SEMTECH SX1242ISETRT

SX1242
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
SX1242 - Low Cost Integrated Transmitter IC
344.940 MHz RF Transmitter
GENERAL DESCRIPTION
APPLICATIONS
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).
Part Number
Temperature Range
Qty. per Reel
Package
SX1242ISETRT
-40 °C to +85 °C
2500
SOIC8-EP
Pb-Free, Halogen Free, RoHS/WEEE compliant product.
DATA
GND
XTAL
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Low-Cost Consumer Electronic Applications
Remote Keyless Entry (RKE)
Remote Control / Security Systems
Audio Accessories
Process and building / home control
KEY PRODUCT FEATURES
ORDERING INFORMATION
GND
Š
Š
Š
Š
Š
Š
Š
Š
Š
Š
Š
+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
1
8
RFOUT
v
v
v
VDD
2
3
M/N
CP
PFD
7
6
TX ENABLE
VDD
4
ΣΔ
Page 1
5
v
www.semtech.com
SX1242
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
Table of contents
Section
1.
2.
Page
General Description ................................................................................................................................................. 3
1.1.
Pin Diagram ..................................................................................................................................................... 3
1.2.
Marking Diagram.............................................................................................................................................. 4
1.3.
Pin Description................................................................................................................................................. 4
Electrical Characteristics ......................................................................................................................................... 5
2.1.
ESD Notice ...................................................................................................................................................... 5
2.2.
Absolute Maximum Ratings ............................................................................................................................. 5
2.3.
Operating Range.............................................................................................................................................. 5
2.4.
Electrical Specifications ................................................................................................................................... 6
3.
Circuit Description.................................................................................................................................................... 7
4.
Application Information ............................................................................................................................................ 9
5.
6.
4.1.
Crystal Specification ........................................................................................................................................ 9
4.2.
Reference Design Schematic .......................................................................................................................... 9
4.3.
Reference Design PCB Layout ......................................................................................................................10
4.4.
Reference Design BOM .................................................................................................................................10
Packaging Information ........................................................................................................................................... 11
5.1.
Package Outline Drawing .............................................................................................................................. 11
5.2.
Land Pattern .................................................................................................................................................. 11
5.3.
Thermal Impedance ....................................................................................................................................... 12
5.4.
Tape & Reel Specification.............................................................................................................................. 12
Revision History..................................................................................................................................................... 13
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 2
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
This product datasheet contains a detailed description of the SX1242 performance and functionality.
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 electricallyshort stub.
Further application information may be found in Section 4.
1.1. Pin Diagram
GND
1
8
RFOUT
DATA
2
7
VDD
0
GND
3
6
TX ENABLE
XTAL
4
5
VDD
Figure 1. Pinouts, Top View
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 3
www.semtech.com
SX1242
Integrated Transmitter IC
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
1.2. Marking Diagram
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
Name
Type
0
GND
I
Exposed Pad, Ground
1
GND
I
Ground
2
DATA
I
Transmit Data
3
GND
I
Ground
4
XTAL
I/O
5
VDD
I
Power Supply, 1.8 V to 3.7 V
6
TX ENABLE
I
Control PIn for Transmitter
7
VDD
I
Power Supply, 1.8 V to 3.7 V
8
RFOUT
O
Transmitter RF Output
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Function
Reference Crystal
Page 4
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
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
Min
Max
Unit
VDDmr
Supply Voltage
-0.5
3.9
V
Tmr
Temperature
-55
+115
°C
Tjunc
Junction Temperature
-55
+125
°C
Tstor
Storage Temperature
-55
150
°C
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
Min
Max
Unit
VDDop
Supply voltage
1.8
3.7
V
Top
Operational temperature range
-40
85
°C
Clop
Load capacitance on digital ports
-
25
pF
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 5
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
2.4. Electrical Specifications
The table below gives the electrical specifications of the transmitter under the following conditions: Supply voltage = 3.3 V,
temperature = 25 °C, fXOSC = 26 MHz, fRF = 344.94 MHz, bit rate = 5 kbit/s and output power = +12 dBm terminated in a
matched 50 ohm impedance, unless otherwise specified.
Table 4
Symbol
Transmitter Specifications
Description
Conditions
Min
Typ
Max
Unit
-
0.5
1
µA
-
22
-
mA
0.5
-
10
kbps
-
50
-
dB
9
12
-
dBm
-
-
3
7
dB
dB
-
-
-76
-
344.94
-
MHz
26
26
26
MHz
-
-
+/-25
ppm
Current Consumption
IDDSL
Supply current in sleep mode
IDDT
Supply current in transmit mode
with appropriate external matching.
