UPC1678G

Manufacturer Part NumberUPC1678G
DescriptionSilicon middle-power output high frequency wide-band amplifier
ManufacturerNEC
UPC1678G datasheet
 


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TEST CIRCUIT

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TEST CIRCUIT

50
IN
1 800 pF
INDUCTOR FOR THE OUTPUT PIN
The internal output transistor of this IC consumes 30 mA, to output medium power. To supply current for output
transistor, connect an inductor between the V
The inductor has both DC and AC effects. In terms of DC, the inductor biases the output transistor with minimum
voltage drop to output enable high level. In terms of AC, the inductor make output-port impedance higher to get
enough gain. In this case, large inductance and Q is suitable.
CAPACITORS FOR THE V
, INPUT AND OUTPUT PINS
CC
Capacitors of 1 800 pF are recommendable as the bypass capacitor for the V
for the input and output pins.
The bypass capacitor connected to the V
can be supplied against V
fluctuation.
CC
The coupling capacitors, connected to the input and output pins, are used to cut the DC and minimize RF serial
impedance. Their capacitance are therefore selected as lower impedance against a 50
perform as high pass filters, suppressing low frequencies to DC.
To obtain a flat gain from 100 MHz upwards, 1 800 pF capacitors are used in the test circuit. In the case of under
100 MHz operation, increase the value of coupling capacitor such as 10 000 pF. Because the coupling capacitors
are determined by equation, C = 1/(2 Rfc).
V
CC
1 800 pF
L
8
50
1
5
1 800 pF
2, 3, 4, 6, 7
L: 20.5 T, 2 mm I.D., 0.25 UEW
(about 300 nH)
pin (pin 8) and output pin (pin 5).
CC
CC
pin is used to minimize ground impedance of V
CC
Data Sheet P11491EJ4V0DS00
PC1678G
OUT
pin and the coupling capacitors
pin. So, stable bias
CC
load. The capacitors thus
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