1.2 V Micropower, Precision Shunt Voltage Reference AD1580 PIN CONFIGURATIONS FEATURES AD1580 V+ 1 3 The AD1580 is available in two grades, A and B, both of which are provided in the SOT-23 and SC70 packages, the smallest surface-mount packages available. Both grades are specified over the industrial temperature range of −40°C to +85°C. 1 NC (OR V–) 00700-002 TOP VIEW NC = NO CONNECT TOP VIEW NC = NO CONNECT Figure 1. SOT-23 Figure 2. SC70 50 45 40 QUANTITY 35 30 25 20 15 00700-003 10 5 0 –40 –30 –20 –10 0 10 20 30 40 TEMPERATURE DRIFT (ppm/°C) Figure 3. Reverse Voltage Temperature Drift Distribution The AD1580 1 is a low cost, 2-terminal (shunt), precision band gap reference. It provides an accurate 1.225 V output for input currents between 50 μA and 10 mA. 300 250 QUANTITY 200 150 100 50 0 –10 00700-004 The low minimum operating current makes the AD1580 ideal for use in battery-powered 3 V or 5 V systems. However, the wide operating current range means that the AD1580 is extremely versatile and suitable for use in a wide variety of high current applications. 3 V+ 2 GENERAL DESCRIPTION The superior accuracy and stability of the AD1580 is made possible by the precise matching and thermal tracking of on-chip components. Proprietary curvature correction design techniques have been used to minimize the nonlinearities in the voltage output temperature characteristics. The AD1580 is stable with any value of capacitive load. NC (OR V–) V– 2 APPLICATIONS Portable, battery-powered equipment Cellular phones, notebook computers, PDAs, GPSs, and DMMs Computer workstations Suitable for use with a wide range of video RAMDACs Smart industrial transmitters PCMCIA cards Automotive 3 V/5 V, 8-bit to 12-bit data converters AD1580 V– 1 00700-001 Wide operating range: 50 µA to 10 mA Initial accuracy: ±0.1% maximum Temperature drift: ±50 ppm/°C maximum Output impedance: 0.5 Ω maximum Wideband noise (10 Hz to 10 kHz): 20 µV rms Operating temperature range: −40°C to +85°C High ESD rating 4 kV human body model 400 V machine model Compact, surface-mount SOT-23 and SC70 packages –8 –6 –4 –2 0 2 4 6 8 10 OUTPUT ERROR (mV) Figure 4. Reverse Voltage Error Distribution Protected by U.S. Patent No. 5,969,657. Rev. F 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: 781.461.3113 ©2003-2011 Analog Devices, Inc. All rights reserved. AD1580 TABLE OF CONTENTS Features .............................................................................................. 1 Voltage Output Nonlinearity vs. Temperature ..........................7 Applications ....................................................................................... 1 Reverse Voltage Hysteresis ...........................................................7 General Description ......................................................................... 1 Output Impedance vs. Frequency ...............................................7 Pin Configurations ........................................................................... 1 Noise Performance and Reduction .............................................8 Revision History ............................................................................... 2 Turn-On Time ...............................................................................8 Specifications..................................................................................... 3 Transient Response .......................................................................9 Absolute Maximum Ratings............................................................ 4 Precision Micropower Low Dropout Reference .......................9 ESD Caution .................................................................................. 4 Using the AD1580 with 3 V Data Converters ...........................9 Typical Performance Characteristics ............................................. 5 Outline Dimensions ....................................................................... 11 Theory of Operation ........................................................................ 