4 STAGE FET LNA BIAS CONTROLLER

DESCRIPTION

The UTC L8403 is an advanced GaAs and HEMT FETs bias

controller. It is designed to operate from minimal supply rails and

intended primarily for satellite Low Noise Blocks (LNBs).

The UTC L8403 provides drain voltage and current control for

up to 4 external grounded source FETs with the addition of one

capacitor and two resistors.

The UTC L8403 is generating the regulated negative rail

required for FET gate biasing whilst operating from a single

supply of 2.1V to 5V.

The -2V negative bias can also be used to supply other

external circuits. The UTC L8403 uses two resistors to split

control between two pairs of FETs and set drain currents. This

allows the operating current of input FETs to be adjusted to

minimize noise, whilst the following FET stages can separately be

adjusted for maximum gain.

FEATURES

* Provides Bias for up to 4 GaAs and HEMT FETs

* Operating Range of 2.1V to 5V

* Ultra-low Operating Current of 0.95mA

* Dynamic FET Protection

* Amplifier FET Drain Voltages set at 2.0V

* Regulated Negative Rail Generator Requires only 1 External Capacitor

* Expended Temperature Range of -40°C to +105°C