µ
PC2709TB
TEST CIRCUIT
V
CC
1 000 pF
C
3
L
6
50
Ω
IN
1 000 pF
C
1
1
4
C
2
1 000 pF
50
Ω
OUT
2, 3, 5
Components of test circuit for
measuring electrical characteristics
TYPE
C
3
L
C
1
to C
2
Capacitor
Bias Tee
Bias Tee
VALUE
1 000 pF
1 000 nH
1 000 pF
C1 to C3
L
Example of actural application components
TYPE
Chip capacitor
Chip inductor
VALUE
1 000 pF
300 nH
100 nH
10 nH
OPERATING FREQUENCY
100 MHz or higher
10 MHz or higher
100 MHz or higher
1.0 GHz or higher
INDUCTOR FOR THE OUTPUT PIN
The internal output transistor of this IC consumes 20 mA, to output medium power. To supply current for output
transistor, connect an inductor between the V
CC
pin (pin 6) and output pin (pin 4). Select large value inductance, as
listed above.
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
CC
, INPUT, AND OUTPUT PINS
Capacitors of 1 000 pF are recommendable as the bypass capacitor for the V
CC
pin and the coupling capacitors
for the input and output pins.
The bypass capacitor connected to the V
CC
pin is used to minimize ground impedance of V
CC
pin. So, stable bias
can be supplied against V
CC
fluctuation.
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
Ω
load. The capacitors thus
perform as high pass filters, suppressing low frequencies to DC.
To obtain a flat gain from 100 MHz upwards, 1 000 pF capacitors are used in the test circuit. In the case of under
10 MHz operation, increase the value of coupling capacitor such as 10 000 pF. Because the coupling capacitors are
determined by equation, C = 1/(2
πRfc).
6
Data Sheet P12653EJ2V1DS00
NEC [ NEC ]
