ADR430 ADR431 ADR433 ADR434 ADR435 ADR439 ADR430B ADR430A ADR431B ADR431A - Datasheet Archive

 

with Current Sink and Source Capability ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 FEATURES PIN CONFIGURATIONS Low noise (0.1 Hz

 

Ultralow Noise XFET® Voltage References with Current Sink and Source Capability ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 FEATURES PIN CONFIGURATIONS Low noise (0.1 Hz to 10 Hz): 3.5 µV p-p @ 2.5 V output No external capacitor required Low temperature coefficient A Grade: 10 ppm/°C max B Grade: 3 ppm/°C max Load regulation: 15 ppm/mA Line regulation: 20 ppm/V Wide operating range ADR430 ADR430: 4.1 V to 18 V ADR431 ADR431: 4.5 V to 18 V ADR433 ADR433: 5.0 V to 18 V ADR434 ADR434: 6.1 V to 18 V ADR435 ADR435: 7.0 V to 18 V ADR439 ADR439: 6.5 V to 18 V High output current: +30 mA/-20 mA Wide temperature range: -40°C to +125°C TP 1 ADR43x 8 TP NC TOP VIEW 6 VOUT (Not to Scale) GND 4 5 TRIM VIN 2 7 NC = NO CONNECT 04500-0-001 NC 3 Figure 1. 8-Lead MSOP (RM Suffix) ADR43x 8 TP NC TOP VIEW NC 3 (Not to Scale) 6 VOUT 5 TRIM GND 4 7 NC = NO CONNECT 04500-0-041 TP 1 VIN 2 Figure 2. 8-Lead SOIC (R Suffix) APPLICATIONS Precision data acquisition systems High resolution data converters Medical instruments Industrial process control systems Optical control circuits Precision instruments GENERAL DESCRIPTION The ADR43x series is a family of XFET voltage references featuring low noise, high accuracy, and low temperature drift performance. Using ADI's patented temperature drift curvature correction and XFET (eXtra implanted junction FET) technology, the ADR43x's voltage change versus temperature nonlinearity is minimized. The XFET references operate at lower current (800 µA) and supply headroom (2 V) than buried-Zener references. BuriedZener references require more than 5 V headroom for operations. The ADR43x XFET references are the only low noise solutions for 5 V systems. The ADR43x series has the capability to source up to 30 mA and sink up to 20 mA of output current. It also comes with a TRIM terminal to adjust the output voltage over a 0.5% range without compromising performance. The ADR43x is available in the 8-lead mini SOIC and 8-lead SOIC packages. All versions are specified over the extended industrial temperature range (-40°C to +125°C). Table 1. Selection Guide Model ADR430B ADR430B ADR430A ADR430A ADR431B ADR431B ADR431A ADR431A ADR433B ADR433B ADR433A ADR433A ADR434B ADR434B ADR434A ADR434A ADR435B ADR435B ADR435A ADR435A ADR439B ADR439B ADR439A ADR439A VOUT (V) 2.048 2.048 2.500 2.500 3.000 3.000 4.096 4.096 5.000 5.000 4.500 4.500 Accuracy (mV) ±1 ±3 ±1 ±3 ±1.4 ±4 ±1.5 ±5 ±2 ±6 ±2 ±5.4 Temperature Coefficient (ppm/°C) 3 10 3 10 3 10 3 10 3 10 3 10 Rev. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved. ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 TABLE OF CONTENTS Specifications. 3 Applications. 16 ADR430 ADR430 Electrical Characteristics. 3 Output Adjustment . 16 ADR431 ADR431 Electrical Characteristics. 4 Reference for Converters in Optical Network Control Circuits. 16 ADR433 ADR433 Electrical Characteristics. 5 ADR434 ADR434 Electrical Characteristics. 6 ADR435 ADR435 Electrical Characteristics. 7 ADR439 ADR439 Electrical Characteristics. 8 Absolute Maximum Ratings. 9 Package Type . 