ISL21007BFB820Z

Precision, Low Noise FGA™ Voltage References ISL21007 The ISL21007 FGA™ voltage references are extremely low power, high precision, and low noise voltage references fabricated on Intersil’s proprietary Floating Gate Analog technology. The ISL21007 features very low noise (4.5µVP-P for 0.1Hz to 10Hz) and very low operating current (150µA, Max). In addition, the ISL21007 family features guaranteed initial accuracy as low as ±0.5mV. This combination of high initial accuracy, low drift, and low output noise performance of the ISL21007 enables versatile high performance control and data acquisition applications with low power consumption. Features • Reference Output Voltage . . . .1.250V, 2.048V, 2.500V, 3.000V • Initial Accuracy . . . . . . . . . . . . . . . . . . . . . . . ±0.5mV (B grade) • Input Voltage Range ISL21007-12, 20, 25. . . . . . . . . . . . . . . . . . . . . . . 2.7V to 5.5V ISL21007-30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2V to 5.5V • Low Output Voltage Noise . . . . . . . . 4.5µVP-P (0.1Hz to 10Hz) • Supply Current . . . . . . . . . . . . . . . . . . . . . . . . . . . 150µA (Max) • Temperature Coefficient . . . . . . . . . . . . . . 3ppm/°C (B grade) • Operating Temperature Range. . . . . . . . . . .-40°C to +125°C • Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Ld SOIC • Pb-Free (RoHS Compliant) 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 Available Options PART NUMBER ISL21007BFB812Z ISL21007CFB812Z ISL21007DFB812Z ISL21007BFB820Z ISL21007CFB820Z ISL21007DFB820Z ISL21007BFB825Z ISL21007CFB825Z ISL21007DFB825Z ISL21007BFB830Z ISL21007CFB830Z ISL21007DFB830Z VOUT OPTION (V) 1.250 1.250 1.250 2.048 2.048 2.048 2.500 2.500 2.500 3.000 3.000 3.000 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 Related Literature • AN1533, “X-Ray Effects on Intersil FGA References” • AN1494, “Reflow and PC Board Assembly Effects on Intersil FGA References” Pin Configuration ISL21007 (8 LD SOIC) TOP VIEW GND or NC VIN DNC GND 1 2 3 4 8 7 6 5 DNC DNC VOUT TRIM July 14, 2011 FN6326.8 1 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. 2007, 2011. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. ISL21007 Ordering Information PART NUMBER (Notes 1, 2, 3) ISL21007BFB812Z ISL21007CFB812Z ISL21007DFB812Z ISL21007BFB820Z ISL21007CFB820Z ISL21007DFB820Z ISL21007BFB825Z ISL21007CFB825Z ISL21007DFB825Z ISL21007BFB830Z ISL21007CFB830Z ISL21007DFB830Z 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 STD-020. 2. Add “-T*” suffix for tape and reel. Please refer to TB347 for details on reel specifications. 3. For Moisture Sensitivity Level (MSL), please see device information page for ISL21007. For more information on MSL please see techbrief TB363. PART MARKING 21007BF Z12 21007CF Z12 21007DF Z12 21007BF Z20 21007CF Z20 21007DF Z20 21007BF Z25 21007CF Z25 21007DF Z25 21007BF Z30 21007CF Z30 21007DF Z30 VOUT OPTION (V) 1.250 1.250 1.250 2.048 2.048 2.048 2.500 2.500 2.500 3.000 3.000 3.000 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 FN6326.8 July 14, 2011 ISL21007 Pin Descriptions PIN NUMBER 1 2 4 5 6 3, 7, 8 PIN NAME GND or NC VIN GND