . . . . . . . . . . .±0.5mV, ±1.0mV, ±2.0mV • Input Voltage Range. . . . . . . . . . . . . . . . . . . 3.5V to 16.5V • Output Voltage Noise . . . . . . . . .4.5µVP-P (0.1Hz to 10Hz) • Supply Current . . . . . . . . . . . . . . . . . . . . . . . .180µA (Max) • Temperature Coefficient . . . 3ppm/°C, 5ppm/°C, 10ppm/°C • Output Current Capability. . . . . . . . . . . . . . . Up to ±7.0mA • Operating Temperature Range. . . . . . . . . -40°C to +125°C • Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Ld SOIC • Pb-Free (RoHS Compliant) Available Options VOUT OPTION (V) 1.250 1.250 1.250 2.500 2.500 2.500 4.096 4.096 4.096 5.000 5.000 5.000 INITIAL ACCURACY (mV) ±0.5 ±1.0 ±2.0 ±0.5 ±1.0 ±2.0 ±0.5 ±1.0 ±2.0 ±0.5 ±1.0 ±2.0 TEMPCO. (ppm/°C) 3 5 10 3 5 10 3 5 10 3 5 10 Applications • High Resolution A/Ds and D/As • Digital Meters • Bar Code Scanners • Basestations • Battery Management/Monitoring • Industrial/Instrumentation Equipment PART NUMBER ISL21009BFB812Z ISL21009CFB812Z ISL21009DFB812Z ISL21009BFB825Z ISL21009CFB825Z ISL21009DFB825Z ISL21009BFB841Z ISL21009CFB841Z ISL21009DFB841Z ISL21009BFB850Z ISL21009CFB850Z ISL21009DFB850Z Pinout ISL21009 (8 LD SOIC) TOP VIEW GND OR NC 1 VIN 2 DNC 3 GND 4 8 DNC 7 DNC 6 VOUT 5 TRIM OR NC 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. FGA is a trademark of Intersil Corporation. Copyright Intersil Americas Inc. 2007, 2009. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL21009 Pin Descriptions PIN NUMBER 1 2 4 5 6 3, 7, 8 PIN NAME GND or NC VIN GND TRIM or NC VOUT DNC DESCRIPTION Can be either Ground or No Connect Power Supply Input Connection Ground Connection Allows user trim typically ±2.5%. Leave Unconnected when unused. Voltage Reference Output Connection Do Not Connect; Internal Connection – Must Be Left Floating Ordering Information PART NUMBER (Notes 1, 2) ISL21009BFB812Z ISL21009CFB812Z ISL21009DFB812Z ISL21009BFB825Z ISL21009CFB825Z ISL21009DFB825Z ISL21009BFB841Z ISL21009CFB841Z ISL21009DFB841Z ISL21009BFB850Z ISL21009CFB850Z ISL21009DFB850Z NOTES: 1. 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 STD020. 2. Add “-TK” suffix for tape and reel. Please refer to TB347 for details on reel specifications. PART MARKING 21009BF Z12 21009CF Z12 21009DF Z12 21009BF Z25 21009CF Z25 21009DF Z25 21009BF Z41 21009CF Z41 21009DF Z41 21009BF Z50 21009CF Z50 21009DF Z50 VOUT OPTION (V) 1.250 1.250 1.250 2.500 2.500 2.500 4.096 4.096 4.096 5.000 5.000 5.000 GRADE ±0.5mV, 3ppm/°C ±1.0mV, 5ppm/°C ±2.0mV, 10ppm/°C ±0.5mV, 3ppm/°C ±1.0mV, 5ppm/°C ±2.0mV, 10ppm/°C ±0.5mV, 3ppm/°C ±1.0mV, 5ppm/°C ±2.0mV, 10ppm/°C ±0.5mV, 3ppm/°C ±1.0mV, 5ppm/°C ±2.0mV, 10ppm/°C TEMP. RANGE (°C) -40 to +125 -40 to +125 -40 to +125 -40 to +125 -40 to +125 -40 to +125 -40 to +125 -40 to +125 -40 to +125 -40 to +125 -40 to +125 -40 to +125 PACKAGE (Pb-Free) 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC 8 Ld SOIC PKG. DWG. # M8.15 M8.15 M8.15 M8.15 M8.15 M8.15 M8.15 M8.15 M8.15 M8.15 M8.15 M8.15 2 FN6327.7 September 16, 2009 ISL21009 1 +5V C1 10µF 2 3 4 8 7 6 5 GND VIN NC GND ISL21009-25 NC NC VOUT NC SPI BUS X79000 1 2 3 4 5 6 7 8 9 10 SCK A0 A1 A2 SI SO RDY UP DOWN OE CS CLR VCC VH VL VREF VSS VOUT VBUF VFB 20 19 18 17 16 15 14 13 12 11 LOW NOISE DAC OUTPUT C1 0.001µF FIGURE 1. TYPICAL APPLICATION PRECISION 12-BIT SUB-RANGING DAC 3 FN6327.7 September 16, 2009 ISL21009 Absolute Voltage Ratings Max Voltage VIN to GND . . . . . . . . . . . . . . . . . . . . . . . -0.5V to +18V Max Voltage VOUT to GND (10s) . . . . . . . . . . . . . -0.5V to VOUT +1V Voltage on “DNC” pins . . . . No connections permitted to these pins. ESD Ratings Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6kV Charged Device Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2kV Thermal Information Thermal Resistance (Typical, Note 3) θJA (°C/W) 8 Ld SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Storage Temperature Range . . . . . . . . . . . . . . . . . -65°C to +150°C Pb-free Reflow Profile (Note 4). . . . . . . . . . . . . . . . . . see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp Recommended Operating Conditions Temperature Range (Industrial) . . . . . . . . . . . . . . . -40°C to +125°C 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. IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA NOTES: 3. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details. 4. Post-reflow drift for the ISL21009 devices will range from 100µV to 1.0mV based on experimental results with devices tested in sockets and also on FR4 multi-layer PC boards. The design engineer must take this into account when considering the reference voltage after assembly. Common Electrical Specifications (ISL21009-12, -25, -41, -50) TA = -40°C to +125°C, IOUT = 0, unless otherwise specified. PARAMETER VOA DESCRIPTION VOUT Accuracy @ TA = +25°C ISL21009B ISL21009C ISL21009D TC VOUT Output Voltage Temperature Coefficient (Note 5) ISL21009B ISL21009C ISL21009D IIN ΔVOUT / VOUT ISC tR Supply Current Trim Range Short Circuit Current Turn-on Settling Time Ripple Rejection eN VN Output Voltage Noise Broadband Voltage Noise TA = +25°C, VOUT tied to GND VOUT = ±0.1% f = 10kHz 0.1Hz ≤ f ≤ 10Hz 10Hz ≤ f ≤ 1kHz ±2.0 95 ±2.5 10 100 60 4.5 2.2 CONDITIONS MIN -0.5 -1.0 -2.0 TYP MAX +0.5 +1.0 +2.0 3 5 10 180 UNIT mV mV mV ppm/°C ppm/°C ppm/°C µA % mA µs dB µVP-P µVRMS Electrical Specifications (ISL21009-12, VOUT = 1.250V) VIN = 5.0V, TA = -40°C to +125°C, IOUT = 0, unless otherwise specified. PARAMETER VOUT VIN ΔVOUT/ΔVIN DESCRIPTION Output Voltage Input Voltage Range Line Regulation 3.5V < VIN < 5.5V 5.5V < VIN < 16.5V ΔVOUT/ΔIOUT Load Regulation Sourcing: 0mA ≤ IOUT ≤ 7mA Sinking: -7mA ≤ IOUT ≤ 0mA ΔVOUT/ΔTA ΔVOUT/Δt Thermal Hysteresis (Note 6) Long Term Stability (Note 7) ΔTA = +165°C TA = +25°C 3.5 50 10 10 20 50 50 CONDITIONS MIN TYP 1.250 16.5 150 50 50 100 MAX UNIT V V µV/V µV/V µV/mA µV/mA ppm ppm 4 FN6327.7 September 16, 2009 ISL21009 Electrical Specifications (ISL21009-25, VOUT = 2.50V) PARAMETER VOUT VIN ΔVOUT/ΔVIN DESCRIPTION Output