
11-146
RF2919
Rev A12 001113
11
T
Pin
1
Function
VCC1
Description
This pin is used to supply DC bias to the receiver RF circuits. An RF
bypass capacitor should be connected directly to this pin and returned
to ground. A 100pF capacitor is recommended for 915MHz applica-
tions. A 220pF capacitor is recommended for 433MHz applications.
RF input pin for the receiver electronics. RX IN input impedance is a
low impedance when enabled. RX IN is a high impedance when the
receiver is disabled.
Interface Schematic
2
RX IN
3
GND1
Ground connection for RF receiver functions. Keep traces physically
short and connect immediately to ground plane for best performance.
Output pin for the receiver RF low noise amplifier. This pin is an open
collector output and requires an external pull up coil to provide bias and
tune the LNA output.
4
LNA OUT
5
GND2
GND2 is connection for the 40 dB IF limiting amplifier. Keep traces
physically short and connect immediately to ground plane for best per-
formance.
RF input to the RF Mixer. An LC matching network between LNA OUT
and MIX IN can be used to connect the LNA output to the RF mixer
input in applications where an image filter is not needed or desired.
6
MIX IN
7
8
GND3
MIX OUT
GND3 is the ground connection for the receiver RF mixer.
IF output from the RF mixer. Interfaces directly to 10.7MHz ceramic IF
filters as shown in the application schematic. A pull-up inductor and
series matching capacitor should be used to present a 330
termina-
tion impedance to the ceramic filter. Alternately, an IF tank can be used
to tailor the IF frequency and bandwidth to meet the needs of a given
application. In addition to the matching components, a 15pF capacitor
should be placed from this pin to ground.
Balanced IF input to the 40dB limiting amplifier strip. A DC blocking
capacitor is required on this input, 10nF is recommended.
9
IF1 IN-
10
IF1 IN+
Functionally the same as pin 9 except non-inverting node amplifier
input. In single-ended applications, this input should be bypassed
directly to ground through a 10nF capacitor.
DC feedback node for the 40dB limiting amplifier strip. A 10nF bypass
capacitor from this pin to ground is recommended.
See pin 11.
See pin 9.
11
IF1 BP+
See pin 9.
12
13
IF1 BP-
IF1 OUT
See pin 9.
IF output from the 40dB limiting amplifier. The IF1 OUT output presents
a nominal 330
output resistance and interfaces directly to 10.7MHz
ceramic filters.
14
VREF IF
DC voltage reference for the IF limiting amplifiers (typically 1.1V). A
10nF capacitor from this pin to ground is recommended.
Ground connection for 60dB IF limiting amplifier. Keep traces physically
short and connect immediately to ground plane for best performance.
15
GND5
RX IN
LNA OUT
MIX IN
MIX OUT+
V
CC
IF1 IN-
IF1 IN+
330
330
60 k
60 k
IF1 BP+
IF1 BP-
IF1 OUT