SX1242
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
SX1242 - Low Cost Integrated Transmitter IC
344.940 MHz RF Transmitter
GENERAL DESCRIPTION
The SX1242 is an ultra-low-cost, fully integrated standalone
OOK transmitter suitable for operation at 344.940 MHz
The SX1242 is designed for use without the requirement for
configuration via an MCU.
The SX1242 offers integrated radio performance with cost
efficiency and is suited for operation in North America (FCC
part 15.231).
APPLICATIONS
Low-Cost Consumer Electronic Applications
Remote Keyless Entry (RKE)
Remote Control / Security Systems
Audio Accessories
Process and building / home control
ORDERING INFORMATION
Part Number
SX1242ISETRT
Temperature Range
-40 °C to +85 °C
Qty. per Reel
2500
Package
SOIC8-EP
KEY PRODUCT FEATURES
+12 dBm Output Power
344.940 MHz Operation
OOK Bit Rates up to 10 kbps
Pre-Configured Modes for Operation without MCU
1.8 to 3.7 V Supply Range
Low BOM Fully Integrated TX
Pb-Free, Halogen Free, RoHS/WEEE compliant product.
GND
1
2
3
4
CP
M/N
8
7
6
5
RFOUT
v
v
v
DATA
VDD
GND
PFD
TX ENABLE
VDD
XTAL
ΣΔ
v
SX1242, Rev 2, March 2011
©2011 Semtech Corp.
Page 1
www.semtech.com
SX1242
ADVANCED COMMUNICATIONS & SENSING
Table of contents
Section
Page
DATASHEET
1.
General Description ................................................................................................................................................. 3
1.1.
1.2.
1.3.
Pin Diagram ..................................................................................................................................................... 3
Marking Diagram.............................................................................................................................................. 4
Pin Description................................................................................................................................................. 4
ESD Notice ...................................................................................................................................................... 5
Absolute Maximum Ratings ............................................................................................................................. 5
Operating Range.............................................................................................................................................. 5
Electrical Specifications ................................................................................................................................... 6
2.
Electrical Characteristics ......................................................................................................................................... 5
2.1.
2.2.
2.3.
2.4.
3.
4.
Circuit Description.................................................................................................................................................... 7
Application Information ............................................................................................................................................ 9
4.1.
4.2.
4.3.
4.4.
Crystal Specification ........................................................................................................................................ 9
Reference Design Schematic .......................................................................................................................... 9
Reference Design PCB Layout ......................................................................................................................10
Reference Design BOM .................................................................................................................................10
Package Outline Drawing .............................................................................................................................. 11
Land Pattern .................................................................................................................................................. 11
Thermal Impedance ....................................................................................................................................... 12
Tape & Reel Specification.............................................................................................................................. 12
5.
Packaging Information ........................................................................................................................................... 11
5.1.
5.2.
5.3.
5.4.
6.
Revision History..................................................................................................................................................... 13
SX1242, Rev 2, March 2011
©2011 Semtech Corp.
Page 2
www.semtech.com
SX1242
Integrated Transmitter IC
ADVANCED COMMUNICATIONS & SENSING
This product datasheet contains a detailed description of the SX1242 performance and functionality.
DATASHEET
1. General Description
The SX1242 is a fully-integrated multi-band, single chip transmitter IC capable of OOK modulation of an input data stream.
The SX1242 is configured, by default, to operate without a microcontroller at a pre-configured RF setting of 344.940 MHz.
Another key feature of the SX1242 is its low current consumption in transmit and sleep modes and its wide voltage
operating range from 1.8 V to 3.7 V. This makes the SX1242 suitable for low-cost battery chemistries or energy harvesting
applications.
The internal architecture of the SX1242 is shown in Figure 1. The SX1242 comprises a low-consumption PLL and power
amplifier. OOK Modulation is performed via ramping of the PA reference DAC.
The SX1242 is designed for use with a variety of low-cost antenna technologies including PCB-etched loop or electrically-
short stub.
Further application information may be found in Section 4.
1.1. Pin Diagram
GND
1
2
0
3
4
Figure 1. Pinouts, Top View
8
7
6
5
RFOUT
DATA
VDD
GND
TX ENABLE
XTAL
VDD
SX1242, Rev 2, March 2011
©2011 Semtech Corp.
Page 3
www.semtech.com
SX1242
Integrated Transmitter IC
ADVANCED COMMUNICATIONS & SENSING
1.2. Marking Diagram
DATASHEET
SX1242
yyww
xxxxx
Figure 2. Marking Diagram
Notes:
yyww refers to the date code
xxxxx refers to lot numbers
1.3. Pin Description
Table 1
SX1242 Pinout Description
Number
0
1
2
3
4
5
6
7
8
Name
GND
GND
DATA
GND
XTAL
VDD
TX ENABLE
VDD
RFOUT
Type
I
I
I
I
I/O
I
I
I
O
Function
Exposed Pad, Ground
Ground
Transmit Data
Ground
Reference Crystal
Power Supply, 1.8 V to 3.7 V
Control PIn for Transmitter
Power Supply, 1.8 V to 3.7 V
Transmitter RF Output
SX1242, Rev 2, March 2011
©2011 Semtech Corp.
Page 4
www.semtech.com
SX1242
Integrated Transmitter IC
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
2. Electrical Characteristics
2.1. ESD Notice
The SX1242 is a high performance radio frequency device, and satisfies Class 2 of the JEDEC
standard JESD22-A114-B (human body model) on all pins.
It should thus be handled with all necessary ESD precautions to avoid any permanent damage.
2.2. Absolute Maximum Ratings
Stresses above the values listed below may cause permanent device failure. Exposure to absolute maximum ratings for
extended periods may affect device reliability.
Table 2
Absolute Maximum Ratings
Symbol
Description
Supply Voltage
Temperature
Junction Temperature
Storage Temperature
Min
-0.5
-55
-55
-55
Max
3.9
+115
+125
150
Unit
V
°C
°C
°C
VDDmr
Tmr
Tjunc
Tstor
2.3. Operating Range
Operating ranges define the limits for functional operation and the parametric characteristics of the device as described in
this section. Functionality outside these limits is not implied.
Table 3
Operating Range
Symbol
Description
Supply voltage
Operational temperature range
Load capacitance on digital ports
Min
1.8
-40
-
Max
3.7
85
25
Unit
V
°C
pF
VDDop
Top
Clop
SX1242, Rev 2, March 2011
©2011 Semtech Corp.
Page 5
www.semtech.com
京公网安备 11010802033920号
EEWORLD
