 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| VRE204 Precision Surface Mount Reference Supply THALER CORPORATION * 2015 N. FORBES BOULEVARD * TUCSON, AZ. 85745 * (520) 882-4000 FEATURES * VERY HIGH ACCURACY: 4.5000 V OUTPUT 0.4 mV * EXTREMELY LOW DRIFT: 0.6 ppm/C -55C to +125C * EXCELLENT STABILITY: 6ppm/1000 Hrs. Typ. * EXCELLENT LINE REGULATION: 6 ppm/V Typ. * WIDE SUPPLY RANGE: +13.5 V to +22.0 V * HERMETIC 20 TERMINAL CERAMIC LCC * MILITARY PROCESSING AVAILABLE APPLICATIONS * PRECISION A/D and D/A CONVERTERS * TRANSDUCER EXCITATION * ACCURATE COMPARATOR THRESHOLD REFERENCE * HIGH RESOLUTION SERVO SYSTEMS * DIGITAL VOLTMETERS * HIGH PRECISION TEST and MEASUREMENT INSTRUMENTS DESCRIPTION VRE204 Series Precision Voltage References provide ultrastable +4.500 V outputs with up to 0.4 mV initial accuracy and temperature coefficient as low as 0.6 ppm/C over the full military temperature range. These references are specifically designed to be used with the Crystal Semiconductor line of successive-approximation type Analog-to-Digital Converters (ADCs). This line of ADCs sets new standards for temperature drift, which can only be as good as the external reference used. The Thaler VRE204 combined with a Crystal ADC will provide the lowest drift data conversion obtainable. SELECTION GUIDE Type Output Temperature Max. Volt Operating Range Deviation -25C to +85C -25C to +85C -55C to +125C -55C to +125C 0.4mV 0.2mV 0.6mV 0.3mV VRE204C +4.5V VRE204CA +4.5V VRE204M +4.5V VRE204MA +4.5V VRE204 series devices are available in two operating temperature ranges, -25C to +85C and -55C to +125C, and two performance grades. All devices are packaged in 20 terminal LCC ceramic packages for maximum long-term stability. "M" versions are screened for high reliability and quality. Superior stability, accuracy, and quality make the VRE204 ideal for all precision applications which may require a 4.5V reference. High-accuracy test and measurement instrumentation, and transducer excitation are some other applications which can benefit from the high accuracy of the VRE204. VRE204DS REV. C JUNE 1995 ELECTRICAL SPECIFICATIONS Vps =15V, T = 25C, RL = 10K unless otherwise noted. VRE204 CA MIN TYP MAX MIN MODEL PARAMETERS MIN C TYP MAX M MA UNITS TYP MAX MIN TYP MAX ABSOLUTE MAXIMUM RATINGS Power Supply +13.5 +22 Operating Temperature -25 85 Storage Temperature -65 150 Short Circuit Protection Continuous OUTPUT VOLTAGE * * * * * * * * -55 * * * 125 * * -55 * * * 125 * V C C VRE204 OUTPUT VOLTAGE ERRORS Initial Error Warmup Drift Tmin - Tmax (1) Long-Term Stability Noise (.1-10Hz) OUTPUT CURRENT Range REGULATION Line Load OUTPUT ADJUSTMENT Range Temperature Coeff. POWER SUPPLY CURRENTS 10 +4.5 * * * V 800 2 400 6 3 * * 1 400 2 200 * * 800 * 600 * * 400 300 V ppm V ppm/1000hrs Vpp * * * mA 6 3 10 * * * * * * * * * ppm/V ppm/mA 10 4 (2) * * * * * * mV V/C/mV VRE204 +PS 5 7 * * * * * * mA NOTES: *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. VRE204DS REV. C JUNE 1995 TYPICAL PERFORMANCE CURVES VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE Temperature oC VRE204C Temperature oC VRE204CA VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE Temperature oC VRE204M Temperature oC VRE204MA QUIESCENT CURRENT VS. TEMP JUNCTION TEMP. RISE VS. OUTPUT CURRENT PSRR VS. FREQUENCY Temperature oC Output Current (mA) Frequency (Hz) VRE204DS REV. C JUNE 1995 DISCUSSION OF PERFORMANCE THEORY OF OPERATION The following discussion refers to the schematic below. A FET current source is used to bias a 6.3 zener diode. The zener voltage is divided by the resistor network R1 and R2. This voltage is then applied to the noninverting input of the operational amplifier which amplifies the voltage to produce a 4.5000V output. The gain is determined by the resistor networks R3 and R4: G=1 + R4/R3. The 6.3 zener diode is used because it is the most stable diode over time and temperature. The current source provides a closely regulated zener current, which 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. APPLICATION INFORMATION Figure 2 shows the proper connection of the VRE204 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 VRE204 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. VRE204 FIGURE 1 VRE204DS REV. C JUNE 1995 EXTERNAL CONNECTIONS 3 4 2 1 20 19 18 17 16 15 14 +15V 5 6 7 8 9 12 13 VOUT = +4.5V 10 11 Ref. Gnd. 10k FIGURE 2 PIN CONFIGURATION NC NC NC NC NC 3 NC VIN NC NC NC 2 1 20 19 18 NC NC NC VOUT NC 4 5 6 7 8 9 REF GND TOP VIEW 17 16 15 14 VRE204 10 11 12 13 GND NC TRIM NC MECHANICAL INCHES DIM A B D D1 E E1 j h L MIN 0.090 0.022 0.342 0.048 0.342 0.045 MAX 0.110 0.028 0.358 0.052 0.358 0.055 MILLIMETER MIN 2.29 0.56 8.68 1.22 8.68 1.114 .254 REF 1.02 REF 1.14 1.40 MAX 2.79 0.71 9.09 1.32 9.09 1.40 0.010 REF 0.040 REF 0.045 0.055 VRE204DS REV. C JUNE 1995 |
Price & Availability of VRE204MA
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |