
Preliminary
8-42
RF2489
Rev A10 011017
8
Pin
Function
Description
Interface Schematic
16
GND
Low-inductance ground required.
17
PCS LNA
OUT
PCS LNA output. Small external inductance required for best imped-
ance match to 50
Ω.
18
VCC2
PCS LNA VCC connection. A series inductance required for matching.
19
GND
Low-inductance ground required.
20
PCS LNA IN PCS LNA input. Simple external matching required for best perfor-
mance.
See pin 17.
21
GND
Low-inductance ground required.
22
CELL LNA
IN
Cellular LNA input. Simple external matching required for best perfor-
mance.
23
CELL LNA
EMITTER
Cellular LNA emitter. A small inductor connects this pin to ground. Cel-
lular LNA gain can be adjusted by the inductance.
See pin 22.
24
CELL LNA
OUT
Cellular LNA output. Simple external L-C matching required.
See pin 22.
25
ISET1
Resistor to ground sets both LNA and mixer currents. Lower resistance
results in lower currents for both the LNA and mixer.
26
ISET2
Resistor to ground sets LNA current. Higher resistance results in lower
current.
27
GND
Low-inductance ground required.
28
CELL MIX
IN
Cellular mixer RF single-end input. External L-C network required for
best performance.
29
VCC1
VCC for internal references, logic, and mixer preamplifiers. Internal RF
bypass capacitor. External bypass capacitor between 1nF and 47nF
required.
30
BAND SEL
Logic input. High level selects PCS band; low level selects cellular
band. The LO divider circuitry is disabled when BAND SEL is high,
regardless of the state of pin 5 (/2 SELECT). When BAND SEL is low,
pin 5 can be selected high or low. If using a single LO input, pin 5 can
be tied to a high state allowing BAND SEL to control the LO divider
function.
31
IP SET
Logic input. High selects external LNA current reference set by the
resistor connected from ISET2 to ground.
32
IF SEL
Logic input. High selects FM IF outputs; low selects CDMA IF outputs.
PCS LNA IN
V
CC
PCS LNA OUT
CELL LNA IN
V
CC
CELL LNA OUT
CELL LNA EMITTER
CELL MIX IN
BAND SEL
IP SET
IF SEL