9 ESD Caution. 9 Typical Performance Characteristics . 10 Theory of Operation . 15 Basic Voltage Reference Connections. 15 Noise Performance . 15 Negative Precision Reference without Precision Resistors . 16 High Voltage Floating Current Source . 17 Kelvin Connections. 17 Dual Polarity References . 17 Programmable Current Source . 18 Programmable DAC Reference Voltage . 18 Precision Voltage Reference for Data Converters. 19 Precision Boosted Output Regulator . 19 Outline Dimensions . 20 Ordering Guide . 21 Turn-On Time . 15 REVISION HISTORY 9/04-Data Sheet Changed from Rev. A to Rev. B Added New Grade .Universal Changes to Specifications . 3 Replaced Figure 3, Figure 4, Figure 5. 10 Updated Ordering Guide. 21 6/04-Data Sheet Changed from Rev. 0 to Rev. A Changes to Format .Universal Changes to the Ordering Guide. 20 12/03-Revision 0: Initial Version Rev. B | Page 2 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 SPECIFICATIONS ADR430 ADR430 ELECTRICAL CHARACTERISTICS VIN = 4.1 V to 18 V, ILOAD = 0 mA, TA = 25°C, unless otherwise noted. Table 2. Parameter Output Voltage B Grade A Grade Initial Accuracy B Grade B Grade A Grade A Grade Temperature Coefficient SOIC-8 (B Grade) SOIC-8 (A Grade) MSOP-8 Line Regulation Load Regulation Quiescent Current Voltage Noise Voltage Noise Density Turn-On Settling Time Long-Term Stability1 Output Voltage Hysteresis Ripple Rejection Ratio Short Circuit to GND Supply Voltage Operating Range Supply Voltage Headroom 1 Symbol Conditions Typ Max Unit 2.047 2.045 2.048 2.048 2.049 2.051 V V 1 0.05 3 0.15 VO VO Min mV % mV % 1 2 2 3 10 10 ppm/°C ppm/°C 5 20 ppm/V 15 ppm/mA 15 800 ppm/mA µA µV p-p nVHz µs ppm ppm dB mA V V VOERR VOERR VOERR VOERR TCVO TCVO TCVO VO/VIN VO/ILOAD IIN eN p-p eN tR VO VO_HYS RRR ISC VIN VIN - VO -40°C < TA < +125°C -40°C < TA < +125°C -40°C < TA < +125°C VIN = 4.1 V to 18 V -40°C < TA < +125°C ILOAD = 0 mA to 10 mA, VIN = 5.0 V -40°C < TA < +125°C ILOAD = -10 mA to 0 mA, VIN = 5.0 V -40°C < TA < +125°C No load, -40°C < TA < +125°C 0.1 Hz to 10.0 Hz 1 kHz CIN = 0 1,000 h 560 3.5 60 10 40 20 ­70 40 fIN = 10 kHz 4.1 2 18 The long-term stability specification is noncumulative. The drift in subsequent 1,000 hour periods is significantly lower than in the first 1,000 hour period. Rev. B | Page 3 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 ADR431 ADR431 ELECTRICAL CHARACTERISTICS VIN = 4.5 V to 18 V, ILOAD = 0 mA, TA = 25°C, unless otherwise noted. Table 3. Parameter Output Voltage B Grade A Grade Initial Accuracy B Grade B Grade A Grade A Grade Temperature Coefficient SOIC-8 (B Grade) SOIC-8 (A Grade) MSOP-8 Line Regulation Load Regulation Quiescent Current Voltage Noise Voltage Noise Density Turn-On Settling Time Long-Term Stability1 Output Voltage Hysteresis Ripple Rejection Ratio Short Circuit to GND Supply Voltage Operating Range Supply Voltage Headroom 1 Symbol Conditions Typ Max Unit 2.499 2.497 2.500 2.500 2.501 2.503 V V 1 0.04 3 0.13 VO VO Min mV % mV % 1 2 2 3 10 10 ppm/°C ppm/°C ppm/°C 5 20 ppm/V 15 ppm/mA 15 800 ppm/mA µA µV p-p nVHz µs ppm ppm dB mA V V VOERR VOERR VOERR VOERR TCVO TCVO TCVO VO/VIN VO/ILOAD IIN eN p-p eN tR VO VO_HYS RRR ISC VIN VIN ­ VO -40°C < TA < +125°C -40°C < TA < +125°C -40°C < TA < +125°C VIN = 4.5 V to 18 V -40°C < TA < +125°C ILOAD = 0 mA to 10 mA, VIN = 