TRIM VOUT DNC Ground or No Connection Power Supply Input Connection Ground Allows user trim VOUT ±2.5% Voltage Reference Output Connection Do Not Connect; Internal Connection - Must Be Left Floating DESCRIPTION Typical Application Circuit 1 GND +3V C1 10µF 2 VIN 3 NC 4 GND NC 8 NC 7 VOUT 6 TRIM 5 ISL21007-12, 20, 25, 30 SPI BUS X79000 1 SCK 2 A0 3 A1 4 A2 5 SI 6 SO 7 RDY 8 UP 9 DOWN 10 OE CS 20 CLR 19 VCC 18 VH 17 VL 16 VREF 15 VSS 14 VOUT 13 VBUF 12 VFB 11 LOW NOISE DAC OUTPUT C1 0.001µF FIGURE 1. TYPICAL APPLICATION PRECISION 12-BIT SUBRANGING DAC 3 FN6326.8 July 14, 2011 ISL21007 Absolute Voltage Ratings Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Max Voltage VIN to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to +6.5V Max Voltage VOUT to GND (10s). . . . . . . . . . . . . . . . . . . . . . -0.5V to VOUT + 1 Voltage on “DNC” pins . . . . . . . . . No connections permitted to these pins. ESD Rating Human Body Model (HBM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6kV Machine Model (MM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600V Charged Device Model (CDM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2kV Thermal Information Thermal Resistance (Typical, Note 5) θJA (°C/W) 8 Ld SOIC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113.12 Continuous Power Dissipation (Note 5) . . . . . . . . . . . . . . . . . . . .TA = +70°C 8 Ld SOIC Derate 5.88mW/°C above +70°C. . . . . . . . . . . . . . . . . . 471mW Pb-Free Reflow Profile (Note 6). . . . . . . . . . . . . . . . . . . . . . . . see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp Recommended Operating Conditions Temperature Range (Industrial) . . . . . . . . . . . . . . . . . . . . .-40°C to +125°C Environmental Operating Conditions X-Ray Exposure (Note 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10mRem 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: 4. Measured with no filtering, distance of 10” from source, intensity set to 55kV and 70mA current, 30s duration. Other exposure levels should be analyzed for Output Voltage drift effects. See “Applications Information” on page 16. 5. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details. 6. Post-reflow drift for the ISL21007 devices will range from 100µV to 1.0mV based on experimental results with devices on FR4 double sided boards. The design engineer must take this into account when considering the reference voltage after assembly. Common Electrical Specifications (ISL21007-12, -20, -25, -30) specified. Boldface limits apply over the operating temperature range, -40°C to +125°C. PARAMETER VOA DESCRIPTION VOUT Accuracy @ TA = +25°C ISL21007B ISL21007C ISL21007D TC VOUT Output Voltage Temperature Coefficient (Note NOTES:) ISL21007B ISL21007C ISL21007D IIN Supply Current Trim Range tR Turn-on Settling Time Ripple Rejection eN VN Output Voltage Noise Broadband Voltage Noise Noise Density VOUT = ±0.1% f = 10kHz 0.1Hz ≤ f ≤ 10Hz 10Hz ≤ f ≤ 1kHz f = 1kHz CONDITIONS TA = -40°C to +125°C, unless otherwise MIN MAX (Note 10) TYP (Note 10) -0.5 -1.0 -2.0 +0.5 +1.0 +2.0 3 5 10 75 ±2.0 ±2.5 120 60 4.5 2.2 60 150 UNIT mV mV mV