6 Ordering Guide .......................................................................... 12 Applying the AD1580 .................................................................. 6 Package Branding Information ................................................ 12 Temperature Performance ........................................................... 6 REVISION HISTORY 7/11—Rev. E to Rev. F Changes to Ordering Guide .......................................................... 12 Updated Outline Dimensions ....................................................... 11 Changes to Ordering Guide .......................................................... 12 7/11—Rev. D to Rev. E Updated Outline Dimensions ....................................................... 11 Changes to Ordering Guide .......................................................... 12 7/04—Rev. A to Rev. B Changes to Ordering Guide .............................................................2 1/08—Rev. C to Rev. D Changes to Figure 5 .......................................................................... 5 Changes to Figure 6 Caption ........................................................... 5 Changes to Ordering Guide .......................................................... 12 7/06—Rev. B to Rev. C Updated Format ..................................................................Universal Changes to Figure 13 ........................................................................ 7 Changes to Figure 16 ........................................................................ 8 10/03—Rev. 0 to Rev. A Renumbered Figures and TPCs ........................................ Universal Edits to Features.................................................................................1 Edits to General Description ...........................................................1 Edits to Ordering Guide ...................................................................2 Updated Figures 5 Through 7 ..........................................................4 Updated Outline Dimensions ..........................................................8 Rev. F | Page 2 of 12 AD1580 SPECIFICATIONS TA = 25°C, IIN = 100 µA, unless otherwise noted. Table 1. AD1580A Model REVERSE VOLTAGE OUTPUT (SOT-23) REVERSE VOLTAGE OUTPUT (SC70) REVERSE VOLTAGE TEMPERATURE DRIFT −40°C to +85°C MINIMUM OPERATING CURRENT, TMIN to TMAX REVERSE VOLTAGE CHANGE WITH REVERSE CURRENT 50 μA < IIN < 10 mA, TMIN to TMAX 50 μA < IIN < 1 mA, TMIN to TMAX DYNAMIC OUTPUT IMPEDANCE (∆VR/ΔIR) IIN = 1 mA ± 100 μA (f = 120 Hz) OUTPUT NOISE RMS Noise Voltage: 10 Hz to 10 kHz Low Frequency Noise Voltage: 0.1 Hz to 10 Hz TURN-ON SETTLING TIME TO 0.1% 1 OUTPUT VOLTAGE HYSTERESIS 2 TEMPERATURE RANGE Specified Performance, TMIN to TMAX Operating Range 3 Min 1.215 Typ 1.225 AD1580B Max 1.235 Min 1.224 1.2225 Typ 1.225 1.225 100 50 Max 1.226 1.2275 Unit V V 50 50 ppm/°C μA 2.5 0.5 6 2.5 0.5 6 mV mV 0.4 1 0.4 0.5 Ω 20 5 5 80 −40 −55 20 5 5 80 +85 +125 −40 −55 μV rms μV p-p µs µV +85 +125 Measured with no load capacitor. Output hysteresis is defined as the change in the +25°C output voltage after a temperature excursion to +85°C and then to −40°C. 3 The operating temperature range is defined as the temperature extremes at which the device continues to function. Parts may deviate from their specified performance. 1 2 Rev. F | Page 3 of 12 °C °C AD1580 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter Reverse Current Forward Current Internal Power Dissipation1 SOT-23 (RT) Storage Temperature Range Operating Temperature Range AD1580/RT Lead Temperature, Soldering Vapor Phase (60 sec) Infrared (15 sec) ESD Susceptibility2 Human Body Model Machine Model 1 2 0.3 W −65°C to +150°C 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 above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. −55°C to +125°C ESD CAUTION Rating 25 mA 20 mA 215°C 220°C 4 kV 400 V Specification is for device in free air at 25°C, SOT-23 package. θJA = 300°C/W. The human body model is a 100 pF capacitor discharged through 1.5 