Logic “1” or “Mark” frequency transmitted*
RF and Baseband Specifications
BRO
Bit rate, OOK
OOK_B
OOK modulation depth
RFOP
RF output power into 50 ohms
DRFOPV
Variation in RF output power with
supply voltage
PHN
Transmitter phase noise
FCN
Carrier frequency
FXOSC
Crystal Oscillator Frequency
DFXOSC
Frequency Variation of the Oscillator Circuit
Permissible range
Optimized matching network
2.5 V to 3.3 V
1.8 V to 3.7 V
100 kHz Offset from carrier
No crystal contribution
dBc/Hz
Timing Specifications
TS_TR
Time from Sleep to Tx mode
-
-
2
ms
RAMP
PA Ramp up and down time**
-
20
-
us
*
Logic “1” transmission indicated by transmission of carrier frequency at power level RFOP.
**
Ramp-up time of the internal regulator turning the PA on. The typical 10% - 90% power ramp-up time is 10us
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 6
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
3. Circuit Description
The SX1242 compromises a low-consumption fractional-N Sigma-Delta type PLL and power amplifier.
A simplified block diagram of the internal architecture and application schematic is illustrated below in Figure 3
GND
DATA
GND
XTAL
1
8
RFOUT
v
v
v
VDD
2
M/N
CP
3
PFD
7
6
TX ENABLE
VDD
4
ΣΔ
5
v
Figure 3. SX1242 Simplified Block Diagram and Application Schematic
3.1. PLL
The VCO operates at twice the RF channel frequency and is derived from a 26 MHz crystal oscillator reference
3.2. Transmitter
The Power Amplifier (PA) is connected to the RFOUT pin and delivers 12 dBm in a 50 ohm load. The bit stream to be
transmitted over the air is sent to the chip via the pin DATA. During modulation, the rising and falling transitions are
smoothed with a ramp-up/ramp-down time of typically 20 μs via the PA reference DAC.
3.3. SX1242 Operating Modes
The SX1242 operating modes are defined by the status of the pin TX ENABLE and are documented in Table 5.
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 7
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
Table 5
SX1242 Operating Modes
TX Enable Status
Mode
Enabled Blocks
0 (GND)
Sleep
All blocks are off
1 (VDD)
Transmit
The blocks are switched on according to a predefined sequence and
the data is transmitted once the sequence is completed
The behavior of the SX1242 is illustrated in the timing diagram below:
TS_TR
DATA
RFOUT
TX ENABLE
TRANSMIT
SLEEP
Figure 4. SX1242 Timing Diagram(Not to scale)
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 8
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
4. Application Information
4.1. Crystal Specification
The SX1242 is designed to operate with a low-cost 26 MHz crystal. The recommended crystal specification is tabulated
below in Table 6.
Table 6
SX1242 Quartz Crystal Reference Oscillator Specification
Symbol
Description
FXOSC
Crystal Frequency
LM
Conditions
Min
Typ
Max
Unit
26
26
26
MHz
Crystal Motional Inductance
-
12.655
-
mH
CM
Crystal Motional Capacitance
-
2.962
-
fF
RS
Crystal Serial Resistance
-
20
100
Ohms
C0
Crystal Shunt Capacitance
-
1.0
7.0
pF
CL
Load Capacitance
-
15
-
pF
4.2. Reference Design Schematic
C5
C11
C6
POD_INI
1
2
3
TX EN
VDD
DATA
GND
NC
4 NC
NC
8
7
6
NC 5
1
2
3
GND
TX EN
L3
C3
C12
C4
VDD 7
DATA
4 XTAL
C2
L2
U1 SX1242
8
GND RFOUT
C8
L1
6
VDD 5
C7
Q1
VDD
C10
Figure 5. Application Module Schematic
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 9
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
4.3. Reference Design PCB Layout
The SX1242 reference design PCB layout is illustrated below:
Figure 6. Reference Design PCB Layout
4.4. Reference Design BOM
The following table summarizes the reference design BOM:
Table 7
Reference Design BOM
Re fDe s
U1
Q1
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
L1
L2
L3
MPN
SX1242ISETRT
LQG15- or equivalent
LQG15- or equivalent
LQG15- or equivalent
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Pa ckage
SO8
HC49
0402
0402
0402
0402
0402
0402
0402
0402
0402
0402
0402
0402
0402
Va lue
SX1242
26 MHz
100pF
12pF
100nF
100pF
4.7pF
12pF
2.2pF
100nF
1uF
Zero ohm
120nH
39nH
22n
Page 10
Qty
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
De scription
RF transmitter IC
Crystal 26 MHz CL=15 pF
Capacitor NPO (+/-5% )
Capacitor NPO (+/-5% )
Capacitor X7R (+/-5% )
Capacitor NPO (+/-5% )
Capacitor NPO (+/-0.25pF)
Capacitor NPO (+/-5% )
Capacitor NPO (+/-0.25pF)
Capacitor X7R (+/-5% )
Capacitor X5R (+/-5% )
Resistor Zero Ohm
Multilayer chip inductor (+/-5% )
Multilayer chip inductor (+/-5% )
Multilayer chip inductor (+/-5% )
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
5. Packaging Information
The SX1242 is delivered in an SOIC package with 8 leads and an exposed pad. See details below.