5.0 V -40°C < TA < +125°C ILOAD = -10 mA to 0 mA, VIN = 5.0 V -40°C < TA < +125°C No load, -40°C < TA < +125°C 0.1 Hz to 10.0 Hz 1 kHz CIN = 0 1,000 h 580 3.5 80 10 40 20 -70 40 fIN = 10 kHz 4.5 2 18 The long-term stability specification is noncumulative. The drift in subsequent 1,000 hour periods is significantly lower than in the first 1,000 hour period. Rev. B | Page 4 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 ADR433 ADR433 ELECTRICAL CHARACTERISTICS VIN = 5 V to 18 V, ILOAD = 0 mA , TA = 25°C, unless otherwise noted. Table 4. Parameter Output Voltage B Grade A Grade Initial Accuracy B Grade B Grade A Grade A Grade Temperature Coefficient SOIC-8 (B Grade) SOIC-8 (A Grade) MSOP-8 Line Regulation Load Regulation Quiescent Current Voltage Noise Voltage Noise Density Turn-On Settling Time Long-Term Stability1 Output Voltage Hysteresis Ripple Rejection Ratio Short Circuit to GND Supply Voltage Operating Range Supply Voltage Headroom Symbol Conditions Typ Max Unit 2.9985 2.996 3.000 3.000 3.0015 3.004 V V 1.5 0.05 4 0.13 VO VO Min mV % mV % 1 2 2 3 10 10 ppm/°C ppm/°C ppm/°C 5 20 ppm/V 15 ppm/mA 15 800 ppm/mA µA µV p-p nVHz µs ppm ppm dB mA V V VOERR VOERR VOERR VOERR TCVO VO/VIN VO/ILOAD IIN eN p-p eN tR VO VO_HYS RRR ISC VIN VIN - VO -40°C < TA < +125°C -40°C < TA < +125°C -40°C < TA < +125°C VIN = 5 V to 18 V -40°C < TA < +125°C ILOAD = 0 mA to 10 mA, VIN = 6 V -40°C < TA < +125°C ILOAD = -10 mA to 0 mA, VIN = 6 V -40°C < TA < +125°C No load, -40°C < TA < +125°C 0.1 Hz to 10.0 Hz 1 kHz CIN = 0 1,000 h 590 3.75 90 10 40 20 -70 40 fIN = 10 kHz 5 2 1 18 The long-term stability specification is noncumulative. The drift in subsequent 1,000 hour periods is significantly lower than in the first 1,000 hour period. Rev. B | Page 5 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 ADR434 ADR434 ELECTRICAL CHARACTERISTICS VIN = 6.1 V to 18 V, ILOAD = 0 mA, TA = 25°C, unless otherwise noted. Table 5. Parameter Output Voltage B Grade A Grade Initial Accuracy B Grade B Grade A Grade A Grade Temperature Coefficient SOIC-8 (B Grade) SOIC-8 (A Grade) MSOP-8 Line Regulation Load Regulation Quiescent Current Voltage Noise Voltage Noise Density Turn-On Settling Time Long-Term Stability1 Output Voltage Hysteresis Ripple Rejection Ratio Short Circuit to GND Supply Voltage Operating Range Supply Voltage Headroom 1 Symbol Conditions Typ Max Unit 4.0945 4.091 4.096 4.096 4.0975 4.101 V V 1.5 0.04 5 0.13 VO VO Min mV % mV % 1 2 2 3 10 10 ppm/°C ppm/°C ppm/°C 5 20 ppm/V 15 ppm/mA 15 800 ppm/mA µA µV p-p nVHz µs ppm ppm dB mA V V VOERR VOERR VOERR VOERR TCVO VO/VIN VO/ILOAD IIN eN p-p eN tR VO VO_HYS RRR ISC VIN VIN - VO -40°C < TA < +125°C -40°C < TA < +125°C -40°C < TA < +125°C VIN = 6.1 V to 18 V -40°C < TA < +125°C ILOAD = 0 mA to 10 mA, VIN = 7 V -40°C < TA < +125°C ILOAD = -10 mA to 0 mA, VIN = 7 V -40°C < TA < +125°C No load, -40°C < TA < +125°C 0.1 Hz to 10.0 Hz 1 kHz CIN = 0 1,000 h 595 6.25 100 10 40 20 -70 40 fIN = 10 kHz 6.1 2 18 The long-term stability specification is noncumulative. The drift in subsequent 1,000 hour periods is significantly lower than in the first 1,000 hour period. Rev. B | Page 6 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 ADR435 ADR435 ELECTRICAL CHARACTERISTICS VIN = 7 V to 18 V, ILOAD = 0 mA, TA = 25°C, unless otherwise