max2364ecm-t Maxim Integrated Products, Inc., max2364ecm-t Datasheet - Page 13

• Manufacturer Part Number: max2364ecm-t
• Description: Max2360, Max2362, Max2364 Complete Dual-band Quadrature Transmitters
• Manufacturer: Maxim Integrated Products, Inc.

Two major concepts should be employed to produce a
noise-free and EMC-compliant transmitter: minimize cir-
cular current-loop area to reduce H-field radiation and
minimize voltage drops to reduce E-field radiation. To
minimize circular current-loop area, bypass as close to
the part as possible and use the distributed capaci-
tance of a ground plane. To minimize voltage drops,
make V
short.
The “don't care” bits in the registers should be “0” in
order to minimize electromagnetic radiation due to
unnecessary bit banging. RC filtering can also be used
to slow the clock edges on the 3-wire interface, reduc-
ing high-frequency spectral content. RC filtering also
Figure 1. Register Configuration
CC
CONFIGURATION REGISTER
RFM DIVIDE REGISTER
RFR DIVIDE REGISTER
IFM DIVIDE REGISTER
IFR DIVIDE REGISTER
CONTROL REGISTER
traces short and wide, and make RF traces
TEST REGISTER
______________________________________________________________________________________
Compliance Considerations
MSB
B19
X = DON’T CARE
X
X
X
X
X
X
X
Electromagnetic
B18
X
X
X
X
X
X
X
B17
B17
X
X
X
X
X
X
B16
B16
X
X
X
X
X
X
B15
B15
B15
B15
X
X
X
X
B14
B14
B14
B14
X
X
X
X
B13
B13
B13
B13
B13
X
X
X
B12
B12
B12
B12
B12
B12
X
X
Quadrature Transmitters
B11
B11
B11
B11
B11
B11
X
X
DATA 20 BITS
RFM DIVIDE RATIO (18)
B10
B10
B10
B10
B10
B10
B10
provides for transient protection against IEC802 testing
by shunting high frequencies to ground, while the
series resistance attenuates the transients for error-free
operation. The same applies to the override pins
(SHDN, TXGATE, IDLE).
High-frequency bypass capacitors are required close
to the pins with a dedicated via to ground. The 48-pin
TQFP-EP package provides minimal inductance ground
by using an exposed paddle under the part. Provide at
least five low-inductance vias under the paddle to
ground, to minimize ground inductance. Use a solid
ground plane wherever possible. Any cutout in the
ground plane may act as slot radiator and reduce its
shield effectiveness.
Keep the RF LO traces as short as possible to reduce
LO radiation and susceptibility to interference.
CONFIGURATION BITS (16)
X
24 BIT REGISTER
CONTROL BITS (16)
B9
B9
B9
B9
B9
B9
B9
X
IFM DIVIDE RATIO (14)
Complete Dual-Band
B8
B8
RFR DIVIDE RATIO (13)
B8
B8
B8
B8
B8
X
B7
B7
B7
B7
B7
B7
B7
B7
RFR DIVIDE RATIO (11)
B6
B6
B6
B6
B6
B6
B6
B6
B5
B5
B5
B5
B5
B5
B5
B5
TEST BITS (8)
B4
B4
B4
B4
B4
B4
B4
B4
B3
B3
B3
B3
B3
B3
B3
B3
B2
B2
B2
B2
B2
B2
B2
B2
B1
B1
B1
B1
B1
B1
B1
B1
B0
B0
B0
B0
B0
B0
B0
B0
ADDRESS 4 BITS
A3
0
0
0
0
0
0
0
ADDRESS
ADDRESS
ADDRESS
ADDRESS
ADDRESS
ADDRESS
ADDRESS
A2
0
0
0
0
1
1
1
A1
0
0
1
1
0
0
1
LSB
A0
0
1
0
1
0
1
1
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