kΩ. For the machine model, a 200 pF capacitor is discharged directly into the device. Rev. F | Page 4 of 12 AD1580 TYPICAL PERFORMANCE CHARACTERISTICS 100 500 REVERSE CURRENT (µA) 80 0 –500 –1000 40 +85°C 20 00700-005 –1500 –2000 –55 60 –35 –15 5 25 45 65 85 105 +25°C –40°C 0 125 0 0.2 0.4 0.8 1.0 1.2 4 1.0 3 0.8 +25°C FORWARD VOLTAGE (V) –40°C TA = +125°C 1 TA = –40°C TO +85°C –1 0.01 0.1 1 REVERSE CURRENT (mA) 0 0.01 10 00700-007 200 1k 10k 1 10 Figure 9. Forward Voltage vs. Forward Current 400 100 0.1 FORWARD CURRENT (mA) 600 10 0.4 0.2 Figure 6. Reverse Voltage Change vs. Reverse Current 1.0 +85°C 0.6 00700-009 0 1.4 Figure 8. Reverse Current vs. Reverse Voltage 00700-006 REVERSE VOLTAGE CHANGE (mV) Figure 5. Output Drift for Different Temperature Characteristics NOISE VOLTAGE (nV/ Hz) 0.6 REVERSE VOLTAGE (V) TEMPERATURE (°C) 2 00700-008 REVERSE VOLTAGE CHANGE (ppm) 1000 100k 1M FREQUENCY (Hz) Figure 7. Noise Spectral Density Rev. F | Page 5 of 12 100 AD1580 THEORY OF OPERATION Figure 12 shows a typical connection of the AD1580BRT operating at a minimum of 100 µA. This connection can provide ±1 mA to the load while accommodating ±10% power supply variations. VS RS IR + IL IL VR IR VOUT 00700-011 The AD1580 uses the band gap concept to produce a stable, low temperature coefficient voltage reference suitable for high accuracy data acquisition components and systems. The device makes use of the underlying physical nature of a silicon transistor base emitter voltage in the forward biased operating region. All such transistors have an approximately −2 mV/°C temperature coefficient (TC), which is unsuitable for use directly as a low TC reference; however, extrapolation of the temperature characteristic of any one of these devices to absolute zero (with collector current proportional to absolute temperature) reveals that its VBE goes to approximately the silicon band gap voltage. Thus, if a voltage could be developed with an opposing temperature coefficient to sum with VBE, a zero TC reference would result. The AD1580 circuit in Figure 10 provides such a compensating voltage, V1, by driving two transistors at different current densities and amplifying the resultant VBE difference (∆VBE, which has a positive TC). The sum of VBE and V1 provides a stable voltage reference. Figure 11. Typical Connection Diagram +5V(+3V) ±10% RS 2.94kΩ (1.30kΩ) VR VOUT 00700-012 V+ Figure 12. Typical Connection Diagram V1 TEMPERATURE PERFORMANCE The AD1580 is designed for reference applications where stable temperature performance is important. Extensive temperature testing and characterization ensure that the device’s performance is maintained over the specified temperature range. VBE V– 00700-010 ΔVBE Figure 10. Schematic Diagram APPLYING THE AD1580 The AD1580 is simple to use in virtually all applications. To operate the AD1580 as a conventional shunt regulator (see Figure 11), an external series resistor is connected between the supply voltage and the AD1580. For a given supply voltage, the series resistor, RS, determines the reverse current flowing through the AD1580. The value of RS must be chosen to accommodate the expected variations of the supply voltage, VS; load current, IL; and the AD1580 reverse voltage, VR; while maintaining an acceptable reverse current, IR, through the AD1580. The minimum value for RS should be chosen when VS is at its minimum and IL and VR are at their maximum, while maintaining the minimum acceptable reverse current. The value of RS should be large enough to limit IR to 10 mA when VS is at its maximum and IL and VR are at their minimum. The equation for selecting RS is as follows: RS = (VS − VR)/(IR + IL) Some confusion exists in the area of defining and specifying reference voltage error over temperature. Historically, references have been characterized using a maximum deviation per degree Celsius, for example, 50 ppm/°C. However, because of nonlinearities in temperature characteristics that originated in standard Zener references (such as S type characteristics), most manufacturers