MAX7034AUI+ Maxim Integrated Products, MAX7034AUI+ Datasheet - Page 8

• 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

315MHz/434MHz ASK Superheterodyne
Receiver
The MAX7034 CMOS superheterodyne receiver and a
few external components provide the complete receive
chain from the antenna to the digital output data.
Depending on signal power and component selection,
data rates can be as high as 33kbps Manchester
(66kbps NRZ).
The MAX7034 is designed to receive binary ASK data
modulated in the 300MHz to 450MHz frequency range.
ASK modulation uses a difference in amplitude of the
carrier to represent logic 0 and logic 1 data.
The MAX7034 is designed to work with a nominal +5.0V
supply voltage. The MAX7034 integrates an internal volt-
age regulator that provides +3.4V to some of the internal
circuits in the device; this voltage is connected to the
AVDD and DVDD pins. The device can be operated from
+3.0V to +3.6V by pulling the EN_REG pin low (which dis-
ables the internal voltage regulator) and connecting the
supply voltage to the AVDD and DVDD pins. If the
MAX7034 is powered from +3.0 to +3.6V, the perfor-
mance is limited to the -40°C to +105°C range.
The LNA is an nMOS cascode amplifier with off-chip
inductive degeneration. The gain and noise figures are
8
_______________________________________________________________________________________
LNAIN
DGND
AGND
DV
AV
V
DD5
DD
DD
5, 10
2, 7
24
14
13
3
LNASRC
LNA
DETECTOR
4
3.4V REG
XTALSEL
DIVIDE
PHASE
16
÷1
BY 64
÷2
Detailed Description
EN_REG
15
XTAL1
1
Low-Noise Amplifier
CRYSTAL
DRIVER
FILTER
LOOP
VCO
LNAOUT MIXIN1 MIXIN2
Voltage Regulator
6
28
XTAL2
8
POWER-
DOWN
27
SHDN
9
DATAOUT
25
Q
SLICER
I
DATA
REJECTION
IMAGE
11
IRSEL
90˚
20
0˚
DSN
dependent on both the antenna matching network at
the LNA input and the LC tank network between the
LNA output and the mixer inputs.
The off-chip inductive degeneration is achieved by
connecting an inductor from LNASRC to AGND. This
inductor sets the real part of the input impedance at
LNAIN, allowing for a more flexible input impedance
match, such as a typical printed-circuit board (PCB)
trace antenna. A nominal value for this inductor with a
50Ω input impedance is 15nH, but is affected by the
PCB trace.
The LC tank filter connected to LNAOUT comprises L1
and C9 (see the Typical Application Circuit ). Select L1
and C9 to resonate at the desired RF input frequency.
The resonant frequency is given by:
where:
L
C
L
capacitance of the PCB traces, package pins, mixer
input impedance, etc. These parasitics at high frequen-
cies cannot be ignored, and can have a dramatic effect
TOTAL
PARASITICS
TOTAL
23
DSP
∑
19
DFO
MIXOUT
12
= L1 + L
= C9 + C
MAX7034
f
RF
and C
=
PARASITICS
PARASITICS
PDOUT
26
2π
PARASITICS
17
IFIN1
L
Functional Diagram
TOTAL
18
21
IFIN2
OPP
RSSI
.
.
100kΩ
R
DF2
1
include inductance and
IF LIMITING
×
FILTER
AMPS
DATA
22
C
DFFB
TOTAL
100kΩ
R
DF1