5.1. Package Outline Drawing
A
D
e
N
DIM
2X E/2
A
A1
A2
b
c
D
E1
E
e
F
H
h
L
L1
N
01
aaa
bbb
ccc
E1 E
1
2
ccc C
2X N/2 TIPS
e/2
B
D
aaa C
A2 A
SEATING
PLANE
C
A1
bxN
bbb
DIMENSIONS
INCHES
MILLIMETERS
MIN NOM MAX MIN NOM MAX
.053
.069
.000
.005
.049
.065
.012
.020
.007
.010
.189 .193 .197
.150 .154 .157
.236 BSC
.050 BSC
.086
.130
.085
.099
.010
.020
.016 .028 .041
(.041)
8
0°
8°
.004
.010
.008
1.75
1.35
0.00
0.13
1.25
1.65
0.31
0.51
0.17
0.25
4.80 4.90 5.00
3.80 3.90 4.00
6.00 BSC
1.27 BSC
2.19
3.30
2.15
2.51
0.25
0.50
0.40 0.72 1.04
(1.05)
8
0°
8°
0.10
0.25
0.20
C A-B D
h
F
EXPOSED PAD
h
H
H
c
GAGE
PLANE
0.25
SEE DETAIL
L
(L1)
DETAIL
A
01
A
SIDE VIEW
NOTES:
1.
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS
OR GATE BURRS.
Figure 7. Package Outline Drawing
5.2. Land Pattern
E
SOLDER MASK
D
DIM
(C)
F
G
Z
Y
THERMAL VIA
Ø 0.36mm
P
X
DIMENSIONS
INCHES
MILLIMETERS
C
D
E
F
G
P
X
Y
Z
(.205)
.134
.201
.101
.118
.050
.024
.087
.291
(5.20)
3.40
5.10
2.56
3.00
1.27
0.60
2.20
7.40
NOTES:
1.
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
3. REFERENCE IPC-SM-782A, RLP NO. 300A.
4. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD
SHALL BE CONNECTED TO A SYSTEM GROUND PLANE.
FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR
FUNCTIONAL PERFORMANCE OF THE DEVICE.
Figure 8. Land Pattern
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 11
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
5.3. Thermal Impedance
The thermal impedance of this package is: Theta ja = 36° C/W typ., calculated from a package in still air, on a 4-layer FR4
PCB, as per the Jedec standard.
5.4. Tape & Reel Specification
Carrier Tape
Tape
Width
(W)
12
+/-0.30
Pocket
Pitch
(P)
8
+/-0.10
Reel
Ao / Bo
Ko
Reel
Size
Reel
Width
Min.
Trailer
Length
Min.
Leader
Length
QTY
per
Unit
6.5 / 5.4
+/-0.30
2.00
+/-0.15
330.2
12.4
400
400
2500
mm
Figure 9. Tape & Reel Specification
Note
Single Sprocket Holes
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 12
www.semtech.com
SX1242
Integrated Transmitter IC
DATASHEET
ADVANCED COMMUNICATIONS & SENSING
6. Revision History
Table 8
Revision History
Revision
Date
1
November 2010 First FINAL datasheet version
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Comment
Page 13
www.semtech.com
SX1242
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
© Semtech 2010
All rights reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The
information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable
and may be changed without notice. No liability will be accepted by the publisher for any consequence of its use. Publication
thereof does not convey nor imply any license under patent or other industrial or intellectual property rights. Semtech assumes
no responsibility or liability whatsoever for any failure or unexpected operation resulting from misuse, neglect improper
installation, repair or improper handling or unusual physical or electrical stress including, but not limited to, exposure to
parameters beyond the specified maximum ratings or operation outside the specified range.
SEMTECH PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED OR WARRANTED TO BE SUITABLE FOR USE IN
LIFE-SUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF
SEMTECH PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE UNDERTAKEN SOLELY AT THE CUSTOMER’S
OWN RISK. Should a customer purchase or use Semtech products for any such unauthorized application, the customer shall
indemnify and hold Semtech and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims,
costs damages and attorney fees which could arise.
Contact information
Semtech Corporation Advanced Communications & Sensing Products
E-mail: [email protected]@semtech.comInternet: http://www.semtech.com
USA
200 Flynn Road, Camarillo, CA 93012-8790.
Tel: +1 805 498 2111 Fax: +1 805 498 3804
FAR EAST
12F, No. 89 Sec. 5, Nanking E. Road, Taipei, 105, TWN, R.O.C.
Tel: +886 2 2748 3380 Fax: +886 2 2748 3390
EUROPE
Semtech Ltd., Units 2 & 3, Park Court, Premier Way, Abbey Park Industrial Estate, Romsey, Hampshire, SO51 9DN.
Tel: +44 (0)1794 527 600 Fax: +44 (0)1794 527 601
ISO9001
CERTIFIED
SX1242, Rev 1, November 2010
©2010 Semtech Corp.
Page 14
www.semtech.com