Voltage Input Voltage Range Line Regulation 3.5V < VIN < 5.5V 5.5V < VIN < 16.5V ΔVOUT/ΔIOUT Load Regulation Sourcing: 0mA ≤ IOUT ≤ 7mA Sinking: -7mA ≤ IOUT ≤ 0mA ΔVOUT/ΔTA ΔVOUT/Δt Thermal Hysteresis (Note 6) Long Term Stability (Note 7) ΔTA = +165°C TA = +25°C 3.5 50 10 10 20 50 50 VIN = 5.0V, TA = -40°C to +125°C, IOUT = 0, unless otherwise specified. MIN TYP 2.500 16.5 150 50 50 100 MAX UNIT V V µV/V µV/V µV/mA µV/mA ppm ppm CONDITIONS Electrical Specifications (ISL21009-41, VOUT = 4.096V) PARAMETER VOUT VIN ΔVOUT/ΔVIN ΔVOUT/ΔIOUT DESCRIPTION Output Voltage Input Voltage Range Line Regulation Load Regulation 4.5V < VIN < 16.5V VIN = 5.0V, TA = -40°C to +125°C, IOUT = 0 unless otherwise specified. MIN TYP 4.096 4.5 50 20 20 50 50 16.5 200 100 150 MAX UNIT V V µV/V µV/mA µV/mA ppm ppm CONDITIONS Sourcing: 0mA ≤ IOUT ≤ 5mA Sinking: -5mA ≤ IOUT ≤ 0mA ΔVOUT/ΔTA ΔVOUT/Δt Thermal Hysteresis (Note 6) Long Term Stability (Note 7) ΔTA = +165°C TA = +25°C Electrical Specifications (ISL21009-50, VOUT = 5.0V) PARAMETER VOUT VIN ΔVOUT/ΔVIN ΔVOUT/ΔIOUT DESCRIPTION Output Voltage Input Voltage Range Line Regulation Load Regulation VIN = 10.0V, TA = -40°C to +125°C, IOUT = 0 unless otherwise specified. MIN TYP 5.000 5.5 16.5 20 10 20 50 50 90 100 150 MAX UNIT V V µV/V µV/mA µV/mA ppm ppm CONDITIONS 5.5V < VIN < 16.5V Sourcing: 0mA ≤ IOUT ≤ 7mA Sinking: -7mA ≤ IOUT ≤ 0mA ΔVOUT/ΔTA ΔVOUT/Δt NOTES: Thermal Hysteresis (Note 6) Long Term Stability (Note 7) ΔTA = +165°C TA = +25°C 5. Over the specified temperature range. Temperature coefficient is measured by the box method whereby the change in VOUT is divided by the temperature range; in this case, -40°C to +125°C = +165°C. 6. Thermal Hysteresis is the change of VOUT measured @ TA = +25°C after temperature cycling over a specified range, ΔTA. VOUT is read initially at TA = +25°C for the device under test. The device is temperature cycled and a second VOUT measurement is taken at +25°C. The difference between the initial VOUT reading and the second VOUT reading is then expressed in ppm. For Δ TA = +165°C, the device under test is cycled from +25°C to +125°C to -40°C to +25°C. 7. Long term drift is logarithmic in nature and diminishes over time. Drift after the first 1000 hours will be approximately 10ppm/√(1kHrs). 5 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-12) (REXT = 100kΩ) 110 105 95 100 IIN (µA) IIN (µA) UNIT 3 95 UNIT 2 90 UNIT 1 85 80 80 5 7 9 11 VIN (V) 13 15 17 5 7 9 11 VIN (V) 13 15 17 85 90 +125°C -40°C +25°C 100 FIGURE 2. IIN vs VIN, 3 UNITS FIGURE 3. IIN vs VIN, 3 TEMPERATURES 60 ΔVOUT (µV) NORMALIZED TO VIN = 5V 40 20 0 UNIT 3 -20 -40 -60 3.5 UNIT 1 UNIT 2 ΔVOUT (µV) (NORMALIZED TO VIN = 5.0V) 60 40 20 0 -20 -40 -60 -80 -100 3.5 5.5 7.5 9.5 VIN (V) 11.5 13.5 15.5 +125°C -40°C +25°C 5.5 7.5 9.5 VIN (V) 11.5 13.5 15.5 FIGURE 4. LINE REGULATION, 3 UNITS FIGURE 5. LINE REGULATION OVER-TEMPERATURE 0.06 0.04 0.02 ΔVOUT (mV) 0.00 -0.02 -0.04 -0.06 -0.08 -0.10 -0.12 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 +25°C +125°C -40°C VOUT (V) NORMALIZED TO 1.250V 0.08 1.25020 1.25015 1.25010 1.25005 1.25000 1.24995 1.24990 1.24985 1.24980 -40 -15 10 35 60 85 110 UNIT 3 UNIT 2 UNIT 1 SINKING OUTPUT CURRENT (mA) SOURCING TEMPERATURE (°C) FIGURE 6. LOAD REGULATION FIGURE 7. VOUT vs TEMPERATURE, 3 UNITS 6 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-12) (REXT = 100kΩ) 0 -10 -20 -30 PSRR (dB) -40 -50 -60 -70 -80 -90 -100 1 10 100 1k 10k 100k 1M 10M 10nF 100nF 1nF 500kHz PEAK VIN (DC) = 10V (Continued) X = 10µs/DIV Y = 200mV/DIV NO LOAD FREQUENCY (Hz) FIGURE 8. PSRR AT DIFFERENT CAPACITIVE LOADS FIGURE 9. LINE TRANSIENT RESPONSE, NO CAPACITIVE LOAD X = 5µs/DIV Y = 20mV/DIV VIN VREF X = 100µs/DIV Y = 1V/DIV FIGURE 10. LINE TRANSIENT RESPONSE, 0.001µF LOAD CAPACITANCE FIGURE 11. TURN-ON TIME 200 180 160 140 ZOUT ( Ω) 120 100 80 60 40 20 0 1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 10nF LOAD NO LOAD 1nF LOAD 2mV/DIV GAIN IS x1000, NOISE IS 4.5µVP-P FIGURE 12. ZOUT vs FREQUENCY FIGURE 13. VOUT NOISE, 0.1Hz TO 10Hz 7 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-12) (REXT = 100kΩ) X = 5µs/DIV Y = 50mV/DIV (Continued) X = 10µs/DIV Y = 500mV/DIV +7mA +50µA -50µA -7mA FIGURE 14. LOAD TRANSIENT RESPONSE FIGURE 15. LOAD TRANSIENT RESPONSE Typical Performance Curves (ISL21009-25) (REXT = 100kΩ) 140 UNIT 1 120 100 IIN (µA) 80 60 40 20 0 3.5 5.5 7.5 9.5 VIN (V) 11.5 13.5 15.5 80 3.5 5.5 7.5 9.5 VIN (V) 11.5 13.5 15.5 UNIT 3 IIN (µA) 110 UNIT 2 +25°C +125°C 120 100 -40°C 90 FIGURE 16. IIN vs VIN, 3 UNITS FIGURE 17. IIN vs VIN, 3 TEMPERATURES VOUT (V) (NORMALIZED TO 2.50V AT VIN = 5V) 2.50010 (NORMALIZED TO VIN = 5.0V) UNIT 2 2.50005 2.50000 UNIT 1 2.49995 2.49990 2.49985 2.49980 3.50 UNIT 3 60 40 20 0 -20 -40 -60 -80 -100 3.5 5.5 7.5 9.5 11.5 VIN (V) 13.5 15.5 +125°C -40°C +25°C 5.50 7.50 9.50 11.5 VIN (V) 13.5 15.5 FIGURE 18. LINE REGULATION ΔVOUT (µV) FIGURE 19. LINE REGULATION OVER-TEMPERATURE 8 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-25) (REXT = 100kΩ) 0.10 0.08 0.06 0.04 ΔVOUT (mV) 0.02 0.00 -0.02 -0.04 -0.06 -0.08 -0.10 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 +25°C -40°C VOUT (V) +125°C (Continued) 2.5002 2.5001 2.5000 2.4999 2.4998 2.4997 2.4996 2.4995 2.4994 2.4993 -40 -20 0 20 40 60 80 100 120 140 UNIT 2 UNIT 1 UNIT 3 SINKING OUTPUT CURRENT (mA) SOURCING TEMPERATURE (°C) FIGURE 20. LOAD REGULATION FIGURE 21. VOUT vs TEMPERATURE 0 -10 -20 -30 PSRR (dB) -40 -50 -60 -70 -80 -90 -100 1 10 100 1k 10k 100k 1M 10M 100nF 10nF 1nF 500kHz PEAK VIN (DC) = 10V NO LOAD FREQUENCY (Hz) FIGURE 22. PSRR AT DIFFERENT CAPACITIVE LOADS FIGURE 23. LINE TRANSIENT RESPONSE, NO CAPACITIVE LOAD 5.2 4.8 4.4 4.0 3.6 3.2 2.8 2.4 2.0 1.6 1.2 0.8 0.4 0 0 VIN HIGH IIN VIN AND VOUT (V) MEDIUM IIN LOW IIN 0.05 0.10 0.15 0.20 TIME (ms) 0.25 0.30 0.35 0.40 FIGURE 24. LINE TRANSIENT RESPONSE, 0.001µF LOAD CAPACITANCE FIGURE 25. TURN-ON TIME 9 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-25) (REXT = 100kΩ) (Continued) GAIN IS x1000, NOISE IS 4.5µVP-P 