MAX7034AUI+ Maxim Integrated Products, MAX7034AUI+ Datasheet - Page 11

• Manufacturer Part Number: MAX7034AUI+
• Description: RF Receiver IC RX 315MHZ/433MHZ ASK
• Manufacturer: Maxim Integrated Products

Specifications of MAX7034AUI+

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The peak-detector output (PDOUT), in conjunction with
an external RC filter, creates a DC output voltage equal
to the peak value of the data signal. The resistor pro-
vides a path for the capacitor to discharge, allowing the
peak detector to dynamically follow peak changes of
the data-filter output voltage. For faster data slicer
response, use the circuit shown in Figure 4. For more
details on hysteresis and peak-detector applications,
refer to Maxim Application Note 3671, Data Slicing
Techniques for UHF ASK Receivers .
A properly designed PCB is an essential part of any
RF/microwave circuit. On high-frequency inputs and
outputs, use controlled-impedance lines and keep them
as short as possible to minimize losses and radiation.
At high frequencies, trace lengths that are on the order
of λ/10 or longer act as antennas.
Keeping the traces short also reduces parasitic induc-
tance. Generally, 1 inch of a PCB trace adds about
20nH of parasitic inductance. The parasitic inductance
can have a dramatic effect on the effective inductance
of a passive component. For example, a 0.5 inch trace
connecting a 100nH inductor adds an extra 10nH of
inductance or 10%.
To reduce the parasitic inductance, use wider traces
and a solid ground or power plane below the signal
traces. Also, use low-inductance connections to ground
on all GND pins, and place decoupling capacitors
close to all V
Figure 2. Generating Data Slicer Threshold
25
DATAOUT
DD
connections.
______________________________________________________________________________________
C4
315MHz/434MHz ASK Superheterodyne
DATA
SLICER
20
DSN
Layout Considerations
R1
MAX7034
DSP
23
Peak Detector
19
DFO
Figure 3. Generating Data Slicer Hysteresis
Figure 4. Using PDOUT for Faster Startup
R1
R2
25
DATAOUT
25
DATAOUT
*OPTIONAL
47nF
DSN
DATA
SLICER
20
DATA
SLICER
DSP
MAX7034
23
25kΩ
R3
DSP
23
C4
DSN
20
19
DFO
Receiver
MAX7034
R4
PDOUT
19
DFO
26
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