ADR512ARTZ

1.2 V Precision Low Noise Shunt Voltage Reference ADR512 Data Sheet FEATURES PIN CONFIGURATION Precision 1.200 V Voltage Reference Ultracompact 3 mm × 3 mm SOT-23 Package No External Capacitor Required Low Output Noise: 4 µV p-p (0.1 Hz to 10 Hz) Initial Accuracy: ±0.3% Max Temperature Coefficient: 60 ppm/°C Max Operating Current Range: 100 µA to 10 mA Output Impedance: 0.3 Ω Max Temperature Range: −40°C to +85°C ADR512 V+ 1 3 TOP VIEW (Not to Scale) NC = NO CONNECT. DO NOT CONNECT TO THIS PIN. 03700-001 V– 2 TRIM/NC Figure 1. 3-Lead SOT-23 Table 1. 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 Model ADR512ARTZ-REEL7 Output Voltage (VO) 1.200 Initial Accuracy (mV) (%) 3.5 0.3 Temperature Coefficient (ppm/°C) 60 GENERAL DESCRIPTION maximum of 10 mA. This low operating current and ease of use make the ADR512 ideally suited for handheld battery-powered applications. Designed for space critical applications, the ADR512 is a low voltage (1.200 V), precision shunt-mode voltage reference in the ultracompact (3 mm × 3 mm) SOT-23 package. The ADR512 features low temperature drift (60 ppm/°C), high accuracy (±0.30%), and ultralow noise (4 µV p-p) performance. A TRIM terminal is available on the ADR512 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. The ADR512’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 µA to a VS RBIAS IL ADR512 IQ VOUT = 1.2V COUT (OPTIONAL) RBIAS = VS – VOUT IL + IQ 03700-002 IL + IQ Figure 2. Typical Operating Circuit Rev. A Document Feedback 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 ©2003–2012 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com ADR512 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Parameter Definitions .......................................................................7 Applications ....................................................................................... 1 Temperature Coefficient...............................................................7 Pin Configuration ............................................................................. 1 Thermal Hysteresis .......................................................................7 General Description ......................................................................... 1 Applications Section..........................................................................8 Revision History ............................................................................... 2 Adjustable Precision Voltage Source ..........................................8 Specifications..................................................................................... 3 Output Voltage Trim .....................................................................8 Electrical Characteristics ............................................................. 3 Using the ADR512 with Precision Data Converters ................8 Absolute Maximum Ratings ............................................................ 4 Precise Negative Voltage Reference ............................................9 Thermal Resistance .......................................................................... 4 Outline Dimensions ....................................................................... 10 ESD Caution .................................................................................. 4 Ordering Guide .......................................................................... 10 Typical Performance Characteristics ............................................. 5 REVISION HISTORY 11/12—Rev. 0 to Rev. A Changes to Table 1 ............................................................................. 