MAX7033EUI+ Maxim Integrated Products, MAX7033EUI+ Datasheet - Page 11

• Manufacturer Part Number: MAX7033EUI+
• Description: RF Receiver IC RX 315MHZ/433MHZ ASK
• Manufacturer: Maxim Integrated Products
• Type: Receiverr

Specifications of MAX7033EUI+

• Package / Case: TSSOP-28
• Operating Frequency: 450 MHz
• Operating Supply Voltage: 3.3 V, 5 V
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

injection is required due to the on-chip image-rejection
architecture. The IF output is driven by a source follow-
er biased to create a driving-point impedance of 330Ω;
this provides a good match to the off-chip 330Ω ceram-
ic IF filter.
The IRSEL pin is a logic input that selects one of the
three possible image-rejection frequencies. When V
= 0V, the image rejection is tuned to 315MHz. V
V
= V
pin is internally set to V
375MHz) when it is left unconnected, thereby eliminating
the need for an external V
The PLL block contains a phase detector, charge
pump, integrated loop filter, VCO, asynchronous 64x
clock divider, and crystal oscillator driver. Besides the
crystal, this PLL does not require any external compo-
nents. The VCO generates a low-side LO. The relation-
ship between the RF, IF, and reference frequencies is
given by:
Table 1. Component Values for Typical Application Circuit
DD5
COMPONENT
DD5
/2 tunes the image rejection to 375MHz, and V
C10
C11
C12
C13
tunes the image rejection to 433MHz. The IRSEL
C1
C2
C3
C4
C5
C6
C7
C8
C9
R1
L1
L2
L3
X1
X2
______________________________________________________________________________________
f
REF
315MHz/433MHz ASK Superheterodyne
VALUE FOR f
=
DD5
10.7MHz ceramic filter
f
RF
32
DD5
/2 voltage.
-
×
Phase-Locked Loop
6.5984MHz
f
M
/2 (image rejection at
IF
1500pF
0.47μF
0.01μF
0.01μF
100pF
100pF
100pF
220pF
470pF
220pF
5.1kΩ
56nH
15nH
15nH
15pF
15pF
2pF
RF
= 433MHz
IRSEL
IRSEL
IRSEL
=
VALUE FOR f
Receiver with AGC Lock
10.7MHz ceramic filter
where:
To allow the smallest possible IF bandwidth (for best sen-
sitivity), minimize the tolerance of the reference crystal.
The IF section presents a differential 330Ω load to pro-
vide matching for the off-chip ceramic filter. The six
internal AC-coupled limiting amplifiers produce an
overall gain of approximately 65dB, with a bandpass-fil-
ter-type response centered near the 10.7MHz IF fre-
quency with a 3dB bandwidth of approximately 10MHz.
The RSSI circuit demodulates the IF by producing a DC
output proportional to the log of the IF signal level, with
a slope of approximately 14.2mV/dB (see the Typical
Operating Characteristics ).
The crystal oscillator in the MAX7033 is designed to
present a capacitance of approximately 3pF between
the XTAL1 and XTAL2. If a crystal designed to oscillate
with a different load capacitance is used, the crystal is
pulled away from its stated operating frequency, intro-
ducing an error in the reference frequency. Crystals
4.7547MHz
1500pF
0.47μF
0.01μF
0.01μF
M = 1 (V
120nH
100pF
100pF
100pF
220pF
470pF
220pF
5.1kΩ
15pF
15pF
15nH
27nH
4pF
RF
= 315MHz
Intermediate Frequency and RSSI
XTALSEL
Applications Information
= V
DD5
Murata SFECV10.7 series
) or 2 (V
Depends on XTAL
Depends on XTAL
TOKO LL1608-FH
Crystal Oscillator
Murata LQP11A
Murata LQP11A
DESCRIPTION
± 0.1pF
XTALSEL
10%
20%
10%
20%
20%
5%
5%
5%
5%
5%
5%
—
= 0V)
11