1.0 V Precision Low Noise Shunt Voltage Reference ADR510 FEATURES Precision 1.000 V Voltage Reference Ultracompact 3 mm 3 mm SOT-23 Package No External Capacitor Required Low Output Noise: 4 V p-p (0.1 Hz to 10 Hz) Initial Accuracy: 0.35% Max Temperature Coefficient: 70 ppm/C Max Operating Current Range: 100 A to 10 mA Output Impedance: 0.3 Max Temperature Range: –40C to +85C PIN CONFIGURATION 3-Lead SOT-23 V+ 1 ADR510 3 TRIM/NC V– 2 ADR510 APPLICATIONS Precision Data Acquisition Systems Battery-Powered Equipment: Cellular Phone, Notebook Computer, PDA, and GPS 3 V/5 V, 8-/12-Bit Data Converters Portable Medical Instruments Industrial Process Control Systems Precision Instruments Output Voltage (VO) Model ADR510ART-REEL7 1.000 Initial Accuracy (mV) (%) Temperature Coefficient (ppm/C) 3.5 70 0.35 A TRIM terminal is available on the ADR510 to provide adjustment of the output voltage over ⫾0.5% without affecting the temperature coefficient of the device. This feature provides users with the flexibility to trim out any system errors. GENERAL DESCRIPTION Designed for space critical applications, the ADR510 is a low voltage (1.000 V), precision shunt-mode voltage reference in the ultracompact (3 mm ⫻ 3 mm) SOT-23 package. The ADR510 features low temperature drift (70 ppm/⬚C), high accuracy (⫾0.35%), and ultralow noise (4 V p-p) performance. The ADR510’s advanced design eliminates the need for an external capacitor, yet it is stable with any capacitive load. The minimum operating current increases from a scant 100 A to a maximum of 10 mA. This low operating current and ease of use make the ADR510 ideally suited for hand-held batterypowered applications. VS IL + IQ ADR510 RBIAS IL VOUT = 1.0V IQ COUT (OPTIONAL) RBIAS = VS – VOUT IL + IQ Figure 1. Typical Operating Circuit REV. 0 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. 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 companies. 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 © 2003 Analog Devices, Inc. All rights reserved. ADR510–SPECIFICATIONS ELECTRICAL CHARACTERISTICS (I Parameter IN = 100 A to 10 mA @ TA = 25C, unless otherwise noted.) Symbol 1 TEMPERATURE COEFFICIENT A GRADE VO VOERR VOERR% TCVO OUTPUT VOLTAGE CHANGE VS. IIN DYNAMIC OUTPUT IMPEDENCE MINIMUM OPERATING CURRENT VOLTAGE NOISE TURN-ON SETTLING TIME2 OUTPUT VOLTAGE HYSTERESIS ∆VR (∆VR/∆IR) IIN eN p-p tR VO_HYS OUTPUT VOLTAGE INITIAL ACCURACY Conditions Min Typ 0.9965 1.0 –3.5 –0.35 0°C < TA < 70°C –40°C < TA < +85°C IIN = 0.1 mA to 10 mA IIN = 1 mA ± 100 µA 0°C < TA < 70°C f = 0.1 Hz to 10 Hz To within 0.1% of Output Max Unit 1.0035 +3.5 +0.35 70 85 3 0.3 V mV % ppm/°C ppm/°C mV Ω µA µV p-p µs ppm 100 4 10 50 NOTES 1 The forward diode voltage characteristic at –1 mA is typically 0.65 V. 2 Measured without a load capacitor. Specifications subject to change without notice. ABSOLUTE MAXIMUM RATINGS* Reverse Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 mA Forward Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA Storage Temperature Range RT Package . . . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C Operating Temperature Range . . . . . . . . . . . . –40°C to +85°C Junction Temperature Range RT Package . . . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C Lead Temperature Range (Soldering, 60 Sec) . . . . . . . . 300°C Package Type1 JA2 JC Unit 3-SOT-23 (RT) 230 146 °C/W NOTES 1 Package power dissipation = (T J MAX – TA)/θJA. 2 θJA is specified for worst-case conditions, i.e., θJA is specified for device soldered in circuit board for surface-mount packages. *Absolute maximum ratings apply at 25°C, unless otherwise noted. 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. ORDERING GUIDE Model Output Voltage (VO) ADR510ART-REEL7 1.0 ADR510ART-R2 1.0 Initial Accuracy (mV) (%) Temperature Number Coefficient Package Package of Parts (ppm/C) Description Option Branding per Reel Temperature Range 3.5 3.5 70 70 –40°C to +85°C –40°C to +85°C 0.35 0.35 SOT-23 SOT-23 RT-3 RT-3 RAA RAA 3,000 250 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 the ADR510 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. –2– REV. 0 Typical Performance Characteristics–ADR510 1.002 1.001 VOUT (V) VIN = 5V/DIV 1.000 0.999 VOUT = 500V/DIV 0.998 0.997 TIME (400ns/DIV) 0 10 20 30 40 50 TEMPERATURE (C) 60 70 TPC 1. Typical VOUT vs. Temperature TPC 4. Turn-Off Time VIN = 5V/DIV VIN = 5V/DIV VOUT = 500V/DIV VOUT = 500V/DIV TIME (400ns/DIV) TIME (1ms/DIV) TPC 2. Turn-On Time TPC 5. Turn-Off Time with 1 µ F Input Capacitor DIIN = 100A VIN = 5V/DIV VOUT = 500V/DIV VOUT = 50mV/DIV TIME (400s/DIV) TIME (2s/DIV) TPC 3. Turn-On Time with 1 µ F Input Capacitor TPC 6. Output Response to 100 µ A Input Current Change REV. 0 –3– ADR510 DIIN = 100A 2V/DIV VOUT = 50mV/DIV TIME (2s/DIV) TIME (400ms/DIV) TPC 7. Output Response to 100 µ A Input Current Change with 1 µ F Capacitor TPC 8. 