1 Updated Outline Dimensions ........................................................10 Changes to Ordering Guide ...........................................................10 Rev. A | Page 2 of 12 Data Sheet ADR512 SPECIFICATIONS ELECTRICAL CHARACTERISTICS IIN = 100 µA to 10 mA @ TA = 25°C, unless otherwise noted. Table 2. Parameter Output Voltage 1 Initial Accuracy Temperature Coefficient A Grade Output Voltage Change vs. IIN Dynamic Output Impedence Minimum Operating Current Voltage Noise Turn-On Settling Time 2 Output Voltage Hysteresis 1 2 Symbol VO VOERR TOERR% TCVO ΔVR (ΔVR/ΔIR) IIN eN p-p tR VO_HYS Test Conditions / Comments −40°C < TA < +85°C IIN = 0.1 mA to 10 mA IIN = 1 mA ± 100 µA −40°C < TA < +85°C f = 0.1 Hz to 10 Hz To within 0.1% of Output The forward diode voltage characteristic at −1 mA is typically 0.65 V. Measured without a load capacitor. Rev. A | Page 3 of 12 Min 1.1965 −3.5 −0.3 Typ 1.2 100 4 10 50 Max 1.2035 +3.5 +0.3 60 3 0.3 Unit V mV % ppm/°C mV Ω µA µV p-p µs ppm ADR512 Data Sheet ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Table 3. Parameter Reverse Current Forward Current Storage Temperature Range RT Package Operating Temperature Range Junction Temperature Range RT Package Lead Temperature Range (Soldering, 60 Sec) θJA is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. Rating 25 mA 20 mA Table 4. Thermal Resistance −65°C to +150°C −40°C to +85°C Package Type1 3-SOT-23 (RT) θJC 146 Unit °C/W Package power dissipation = (TJMAX − TA)/θJA. θJA is specified for worst-case conditions, i.e., θJA is specified for device soldered. 1 −65°C to +150°C 300°C θJA2 230 2 ESD CAUTION 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. Rev. A | Page 4 of 12 Data Sheet ADR512 TYPICAL PERFORMANCE CHARACTERISTICS 1.204 1.203 1.202 VIN = 2V/DIV 1.200 1.199 1.198 VOUT = 1V/DIV 10 35 TEMPERATURE (°C) 60 85 Figure 3. Typical VOUT vs. Temperature 03700-006 –15 TIME (400µs/DIV) Figure 6. Turn Off Time VIN = 2V/DIV VIN = 2V/DIV VOUT = 1V/DIV TIME (100µs/DIV) 03700-007 VOUT = 1V/DIV 03700-004 TIME (200µs/DIV) Figure 4. Turn On Time Figure 7. Turn Off Time with 1 μF Input Capacitor ΔIIN = 100µA VIN = 2V/DIV VOUT = 1V/DIV TIME (100µs/DIV) VOUT = 20mV/DIV TIME (2µs/DIV) Figure 5. Turn On Time with 1 μF Input Capacitor 03700-008 1.196 –40 03700-003 1.197 03700-005 VOUT (V) 1.201 Figure 8. Output Response to 100 μA Input Current Change Rev. A | Page 5 of 12 ADR512 Data Sheet ΔIIN = 100µA 2µV/DIV TIME (400ms/DIV) Figure 10. 1 Hz to 10 Hz Noise Figure 9. Output Response to 100 μA Input Current Change With 1 μF Capacitor Rev. A | Page 6 of 12 03700-010 TIME (2µs/DIV) 03700-009 VOUT = 20mV/DIV Data Sheet ADR512 PARAMETER DEFINITIONS TEMPERATURE COEFFICIENT THERMAL HYSTERESIS This is the change of output voltage with respect to 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: Thermal hysteresis is defined as the change of output voltage after the device is cycled through the temperature from +25°C to −40°C to +85°C and back to +25°C. This is a typical value from a sample of parts put through such a cycle. VO (T2 ) −VO (T1 )  ppm  TCVO  = × 10 6   °C  VO (25°C )× (T2 − T1 ) VO _ HYS = VO ( 25°C ) − VO _ TC (1) VO _ HYS [ ppm] = where: VO (25°C ) − VO _ TC VO (25°C ) × 10 6 (2) VO(25°C) = VO at 25°C where: VO(T1) = VO at Temperature 1 VO(25°C) = VO at 25°C VO(T2) = VO at Temperature 2 VO_TC = VO at 25°C after temperature cycle at +25°C to −40°C to +85°C and back to +25°C Rev. A | Page 7 of 12 ADR512 Data Sheet APPLICATIONS SECTION OUTPUT VOLTAGE TRIM • • RBIAS must be small enough to supply the minimum