Datasheet

MAX2306/MAX2308/MAX2309
CDMA IF VGAs and I/Q Demodulators
with VCO and Synthesizer
_______________________________________________________________________________________ 7
Pin Description
PIN
MAX2306
MAX2308 MAX2309
NAME FUNCTION
1, 28 — —
TANKL+,
TANKL-
Differential Tank Input for Low-Frequency Oscillator
— 1, 4 — N.C. No Connection. Must be left open-circuit.
2, 3 2, 3 1, 2
TANKH+,
TANKH-
Differential Tank Input for High-Frequency Oscillator
—— 3BUFEN LO Buffer Amplifier—active low
4 — — MODE Mode Select. High selects CDMA mode; low selects FM mode.
— — 4 LOOUT
Internal VCO Output. Depending on setting of BD bit, LOOUT is
either the VCO frequency (twice the IF frequency) or one-half the
VCO frequency (equal to the IF frequency).
555V
CC
+2.7V to +5.5V Supply
6 6 6 GND Ground
7 7 7 REF Reference Frequency Input
888SHDN
Shutdown Input—active low. Low powers down entire device,
including registers and serial interface.
9, 10 9, 10 9, 10
IOUT+,
IOUT-
Differential In-Phase Baseband Output, or FM signal output if FM_I
mode is selected.
11 11 11 LOCK
Lock Output—open-collector pin. Logic high indicates phase-locked
condition.
12, 13 12, 13 12, 13
QOUT-,
QOUT+
Differential Quadrature-Phase Baseband Output. Disabled if FM_I
mode is selected.
14 14 14 CLK Clock input of the 3-wire serial bus
15 15 15 EN Enable Input. When low, input shift register is enabled.
16 16 16 DATA Data input of the 3-wire serial bus.
17 17 17 V
CC
+2.7V to +5.5V Supply
18 18 18 VGC VGA Gain Control Input. Control voltage range is 0.5V to 2.3V.
19, 20 19, 20 19, 20
CDMA-,
CDMA+
Differential CDMA Input. Active in CDMA mode.
21 21 — FM+ Differential Positive Input. Active in FM mode.
22 22 — FM-
Differential Negative Input for FM signal. Bypass to GND for
single-ended operation.
——22STBY
Standby Input—active low. Low powers down VGA and demodulator
while keeping VCO, PLL, and serial bus on.
23, 24 23, 24 23, 24 BYP Bypass Node. Must be capacitively decoupled (bypassed) to pin 17.