VCR2N

VCR2N/4N/7N Vishay Siliconix JFET Voltage-Controlled Resistors PRODUCT SUMMARY Part Number VCR2N VCR4N VCR7N VGS(off) Max (V) −7 −7 −5 V(BR)GSS Min (V) −25 −25 −25 rDS(on) Max (W) 60 600 8000 FEATURES D Continuous Voltage-Controlled Resistance D High Off-Isolation D High Input Impedance BENEFITS D Gain Ranging Capability/Wide Range Signal Attenuation D No Circuit Interaction D Simplified Drive APPLICATIONS D Variable Gain Amplifiers D Voltage Controlled Oscillator D AGC DESCRIPTION The VCR2N/4N/7N JFET voltage controlled resistors have an ac drain-source resistance that is controlled by a dc bias voltage (VGS) applied to their high impedance gate terminal. Minimum rDS occurs when VGS = 0 V. As VGS approaches the pinch-off voltage, rDS rapidly increases. This series of junction FETs is intended for applications where the drain-source voltage is a low-level ac signal with no dc component. Key to device performance is the predictable rDS change versus VGS bias where: r DS(@ V GS + 0) r DSbias [ V GS 1– V GS(off) These n-channel devices feature rDS(on) ranging from 20 to 8000 W . All packages are hermetically sealed and may be processed per MIL-S-19500 (see Military Information). TO-206AA (TO-18) TO-206AF (TO-72) S S C 1 1 4 2 D Top View 3 G and Case D 2 3 G Top View VCR7N VCR2N, VCR4N For applications information see AN105. Document Number: 70293 S-41225—Rev. F, 28-Jun-04 www.vishay.com 1 VCR2N/4N/7N Vishay Siliconix ABSOLUTE MAXIMUM RATINGSa Gate-Source, Gate-Drain Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −25 V Gate Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mA Power Dissipationb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 mW Operating Junction Temperature Range . . . . . . . . . . . . . . . . . . . −55 to 175_C Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65 to 200_C Lead Temperature (1/16” from case for 10 sec.) . . . . . . . . . . . . . . . . . . . 300_C Notes: a. TA = 25_C unless otherwise noted. b. Derate 2 mW/_C above 25_C. SPECIFICATIONS (TA = 25_C UNLESS OTHERWISE NOTED) Limits VCR2N VCR4N VCR7N Parameter Static Gate-Source Breakdown Voltage Gate-Source Cutoff Voltage Gate Reverse Current Symbol V(BR)GSS VGS(off) IGSS Test Conditions IG = −1 mA, VDS = 0 V VDS = 10 V, ID = 1 mA VGS = −15 V, VDS = 0 V VGS = 0 V, ID = 10 mA Typa −55 Min −25 −3.5 20 Max Min −25 Max Min −25 Max Unit −7 −5 60 −3.5 −7 −0.2 −2.5 −5 −0.1 V nA Drain-Source On-Resistance Gate-Source Forward Voltage rDS(on) VGS(F) VGS = 0 V, ID = 1 mA VGS = 0 V, ID = 0.1 mA VDS = 0 V, IG = 1 mA 0.7 200 600 4000 8000 W V Dynamic Drain-Source On-Resistance Drain-Gate Capacitance Source-Gate Capacitance rds(on) Cdg Csg VGS = 0 V, ID = 0 mA f = 1 kHz VGD = −10 V, IS = 0 mA f = 1 MHz VGS = −10 V, ID = 0 mA f = 1 kHz 20 60 7.5 7.5 200 600 3 3 4000 8000 1.5 pF 1.5 W Notes: a. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing. NCB/NPA/NT TYPICAL CHARACTERISTICS (TA = 25_C UNLESS OTHERWISE NOTED) Output Characteristics (VCR2N) 30 VGS(off) = −4 V 25 ID − Drain Current (mA) 20 15 10 5 VGS = 0 V 0.8 −0.5 V −1.0 V −1.5 V −2.0 V −2.5 V −3.0 V 0 0 0.2 0.4 0.6 0.8 1 VDS − Drain-Source Voltage (V) www.vishay.com 0 0 0.1 0.2 0.3 0.4 0.5 VDS − Drain-Source Voltage (V) Document Number: 70293 S-41225—Rev. F, 28-Jun-04 ID − Drain Current (mA) 1.0 −1.5 V −2.0 V −2.5 V 0.6 −3.0 V −4.0 V −3.5 V Output Characteristics (VCR4N) VGS = 0 V 0.4 0.2 VGS(off) = −4.2 V 2 VCR2N/4N/7N Vishay Siliconix TYPICAL CHARACTERISTICS (TA = 25_C UNLESS OTHERWISE NOTED) Output Characteristics (VCR7N) 200 VGS(off) = −2.5 V VGS = 0 V 120 −0.5 V −1.0 V 80 −1.5 V 40 −2.0 V 0 0 0.2 0.4 0.6 0.8 1 VDS − Drain-Source Voltage (V) 160 ID − Drain Current (mA) APPLICATIONS A simple application of a FET VCR is shown in Figure 1, the circuit for a voltage divider attenuator. The output voltage is: VOUT = R VIN rDS R + rDS It is assumed that the output voltage is not so large as to push the VCR out of the linear resistance region, and that the rDS is not shunted by the load. VOUT VIN The lowest value which VOUT can assume is: VOUT(min) = VIN rDS(on) R + rDS(on) − VGS VCR + Since rDS can be extremely large, the highest value is: FIGURE 1. Simple Attenuator Circuit VOUT(max) = VIN Document Number: 70293 S-41225—Rev. F, 28-Jun-04 www.vishay.com 3 Legal Disclaimer Notice Vishay Notice Specifications of the products displayed herein are subject to change without notice. Vishay Intertechnology, Inc., or anyone on its behalf, assumes no responsibility or liability for any errors or inaccuracies. Information contained herein is intended to provide a product description only. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Vishay's terms and conditions of sale for such products, Vishay assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale and/or use of Vishay products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright, or other intellectual property right. The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications. Customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Vishay for any damages resulting from such improper use or sale. Document Number: 91000 Revision: 08-Apr-05 www.vishay.com 1