now use a maximum limit error band approach to specify devices. This technique involves the measurement of the output at three or more different temperatures to guarantee that the voltage falls within the given error band. The proprietary curvature correction design techniques used to minimize the AD1580 nonlinearities allow the temperature performance to be guaranteed using the maximum deviation method. This method is of more use to a designer than the one that simply guarantees the maximum error band over the entire temperature change. Figure 13 shows a typical output voltage drift for the AD1580 and illustrates the methodology. The maximum slope of the two diagonals drawn from the initial output value at +25°C to the output values at +85°C and −40°C determines the performance grade of the device. For a given grade of the AD1580, the designer can easily determine the maximum total error from the initial tolerance plus temperature variation. Rev. F | Page 6 of 12 AD1580 REVERSE VOLTAGE HYSTERESIS 1.2258 (VMAX – VO) VMAX 1.2254 1.2252 1.2250 VO 1.2248 1.2246 1.2244 1.2242 SLOPE = TC = (VMIN – VO) (–40°C – +25°C) × 1.225 × 10 –6 00700-013 OUTPUT VOLTAGE (V) A major requirement for high performance industrial equipment manufacturers is a consistent output voltage at nominal temperature following operation over the operating temperature range. This characteristic is generated by measuring the difference between the output voltage at +25°C after operation at +85°C and the output, at +25°C after operation at −40°C. Figure 15 displays the hysteresis associated with the AD1580. This characteristic exists in all references and has been minimized in the AD1580. (+85°C – +25°C) × 1.225 × 10 –6 1.2240 1.2238 –55 VMIN –35 –15 5 25 45 65 85 105 40 125 35 TEMPERATURE (°C) Figure 13. Output Voltage vs. Temperature 30 QUANTITY For example, the AD1580BRT initial tolerance is ±1 mV; a ±50 ppm/°C temperature coefficient corresponds to an error band of ±4 mV (50 × 10−6 × 1.225 V × 65°C). Thus, the unit is guaranteed to be 1.225 V ± 5 mV over the operating temperature range. 25 20 15 10 Duplication of these results requires a combination of high accuracy and stable temperature control in a test system. Evaluation of the AD1580 produces a curve similar to that in Figure 5 and Figure 13. 5 0 –400 00700-015 1.2256 SLOPE = TC = –300 –200 –100 0 100 200 300 400 HYSTERESIS VOLTAGE (µV) Figure 15. Reverse Voltage Hysteresis Distribution VOLTAGE OUTPUT NONLINEARITY vs. TEMPERATURE OUTPUT IMPEDANCE vs. FREQUENCY When a reference is used with data converters, it is important to understand how temperature drift affects the overall converter performance. The nonlinearity of the reference output drift represents an additional error that is not easily calibrated out of the system. This characteristic (see Figure 14) is generated by normalizing the measured drift characteristic to the end point average drift. The residual drift error of approximately 500 ppm shows that the AD1580 is compatible with systems that require 10-bit accurate temperature performance. Understanding the effect of the reverse dynamic output impedance in a practical application may be important to successfully apply the AD1580. A voltage divider is formed by the AD1580 output impedance and the external source impedance. When an external source resistor of about 30 kΩ (IR = 100 μA) is used, 1% of the noise from a 100 kHz switching power supply is developed at the output of the AD1580. Figure 16 shows how a 1 µF load capacitor connected directly across the AD1580 reduces the effect of power supply noise to less than 0.01%. 