VRE405

P r o d u c t IIn n o vva t i o n FF r o m rom nno a VRE405 VRE405 DESCRIPTION Precision Dual Voltage Reference FEaTuRES ♦ ♦ ♦ ♦ ♦ ♦ ±5 V Output, ± 0.5 mV (.01%) Temperature Drift: 0.6 ppm/ºC Low Noise: 3 μVP-P (0.1-10hz) Tracking Error: 0.3 mV Max. Excellent Line Regulation: 6 ppm/V Typical Surface Mount and DIP Package Options The VRE405 is a low cost, high precision, ±5 V reference. Available in 14-pin DIP or SMT packages, the device is ideal for new designs that need a high performance reference. The device provides ultrastable ±5 V output with ±0.5 mV (.01%) initial accuracy and a temperature coefficient of 0.6 ppm/°C. This improvement in accuracy is made possible by a unique, patented multipoint laser compensation technique. Another key feature of this reference is the 0.3 mV maximum tracking error between the positive and negative output voltages over the operating temperature range. This is extremely important in high performance systems for reducing overall system errors. For designs which use the DIP package in a socket, there is a reference ground pin to eliminate the reference ground errors. aPPlICaTIONS The VRE405 is recommended for use as a reference for high precision D/A and A/D converters which require an external precision reference. The device is ideal for calibrating scale factor on high resolution A/D converters. The VRE405 offers superior performance over monolithic references. Figure . BlOCK DIaGRaM SElECTION GuIDE Model VRE405AS VRE405AD VRE405BS VRE405BD VRE405CS VRE405CD Initial Error (mV) ±0.5 ±0.5 ±0.8 ±0.8 ±1.0 ±1.0 Temp. Coeff. (ppm/ºC) 0.6 0.6 1.0 1.0 2.0 2.0 Temp. Range (ºC) 0ºC to +70ºC 0ºC to +70ºC 0ºC to +70ºC 0ºC to +70ºC 0ºC to +70ºC 0ºC to +70ºC Package Options SMT14 (GE) DIP14 (KE) SMT14 (GE) DIP14 (KE) SMT14 (GE) DIP14 (KE) 4-pin Surface Mount Package Style GE 4-pin DIP Package Style KE VRE405DS http://www.cirrus.com Copyright © Cirrus Logic, Inc. 2009 (All Rights Reserved) MaR 2009  APEX − VRE405DSREVB VRE405 P r o d u c t I n n o v a t i o nF r o m . ChaRaCTERISTICS aND SPECIFICaTIONS ElECTRICal SPECIFICaTIONS VPS =±15V, T = +25ºC, RL = 10KΩ Unless Otherwise Noted. Model Parameter aBSOluTE RaTINGS Power Supply Operating Temperature Storage Temperature Short Circuit Protection OuTPuT VOlTaGE VRE405 OuTPuT VOlTaGE ERRORS Initial Error Warmup Drift TMIN - TMAX Tracking Error Long-Term Stability Noise (0.1 - 10Hz) OuTPuT CuRRENT Range REGulaTION Line Load OuTPuT aDJuSTMENT Range POWER SuPPlY CuRRENT (Note 4) +PS -PS 7 4 9 6 * * * * * * * * mA mA 20 * * mV 3 3 10 * * * * * * ppm/V ppm/mA ±10 * mA (Note 3) 6 3 (Note2) (Note 1) 1 0.6 0.3 * * ±0.05 2 1.0 0.4 * * ±0.80 3 2.0 0.5 ±1.00 mV ppm ppm/ºC mV ppm/1000hrs. µVpp ±5.0 * * V ±13.5 0 -65 Continuous ±15 ±22 +70 +150 * * * * * * * * * * * * * * * * V ºC ºC Min VRE405a Typ Max Min VRE405B Typ Max Min VRE405C Typ Max units NOTES: * Same as A Models. 1. The specified values are without external trim. 2. The temperature coefficient (TC) is determined by the box method using the following formula: VMAX – VMIN T.C. = x 106 VNOMINAL x (TMAX – TMIN) 4. The tracking error is the deviation between the positive and negative output over the operating temp. range. 5. The specified values are unloaded. 2 VRE405DS P r o d u c t I n n o v a t i o nF r o m VRE405 2. TYPICal PERFORMaNCE CuRVES VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE VOUT vs. TEMPERATURE Temperature oC VRE405A Temperature oC VRE405B POSITIVE OUTPUT (TYP) Temperature oC VRE405C QUIESCENT CURRENT VS. TEMP JUNCTION TEMP. RISE VS. OUTPUT CURRENT PSRR VS. FREQUENCY Temperature oC QUIESCENT CURRENT VS. TEMP Output Current (mA) NEGATIVE OUTPUT (TYP) JUNCTION TEMP. RISE VS. OUTPUT CURRENT Frequency (Hz) PSRR VS. FREQUENCY Temperature oC Output Current (mA) Frequency (Hz) VRE405DS  VRE405 . 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 5 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 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. 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 adjusting the slope, a very stable voltage is produced 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. The VRE405 reference has it’s ground terminal brought out on two pins (pin 6 and 7) which are connected 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 does not effect performance. PIN CONFIGuRaTION N/C 1 2 3 4 5 6 7 14 13 N/C +VOUT N/C +VIN N/C N/C N/C - VOUT N/C VRE405 TOP VIEW 12 11 10 9 8 - VI N N/C REF. GND GND 4 VRE405DS P r o d u c t I n n o v a t i o nF r o m VRE405 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. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those pertaining to warranty, indemnification, and limitation of liability. No responsibility is assumed by Cirrus for the use of this information, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third parties. This document is the property of Cirrus and by furnishing this information, Cirrus grants no license, express or implied under any patents, mask work rights, copyrights, trademarks, trade secrets or other intellectual property rights. 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