160 140 120 ZOUT (Ω) 100 80 60 40 20 0 1 10 100 1k 10k FREQUENCY (Hz) 100k 1M 1nF NO LOAD 100nF 2mV/DIV 10nF FIGURE 26. ZOUT vs FREQUENCY FIGURE 27. VOUT NOISE, 0.1Hz TO 10Hz NO OUTPUT CAPACITANCE NO OUTPUT CAPACITANCE 7mA +50µA -50µA -7mA FIGURE 28. LOAD TRANSIENT RESPONSE FIGURE 29. LOAD TRANSIENT RESPONSE Typical Performance Curves (ISL21009-41) (REXT = 100kΩ) 110 105 95 100 IIN (µA) IIN (µA) UNIT 3 95 UNIT 2 90 UNIT 1 85 80 5 7 9 11 VIN (V) 13 15 17 80 5 7 9 11 VIN (V) 13 15 17 85 90 +125°C -40°C +25°C 100 FIGURE 30. IIN vs VIN, 3 UNITS FIGURE 31. IIN vs VIN, 3 TEMPERATURES 10 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-41) (REXT = 100kΩ) VOUT (V) NORMALIZED TO 4.096V AT VIN = 5.0V 4.0963 4.0962 4.0962 4.0961 4.0961 4.0960 4.0960 4.0959 4.0959 4.0958 4.5 6.5 8.5 10.5 VIN (V) 12.5 14.5 16.5 UNIT 3 UNIT 1 UNIT 2 ΔVOUT (µV) NORMALIZED TO VIN = 5.0V (Continued) 300 250 200 150 100 50 0 -50 +25°C +125°C -40°C -100 -150 -200 4.5 6.5 8.5 10.5 VIN (V) 12.5 14.5 16.5 FIGURE 32. LINE REGULATION, 3 UNITS FIGURE 33. LINE REGULATION OVER-TEMPERATURE 0.05 ΔVOUT (mV) 0.00 -0.05 -0.10 -0.15 -0.20 -7 -40°C +125°C +25°C VOUT (V) NORMALIZED TO 4.096V 0.10 4.0970 4.0965 4.0960 UNIT 2 4.0955 UNIT 3 4.0950 4.0945 -40 UNIT 1 -25 -10 5 20 35 50 65 80 95 110 125 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 SINKING OUTPUT CURRENT (mA) SOURCING TEMPERATURE (°C) FIGURE 34. LOAD REGULATION FIGURE 35. VOUT vs TEMPERATURE 0 -10 -20 PSRR (dB) -30 -40 -50 -60 -70 1nF LOAD -80 1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) X = 10µs/DIV Y = 200mV/DIV 10nF LOAD VIN (DC) = 5V VIN (AC) RIPPLE = 50mVP-P NO LOAD 100nF LOAD FIGURE 36. PSRR AT DIFFERENT CAPACITIVE LOADS FIGURE 37. LINE TRANSIENT RESPONSE, NO CAPACITIVE LOAD 11 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-41) (REXT = 100kΩ) (Continued) VIN VREF X = 10µs/DIV Y = 200mV/DIV X = 50µs/DIV Y = 2V/DIV FIGURE 38. LINE TRANSIENT RESPONSE, 0.001µF LOAD CAPACITANCE FIGURE 39. TURN-ON TIME GAIN IS x10,000 NOISE IS 4.5µVP-P 200 180 160 ZOUT ( Ω) 120 100 80 60 40 20 0 1 10 100 1k 10k 100k 1M 10M 1s/DIV FREQUENCY (Hz) 10nF LOAD NO LOAD 20mV/DIV 140 1nF LOAD FIGURE 40. ZOUT vs FREQUENCY FIGURE 41. VOUT NOISE, 0.1Hz TO 10Hz 7mA +50µA -50µA -7mA NO OUTPUT CAPACITANCE X = 5µs/DIV Y = 50mV/DIV NO OUTPUT CAPACITANCE X = 5µs/DIV Y = 500mA/DIV FIGURE 42. LOAD TRANSIENT RESPONSE FIGURE 43. LOAD TRANSIENT RESPONSE 12 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-50) (REXT = 100kΩ) 140 112µA 120 100 IIN (µA) 80 60 40 20 0 5.5 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 VIN (V) 80 5.5 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 VIN (V) 95µA IIN (µA) 104µA 110 +25°C 100 +125°C 90 -40°C FIGURE 44. IIN vs VIN, 3 UNITS FIGURE 45. IIN vs VIN, 3 TEMPERATURES VOUT (V) (NORMALIZED TO 5.0V AT VIN = 10V) 5.0001 ΔVOUT (µV) (NORMALIZED TO VIN = 10.0V) 5.0000 4.9999 4.9998 104µA 4.9997 4.9996 4.9995 4.9994 5.5 95µA 112µA 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 VIN (V) 100 0 -100 -200 -300 -400 -500 -600 -700 5.50 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 VIN (V) +25°C +125°C -40°C FIGURE 46. LINE REGULATION FIGURE 47. LINE REGULATION OVER-TEMPERATURE 0.10 0.05 0.00 ΔVOUT (mV) -0.05 -0.10 -0.15 -0.20 -0.25 -7 -6 -5 SINKING -4 -3 -2 -1 0 1 2 3 OUTPUT CURRENT (mA) 4 567 SOURCING +125°C +25°C -40°C FIGURE 48. LOAD REGULATION 13 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-50) (REXT = 100kΩ) 5.001 NORMALIZED TO +25°C 5.001 PSRR (dB) 5.000 VOUT (V) UNIT 2 5.000 4.999 4.999 4.998 -40 UNIT 3 -20 0 20 40 60 80 100 120 140 UNIT 1 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 1 10 100 1k 10k 100k 1M 10M 100nF 1nF 10nF VIN (DC) = 10V VIN (AC) RIPPLE = 50mVP-P NO LOAD (Continued) TEMPERATURE (°C) FREQUENCY (Hz) FIGURE 49. VOUT vs TEMPERATURE FIGURE 50. PSRR AT DIFFERENT CAPACITIVE LOADS VIN = 10V DVIN = 1V VIN = 10V DVIN = 1V FIGURE 51. LINE TRANSIENT RESPONSE, NO CAPACITIVE LOAD FIGURE 52. LINE TRANSIENT RESPONSE, 0.001µF LOAD CAPACITANCE 12 VIN (V) AND VOUT (V) 10 8 6 4 2 0 0 270nA 50 VIN ZOUT (W) 450nA 120 1nF 100 80 60 NO LOAD 40 340nA 100 150 TIME (µs) 200 250 300 20 0 1 10 100 1k 10k 100k 1M FREQUENCY (Hz) 10nF FIGURE 53. TURN-ON TIME FIGURE 54. ZOUT vs FREQUENCY 14 FN6327.7 September 16, 2009 ISL21009 Typical Performance Curves (ISL21009-50) (REXT = 100kΩ) GAIN IS x1000 NOISE IS 4.5µVP-P (Continued) 50µA 2mV/DIV -50µA FIGURE 55. VOUT NOISE, 0.1Hz TO 10Hz FIGURE 56. LOAD TRANSIENT RESPONSE 7mA -7mA FIGURE 57. LOAD TRANSIENT RESPONSE Applications Information FGA Technology The ISL21009 voltage reference uses floating gate technology to create references with very low drift and supply current. Essentially the charge stored on a floating gate cell is set precisely in manufacturing. The reference voltage output itself is a buffered version of the floating gate voltage. The resulting reference device has excellent characteristics, which are unique in the industry: very low temperature drift, high initial accuracy, and almost zero supply current. Also, the reference voltage itself is not limited by voltage bandgaps or zener settings, so a wide range of reference voltages can be programmed (standard voltage settings are provided, but customer-specific voltages are available). The process used for these reference devices is a floating gate CMOS process and the amplifier circuitry uses CMOS transistors for amplifier and output transistor circuitry. While providing excellent accuracy, there are limitations in output noise level and load regulation due to the MOS device characteristics. These limitations are addressed with circuit techniques discussed in other sections. Micropower Operation The ISL21009 consumes extremely low supply current due to the proprietary FGA technology. Low noise performance is achieved using optimized biasing techniques. Supply current is typically 95µA and noise is 4.5µVP-P benefitting precision, low noise portable applications such as handheld meters and instruments. 