RF2318 View Datasheet(PDF) - RF Micro Devices
Part Name
Description
Manufacturer
RF2318 Datasheet PDF : 6 Pages
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RF2318
Preliminary
Pin Function Description
Interface Schematic
1
RF IN
RF input pin. This pin is NOT internally DC blocked. A DC blocking
capacitor, suitable for the frequency of operation, should be used in all
applications. The device has internal feedback, and not using a DC
blocking capacitor will disable the temperature compensation.The bias
of the device can be controlled by this pin. Adding an optional 1kΩ
resistor to ground on this pin reduces the bias level, which may be com-
pensated for by a higher supply voltage to maintain the appropriate
bias level. The net effect of this is an increased output power capability,
as well as higher linearity for signals with high crest factors. DC cou-
3
pling of the input is not allowed, because this will override the internal
feedback loop and cause temperature instability.
2
GND
Ground connection. Keep traces physically short and connect immedi-
ately to ground plane for best performance. Each ground pin should
have a via to the ground plane.
3
GND
Same as pin 2.
4
GND
Same as pin 2.
5
GND
Same as pin 2.
6
GND
Same as pin 2.
7
GND
Same as pin 2.
8
RF OUT RF output and bias pin. Because DC is present on this pin, a DC block-
ing capacitor, suitable for the frequency of operation, should be used in
most applications. For biasing, an RF choke in series with a resistor is
needed. The value for the resistor RC is 30Ω (0.5W) for VCC=9V and
82Ω for VCC=12V. The DC voltage on this pin is typically 7V with a cur- RF IN
rent of 63mA. In lower power applications the value of RC can be
increased to lower the current and VD on this pin.
RF OUT
Application Schematic
VCC= 9 - 12 V
RC= 30 - 82 Ω
RF IN
220 pF
1
Optional:
RS=1 - 2 k Ω
2
Note 1
3
4
3.3 µH
220 pF
8
RF OUT
7
6
5
Note 1:
Optional resistor Rs can be used to maintain the correct bias level at higher supply voltages. This
is useful to increase output capability or linearity for signals with high crest factors.
3-24
Rev A2 010228
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