a FEATURES Superior Replacement for Other 1.2 V References Wide Operating Range: 50 mA to 5 mA Low Power: 60 mW Total PD at 50 mA Low Temperature Coefficient: 10 ppm/8C max, 08C to +708C (AD589M) 25 ppm/8C max, –558C to +1258C (AD589U) Two-Terminal “Zener” Operation Low Output Impedance: 0.6 V No Frequency Compensation Required Low Cost MIL-STD-883 Compliant Versions Available PRODUCT DESCRIPTION The AD589 is a two-terminal, low cost, temperature compensated bandgap voltage reference which provides a fixed 1.23 V output voltage for input currents between 50 µA and 5.0 mA. Two-Terminal IC 1.2 V Reference AD589 FUNCTIONAL BLOCK DIAGRAMS SOIC (SO-8) –V Metal Can (H-02A) 1 8 2 7 3 6 4 5 AD589 TOP VIEW +V +V –V BOTTOM VIEW PRODUCT HIGHLIGHTS 1. The AD589 is a two-terminal device which delivers a constant reference voltage for a wide range of input current. The high stability of the AD589 is primarily dependent upon the matching and thermal tracking of the on-chip components. Analog Devices’ precision bipolar processing and thin-film technology combine to provide excellent performance at low cost. 2. Output impedance of 0.6 Ω and temperature coefficients as low as 10 ppm/°C insure stable output voltage over a wide range of operating conditions. Additionally, the active circuit produces an output impedance ten times lower than typical low-TC Zener diodes. This feature allows operation with no external components required to maintain full accuracy under changing load conditions. 4. The AD589 will operate with total current as low as 50 µA (60 µW total power dissipation), ideal for battery powered instrument applications. The AD589 is available in seven versions. The AD589J, K, L and M grades are specified for 0°C to +70°C operation, while the S, T, and U grades are rated for the full –55°C to +125°C temperature range. All grades are available in a metal can (H-02A) package. The AD589J is also available in an 8-pin SOIC package. 3. The AD589 can be operated as a positive or negative reference. “Floating” operation is also possible. 5. The AD589 is an exact replacement for other 1.2 V references, offering superior temperature performance and reduced sensitivity to capacitive loading. 6. The AD589 is available in versions compliant with MILSTD-883. Refer to the Analog Devices Military Products Databook or current AD589/883B data sheet for detailed specifications. 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 which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 617/329-4700 Fax: 617/326-8703 AD589–SPECIFICATIONS (typical @ I Model Min OUTPUT VOLTAGE, TA = +25°C AD589JH/JR Typ Max 1.200 1.235 OUTPUT VOLTAGE CHANGE vs. CURRENT (50 µA–5 mA) = 500 mA and TA = +258C unless otherwise noted) Min AD589KH Typ Max 1.200 1.235 5 DYNAMIC OUTPUT IMPEDANCE 0.6 RMS NOISE VOLTAGE 10 Hz < f < 10 kHz 5 1 TEMPERATURE COEFFICIENT 1.250 Min AD589LH Typ Max 1.200 2 0.6 AD589MH Typ Max 1.200 1.235 1.250 5 2 0.6 5 2 0.6 5 50 25 Min 1.235 1.250 5 100 TURN-ON SETTLING TIME TO 0.1% 2 1.250 IN 25 mV 2 Ω µV 10 25 V 5 5 25 Unit ppm/°C µs 25 OPERATING CURRENT 0.05 5 0.05 5 0.05 5 0.05 5 mA OPERATING TEMPERATURE 0 +70 0 +70 0 +70 0 +70 °C 3 PACKAGE OPTION Metal Can (H-02A) SOIC (R-8) AD589JH AD589JR Model AD589SH Typ Max Min OUTPUT VOLTAGE, TA = +25°C 1.200 1.235 OUTPUT VOLTAGE CHANGE vs. CURRENT (50 µA–5 mA) 1.250 Min 0.6 RMS NOISE VOLTAGE 10 Hz < f < 10 kHz 5 1 TEMPERATURE COEFFICIENT 1.200 1.235 1.250 2 0.6 Unit 1.200 V 2 1.235 1.250 0.6 5 5 mV 2 Ω µV 5 50 25 AD589MH AD589UH Min Typ Max 5 100 TURN-ON SETTLING TIME TO 0.1% AD589LH AD589TH Typ Max 5 DYNAMIC OUTPUT IMPEDANCE 2 AD589KH 25 25 ppm/°C µs 25 OPERATING CURRENT 0.05 5 0.05 5 0.05 5 mA OPERATING TEMPERATURE –55 +125 –55 +125 –25 +125 °C 3 PACKAGE OPTION Metal Can (H-02A) SOIC (SO-8) AD589SH AD589JR AD589TH AD589UH NOTES 1 See the following page for explanation of temperature coefficient measurement method. 2 Optimum performance is obtained at currents below 500 µA. For current operation below 200 µA, stray shunt capacitances should be limited to 20 pF or increased to 1µF. If strays can not be avoided, operation at 500 µA and a shunt capacitor of at least 1000 pF are recommended. 