15 FN6327.7 September 16, 2009 ISL21009 Data Converters in particular can utilize the ISL21009 as an external voltage reference. Low power DAC and ADC circuits will realize maximum resolution with lowest noise. plane underneath will effectively shield it from from 50 to 100 passes through the machine. Since these machines vary in X-ray dose delivered, it is difficult to produce an accurate maximum pass recommendation. Board Mounting Considerations For applications requiring the highest accuracy, board mounting location should be reviewed. The device uses a plastic SOIC package, which will subject the die to mild stresses when the Printed Circuit (PC) board is heated and cooled, slightly changing the shape. Placing the device in areas subject to slight twisting can cause degradation of the accuracy of the reference voltage due to these die stresses. It is normally best to place the device near the edge of a board, or the shortest side, as the axis of bending is most limited at that location. Mounting the device in a cutout also minimizes flex. Obviously mounting the device on flexprint or extremely thin PC material will likewise cause loss of reference accuracy. Noise Performance and Reduction The output noise voltage in a 0.1Hz to 10Hz bandwidth is typically 4.5µVP-P. The noise measurement is made with a bandpass filter made of a 1-pole high-pass filter with a corner frequency at 0.1Hz and a 2-pole low-pass filter with a corner frequency (3dB) at 8.2Hz to create a filter with a 9.9Hz bandwidth. Noise in the 10Hz to 1kHz bandwidth is approximately 2.2µVP-P with no capacitance on the output. This noise measurement is made with a 2 decade bandpass filter made of a 1-pole high-pass filter with a corner frequency at 1/10 of the center frequency and 1-pole low-pass filter with a corner frequency at 10x the center frequency. Load capacitance up to 1000pF can be added but will result in only marginal improvements in output noise and transient response. The output stage of the ISL21009 does not drive heavily capacitive loads well, so for load capacitances above 0.001µF, the noise reduction network shown in Figure 58 is recommended. This network reduces noise significantly over the full bandwidth. Noise is reduced to less than 15µVP-P from 1Hz to 1kHz using this network with a 0.01µF capacitor and a 2kΩ resistor in series with a 10µF capacitor. Also, transient response is improved. The 0.01µF value can be increased for better load transient response with little sacrifice in output stability. Higher output capacitor values can be used without the RC network to address transient loads without stability problems, although there will be more overshoot an longer settling times with values up to 1.0µF. Output capacitor values greater than 1.0µF are not recommended for the ISL21009. . Board Assembly Considerations FGA references provide high accuracy and low temperature drift but some PC board assembly precautions are necessary. Normal Output voltage shifts of 100µV to 1mV can be expected with Pb-free reflow profiles or wave