noted. Table 6. Parameter Output Voltage B Grade A Grade Initial Accuracy B Grade B Grade A Grade A Grade Temperature Coefficient SOIC-8 (B Grade) SOIC-8 (A Grade) MSOP-8 Line Regulation Load Regulation Quiescent Current Voltage Noise Voltage Noise Density Turn-On Settling Time Long-Term Stability1 Output Voltage Hysteresis Ripple Rejection Ratio Short Circuit to GND Supply Voltage Operating Range Supply Voltage Headroom 1 Symbol Conditions Typ Max Unit 4.998 4.994 5.000 5.000 5.002 5.006 V V 2 0.04 6 0.12 VO VO Min mV % mV % 1 2 2 3 10 10 ppm/°C ppm/°C ppm/°C 5 20 ppm/V 15 ppm/mA 15 800 ppm/mA µA µV p-p nV/Hz µs ppm ppm dB mA V V VOERR VOERR VOERR VOERR TCVO VO/VIN VO/ILOAD IIN eN p-p eN tR VO VO_HYS RRR ISC VIN VIN - VO -40°C < TA < +125°C -40°C < TA < +125°C -40°C < TA < +125°C VIN = 7 V to 18 V -40°C < TA < +125°C ILOAD = 0 mA to 10 mA, VIN = 8 V -40°C < TA < +125°C ILOAD = -10 mA to 0 mA, VIN = 8 V -40°C < TA < +125°C No load, -40°C < TA < +125°C 0.1 Hz to 10 Hz 1 kHz CIN = 0 1,000 h 620 8 115 10 40 20 -70 40 fIN = 10 kHz 7 2 18 The long-term stability specification is noncumulative. The drift in subsequent 1,000 hour periods is significantly lower than in the first 1,000 hour period. Rev. B | Page 7 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 ADR439 ADR439 ELECTRICAL CHARACTERISTICS VIN = 6.5 V to 18 V, ILOAD = 0 mV, TA = 25°C, unless otherwise noted. Table 7. Parameter Output Voltage B Grade A Grade Initial Accuracy B Grade B Grade A Grade A Grade Temperature Coefficient SOIC-8 (B Grade) SOIC-8 (A Grade) MSOP-8 Line Regulation Load Regulation Quiescent Current Voltage Noise Voltage Noise Density Turn-On Settling Time Long-Term Stability1 Output Voltage Hysteresis Ripple Rejection Ratio Short Circuit to GND Supply Voltage Operating Range Supply Voltage Headroom 1 Symbol Conditions Typ Max Unit 4.498 4.4946 4.500 4.500 4.502 4.5054 V V 2 0.04 5.4 0.12 VO VO Min mV % mV % 1 2 2 3 10 10 ppm/°C ppm/°C ppm/°C 5 20 ppm/V 15 ppm/mA 15 800 ppm/mA µA µV p-p nV/Hz µs ppm ppm dB mA V V VOERR VOERR VOERR VOERR TCVO VO/VIN VO/ILOAD IIN eN p-p eN tR VO VO_HYS RRR ISC VIN VIN - VO -40°C < TA < +125°C -40°C < TA < +125°C -40°C < TA < +125°C VIN = 6.5 V to 18 V -40°C < TA < +125°C ILOAD = 0 mA to 10 mA, VIN = 6.5 V -40°C < TA < +125°C ILOAD = -10 mA to 0 mA, VIN = 6.5 V -40°C < TA < +125°C No load, -40°C < TA < +125°C 0.1 Hz to 10.0 Hz 1 kHz CIN = 0 1,000 h 600 7.5 110 10 40 20 -70 40 fIN = 10 kHz 6.5 2 18 The long-term stability specification is noncumulative. The drift in subsequent 1,000 hour periods is significantly lower than in the first 1,000 hour period. Rev. B | Page 8 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 ABSOLUTE MAXIMUM RATINGS @ 25°C, unless otherwise noted. Table 8. Parameter Supply Voltage Output Short-Circuit Duration to GND Storage Temperature Range (R, RM Packages) Operating Temperature Range Junction Temperature Range Lead Temperature Range (Soldering, 60 s) PACKAGE TYPE Rating 20 V Indefinite -65°C to +125°C -40°C to +125°C -65°C to +150°C 300°C Table 9. Package Type 8-Lead SOIC (R) 8-Lead MSOP (RM) 1 JA1 130 190 JC 43 Unit °C/W °C/W JA is specified for worst-case conditions (device soldered in circuit board for surface-mount packages). Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Absolute maximum ratings apply individually only, not in combination. ESD CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. Rev. B | Page 9 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 TYPICAL PERFORMANCE CHARACTERISTICS Default conditions: ±5 V, CL = 5 pF, G = 2, Rg = Rf = 1 k, RL = 2 k, VO = 2 V p-p, Frequency = 1 MHz, TA = 25°C. 0.8 2.5009 0.7 SUPPLY CURRENT (mA) OUTPUT VOLTAGE (V) 2.5007 2.5005 2.5003 2.5001 2.4999 +125°C 0.6 +25°C ­40°C 0.5 0.4 ­25 ­10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 0.3 04500-0-015 2.4995 ­40 4 8 10 12 14 16 INPUT VOLTAGE (V) Figure 6. ADR435 ADR435 Supply Current vs. Input Voltage Figure 3. ADR431 ADR431 VOUT vs. Temperature 700 4.0975 650 SUPPLY CURRENT (µA) 4.0980 4.0970 4.0965 4.0960 550 500 450 4.0955 ­25 ­10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 400 ­40 04500-0-016 4.0950 ­40 600 ­25 ­10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 04500-0-019 OUTPUT VOLTAGE (V) 6 04500-0-018 2.4997 Figure 7. ADR435 ADR435 Supply Current vs. Temperature Figure 4. ADR434 ADR434 VOUT vs. Temperature 0.60 5.0025 +125°C 0.58 5.0020 SUPPLY CURRENT (mA) 5.0010 5.0005 5.0000 0.54 0.52 +25°C 0.50 0.48 0.46 ­40°C 0.44 4.9995 ­25 ­10 5 20 35 50 65 80 95 TEMPERATURE (°C) 110 125 0.40 6 8 10 12 14 16 INPUT VOLTAGE (V) Figure 8. ADR431 ADR431 Supply Current vs. Input Voltage Figure 5. ADR435 ADR435 VOUT vs. Temperature Rev. B | Page 10 of 24 18 04500-0-020 4.9990 ­40 0.42 04500-0-017 OUTPUT VOLTAGE (V) 0.56 5.0015 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 2.5 610 DIFFERENTIAL VOLTAGE (V) SUPPLY CURRENT (µA) 580 550 520 490 460 2.0 ­40°C 1.5 +25°C 1.0 +125°C 0.5 ­25 ­10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 0 ­10 04500-0-021 400 ­40 ­5 5 10 Figure 12. ADR431 ADR431 Minimum Input/Output Differential Voltage vs. Load Current Figure 9. ADR431 ADR431 Supply Current vs. Temperature 15 0 LOAD CURRENT (mA) 04500-0-024 430 1.9 IL = 0mA to 10mA NO LOAD 12 MINIMUM HEADROOM (V) LOAD REGULATION (ppm/mA) 1.8 9 6 3 1.7 1.6 1.5 1.4 1.3 1.2 ­10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 1.0 ­40 DIFFERENTIAL VOLTAGE (V) 6 3 5 20 35 50 65 80 95 110 TEMPERATURE (°C) 125 04500-0-023 LOAD REGULATION (ppm/mA) 9 ­10 20 35 50 65 80 95 110 125 2.5 IL = 0mA to 10mA ­25 5 Figure 13. ADR431 ADR431 Minimum Headroom vs. Temperature 12 0 ­40 ­10 TEMPERATURE (°C) Figure 10. ADR431 ADR431 Load Regulation vs. Temperature 15 ­25 2.0 ­40°C 1.5 +25°C 1.0 +125°C 0.5 0 ­10 ­5 0 5 LOAD CURRENT (mA) Figure 14. ADR435 ADR435 Minimum Input/Output Differential Voltage vs. Load Current Figure 11. ADR435 ADR435 Load Regulation vs. Temperature Rev. B | Page 11 of 24 10 04500-0-026 ­25 04500-0-022 0 ­40 04500-0-025 1.1 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 1.9 CLOAD = 0.01µF NO INPUT CAPACITOR NO LOAD VOUT = 1V/DIV 1.5 1.3 VIN = 2V/DIV 1.1 0.9 ­40 ­25 ­10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 04500-0-027 TIME = 4µs/DIV 04500-0-031 MINIMUM HEADROOM (V) 1.7 Figure 18. ADR431 ADR431 Turn-On Response, 0.01 µF Load Capacitor Figure 15. ADR435 ADR435 Minimum Headroom vs. Temperature 20 VIN = 7V TO 18V VOUT = 1V/DIV 12 8 VIN = 2V/DIV 4 TIME = 4µs/DIV ­10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) Figure 19. ADR431 ADR431 Turn-Off Response Figure 16. ADR435 ADR435 Line Regulation vs. Temperature CIN = 0.01µF NO LOAD BYPASS CAPACITOR = 0µF LINE INTERRUPTION VOUT = 1V/DIV 500mV/DIV VIN VOUT = 50mV/DIV VIN = 2V/DIV TIME = 4µs/DIV TIME = 100µs/DIV Figure 17. ADR431 ADR431 Turn-On Response 04500-0-033 ­25 04500-0-028 ­4 ­40 04500-0-032 0 04500-0-030 LINE REGULATION (ppm/V) 16 CIN = 0.01µF NO LOAD Figure 20. ADR431 ADR431 Line Transient Response-No Capacitors Rev. B | Page 12 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 BYPASS CAPACITOR = 0.1µF LINE INTERRUPTION 500mV/DIV VIN VOUT = 50mV/DIV 04500-0-037 TIME = 100µs/DIV 04500-0-034 2µV/DIV TIME = 1s/DIV Figure 21. ADR431 ADR431 Line Transient Response-0.1 µF Bypass Capacitor Figure 24. ADR435 ADR435 0.1 Hz to 10.0 Hz Voltage Noise 1µV/DIV TIME = 1s/DIV Figure 22. ADR431 ADR431 0.1 Hz to 10.0 Hz Voltage Noise 04500-0-038 TIME = 1s/DIV 04500-0-035 50µV/DIV Figure 25. ADR435 ADR435 10 Hz to 10 kHz Voltage Noise 14 NUMBER OF PARTS 12 8 6 4 2 0 ­120 ­90 ­70 ­50 ­30 ­10 10 30 50 70 DEVIATION (PPM) Figure 23. ADR431 ADR431 10 Hz to 10 kHz Voltage Noise Figure 26. ADR431 ADR431 Typical Hysteresis Rev. B | Page 13 of 24 90 120 04500-0-029 TIME = 1s/DIV 04500-0-036 50µV/DIV 10 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 50 10 45 ­10 RIPPLE REJECTION (dB) 35 30 25 ADR435 ADR435 20 15 ADR433 ADR433 ­30 ­50 ­70 ­90 ­110 10 ADR430 ADR430 0 100 1k 10k FREQUENCY (Hz) 100k ­130 ­150 10 Figure 27. Output Impedance vs. Frequency 100 1k 10k 100k FREQUENCY (Hz) Figure 28. Ripple Rejection Ratio Rev. B | Page 14 of 24 1M 04500-0-040 5 04500-0-039 OUTPUT IMPEDANCE () 40 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 THEORY OF OPERATION The intrinsic reference voltage is around 0.5 V with a negative temperature coefficient of about ­120 ppm/°C. This slope is essentially constant to the dielectric constant of silicon and can be closely compensated by adding a correction term generated in the same fashion as the proportional-to-temperature (PTAT) term used to compensate band gap references. The big advantage of an XFET reference is that the correction term is some 30 times lower (therefore, requiring less correction) than for a band gap reference, resulting in much lower noise, because most of the noise of a band gap reference comes from the temperature compensation circuitry. The ADR43x family of references is guaranteed to deliver load currents to 10 mA with an input voltage that ranges from 4.5 V to 18 V. When these devices are used in applications at higher currents, users should use the following equation to account for the temperature effects due to the power dissipation increases. TJ = PD × JA + TA where: TJ and TA are the junction and ambient temperatures, respectively. PD is the device power dissipation. JA is the device package thermal resistance. BASIC VOLTAGE REFERENCE CONNECTIONS Voltage references, in general, require a bypass capacitor connected from VOUT to GND. The circuit in Figure 30 illustrates the basic configuration for the ADR43x family of references. Other than a 0.1 µF capacitor at the output to help improve noise suppression, a large output capacitor at the output is not required for circuit stability. Figure 29 shows the basic topology of the ADR43x series. The temperature correction term is provided by a current source with a value designed to be proportional to absolute