ppm/°C ppm/°C ppm/°C µA % µs dB µVP-P µVRMS nV/√Hz Electrical Specifications (ISL21007-12, VOUT = 1 .250V) PARAMETER VIN VOUT ΔVOUT /ΔVIN DESCRIPTION Input Voltage Range Output Voltage Line Regulation 2.7V < VIN < 5.5V CONDITIONS specified. Boldface limits apply over the operating temperature range, -40°C to +125°C. VIN = 3.0V, TA = -40°C to +125°C, unless otherwise MIN (Note 10) 2.7 1.250 100 700 MAX (Note 10) 5.5 TYP UNIT V V µV/V 4 FN6326.8 July 14, 2011 ISL21007 Electrical Specifications (ISL21007-12, VOUT = 1 .250V) PARAMETER ΔVOUT/ΔIOUT DESCRIPTION Load Regulation CONDITIONS Sourcing: 0mA ≤ IOUT ≤ 7mA Sinking: -7mA ≤ IOUT ≤ 0mA ISC ΔVOUT/ΔTA ΔVOUT/Δt Short Circuit Current Thermal Hysteresis (Note 8) Long Term Stability (Note 9) TA = +25°C, VOUT tied to GND ΔTA = +165°C TA = +25°C VIN = 3.0V, TA = -40°C to +125°C, unless otherwise specified. Boldface limits apply over the operating temperature range, -40°C to +125°C. (Continued) MIN (Note 10) TYP 10 20 40 50 100 MAX (Note 10) 100 150 UNIT µV/mA µV/mA mA ppm ppm specified. Boldface limits apply over the operating temperature range, -40°C to +125°C. PARAMETER VIN VOUT ΔVOUT /ΔVIN ΔVOUT/ΔIOUT DESCRIPTION Input Voltage Range Output Voltage Line Regulation Load Regulation 2.7V < VIN < 5.5V Sourcing: 0mA ≤ IOUT ≤ 7mA Sinking: -7mA ≤ IOUT ≤ 0mA ISC ΔVOUT/ΔTA ΔVOUT/Δt Short Circuit Current Thermal Hysteresis (Note 8) Long Term Stability (Note 9) TA = +25°C, VOUT tied to GND ΔTA = +165°C TA = +25°C CONDITIONS Electrical Specifications (ISL21007-20, VOUT = 2.048V) VIN = 3.0V, TA = -40°C to +125°C, unless otherwise MIN (Note 10) 2.7 2.048 50 10 20 50 50 75 200 100 150 MAX (Note 10) 5.5 TYP UNIT V V µV/V µV/mA µV/mA mA ppm ppm Boldface limits apply over the operating temperature range, -40°C to +125°C. PARAMETER VIN VOUT ΔVOUT /ΔVIN ΔVOUT/ΔIOUT DESCRIPTION Input Voltage Range Output Voltage Line Regulation Load Regulation 2.7V < VIN < 5.5V Electrical Specifications (ISL21007-25, VOUT = 2.500V) CONDITIONS VIN = 3.0V, TA = -40°C to +125°C, unless otherwise specified. MIN (Note 10) 2.7 2.500 50 10 20 50 50 50 200 100 150 MAX (Note 10) 5.5 TYP UNIT V V µV/V µV/mA µV/mA mA ppm ppm Sourcing: 0mA ≤ IOUT ≤ 5mA Sinking: -5mA ≤ IOUT ≤ 0mA ISC ΔVOUT/ΔTA ΔVOUT/Δt Short Circuit Current Thermal Hysteresis (Note 8) Long Term Stability (Note 9) TA = +25°C, VOUT tied to GND ΔTA = +165°C TA = +25°C Electrical Specifications (ISL21007-30, VOUT = 3.000V) Boldface limits apply over the operating temperature range, -40°C to +125°C. PARAMETER VIN VOUT ΔVOUT /ΔVIN ΔVOUT/ΔIOUT DESCRIPTION Input Voltage Range Output Voltage Line Regulation Load Regulation 3.2V < VIN < 5.5V Sourcing: 0mA ≤ IOUT ≤ 7mA Sinking: -7mA ≤ IOUT ≤ 0mA CONDITIONS VIN = 5.0V, TA = -40°C to +125°C, unless otherwise specified. MIN (Note 10) 3.2 3.000 50 10 20 200 100 150 MAX (Note 10) 5.5 TYP UNIT V V µV/V µV/mA µV/mA 5 FN6326.8 July 14, 2011 ISL21007 Electrical Specifications (ISL21007-30, VOUT = 3.000V) PARAMETER ISC ΔVOUT/ΔTA ΔVOUT/Δt NOTES: 7. 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. 8. Thermal Hysteresis is the change of VOUT measured at 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. 