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M
Complete Dual-Band
Quadrature Transmitters
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9
Pin Description (continued)
I+, I-
SHDN
V
CC
IFLO
TANKL-,
TANKL+
VGC
V
CC
V
CC
Q+, Q-
IFOUTL+,
IFOUTL-
IFOUTH-,
IFOUTH+
NAME
25, 26
27
28
29
30, 31
20
21
22
23, 24
18, 19
—
MAX2364
PIN
Differential I-Channel Baseband Inputs to the Modulator. These pins go
directly to the bases of a differential pair and require an external common-
mode bias voltage of 1.4V.
25, 26
25, 26
Shutdown Input. A logic low on
SHDN
shuts down the entire IC. An RC low-
pass filter may be used to reduce digital noise.
27
27
Supply Pin to the VCO Section. Bypass as close to the pin as possible. The
bypass capacitor should not share its vias with any other branches.
28
28
Buffered LO Output. Control the output buffer using register bit BUF_EV and
the divide ratio using the register bit BUF_DIV.
29
29
Differential Tank Pins for the Low-Frequency IF VCO. These pins are internally
biased to 1.6V.
—
30, 31
RF and IF Variable-Gain Control Analog Input. VGC floats to 1.5V. Apply
0.5V to 2.6V to control the gain of the RF and IF stages. An RC filter on this
pin may be used to reduce DAC noise or PDM clock spurs from this line.
20
20
Supply Pin for the IF VGA. Bypass with a capacitor as close to the pin as
possible. The bypass capacitor must not share its ground vias with any other
branches.
21
21
Supply for the I/Q Modulator. Bypass with capacitor as close to the pin as
possible. The bypass capacitor must not share its ground vias with any other
branches.
22
22
Differential Q-Channel Baseband Inputs to the Modulator. These pins go
directly to the bases of a differential pair and require an external common-
mode bias voltage.
23, 24
23, 24
Differential IF Outputs. These ports are active when the register bit IF_SEL is
low. These pins must be inductively pulled up to V
CC
. A differential IF band-
pass filter is connected between this port and IFINL+ and IFINL-. The pull-up
inductors can be part of the filter structure. The differential output impedance
of this port is nominally 600
. The transmission lines from these pins should
be short to minimize the pick-up of spurious signals and noise.
—
18, 19
Differential IF Outputs. These ports are active when the register bit IF_SEL is
high. They do not support FM mode. These pins must be inductively pulled
up to V
CC
. A differential IF bandpass filter is connected between this port
and IFINH+ or IFINH-. The pull-up inductors can be part of the filter structure.
The differential output impedance of this port is nominally 600
. The trans-
mission lines from these pins should be short to minimize the pick-up of spu-
rious signals and noise.
16, 17
16, 17
FUNCTION
MAX2362
MAX2360