1k OUTPUT IMPEDANCE (Ω) 500 400 300 200 100 CL = 0 10 ΔIR = 0.1IR IR = 100µA IR = 1mA –35 –15 5 25 45 65 85 105 0.1 10 125 TEMPERATURE (°C) 00700-016 0 –55 CL = 1µF 1 100 00700-014 RESIDUAL DRIFT ERROR (ppm) 600 100 1k 10k 100k FREQUENCY (Hz) Figure 14. Residual Drift Error Figure 16. Output Impedance vs. Frequency Rev. F | Page 7 of 12 1M AD1580 NOISE PERFORMANCE AND REDUCTION The noise generated by the AD1580 is typically less than 5 µV p-p over the 0.1 Hz to 10 Hz band. Figure 17 shows the 0.1 Hz to 10 Hz noise of a typical AD1580. Noise in a 10 Hz to 10 kHz bandwidth is approximately 20 μV rms (see Figure 18a). If further noise reduction is desired, a 1-pole low-pass filter can be added between the output pin and ground. A time constant of 0.2 ms has a −3 dB point at about 800 Hz and reduces the high frequency noise to about 6.5 μV rms (see Figure 18b). A time constant of 960 ms has a −3 dB point at 165 Hz and reduces the high frequency noise to about 2.9 μV rms (see Figure 18c). Upon application of power (cold start), the time required for the output voltage to reach its final value within a specified error is the turn-on settling time. Two components normally associated with this are time for active circuits to settle and time for thermal gradients on the chip to stabilize. This characteristic is generated from cold start operation and represents the true turn-on waveform after power-up. Figure 21 shows both the coarse and fine turn-on settling characteristics of the device; the total settling time to within 1.0 mV is about 6 µs, and there is no long thermal tail when the horizontal scale is expanded to 2 ms/div. 2.4V VIN 0V 4.5µV p-p 1µV/DIV 00700-017 250mV/DIV 1s/DIV 00700-019 CL = 200pF 5µs/DIV Figure 19. Turn-On Response Time Figure 17. 0.1 Hz to 10 Hz Voltage Noise RL RS = 11.5kΩ 40µV/DIV 21µV rms VIN VR CL VOUT – (a) 00700-020 + Figure 20. Turn-On, Settling, and Transient Test Circuit 20µV/DIV Output turn-on time is modified when an external noise reduction filter is used. When present, the time constant of the filter dominates overall settling. 6.5µV rms, τ = 0.2ms (b) 2.4V 2.90µV rms, τ = 960ms (c) 10ms/DIV VIN 00700-018 10µV/DIV 0V OUTPUT ERROR 1mV/DIV, 2µs/DIV Figure 18. Total RMS Noise Many low power instrument manufacturers are becoming increasingly concerned with the turn-on characteristics of components being used in their systems. Fast turn-on components often enable the end user to keep power off when not needed, and yet those components respond quickly when the power is turned on for operation. Figure 19 displays the turn-on characteristic of the AD1580. Rev. F | Page 8 of 12 OUTPUT 0.5mV/DIV, 2ms/DIV Figure 21. Turn-On Settling 00700-021 TURN-ON TIME AD1580 TRANSIENT RESPONSE PRECISION MICROPOWER LOW DROPOUT REFERENCE Many ADC and DAC converters present transient current loads to the reference. Poor reference response can degrade the converter’s performance. Figure 22 displays both the coarse and fine settling characteristics of the device to load transients of ±50 μA. 1mV/DIV 20mV/DIV IR = 100µA + 50µA STEP The circuit in Figure 24 provides an ideal solution for making a stable voltage reference with low standby power consumption, low input/output dropout capability, and minimum noise output. The amplifier both buffers and optionally scales up the AD1580 output voltage, VR. Output voltages as high as 2.1 V can supply 1 mA of load current. A one-pole filter connected between the AD1580 and the OP193 input can be used to achieve low output noise. The nominal quiescent power consumption is 200 µW. 3V (a) 34.8kΩ 205Ω OP193 4.7µF (b) VOUT = +1.225V OR VOUT = +1.225 (1 + R2/R3) IR = 100µA – 50µA STEP R2 00700-024 1µs/DIV 00700-022 1mV/DIV 20mV/DIV R3 AD1580 Figure 22. Transient Settling Figure 24. Micropower Buffered Reference Figure 22a shows the settling characteristics of the device for an increased reverse current of 50 μA. Figure 22b shows the response when the reverse current is decreased by 50 µA. The transients settle to 1 mV in about 3 µs. USING THE AD1580 WITH 3 V DATA CONVERTERS Attempts to drive a large capacitive load (in excess of 1000 pF) may result in ringing, as shown in the step response (see Figure 23). This is due to the additional poles formed by the load capacitance and the output impedance of the reference. A recommended method of driving capacitive loads of this magnitude is shown in Figure 20. A resistor isolates the capacitive load from the output stage, while the capacitor provides