9. Long term drift is logarithmic in nature and diminishes over time. Drift after the first 1000 hours will be approximately 10ppm/√(1kHrs). 10. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design. DESCRIPTION Short Circuit Current Thermal Hysteresis (Note 8) Long Term Stability (Note 9) CONDITIONS TA = +25°C, VOUT tied to GND ΔTA = +165°C TA = +25°C VIN = 5.0V, TA = -40°C to +125°C, unless otherwise specified. Boldface limits apply over the operating temperature range, -40°C to +125°C. (Continued) MIN (Note 10) TYP 50 50 50 MAX (Note 10) UNIT mA ppm ppm 6 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-12) 120 100 80 IIN (µA) 60 40 20 0 2.5 UNIT 1 IIN (µA) UNIT 2 UNIT 3 95 90 85 80 75 70 65 3.0 3.5 4.0 4.5 VIN (V) 5.0 5.5 6.0 60 2.5 3.0 3.5 -40°C +25°C +125°C (REXT = 100kΩ) 4.0 VIN (V) 4.5 5.0 5.5 FIGURE 2. IIN vs VIN (3 UNITS) FIGURE 3. I IN vs VIN OVER TEMPERATURE VOUT (V) (NORMALIZED TO 1.250V AT VIN = 3.0V) 1.25015 ΔVO (µV) (NORMALIZED TO VIN = 3.0V) 1.25010 1.25005 1.25000 1.24995 1.24990 UNIT 1 1.24985 1.24980 2.5 3.0 3.5 4.0 VIN (V) 4.5 5.0 5.5 UNIT 2 UNIT 3 150 100 50 0 -50 -100 -150 -200 -250 -300 2.5 3.0 3.5 4.0 4.5 VIN (V) 5.0 5.5 6.0 +25°C -40°C +125°C FIGURE 4. LINE REGULATION (3 UNITS) FIGURE 5. LINE REGULATION OVER TEMPERATURE 0.15 +25°C 0.10 ΔVOUT (mV) 0.05 VOUT (V) 0.00 -0.05 -0.10 -0.15 -7 -6 -5 -4 SINKING -3 -2 -1 0 1 2 3 OUTPUT CURRENT (mA) 4567 SOURCING -40°C +125°C 1.25010 1.25005 1.25000 1.24995 1.24990 1.24985 1.24980 1.24975 -40 -20 0 20 40 60 80 100 120 140 UNIT 3 UNIT 2 UNIT 1 TEMPERATURE (°C) FIGURE 6. LOAD REGULATION OVER TEMPERATURE FIGURE 7. VOUT vs TEMPERATURE (3 UNITS) 7 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-12) 0 -20 PSRR (dB) -40 -60 1µF LOAD -80 -100 1.00E+00 1nF LOAD NO LOAD 1.00E+02 1.00E+04 1.00E+0 ΔVIN = -0.3V (REXT = 100kΩ) (Continued) X: 200mV/DIV Y: 10µs/DIV 10nF LOAD 100nF LOAD ΔVIN = +0.3V FREQUENCY (Hz) FIGURE 8. PSRR vs CAPACITIVE LOADS FIGURE 9. LINE TRANSIENT RESPONSE, NO CAPACITIVE LOAD X: 200mV/DIV Y: 10µs/DIV X: 20µs/DIV Y: 1V/DIV ΔVIN = +0.3V VIN ΔVIN = -0.3V VOUT = 1.25V FIGURE 10. LINE TRANSIENT RESPONSE, 0.001µF LOAD CAPACITANCE FIGURE 11. TURN-ON TIME GAIN IS x1000, NOISE IS 4.5µVP-P 140 120 100 ZOUT (Ω) 80 60 40 20 0 1.00E+00 1.00E+01 1.00E+02 1.00E+03 1.00E+04 1.00E+05 1.00E+06 1nF 10nF 100nF NO LOAD FREQUENCY (Hz) FIGURE 12. ZOUT vs FREQUENCY 2mV/DIV FIGURE 13. VOUT NOISE, 0.1Hz TO 10Hz 8 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-12) NO OUTPUT CAPACITANCE X: 50µs/DIV Y: 1V/DIV (REXT = 100kΩ) (Continued) +7mA -7mA FIGURE 14. LOAD TRANSIENT RESPONSE Typical Performance Curves (ISL21007-20) 95 90 85 IIN (uA) IIN (µA) 80 75 70 65 2.7 UNIT 3 3.1 3.5 3.9 4.3 4.7 5.1 5.5 UNIT 1 UNIT 2 95 90 85 80 75 70 65 60 55 (REXT = 100kΩ) +125°C -40°C +25°C 50 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 VIN (V) VIN (V) FIGURE 15. IIN vs VIN (3 UNITS) FIGURE 16. IIN vs VIN OVER TEMPERATURE VOUT (V) (NORMALIZED TO 2.048V AT VIN = 3V) VOUT (V) NORMALIZED TO 2.048V AT VIN = 3.0V 2.04815 UNIT 2 2.04810 2.04805 UNIT 1 2.04800 2.04795 2.04790 2.5 UNIT 3 2.04815 -40°C 2.04810 +125°C +25°C 2.04800 