temperature. The general equation is VOUT = G × (VP - R1 × I PTAT ) ADR43x devices are created by on-chip adjustment of R2 and R3 to achieve 2.048 V or 2.500 V, respectively, at the reference output. I1 VIN I1 ADR43x IPTAT VOUT R2 * R1 *EXTRA CHANNEL IMPLANT VOUT = G(VP ­ R1 × IPTAT) R3 GND 04500-0-002 VP 8 TP 1 VIN 2 10µF + 0.1µF ADR43x TP 7 NIC 6 NIC 3 TOP VIEW (Not to Scale) 4 (1) where: G is the gain of the reciprocal of the divider ratio. VP is the difference in pinch-off voltage between the two JFETs. IPTAT is the positive temperature coefficient correction current. (2) 5 OUTPUT TRIM 0.1µF NIC = NO INTERNAL CONNECTION TP = TEST PIN (DO NOT CONNECT) 04500-0-003 The ADR43x series of references uses a new reference generation technique known as XFET (eXtra implanted junction FET). This technique yields a reference with low supply current, good thermal hysteresis, and exceptionally low noise. The core of the XFET reference consists of two junction field-effect transistors (JFETs), one of which has an extra channel implant to raise its pinch-off voltage. By running the two JFETs at the same drain current, the difference in pinch-off voltage can be amplified and used to form a highly stable voltage reference. Figure 30. Basic Voltage Reference Configuration NOISE PERFORMANCE The noise generated by the ADR43x family of references is typically less than 3.75 µV p-p over the 0.1 Hz to 10.0 Hz band for ADR430 ADR430, ADR431 ADR431, and ADR433 ADR433. Figure 22 shows the 0.1 Hz to 10 Hz noise of the ADR431 ADR431, which is only 3.5 µV p-p. The noise measurement is made with a band-pass filter made of a 2-pole high-pass filter with a corner frequency at 0.1 Hz and a 2-pole low-pass filter with a corner frequency at 10.0 Hz. TURN-ON TIME Upon application of power (cold start), the time required for the output voltage to reach its final value within a specified error band is defined as the turn-on settling time. Two components normally associated with this are the time for the active circuits to settle and the time for the thermal gradients on the chip to stabilize. Figure 17 and Figure 18 show the turn-on settling time for the ADR431 ADR431. Figure 29. Simplified Schematic Device Power Dissipation Considerations Rev. B | Page 15 of 24 ADR430/ADR431/ADR433/ADR434/ADR435/ADR439 APPLICATIONS SOURCE FIBER OUTPUT ADJUSTMENT GIMBAL + SENSOR ACTIVATOR LEFT AMPL TRIM AMPL ADR431 ADR431 ADR431 ADR431 ADC DAC ADR431 ADR431 DSP GND OUTPUT VO = ±0.5% Figure 32. All-Optical Router Network R1 470k NEGATIVE PRECISION REFERENCE WITHOUT PRECISION RESISTORS RP 10k GND R2 10k (ADR420 ADR420) 15k (ADR421 ADR421) 04500-0-004 ADR43x PREAMP CONTROL ELECTRONICS INPUT VO ACTIVATOR RIGHT MEMS MIRROR DAC VIN DESTINATION FIBER LASER BEAM 04500-0-005 The ADR43x trim terminal can be used to adjust the output voltage over a ±0.5% range. This feature allows the system designer to trim system errors out by setting the reference to a voltage other than the nominal. This is also helpful if the part is used in a system at temperature to trim out any error. Adjustment of the output has negligible effect on the temperature performance of the device. To avoid degrading temperature coefficients, both the trimming potentiometer and the two resistors need to be low temperature coefficient types, preferably