a single-pole low-pass filter and lowers the output noise. The AD1580 low output drift (50 ppm/°C) and compact subminiature SOT-23 package make it ideally suited for today’s high performance converters in space critical applications. One family of ADCs for which the AD1580 is well suited is the AD7714-3 and AD7715-3. The AD7714/AD7715 are chargebalancing ( ∑-∆) ADCs with on-chip digital filtering intended for the measurement of wide dynamic range, low frequency signals such as those representing chemical, physical, or biological processes. Figure 25 shows the AD1580 connected to the AD7714-3/AD7715-3 for 3 V operation. 3V 2.0V 34.8kΩ AD7714-3 AND AD7715–3 REFIN(+) AD1580 REFIN(–) RSW 5kΩ (TYP) CREF (3pF TO 8pF) HIGH IMPEDANCE >1GΩ SWITCHING FREQUENCY DEPENDS ON fCLKIN CL = 0.01µF 50µs/DIV 00700-023 10mV/DIV Figure 25. Reference Circuit for the AD7714-3 and AD7715-3 Figure 23. Transient Response with Capacitive Load Rev. F | Page 9 of 12 00700-025 VIN 1.8V AD1580 The AD1580 is ideal for creating the reference level to use with 12-bit multiplying DACs, such as the AD7943, AD7945, and AD7948. In the single-supply bias mode (see Figure 26), the impedance seen looking into the IOUT2 terminal changes with DAC code. If the AD1580 drives IOUT2 and AGND directly, less than 0.2 LSBs of additional linearity error results. The buffer amp eliminates any linearity degradation that could result from variations in the reference level. 3.3V VDD RBF C1 IOUT1 VIN VREF DAC IOUT2 AD7943/ AD7945/ AD7948 AGND A1 VOUT A1: OP295 AD822 OP2283 DGND 3.3V A1 AD1580 SIGNAL GROUND Figure 26. Single-Supply System Rev. F | Page 10 of 12 00700-026 41.2kΩ AD1580 OUTLINE DIMENSIONS 3.04 2.90 2.80 1.40 1.30 1.20 3 1 2.64 2.10 1.35 1.25 1.15 2 0.60 0.45 1.02 0.95 0.88 2.20 2.00 1.80 2 1 1.03 0.89 2.05 1.78 1.12 0.89 0.100 0.013 0.65 BSC 0.54 REF GAUGE PLANE 2.40 2.10 1.80 3 1.00 0.80 0.40 0.10 1.10 0.80 0.180 0.085 011909-C 0.60 MAX 0.30 MIN COMPLIANT TO JEDEC STANDARDS TO-236-AB Figure 27. 3-Lead Small Outline Transistor Package [SOT-23-3] (RT-3) Dimensions shown in millimeters 4.10 4.00 3.90 1.55 1.50 1.45 2.05 2.00 1.95 8.30 8.00 7.70 3.55 3.50 3.45 3.20 3.10 2.90 1.00 MIN 0.30 0.20 0.10 0.26 0.10 ALL DIMENSIONS COMPLIANT WITH EIAJ SC70 7” REEL 100.00 OR 13” REEL 330.00 0.35 0.30 0.25 2.80 2.70 2.60 SEATING PLANE Figure 28. 3-Lead Thin Shrink Small Outline Transistor Package [SC70] (KS-3) Dimensions shown in millimeters 1.10 1.00 0.90 1.10 1.00 0.90 0.40 0.25 0.10 MAX COPLANARITY 0.10 072809-A 0.25 14.40 MIN 1.50 MIN 20.20 MIN 7” REEL 50.00 MIN OR 13” REEL 100.00 MIN 13.20 13.00 12.80 0.75 MIN 9.90 8.40 6.90 DIRECTION OF UNREELING Figure 29. Tape and Reel Dimensions (RT-3 and KS-3) Dimensions shown in millimeters Rev. F | Page 11 of 12 053006-0 0.51 0.37 SEATING PLANE AD1580 ORDERING GUIDE Model 1 AD1580ART-REEL AD1580ARTZ-REEL AD1580ARTZ-REEL7 AD1580BRT-REEL7 AD1580BRTZ-R2 AD1580BRTZ-REEL7 AD1580BKSZ-REEL AD1580BKSZ-REEL7 1 Temperature Range −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C Initial Output Error 10 mV 10 mV 10 mV 1 mV 1 mV 1 mV 2.5 mV 2.5 mV Temperature Coefficient 100 ppm/°C 100 ppm/°C 100 ppm/°C 50 ppm/°C 50 ppm/°C 50 ppm/°C 50 ppm/°C 50 ppm/°C Package Description 3-Lead SOT-23-3 3-Lead SOT-23-3 3-Lead SOT-23-3 3-Lead SOT-23-3 3-Lead SOT-23-3 3-Lead SOT-23-3 3-Lead SC70 3-Lead SC70 Package Option RT-3 RT-3 RT-3 RT-3 RT-3 RT-3 KS-3 KS-3 Branding 0Axx R0Y R0Y 0Bxx R2E R2E R2E R2E Z = RoHS Compliant Part. PACKAGE BRANDING INFORMATION In the SOT-23 package (RT), four marking fields identify the device generic, grade, and date of processing. The first field is the product identifier. A 0 identifies the generic as the AD1580. The second field indicates the device grade: A or B. In the third field, a numeral or letter indicates a calendar year: 5 for 1995, A for 2001. In the fourth field, letters A through Z represent a two-week window within the calendar year, starting with A for the first two weeks of January. ©2003-2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D00700-0-7/11(F) Rev. F | Page 12 of 12