VRE100/101/102 Precision Reference Supplies THALER CORPORATION • 2015 N. FORBES BOULEVARD • TUCSON, AZ. 85745 • (520) 882-4000 FEATURES APPLICATIONS • VERY HIGH ACCURACY: 10.000 V OUTPUT ±0.5 mV • PRECISION A/D and D/A CONVERTERS • EXTREMELY LOW DRIFT: 0.5 ppm/°C 55°C to +125°C • TRANSDUCER EXCITATION • LOW WARM-UP DRIFT: 1.0 ppm Typ. • ACCURATE COMPARATOR THRESHOLD REFERENCE • EXCELLENT STABILITY: 6 ppm/1000 Hrs. Typ. • HIGH RESOLUTION SERVO SYSTEMS • EXCELLENT LINE REGULATION: 3 ppm/V Typ. • DIGITAL VOLTMETERS • HERMETIC 14-PIN CERAMIC DIP • HIGH PRECISION TEST and MEASUREMENT INSTRUMENTS • MILITARY PROCESSING OPTION • PIN & FUNCTION COMPATIBLE WITH AD2700, AD2710 Series DESCRIPTION VRE100 Series Precision Voltage References provide ultrastable +10.000V (VRE100), 10.000V (VRE101) and ±10.000V (VRE102) outputs with ±0.5 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 VRE100 series the most accurate and stable 10V reference available. SELECTION GUIDE Type Output Temperature Operating Range VRE100C VRE100CA VRE100M VRE100MA +10V +10V +10V +10V -25°C to +85°C -25°C to +85°C -55°C to +125°C -55°C to +125°C Max. Volt Deviation 0.6mV 0.3mV 1.0mV 0.5mV VRE101C VRE101CA VRE101M VRE101MA -10V -10V -10V -10V -25°C to +85°C -25°C to +85°C -55°C to +125°C -55°C to +125°C 0.6mV 0.3mV 1.0mV 0.5mV VRE102C VRE102CA VRE102M VRE102MA ±10V ±10V ±10V ±10V -25°C to +85°C -25°C to +85°C -55°C to +125°C -55°C to +125°C 0.6mV 0.3mV 1.0mV 0.5mV VRE100/101/102 devices are available in two operating temperature ranges, -25°C to +85°C and -55°C to +125°C, and two performance grades. All devices are packaged in 14-pin hermetic ceramic packages for maximum long-term stability. "M" versions are screened for high reliability and quality. Superior stability, accuracy, and quality make these references ideal for precision applications such as A/D and D/A converters, high-accuracy test and measurement instrumentation, and transducer excitation. VRE100DS REV. D MAY 1995 4-20 ELECTRICAL SPECIFICATIONS VRE100/101/102 Vps =±15V, T = 25°C, RL = 10KΩ 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 VRE100 VRE101 VRE102 +10 -10 ±10 V V V OUTPUT VOLTAGE ERRORS Initial Error Warmup Drift Tmin - Tmax (1) Long-Term Stability Noise (.1-10Hz) 1.0 0.5 2 1.5 1 0.6 0.3 6 6 0.8 2 1 1.0 * * 0.5 * * * * mV ppm mV ppm/1000hr. µVpp OUTPUT CURRENT Range ±10 * * * mA REGULATION Line Load 3 3 10 * * * * * * * * * ppm/V ppm/mA OUTPUT ADJUSTMENT Range Temperature Coefficient POWER SUPPLY CURRENTS 20 4 * * * * mV µV/°C/mV (2) VRE100 +PS VRE101 -PS VRE102 +PS VRE102 -PS NOTES: * * 5 5 7 4 7 7 9 6 * * * * * * * * * * * * * * * * * * * * * * * * mA mA mA mA *Same as C Models. 1.Using the box method, the specified value is the maximum deviation from the output voltage at 25°C over the specified operating temperature range. 2.The specified values are unloaded. VRE100DS REV. D MAY 1995 4-21 TYPICAL PERFORMANCE CURVES VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE Temperature oC VRE100/101/102C Temperature oC VRE100/101/102CA Temperature oC VRE100/101/102M Temperature oC VRE100/101/102MA VRE100/101 QUIESCENT CURRENT VS. TEMP Temperature oC JUNCTION TEMP. RISE VS. OUTPUT CURRENT Output Current (mA) PSRR VS. FREQUENCY Frequency (Hz) VRE102 POSITIVE OUTPUT QUIESCENT CURRENT VS. TEMP Temperature oC JUNCTION TEMP. RISE VS. OUTPUT CURRENT Output Current (mA) PSRR VS. FREQUENCY Frequency (Hz) NEGATIVE OUTPUT QUIESCENT CURRENT VS. TEMP Temperature oC JUNCTION TEMP. RISE VS. OUTPUT CURRENT Output Current (mA) PSRR VS. FREQUENCY Frequency (Hz) VRE100DS REV. D MAY 1995 4-22 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. 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. Figure 1 shows the proper connection of the VRE100 series voltage reference with the optional trim resistors. When trimming the VRE102, the positive voltage should be trimmed first since the negative voltage tracks the positive side. Pay careful attention to the circuit layout to avoid noise pickup and voltage drops in the lines. The VRE100 series voltage references have the ground terminal brought out on two pins (pin 6 and pin 7) 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 7 to the power supply ground and pin 6 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 doesn't effect performance. The VRE series voltage references can be connected with or without the use of pin 6 and still provide performance superior to the 2700 and 2710 series voltage references. VRE100 VRE102 VRE100DS REV. D MAY 1995 4-23 FIGURE 1 EXTERNAL CONNECTIONS 1. Optional Fine Adjust for approximately ±20mV. VRE101 center tap connects to -PS. PIN CONFIGURATION TOP VIEW TOP VIEW NC NC NC NC VRE100 NC REF. GND GND FINE ADJ. +10V NC FINE ADJ. NC +PS NC NC NC NC NC TOP VIEW FINE ADJ. NC VRE101 REF. GND GND -10V FINE ADJ. -ADJ. +ADJ. -10V +10V -ADJ. +ADJ. VRE102 -PS -PS +PS NC NC NC NC REF. GND NC NC GND NC MECHANICAL 14-PIN HYBRID PACKAGE INCHES MILLIMETER INCHES MILLIMETER DIM MIN MAX MIN MAX DIM MIN MAX MIN MAX E .480 .500 12.1 12.7 A .120 .155 3.0 4.0 L .195 .215 4.9 5.4 Q .015 .035 0.4 0.9 D .775 .805 19.7 20.4 Q1 N/A .030 N/A 0.7 B .016 .020 0.4 0.5 C .009 .012 0.2 0.3 B1 .038 .042 0.9 1.0 G1 .290 .310 7.3 7.8 B2 .095 .105 2.4 2.6 S .085 .105 2.1 2.6 P .004 .006 0.10 0.15 VRE100DS REV. D MAY 1995 4-24