1 Hz to 10 Hz Noise PARAMETER DEFINITIONS Temperature Coefficient APPLICATIONS SECTION The ADR510 is a 1.0 V precision shunt voltage reference. It is designed to operate without an external output capacitor between the positive and negative terminals for stability. An external capacitor can be used for additional filtering of the supply. This is the change of output voltage with respect to the operating temperature changes, normalized by the output voltage at 25°C. This parameter is expressed in ppm/°C and can be determined with the following equation VO (T2 ) − VO (T1 ) ppm TCVO × 106 = C ° VO (25°C ) × (T2 − T1 ) where: As with all shunt voltage references, an external bias resistor (RBIAS) is required between the supply voltage and the ADR510 (see Figure 1). RBIAS sets the current that is required to pass through the load (IL) and the ADR510 (IQ). The load and the supply voltage can vary, thus RBIAS is chosen based on (1) VO(25°C) = VO at 25°C VO(T1 ) = VO at Temperature 1 VO(T2) = VO at Temperature 2 Thermal Hysteresis Thermal hysteresis is defined as the change of output voltage after the device is cycled through the temperature from 25°C to 0°C to 70°C and back to 25°C. This is a typical value from a sample of parts put through such a cycle. VO (25°C ) −VO _ TC where: VO (25°C ) × 106 RBIAS must be small enough to supply the minimum IQ current to the ADR510 even when the supply voltage is at its minimum and the load current is at its maximum value. • RBIAS also needs to be large enough so that IQ does not exceed 10 mA when the supply voltage is at its maximum and the load current is at its minimum. Given these conditions, RBIAS is determined by the supply voltage (VS), the load and operating current (IL and IQ) of the ADR510, and the ADR510’s output voltage. VO _ HYS = VO (25°C ) −VO _ TC VO _ HYS [ ppm ] = • RBIAS = (VS – VOUT ) / (IL + IQ ) (2) (3) VO(25°C) = VO at 25°C VO_TC = VO at 25°C after temperature cycle at 25°C to –40°C to 85°C and back to 25°C –4– REV. 0 ADR510 Figure 4 shows the ADR510 serving as an external reference to the AD7533, a CMOS multiplying DAC. Such a DAC requires a negative voltage input in order to provide a positive output range. In this application, the ADR510 is supplying a –1.0 V reference to the REF input of the AD7533. Adjustable Precision Voltage Source The ADR510, combined with a precision low input bias op amp such as the AD8610, can be used to output a precise adjustable voltage. Figure 2 illustrates the implementation of this application using the ADR510. The output of the op amp, VOUT, is determined by the gain of the circuit, which is completely dependent on Resistors R2 and R1. VOUT = 1 + R2 R1 0 MSB ADR510 (4) 9 LSB 1 VDD AD7533 1 An additional capacitor in parallel with R2 can be added to filter out high frequency noise. The value of C2 is dependent on the value of R2. R2 GN 3 2 1 15 –VDD VOUT = 0V TO 1.0V VCC RBIAS 1.0V AD8610 Figure 4. ADR510 as a Reference for a 10-Bit CMOS DAC (AD7533) VOUT = (1 + R2/R1) Precise Negative Voltage Reference ADR510 The ADR510 is suitable for use in applications where a precise negative voltage reference is desired, including the application detailed in Figure 4. R2 R1 C2 (OPTIONAL) Figures 5 shows the ADR510 configured to provide a –1.0 V output. Figure 2. Adjustable Precision Voltage Source Output Voltage Trim ADR510 Using a mechanical or digital potentiometer, the output voltage of the ADR510 can be trimmed ± 0.5%. The circuit in Figure 3 illustrates how the output voltage can be trimmed, using a 10 kΩ potentiometer. Note that trimming using other resistor values may not produce an accurate output from the ADR510. –1.0V R1 –VDD VCC Figure 5. Precise –1.0 V Reference Configuration RBIAS Since the ADR510 characteristics resemble those of a Zener diode, the cathode shown in Figure 5 will be 1.0 V higher with respect to the anode (V+ with respect to V– on the ADR510 package). Since the cathode of the ADR510 is tied to ground, the anode must be –1.0 V. VOUT ADR510 R1 470k POT 10k R1 in Figure 5 should be chosen so that 100 µA to 10 mA is provided to properly bias the ADR510. Figure 3. Output Voltage Trim VDD (5) I The R1 resistor should be chosen so that power dissipation is at a minimum. An ideal resistor value can be determined through manipulation of Equation 5. R1 = Using the ADR510 with Precision Data Converters The compact ADR510 and its low minimum operating current requirement make it ideal for use in battery-powered portable instruments, such as the AD7533 CMOS multiplying DAC, that use precision data converters. REV. 0 –5– ADR510 OUTLINE DIMENSIONS 3-Lead Small Outline Transistor Package [SOT-23] (RT-3) Dimensions shown in millimeters 3.04 2.90 2.80 1.40 1.30 1.20 3 1 2.64 2.10 2 PIN 1 0.95 BSC 1.90 BSC 1.12 0.89 0.10 0.01 SEATING PLANE 0.50 0.30 0.60 0.50 0.40 0.20 0.08 COMPLIANT TO JEDEC STANDARDS TO-236AB –6– REV. 0 –7– –8– C03270–0–8/03(0)