VRE210 Precision Surface Mount Reference Supplies THALER CORPORATION * 2015 N. FORBES BOULEVARD * TUCSON, AZ. 85745 * (520) 882-4000 FEATURES APPLICATIONS * PIN AND FUNCTION COMPATIBLE WITH REF01 * PRECISION A/D and D/A CONVERTERS * VERY HIGH ACCURACY: 10.000 V OUTPUT 0.3 mV * TRANSDUCER EXCITATION * EXTREMELY LOW DRIFT: 0.5 ppm/C 55C to +125C * ACCURATE COMPARATOR THRESHOLD REFERENCE * LOW WARM-UP DRIFT: 1 ppm Typ. * HIGH RESOLUTION SERVO SYSTEMS * EXCELLENT STABILITY: 6 ppm/1000 Hrs. Typ. * DIGITAL VOLTMETERS * EXCELLENT LINE REGULATION: 3 ppm/V Typ. * HERMETIC 20 TERMINAL CERAMIC LCC * HIGH PRECISION TEST and MEASUREMENT INSTRUMENTS * MILITARY PROCESSING OPTION DESCRIPTION VRE210 Series Precision Voltage References provide ultrastable +10.000V outputs with 0.3 mV initial accuracy and temperature coefficient as low as 0.5 ppm/C over the full military temperature range. This improvement in accuracy is made possible by a unique, proprietary multipoint laser compensation technique developed by Thaler Corporation. Significant improvements have been made in other performance parameters as well, including initial accuracy, warm-up drift, line regulation, and long-term stability, making the VRE210 series the most accurate and stable 10V surface mount references available. SELECTION GUIDE Output Temperature Operating Range Max. Volt Deviation VRE210C VRE210CA +10V +10V -25C to +85C -25C to +85C 0.6mV 0.3mV VRE210M VRE210MA +10V +10V -55C to +125C -55C to +125C 1.0mV 0.5mV Type VRE210 devices are available in two operating temperature ranges, -25C to +85C and -55C to +125C, and two electrical performance grades. All devices are packaged in 20 terminal ceramic LCC packages for maximum long-term stability. "M" versions are screened for high reliability and quality. VRE210DS REV. C JUNE 1995 ELECTRICAL SPECIFICATIONS VRE210 Vps =15V, T = 25C, RL = 10K unless otherwise noted. MODEL C PARAMETERS MIN CA TYP MAX M MIN TYP MAX MIN * * * * * * MA TYP MAX MIN TYP MAX UNITS ABSOLUTE MAXIMUM RATINGS Power Supply +13.5 +22 Operating Temperature -25 85 Storage Temperature -65 150 Short Circuit Protection Continuous * -55 * * 125 * * -55 * * 125 * * * * * * * V C C OUTPUT VOLTAGE VRE210 +10 V OUTPUT VOLTAGE ERRORS Initial Error Warmup Drift Tmin - Tmax (1) Long-Term Stability Noise (.1-10Hz) 500 300 2 800 1 600 300 6 6 400 2 1 1000 * * 500 * * * * V ppm V ppm/1000hrs Vpp OUTPUT CURRENT Range 10 * * * mA REGULATION Line Load 3 3 10 * * * * * * * * * ppm/V ppm/mA OUTPUT ADJUSTMENT Range Temperature Coeff. POWER SUPPLY CURRENTS 20 4 * * * * mV mV/C/mV (2) VRE210 +PS NOTES: * * 5 7 * * * * * * mA *Same as C Models. 1.Using the box method, the specified value is the maximum deviation from the output voltage at 25C over the specified operating temperature range. 2.The specified values are unloaded. VRE210DS REV. C JUNE 1995 TYPICAL PERFORMANCE CURVES VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE Temperature oC VRE210CA Temperature oC VRE210C VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE Temperature oC VRE210M Temperature oC VRE210MA QUIESCENT CURRENT VS. TEMP Temperature oC JUNCTION TEMP. RISE VS. OUTPUT CURRENT Output Current (mA) PSRR VS. FREQUENCY Frequency (Hz) VRE210DS REV. C JUNE 1995 DISCUSSION OF PERFORMANCE THEORY OF OPERATION APPLICATION INFORMATION The following discussion refers to the schematic below. In operation, approximately 6.3 volts is applied to the noninverting input of the op amp. The voltage is amplified by the op amp to produce a 10.000V output. The gain is determined by the networks R1 and R2: G=1 + R2/R1. The 6.3V zener diode is used because it is the most stable diode over time and temperature. Figure 2 shows the proper connection of the VRE210 series voltage references with the optional trim resistors. Pay careful attention to the circuit layout to avoid noise pickup and voltage drops in the lines. The zener operating current is derived from the regulated output voltage through R3. This feedback arrangement provides a closely regulated zener current. This current determines the slope of the references' voltage vs. temperature function. By trimming the zener current a lower drift over temperature can be achieved. But since the voltage vs. temperature function is nonlinear this compensation technique is not well suited for wide temperature ranges. Thaler Corporation has developed a nonlinear compensation network of thermistors and resistors that is used in the VRE series voltage references. This proprietary network eliminates most of the nonlinearity in the voltage vs. temperature function. By then adjusting the slope, Thaler Corporation produces a very stable voltage over wide temperature ranges. This network is less than 2% of the overall network resistance so it has a negligible effect on long term stability. By using highly stable resistors in our network, we produce a voltage reference that also has very good long term stability. The VRE210 series voltage references have the ground terminal brought out on two pins (pin 9 and pin 10) which are connected together internally. This allows the user to achieve greater accuracy when using a socket. Voltage references have a voltage drop across their power supply ground pin due to quiescent current flowing through the contact resistance. If the contact resistance was constant with time and temperature, this voltage drop could be trimmed out. When the reference is plugged into a socket, this source of error can be as high as 20ppm. By connecting pin 10 to the power supply ground and pin 9 to a high impedance ground point in the measurement circuit, the error due to the contact resistance can be eliminated. If the unit is soldered into place, the contact resistance is sufficiently small that it does not effect performance. VRE210 FIGURE 1 VRE210DS REV. C JUNE 1995 EXTERNAL CONNECTIONS 3 +15V 2 1 20 4 19 18 5 17 6 16 7 15 8 14 9 10 12 13 11 VOUT = +10V Ref. Gnd. 10k FIGURE 2 PIN CONFIGURATION NC NC NC NC NC 3 2 1 20 19 18 NC TOP VIEW 17 NC VRE210 16 NC 7 15 VOUT 8 14 NC NC 4 VIN 5 NC 6 NC NC 9 10 11 REF GND GND 12 13 NC TRIM NC MECHANICAL INCHES MILLIMETER DIM MIN MAX MIN MAX A 0.090 0.110 2.29 2.79 B 0.022 0.028 0.56 0.71 D 0.342 0.358 8.68 9.09 D1 0.048 0.052 1.22 1.32 E 0.342 0.358 8.68 9.09 E1 0.045 0.055 1.114 1.40 j 0.010 REF .254 REF h 0.040 REF 1.02 REF L 0.045 0.055 1.14 1.40 VRE210DS REV. C JUNE 1995