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Unisonic Technologies |
UNISONIC TECHNOLOGIES CO., LTD
L8401
LINEAR INTEGRATED CIRCUIT
FET BIAS CONTROLLER
DESCRIPTION
The UTC L8401 is designed to bias the MOSFETs that
are commonly used in LNBs that can implies minimum
external components requires.
FEATURES
* Can Bias up to 4 FETs
* Drain Current Adjustable by Two External Resistors.
* Two Sets of Drain Current can be Setted.
ORDERING INFORMATION
Ordering Number
L8401G-R16-R
Package
SSOP-16
Packing
Tape Reel
MARKING
www.unisonic.com.tw
Copyright © 2015 Unisonic Technologies Co., Ltd
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QW-R123-018.B
L8401
PIN CONFIGURATION
LINEAR INTEGRATED CIRCUIT
FUNCTIONAL DIAGRAM
Fig.1
FUNCTIONAL DESCRIPTION
The UTC L8401 includes one negative supply required for gate biasing from the single supply voltage, and all the
other bias requirements for external FETs.
A low current negative supply voltage includes an internal OSC and two 47nF external cap. The negative rail
generator is common to all devices. This negative supply voltage used to drive the FET’s gate to obtain the required
drain current because of he FET is a depletion mode transistor.
There are for stages in the IC to baising the four external FETS. The drain voltage of the external FET FET1~4 is
2.2 volts set by the UTC L8401.
The drain current of external FET is determined by the external resist RCAL1 or RCAL2. External resistor RCAL1 sets
the drain current of FET1 and FET 2, and resistor RCAL2 sets the drain current of FET3 and FET4.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
2 of 5
QW-R123-018.B
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