IQ current to the ADR512 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 ADR512, and the ADR512’s output voltage. RBIAS = (VS − VOUT)/(IL + IQ) (3) ADJUSTABLE PRECISION VOLTAGE SOURCE The ADR512, combined with a precision low input bias op amp such as the AD8610, can be used to output a precise adjustable voltage. Figure 11 illustrates the implementation of this application using the ADR512. VCC RBIAS VOUT ADR512 VOUT USING THE ADR512 WITH PRECISION DATA CONVERTERS The compact ADR512 package and the device’s 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. Figure 13 shows the ADR512 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 ADR512 is supplying a −1.2 V reference to the REF input of the AD7533. (4) 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. VCC 1.2V AD8610 VOUT = 1.2V (1 + R2/R1) C2 (OPTIONAL) 03700-011 R2 R1 0 MSB + ADR512 – VDD 9 LSB 1 AD7533 1 R2 GN 3 2 1 15 –VDD + VOUT = 0V TO 1.2V – Figure 13. ADR512 as a Reference for a 10-Bit CMOS DAC (AD7533) RBIAS ADR512 R1 100kΩ Figure 12. Output Voltage Trim The output of the op amp, VOUT, is determined by the gain of the circuit, which is completely dependent on resistors R2 and R1. R2 =1+ R1 POT 50kΩ 03700-013 As with all shunt voltage references, an external bias resistor (RBIAS) is required between the supply voltage and the ADR512 (see Figure 2). RBIAS sets the current that is required to pass through the load (IL) and the ADR512 (IQ). The load and the supply voltage can vary, thus RBIAS is chosen based on Using a mechanical or digital potentiometer, the output voltage of the ADR512 can be trimmed ±0.5%. The circuit in Figure 12 illustrates how the output voltage can be trimmed, using a 10 kΩ potentiometer. 03700-012 The ADR512 is a 1.2 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. Figure 11. Adjustable Precision Voltage Source Rev. A | Page 8 of 12 Data Sheet ADR512 PRECISE NEGATIVE VOLTAGE REFERENCE The ADR512 is suitable for use in applications where a precise negative voltage reference is desired, including the application detailed in Figure 13. package). Since the cathode of the ADR512 is tied to ground, the anode must be −1.2 V. R1 in Figure 14 should be chosen so that 100 μA to 10 mA is provided to properly bias the ADR512. Figure 14 shows the ADR512 configured to provide a −1.2 V output. R1 = (5) The resistor R1 should be chosen so that power dissipation is at a minimum. An ideal resistor value can be determined through manipulation of Equation 5. + ADR512 – –1.2V 03700-014 R2 –VDD VDD I Figure 14. Precise −1.2 V Reference Configuration Since the ADR512 characteristics resemble those of a Zener diode, the cathode shown in Figure 14 will be 1.2 V higher with respect to the anode (V+ with respect to V− on the ADR512 Rev. A | Page 9 of 12 ADR512 Data Sheet OUTLINE DIMENSIONS 3.04 2.90 2.80 1.40 1.30 1.20 3 1 2 0.60 0.45 2.05 1.78 1.02 0.95 0.88 2.64 2.10 1.03 0.89 1.12 0.89 0.100 0.013 GAUGE PLANE 0.54 REF 0.180 0.085 0.25 0.60 MAX 0.30 MIN 011909-C 0.51 0.37 SEATING PLANE COMPLIANT TO JEDEC STANDARDS TO-236-AB Figure 15. 3-Lead Small Outline Transistor Package [SOT-23] (RT-3) Dimensions shown in millimeters ORDERING GUIDE Initial Accuracy Model ADR512ARTZ-REEL7 Output Voltage (VO) 1.2 (mV) 3.5 (%) 0.3 Temperature Coefficient (ppm/°C) 60 Package Description 3-Lead SOT-23 Rev. A | Page 10 of 12 Package Option RT-3 Branding R1R Number of Parts per Reel 3,000 Temperature Range −40°C to +85°C Data Sheet ADR512 NOTES Rev. A | Page 11 of 12 ADR512 Data Sheet NOTES ©2003–2012 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D03700-0-11/12(A) Rev. A | Page 12 of 12