VRE119

P r o d u c t IIn n o vva t i o n FF r o m rom nno a VRE117/119 VRE117/119 DESCRIPTION Precision Voltage Reference FEaTuRES ♦ Very High Accuracy: ±3 V Output, ±0.2 mV ♦ Extremely Low Drift: 0.6 ppm/°C (-55°C to +125°C) ♦ Low Warm-up Drift: 1 ppm Typical ♦ Excellent Stability: 6 ppm/1000 Hrs. Typical ♦ Excellent Line Regulation: 3 ppm/V Typical ♦ Hermetic 14-pin Ceramic DIP ♦ Military Processing Option VRE117/119 Series Precision Voltage References provide ultrastable +3 V (VRE117), and ±3 V (VRE119) output with ±0.2 mV initial accuracy and temperature coefficient as low as 0.6 ppm/°C over the full military temperature range. This improvement in accuracy is made possible by a unique, proprietary multipoint laser compensation technique. 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 VRE117/119 series the most accurate and stable 3 V reference available. VRE117/119 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. 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 Figure 1. BlOCK DIaGRaMS VRE117 VRE119 VRE117DS http://www.cirrus.com Copyright © Cirrus Logic, Inc. 2009 (All Rights Reserved) MaR 2009 1 APEX − VRE117DSREVD VRE117/119 SElECTION GuIDE Model VRE117M VRE117MA VRE119C Output (V) +3 +3 ±3 Temperature Operating Range -55°C to +125°C -55°C to +125°C -25°C to +85°C P r o d u c t I n n o v a t i o nF r o m Volt Deviation (MaX) ±400µV ±200µV ±200µV 1. ChaRaCTERISTICS aND SPECIFICaTIONS ElECTRICal SPECIFICaTIONS VPS =±15V, T = +25°C, RL = 10K Ω UnLESS OTHERWISE nOTED. Model Parameter Power Supply Operating Temperature Storage Temperature Short Circuit Protection OuTPuT VOlTaGE VRE117 VRE119 OuTPuT VOlTaGE ERRORS Initial Error Warmup Drift TMIn - TMAX (note1) 6 1.5 ±10 3 3 5 1 5 7 4 7 9 6 10 * * * * * * * * * * * * Long-Term Stability noise (0.1 - 10Hz) OuTPuT CuRRENT Range REGulaTION Line Load OuTPuT aDJuSTMENT Range Temperature Coefficient POWER SuPPlY CuRRENT (note 2) VRE117 ±PS VRE119 +PS VRE119 -PS * 2 200 * * ±300 2 400 ±300 +3.0 ±3.0 * * Min ±13.5 -25 -65 Continuous aBSOluTE MaXIMuM RaTINGS ±22 +85 +150 * -55 * * * +125 * * VRE119C Typ Max Min VRE117M Typ Max hermetic 14-pin Ceramic DIP Package Style hC VRE117Ma Min Typ Max * +125 * * * * ±200 1 200 * * V V µV ppm µV ppm/1000hrs. µVpp mA * * * * * * * * * * * ppm/V ppm/mA mV µV/ºC/mV mA mA mA units V ºC ºC -55 * nOTES: * 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. 2 VRE117DS P r o d u c t I n n o v a t i o nF r o m VRE117/119 2. TYPICal PERFORMaNCE GRaPhS VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE Temperature oC VRE119C Temperature oC VRE117M Temperature oC VRE117MA VRE117 QUIESCENT CURRENT VS. TEMP JUNCTION TEMP. RISE VS. OUTPUT CURRENT PSRR VS. FREQUENCY Temperature oC Output Current (mA) Frequency (Hz) VRE119 POSITIVE OUTPUT QUIESCENT CURRENT VS. TEMP JUNCTION TEMP. RISE VS. OUTPUT CURRENT PSRR VS. FREQUENCY Temperature oC QUIESCENT CURRENT VS. TEMP Output Current (mA) NEGATIVE OUTPUT JUNCTION TEMP. RISE VS. OUTPUT CURRENT Frequency (Hz) PSRR VS. FREQUENCY Temperature oC Output Current (mA) Frequency (Hz) VRE117DS  VRE117/119 . ThEORY OF OPERaTION P r o d u c t I n n o v a t i o nF r o m The following discussion refers to the block diagram in Figure 1. A FET current source is used to bias a 6.3 V 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 3 V output. The gain is determined by the resistor networks R3 and R4: G=1 + R4/R3. The 6.3 V 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 reference’s 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 method leaves a residual error over wide temperature ranges. To remove this residual error, a nonlinear compensation network of thermistors and resistors is used in the VRE117/119 series references. This proprietary network eliminates most of the nonlinearity in the voltage vs. temperature function. By then adjusting the slope, The VRE117/119 series 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. 4. aPPlICaTION INFORMaTION The proper connection of the VRE117 series voltage reference with the optional trim resistors is shown below. When trimming the VRE119, 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 VRE117/119 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 20 ppm. 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. EXTERNal CONNECTIONS 1. Optional Fine Adjust for approximately ±5mV. 4 VRE117DS P r o d u c t I n n o v a t i o nF r o m VRE117/119 PIN CONFIGuRaTION TOP VIEW NC NC NC -PS NC REF. GND GND FINE ADJ. +3.0V (-3.0V) FINE ADJ. FINE -ADJ. -3.0V FINE -ADJ. -PS NC REF. GND GND TOP VIEW FINE +ADJ. +3.0V VRE117 +PS (-PS) NC NC NC VRE119 FINE +ADJ. +PS NC NC NC CONTaCTING CIRRuS lOGIC SuPPORT For all Apex Precision Power product questions and inquiries, call toll free 800-546-2739 in north America. For inquiries via email, please contact tucson.support@cirrus.com. International customers can also request support by contacting their local Cirrus Logic Sales Representative. To find the one nearest to you, go to www.cirrus.com IMPORTAnT nOTICE Cirrus Logic, Inc. and its subsidiaries ("Cirrus") believe that the information contained in this document is accurate and reliable. However, the information is subject to change without notice and is provided "AS IS" without warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. 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