2.04805 3.0 3.5 4.0 VIN(V) 4.5 5.0 5.5 2.04795 2.5 3.0 3.5 4.0 VIN(V) 4.5 5.0 5.5 FIGURE 17. LINE REGULATION (3 UNITS) FIGURE 18. LINE REGULATION OVER TEMPERATURE 9 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-20) VOUT(V) NORMALIZED TO 2.048V AT +25°C Δ VOUT (mV) NORMALIZED TO 0mA 1.6 1.2 0.0 0.4 0.0 -0.4 -0.8 -1.2 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 +25°C -40°C +125°C 2.0496 2.0492 2.0488 2.0484 2.0480 2.0476 UNIT 3 2.0472 -40 -25 -10 5 20 35 50 65 80 95 110 125 UNIT 2 UNIT 1 (REXT = 100kΩ) (Continued) SINKING OUTPUT CURRENT (mA) SOURCING TEMPERATURE (°C) FIGURE 19. LOAD REGULATION OVER TEMPERATURE FIGURE 20. VOUT vs TEMPERATURE (3 UNITS) X: 200mV/DIV Y: 10µs/DIV 0 10nF LOAD -20 PSRR (dB) -40 -60 -80 -100 1.0E+01 1µF LOAD ΔVIN = -0.3V 100nF LOAD ΔVIN = +0.3V NO LOAD 1.0E+03 FREQUENCY (Hz) 1.0E+05 FIGURE 21. PSRR vs CAPACITIVE LOADS FIGURE 22. LINE TRANSIENT RESPONSE, NO CAPACITIVE LOAD X: 200mV/DIV Y: 10µs/DIV X: 100µs/DIV Y: 2V/DIV ΔVIN = +0.3V VIN VOUT = 2.048V ΔVIN = -0.3V FIGURE 23. LINE TRANSIENT RESPONSE, 0.001µF LOAD CAPACITANCE FIGURE 24. TURN-ON TIME 10 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-20) 140 120 100 ZOUT (Ω) 80 60 40 20 0 1.00E+00 1.00E+01 1.00E+02 1.00E+03 1.00E+04 1.00E+05 1.00E+06 (REXT = 100kΩ) (Continued) GAIN IS x1000, NOISE IS 4.5µVP-P 1nF 10nF 100nF 2mV/DIV FREQUENCY (Hz) NO LOAD FIGURE 25. ZOUT VS FREQUENCY FIGURE 26. VOUT NOISE, 0.1Hz TO 10Hz X: 20µs/DIV Y: 200mV/DIV +7mA X: 20µs/DIV Y: 200mV/DIV +7mA -7mA -7mA FIGURE 27. LOAD TRANSIENT RESPONSE, 0.001µF LOAD CAPACITANCE FIGURE 28. LOAD TRANSIENT RESPONSE, NO CAPACITIVE LOAD Typical Performance Curves (ISL21007-25) 120 UNIT 3 100 80 IIN (µA) 60 40 20 0 2.5 3.0 3.5 4.0 VIN (V) 4.5 5.0 5.5 6.0 UNIT 1 UNIT 2 IIN (µA) 100 95 90 85 80 75 70 65 60 2.5 (REXT = 100kΩ) +125°C +25°C -40°C 3.0 3.5 4.0 VIN (V) 4.5 5.0 5.5 FIGURE 29. IIN vs VIN (3 UNITS) FIGURE 30. IIN vs VIN OVER TEMPERATURE 11 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-25) VOUT (V) (NORMALIZED TO 2.500V AT VIN = 3V) 2.5002 2.5001 2.5000 2.4999 2.4998 2.4997 2.4996 2.5 UNIT 3 UNIT 1 ΔVO (µV) (NORMALIZED TO VIN = 3.0V) 100 50 0 -50 -100 -150 -200 -250 -300 -350 -400 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 -40°C +25°C +125°C (REXT = 100kΩ) (Continued) UNIT 2 3.0 3.5 4.0 VIN (V) 4.5 5.0 5.5 VIN (V) FIGURE 31. LINE REGULATION (3 UNITS) FIGURE 32. LINE REGULATION OVER TEMPERATURE 0.6 0.4 0.2 ΔVOUT (mV) 0 -0.2 -0.4 -0.6 -0.8 -1.0 -7 -6 -5 -4 SINKING +25°C +125°C -40°C VOUT (V) 2.5003 2.5002 2.5001 2.5000 2.4999 2.4998 2.4997 2.4996 2.4995 2.4994 UNIT 2 UNIT 1 UNIT 3 -20 0 20 40 60 80 100 120 140 -3 -2 -1 0 1 2 3 4 5 6 7 2.4993 -40 OUTPUT CURRENT (mA) SOURCING TEMPERATURE (°C) FIGURE 33. LOAD REGULATION OVER TEMPERATURE FIGURE 34. VOUT vs TEMPERATURE (3 UNITS) X: 200mV/DIV Y: 10µs/DIV 10 0 -10 -20 PSRR (dB) -30 -40 -50 -60 -70 -80 -90 -100 1.E+00 1.E+02 1.E+04 1.E+06 ΔVIN = -0.3V NO LOAD 1nF 10nF 100nF 1µF ΔVIN = +0.3V FREQUENCY (Hz) FIGURE 35. PSRR vs CAPACITIVE LOADS FIGURE 36. LINE TRANSIENT RESPONSE, NO CAPACITIVE LOAD 12 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-25) X: 200mV/DIV Y: 10µs/DIV (REXT = 100kΩ) (Continued) X: 20µs/DIV Y: 1V/DIV ΔVIN = +0.3V VIN ΔVIN = -0.3V VOUT = 2.5V FIGURE 37. LINE TRANSIENT RESPONSE, 0.001µF LOAD CAPACITANCE FIGURE 38. TURN-ON TIME GAIN IS x1000, NOISE IS 4.5µVP-P 140 120 100 ZOUT (Ω) 80 60 40 20 0 1.00E+00 1.00E+01 1.00E+02 1.00E+03 1.00E+04 1.00E+05 1.00E+06 1nF 10nF 100nF NO LOAD FREQUENCY (Hz) 2mV/DIV FIGURE 39. ZOUT vs FREQUENCY FIGURE 40. VOUT NOISE, 0.1Hz TO 10Hz NO OUTPUT CAPACITANCE X: 50µs/DIV Y: 500mV/DIV +5mA -5mA FIGURE 41. LOAD TRANSIENT RESPONSE 13 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-30) 120 UNIT 2 100 80 IIN (µA) 60 40 20 0 3.2 3.7 4.2 VIN (V) 4.7 5.2 UNIT 1 IIN (µA) UNIT 3 100 80 60 40 20 0 3.2 3.7 4.2 VIN (V) 4.7 5.2 +25°C -40°C 120 +125°C (REXT = 100kΩ) FIGURE 42. IIN vs VIN (3 UNITS) FIGURE 43. IIN vs VIN OVER TEMPERATURE VOUT(V) NORMALIZED TO 3.0V AT 5.0VIN UNIT 1 UNIT 2 UNIT 3 VOUT (V) NORMALIZED TO 3.0V AT 5.0VIN 3.0005 2.9995 2.9985 2.9975 2.9965 2.9955 3.2 3.001 3.000 2.999 2.998 2.997 2.996 2.995 2.994 3.2 3.6 4.0 4.4 VIN (V) 4.8 5.2 5.6 -40°C +25°C +125°C 3.6 4.0 4.4 VIN (V) 4.8 5.2 5.6 FIGURE 44. LINE REGULATION (3 UNITS) FIGURE 45. LINE REGULATION OVER TEMPERATURE Δ VOUT (mV) NORMALIZED TO 0mA 0.10 0.05 0.00 -0.05 -0.10 -0.15 -0.20 -0.25 -7 -6 -5 -4 -3 -2 -1 SINKING 0 1 2 3 4 5 6 7 +125°C +25°C -40°C VOUT (V) NORMALIZED TO 3.0V AT +25°C 3.0006 3.0004 3.0002 3.0000 2.9998 2.9996 2.9994 2.9992 2.9990 -40 -25 -10 5 20 35 50 65 80 95 110 125 UNIT 1 UNIT 2 UNIT 3 LOAD (mA) SOURCING TEMPERATURE (°C) FIGURE 46. LOAD REGULATION OVER TEMPERATURE FIGURE 47. VOUT vs TEMPERATURE (3 UNITS) 14 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-30) 10 0 VIN (DC) = 5.0V -10 VIN (AC) = 50mVP-P -20 -30 -40 -50 -60 -70 -80 -90 -100 1.E+00 1.E+02 (REXT = 100kΩ) (Continued) X: 200mV/DIV Y: 10µs/DIV NO LOAD 1nF 10nF 100nF 1µF ΔVIN = +0.5V PSRR (dB) ΔVIN = -0.5V 1.E+04 1.E+06 FREQUENCY (Hz) FIGURE 48. PSRR vs CAPACITIVE LOADS FIGURE 49. LINE TRANSIENT RESPONSE, NO CAPACITIVE LOAD X: 200mV/DIV Y: 10µs/DIV VIN = 5.0V ΔVIN = +0.5V VOUT = 3.0V ΔVIN = -0.5V 1V/DIV 20µs/DIV FIGURE 50. LINE TRANSIENT RESPONSE, 0.001µF LOAD CAPACITANCE FIGURE 51. TURN-ON TIME GAIN IS x1000, NOISE IS 4.5µVP-P 140 120 100 ZOUT (Ω) 80 60 40 20 0 1.00E+00 1.00E+01 1.00E+02 1.00E+03 1.00E+04 1.00E+05 1.00E+06 1nF 10nF 100nF NO LOAD FREQUENCY (Hz) FIGURE 52. ZOUT vs FREQUENCY 2mV/DIV FIGURE 53. VOUT NOISE, 0.1Hz TO 10Hz 15 FN6326.8 July 14, 2011 ISL21007 Typical Performance Curves (ISL21007-30) (REXT = 100kΩ) (Continued) +7mA 200mV/DIV -7mA 100µs/DIV FIGURE 54. LOAD TRANSIENT RESPONSE Applications Information FGA Technology The ISL21007 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. max temperature profile should not be exceeded. Expect up to 1mV drift from the solder reflow process. FGA references are susceptible to excessive X-radiation like that used in PC board manufacturing. Initial accuracy can change 10mV or more under extreme radiation. If an assembled board needs to be X-rayed, care should be taken to shield the FGA reference device. Board Mounting Considerations For applications requiring the highest accuracy, board mounting location should be reviewed. Placing the device in areas subject to slight twisting can cause degradation of the accuracy of the reference voltage due to 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. Obviously, mounting the device on flexprint or extremely thin PC material will likewise cause loss of reference accuracy. 