solder on multi-layer FR4 PC boards. Precautions should be taken to avoid excessive heat or extended exposure to high reflow or wave solder temperatures, this may reduce device initial accuracy. Post-assembly x-ray inspection may also lead to permanent changes in device output voltage and should be minimized or avoided. If x-ray inspection is required, it is advisable to monitor the reference output voltage to verify excessive shift has not occurred. If large amounts of shift are observed, it is best to add an X-ray shield consisting of thin zinc (300µm) sheeting to allow clear imaging, yet block x-ray energy that affects the FGA reference. Special Applications Considerations In addition to post-assembly examination, there are also other X-ray sources that may affect the FGA reference long term accuracy. Airport screening machines contain X-rays and will have a cumulative effect on the voltage reference output accuracy. Carry-on luggage screening uses low level X-rays and is not a major source of output voltage shift, although if a product is expected to pass through that type of screening over 100 times it may need to consider shielding with copper or aluminum. Checked luggage X-rays are higher intensity and can cause output voltage shift in much fewer passes, so devices expected to go through those machines should definitely consider shielding. Note that just two layers of 1/2 ounce copper planes will reduce the received dose by over 90%. The leadframe for the device which is on the bottom also provides similar shielding. If a device is expected to pass through luggage X-ray machines numerous times, it is advised to mount a 2-layer (minimum) PC board on the top, and along with a ground 16 VIN = 5.0V 10µF 0.1µF VIN VO ISL21009-25 GND 0.01µF 10µF 2kΩ FIGURE 58. HANDLING HIGH LOAD CAPACITANCE Turn-On Time The ISL21009 devices have low supply current and thus, the time to bias up internal circuitry to final values will be longer than with higher power references. Normal turn-on time is typically 100µs, as shown in Figure 25. Circuit design must take this into account when looking at power-up delays or sequencing. FN6327.7 September 16, 2009 ISL21009 Temperature Coefficient The limits stated for temperature coefficient (tempco) are governed by the method of measurement. The overwhelming standard for specifying the temperature drift of a reference is to measure the reference voltage at two temperatures, take the total variation, (VHIGH – VLOW), and divide by the temperature extremes of measurement (THIGH – TLOW). The result is divided by the nominal reference voltage (at T = +25°C) and multiplied by 106 to yield ppm/°C. This is the “Box” method for specifying temperature coefficient. Output Voltage Adjustment The output voltage can be adjusted up or down by 2.5% by placing a potentiometer from VOUT to GND and connecting the wiper to the TRIM pin. The TRIM input is high impedance so no series resistance is needed. The resistor in the potentiometer should be a low tempco (