70293 电路图.pdf

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1、VCR2N/4N/7N Vishay Siliconix Document Number: 70293 S-41225Rev. F, 28-Jun-04 1 JFET Voltage-Controlled Resistors PRODUCT SUMMARY Part NumberVGS(off) Max (V)V(BR)GSS Min (V)rDS(on) Max (?) VCR2N72560 VCR4N725600 VCR7N5258000 FEATURESBENEFITSAPPLICATIONS ? Continuous Voltage-Controlled Resistance ? Hi

2、gh Off-Isolation ? High Input Impedance ? Gain Ranging Capability/Wide Range Signal Attenuation ? No Circuit Interaction ? Simplified Drive ? Variable Gain Amplifiers ? Voltage Controlled Oscillator ? AGC DESCRIPTION The VCR2N/4N/7N JFET voltage controlled resistors have an ac drain-source resistanc

3、e 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

4、 signal with no dc component. Key to device performance is the predictable rDS change versus VGS bias where: rDSbias ? rDS( VGS? 0) 1? VGS VGS(off)? These n-channel devices feature rDS(on) ranging from 20 to 8000 ? . All packages are hermetically sealed and may be processed per MIL-S-19500 (see Mili

5、tary Information). D S G and Case TO-206AA (TO-18) Top View 1 23 SC TO-206AF (TO-72) DG Top View 1 23 4 VCR2N, VCR4N VCR7N For applications information see AN105. RadioFans.CN 收音机爱 好者资料库 VCR2N/4N/7N Vishay Siliconix 2 Document Number: 70293 S-41225Rev. F, 28-Jun-04 ABSOLUTE MAXIMUM RATINGSa Gate-Sou

6、rce, Gate-Drain Voltage25 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gate Current10 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Dissipationb300 mW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7、. . . . . Operating Junction Temperature Range55 to 175?C. . . . . . . . . . . . . . . . . . . Storage Temperature 65 to 200?C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lead Temperature (1/16” from case for 10 sec.)300?C. . . . . . . . . . . . . . . . . . . Notes: a.TA = 2

8、5?C unless otherwise noted. b.Derate 2 mW/?C above 25?C. SPECIFICATIONS (TA = 25?C UNLESS OTHERWISE NOTED) Limits VCR2NVCR4NVCR7N ParameterSymbolTest ConditionsTypaMinMaxMinMaxMinMaxUnit Static Gate-Source Breakdown VoltageV(BR)GSSIG = 1 ?A, VDS = 0 V55252525 V Gate-Source Cutoff VoltageVGS(off)VDS

9、= 10 V, ID = 1 ?A3.573.572.55 V Gate Reverse CurrentIGSSVGS = 15 V, VDS = 0 V50.20.1nA VGS = 0 V, ID = 10 mA2060 Drain-Source On-ResistancerDS(on) VGS = 0 V, ID = 1 mA200600 ? DS(on) VGS = 0 V, ID = 0.1 mA40008000 Gate-Source Forward VoltageVGS(F)VDS = 0 V, IG = 1 mA0.7V Dynamic Drain-Source On-Resi

10、stancerds(on) VGS = 0 V, ID = 0 mA f = 1 kHz 206020060040008000? Drain-Gate CapacitanceCdg VGD = 10 V, IS = 0 mA f = 1 MHz 7.531.5 pF Source-Gate CapacitanceCsg VGS = 10 V, ID = 0 mA f = 1 kHz 7.531.5 pF Notes:NCB/NPA/NT a.Typical values are for DESIGN AID ONLY, not guaranteed nor subject to product

11、ion testing. TYPICAL CHARACTERISTICS (TA = 25?C UNLESS OTHERWISE NOTED) 00.20.40.60.81 0 Output Characteristics (VCR2N) VDS Drain-Source Voltage (V) 0.5 V 2.0 V 2.5 V 1.0 V 1.5 V 00.10.20.30.40.5 Output Characteristics (VCR4N) VDS Drain-Source Voltage (V) 3.0 V 30 25 20 15 5 10 1.0 0 0.8 0.6 0.4 0.2

12、 VGS(off) = 4 V VGS = 0 V VGS(off) = 4.2 V VGS = 0 V 4.0 V 3.5 V 1.5 V 2.0 V 3.0 V 2.5 V ID Drain Current (mA) ID Drain Current (mA) RadioFans.CN 收音机爱 好者资料库 VCR2N/4N/7N Vishay Siliconix Document Number: 70293 S-41225Rev. F, 28-Jun-04 3 TYPICAL CHARACTERISTICS (TA = 25?C UNLESS OTHERWISE NOTED) 00.20

13、.40.60.81 Output Characteristics (VCR7N) VDS Drain-Source Voltage (V) 200 0 160 120 80 40 0.5 V 2.0 V 1.0 V 1.5 V VGS(off) = 2.5 V VGS = 0 V ID Drain Current (?A) APPLICATIONS A simple application of a FET VCR is shown in Figure 1, the circuit for a voltage divider attenuator. VIN FIGURE 1. Simple A

14、ttenuator Circuit VOUT R + VGSVCR The output voltage is: R + rDS VIN rDS VOUT = 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. The lowest value which VOUT can assume is: R + rDS(on) VIN rDS(on

15、) VOUT(min) = Since rDS can be extremely large, the highest value is: VOUT(max) = VIN RadioFans.CN 收音机爱 好者资料库 Document Number: Revision: 18-Jul-081 Disclaimer Legal Disclaimer Notice Vishay All product specifications and data are subject to change without notice. Vishay Intertechnology, Inc., its af

16、filiates, agents, and employees, and all persons acting on its or their behalf (collectively, “Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein or in any other disclosure relating to any product. Vishay disclaims any and all liability arising o

17、ut of the use or application of any product described herein or of any information provided herein to the maximum extent permitted by law. The product specifications do not expand or otherwise modify Vishays terms and conditions of purchase, including but not limited to the warranty expressed therei

18、n, which apply to these products. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document or by any conduct of Vishay. The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications unless

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