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 Pbfree 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. Micropower Operation The ISL21007 consumes extremely low supply current due to the proprietary FGA technology. Low noise performance is achieved using optimized biasing techniques. Supply current is typically 75µA and noise is 4.5µVP-P benefitting precision, low noise portable applications such as handheld meters and instruments. Data Converters in particular can utilize the ISL21007 as an external voltage reference. Low power DAC and ADC circuits will realize maximum resolution with lowest noise. Handling and Board Mounting FGA references provide excellent initial accuracy and low temperature drift at the expense of very little power drain. There are some precautions to take to insure this accuracy is not compromised. Excessive heat during solder reflow can cause excessive initial accuracy drift, so the recommended +260°C 16 Special Applications Considerations In addition to post-assembly examination, there are also other Xray sources that may affect the FGA reference long term accuracy. Airport screening machines contain X-rays and will FN6326.8 July 14, 2011 ISL21007 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, however, 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, thus 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, along with a ground plane underneath, which will effectively shield it 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. Turn-On Time The ISL21007 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 120µs. This is shown in Figure 10. Circuit design must take this into account when looking at power-up delays or sequencing. 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. 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 at 12.6Hz to create a filter with a 9.9Hz bandwidth. Noise in the 10kHz to 1MHz bandwidth is approximately 40µVP-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 10 times 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 ISL21007 is not designed to drive heavily capacitive loads, so for load capacitances above 0.001µF, the noise reduction network shown in Figure 55 is recommended. This network reduces noise significantly over the full bandwidth. Noise is reduced to less than 20µVP-P from 1Hz to 1MHz using this network with a 0.01µF capacitor and a 2kΩ resistor in series with a 10µF capacitor. Also, transient response is improved with higher value output capacitor. The 0.01µF value can be increased for better load transient response with little sacrifice in output stability. Output Voltage Adjustment The output voltage can be adjusted up or down by 2.5% by placing a potentiometer from VOUT to ground, 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 (