3 H = Hermetic Metal Can; SO = SOIC. Specifications shown in boldface are tested on all production units at final electrical test. Specifications subject to change without notice. ABSOLUTE MAXIMUM RATINGS AD589 CHIP DIMENSIONS AND PAD LAYOUT Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mA Reverse Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mA Power Dissipation1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 mW Storage Temperature . . . . . . . . . . . . . . . . . . . –65°C to +175°C Operating Junction Temperature Range . . . . –55°C to +150°C Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . . +300°C 0.040 (1.016) NOTE 1 Absolute maximum power dissipation is limited by maximum current through the device. Maximum rating at elevated temperatures must be computed assuming TJ ≤ 150°C, and θJA = 400 = C/W. 0.060 (1.524) THE AD589 IS AVAILABLE IN CHIP FORM WITH FULLY TESTED AND GUARANTEED SPECIFICATIONS. CONSULT FACTORY FOR AVAILABLE GRADES AND PRICING. –2– REV. B Understanding the Specifications–AD589 VOLTAGE VARIATION VS. TEMPERATURE DYNAMIC PERFORMANCE 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 Centigrade; i.e., 10 ppm/°C. However, because of nonlinearities in temperature characteristics, which originated in standard Zener references (such as “S” type characteristics) most manufacturers have begun to use a maximum limit error band approach to specify devices. This technique involves measurement of the output at 3, 5 or more different temperatures to guarantee that the output voltage will fall within the given error band. The temperature characteristics of the AD589 consistently follows the curve shown in Figure 1. Three-point measurement guarantees the error band over the specified temperature range. The temperature coefficients specified on the previous page represent the slopes of the diagonals of the error band from +25°C to TMIN and +25°C to TMAX. Many low power instrument manufacturers are becoming increasingly concerned with the turn-on characteristics of the components being used in their systems. Fast turn-on components often enable the end user to keep power off when not needed, and yet respond quickly when the power is turned on for operation. Figure 3 displays the turn-on characteristics of the AD589. This characteristic is generated from cold-start operation and represents the true turn-on waveform after an extended period with the supplies off. The figure shows both the coarse and fine transient characteristics of the device; the total settling time to within ± 1 millivolt is about 25 µs, and there is no long thermal tail appearing after that point. 200mV 10mV 10µs 100 90 1.2370 OUTPUT VOLTAGE – V 1.2365 10 0% 1.2360 Figure 3. Output Settling Characteristics 1.2355 +V 1.2350 R1 R5 R6 Q5 1.2345 –50 –25 0 +25 +50 +75 +100 +125 Q8 TEMPERATURE – °C R7 R2 Figure 1. Typical AD589 Temperature Characteristics Q3 C1 Q9 Q4 R3 Q7 1000 Q2 NOISE SPECTRAL DENSITY – nV/ Hz Q1 –V Figure 4. Schematic Diagram 100 10 0 10 100 1k 10k FREQUENCY – Hz 100k 1M Figure 2. Noise Spectral Density REV.B R4 –3– AD589 APPLICATION INFORMATION +5V 6.2kΩ The AD589 functions as a two-terminal shunt-type regulator. It provides a constant 1.23 V output for a wide range of input current from 50 µA to 5 mA. Figure 5 shows the simplest configuration for an output voltage of 1.2 V or less. Note that no frequency compensation is required. If additional filtering is desired for ultralow noise applications, minimum recommended capacitance is 1000 pF. +V 10kΩ AD589 7107 REF HI 1kΩ C547c–2–7/88 REF LO COMMON +5V b. With 7107 Panel Meter A/D 6.8kΩ Figure 7. AD589 Used as Reference for CMOS A/D Converters AD589 10kΩ The AD589 also is useful as a reference for CMOS multiplying DACs such as the AD7533. These DACs require a negative reference voltage in order to provide a positive output range. Figure 8 shows the AD589 used to supply an equivalent –1.0 V reference to an AD7533. VOUT Figure 5. Basic Configuration for 1.2 V or Less The AD589 can also be used as a building block to generate other values of reference voltage. Figure 6 shows a circuit which produces a buffered 10 V output. Total supply current for this circuit is approximately 2 mA. BIT 1 2 3 4 5 6 7 8 9 MSB 14 +15V AD589 REF +15V AD7533 SERIES 15 R2 5kΩ 7 2 R1 39kΩ 6 GND 3 AD108A 2 8 3 LSB VDD AD589 15kΩ 1 4 BIT 10 10V –15V OUT2 1kΩ 1 16 OUT1 RFB 0.01µF VOUT = 0 TO 1.00V 1kΩ AD542L 8.2kΩ Figure 8. AD589 as Reference for 10-Bit CMOS DAC Figure 6. Single Supply Buffered 10 V Reference The low power operation of the AD589 makes it ideal for use in battery operated portable equipment. It is especially useful as a reference for CMOS analog-to-digital converters. Figure 7 shows the AD589 used in conjunction with two popular integrating type CMOS A/D converters. OUTLINE DIMENSIONS AND PIN DESIGNATIONS Dimensions shown in inches and (mm). 0.195 (4.95) DIA 0.178 (4.52) +5V 5.6kΩ 6.8kΩ AD589 2kΩ 0.150 (3.81) 0.125 (3.17) +V 45° 7109 REF+ REF– 0.036 (0.91) 0.046 (1.17) REF OUT 0.028 (0.71) 0.048 (1.22) 0.015 (0.38) 0.019 (0.48) 0.500 (12.7) MIN a. With 7109 12-Bit Binary A/D –4– REV. B PRINTED IN U.S.A. 0.209 (5.31) DIA 0.230 (5.84) 0.10 (2.54)