BYI datasheet Rev A

Microsemi reserves the right to change, without notice, the specifications and information contained

GENERAL DESCRIPTION

The BYI-1 is a semiconductor device specifically designed for use in linear

amplifier bias circuitry. The byistor acts as a low impedance D.C. bias source

which has two modes for thermal compensation.

CASE OUTLINE

BYI – 1

55FT

FEATURES

•

The package can be physically attached to the same heatsink used for the

RF Power Transistors

•

Contains a diode fabricated like an RF Power Transistor (same material,

geometry and diffusion) which provides one mode of thermal tracking

•

Contains a silicon resistor which provides a second mode of thermal

tracking

•

Fabricated and assembled with the same consistency and precision used

in building RF Power Transistors.

BYISTOR SPECIFICATIONS

Resistor = 0.70 +/- 0.12

Ω, (T

Maximum Temperatures

Storage Temperature

- 65 to +150

Operating Junction Temperature

+150

BYISTOR – A DEVICE FOR LINEAR AMPLIFIER BIAS NETWORKS

An essential part of any linear solid state amplifier is the D.C. Bias circuitry. The bias circuitry for class AB must meet all

of the following basic requirements:

•

Provide voltage/current capability compatible with the static (zero RF drive) collector current requirements of the

amplifier

•

Provide a low impedance voltage source with sufficient current capability to counter the negative rectification

effect of the RF drive on the base of the transistor

•

eliminate the possibility of D.C. thermal runaway of the amplifier

Microsemi Corp. is delivering a semiconductor device called a BYISTOR, to be used as the key element in a transistor

bias network. The advantages of using a BYISTOR are the excellent temperature tracking for D.C. stability and the

significantly simplified bias circuit. Furthermore, supplemental emitter resistance is not needed to insure D.C. stability.

Jan 2009

BYI-1

BYISTOR FOR LINEAR

POWER AMPLIFIERS

Reference

Injector

Supplier