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GROUNDED EMITTER ZENER BIASING

IP.com Disclosure Number: IPCOM000005438D
Original Publication Date: 1982-Jan-01
Included in the Prior Art Database: 2001-Oct-10
Document File: 2 page(s) / 74K

Publishing Venue

Motorola

Related People

Raymond Sommerer: AUTHOR

Abstract

GED An arrangement for setting collector current and collector voltage operating point Using a Zener diode Is shown in the figure. The transistor used is 21\16603(MRFSOl). From the data sheet for the MRF901 In the Motorola RF Data Manual, pages 16.99 through 16.102, at the operating point, the collector current, lc - 10 mA, the supply voltage V,, = + 10 V and the transition frequency ft approximately equalS 4.4 Giiz.

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@ MOmROLA Technical Developments Volume 2 January 1982

GROUNDED EMITTER ZENER BIASING By Raymond Sommerer

GED

    An arrangement for setting collector current and collector voltage operating point Using a Zener diode Is shown in the figure. The transistor used is 21\16603(MRFSOl). From the data sheet for the MRF901 In the Motorola RF Data Manual, pages 16.99 through 16.102, at the operating point, the collector current, lc - 10 mA, the supply voltage V,, = + 10 V and the transition frequency ft approximately equalS 4.4 Giiz.

   R2 and C2 are used to exclude the noise generated by the Zener diode from the input circuit. The 1 N4103 is a 9.1 V (nominal) Zener at 256 microamps. X is a stripline colelctor load (minimum reSiStSnCS). If R2 is selected to equal Rl, and the DC beta, 0, is nominally 50, then the DC drop across R2 is l/50 Of the drop across Rl. The Zener impedance is approximately 200 ohms.

   The 9.1 V Zener will set the collector voltage at approximately 9.8 V (9.1 V + 0.7 V). The value Of Rl will set the collector current. For 10 mA, Rl = (15 V - 9.8 V)/lO mA = 520 ohms. Vn,, the DC drop across R2 (chosen to be 520 ohms) approximately equals I/g (10 mA) (520 ohms). For a p of 50, Vn, = 0.104 V.

If the collector current increases or decreases, the collector voltage will follow inversely, and the Zener will supply the necessary base drive to defeat the collector change.

GROUNDED EMITTER ZENER BIASING

   Where the value of both R, and R, is selected to be 510 ohms, Cl...