
8-309
RF2498
Rev A4 070308
Pin
Function
Type Description
Interface Schematic
1
GPS+
AO
GPS IF output. Open collector.
2
GPS-
AO
GPS IF output. Open collector.
See pin 1.
3
CDMA+
AO
CDMA IF output. Open collector.
4
CDMA-
AO
CDMA IF output. Open collector.
See pin 3.
5FM+
AO
FM IF output. Open collector. “Current combiner” IF interface
to SAW filter recommended. (See “IF Output Matching Net-
work” section.)
6FM-
AO
FM IF output. Open collector. “Current combiner” IF interface
to SAW filter recommended. (See “IF Output Matching Net-
work” section.)
See pin 5.
7VCC2
P
VCC connection for internal LO amplifiers. Internal RF bypass
capacitor. External bypass capacitor between 1nF and 47nF
required.
8LO IN
AI
LO single-end input. Matched to 50
Ω.
9LO OUT
AO
LO output. Internal DC block.
10
/2 SELECT
DI
Logic input. Low enables /2 circuitry in cellular mode.
The divider is disabled when BAND SEL (pin 27) is high,
regardless of the state of pin 10. The divider can only be
enabled when BAND SEL is low and pin10 is low. Pin 10 can
be tied to a low state allowing BANDSEL (pin 27) to control the
LO divider function, if using a single LO input source.
See pin 11.
11
TX BUFF
ENABLE
DI
Logic input. High enables TX LO output buffer amplifiers.
12
PCS RFA
VCC
P
VCC connection for PCS mixer preamplifier.
13
PCS MIX IN
AI
PCS mixer RF single-end input.
14
CELL MIX
IN
AI
Cellular mixer RF single-end input. Matched to 50
Ω.
GPS+
GPS-
CDMA+
CDMA-
FM+
FM-
LO IN
70
Ω
TX BUF
PCS MIX IN
CELL MIX IN