SX1223
SX1223
425 – 475 MHz / 850 – 950 MHz
Integrated UHF Transmitter
GENERAL DESCRIPTION
The SX1223 is a single chip transmitter operating in
UHF frequency bands including the 434, 869 and 915
MHz license-free ISM (Industrial Scientific and
Medical) bands. Its highly integrated architecture
allows for minimum external components while
maintaining design flexibility. All major RF
communication parameters are programmable and
most of them can be set dynamically. The SX1223
offers the advantage of high data rate communication
at rates of up to 153.6 kbit/s. The SX1223 is
optimized for low cost applications while offering high
RF output power. The device is suitable for
applications which have to satisfy either the European
(ETSI-300-220) or the North American (FCC part 15)
regulatory standards.
KEY PRODUCT FEATURES
•
•
•
•
•
•
•
RF output power: up to +10 dBm
Low power consumption:
T
X
= 25.8 mA @ 10 dBm (typical)
Supply voltage down to 2.0 V
Data rate from 1.2 to 153.6 kbit/s
On-chip frequency synthesizer
Continuous phase 2-level FSK modulation
Very small RoHS green package (TQFN24, 4mm
x 4mm)
ORDERING INFORMATION
Part number
SX1223I073TRT
(1)
(1)
Temperature
range
-40 ° to +85 °
C
C
Package
TQFN24
APPLICATIONS
•
•
•
Automated Meter Reading (AMR)
Home Automation and Access Control
High-Quality Speech, Music and Data over RF
TR refers to tape & reel.
T refers to Lead Free package.
This device is WEEE and RoHS compliant.
Rev 5 May 2007
www.semtech.com
SX1223
Table of Contents
1
2
3
3.1
3.2
3.2.1
3.2.2
4
4.1
4.1.1
4.1.2
4.1.3
4.1.4
4.1.5
4.1.6
4.2
4.2.1
4.2.2
4.2.3
4.2.4
4.2.5
4.2.6
4.2.7
4.2.8
4.3
4.4
5
5.1
5.2
5.2.1
5.2.2
5.2.3
6
6.1
6.2
6.3
6.4
6.5
7
Functional Block Diagram .................................................................................................................. 3
Pin description..................................................................................................................................... 4
Electrical Characteristics.................................................................................................................... 5
Absolute Maximum Operating Ranges.................................................................................................. 5
Specifications ........................................................................................................................................ 5
Operating Range ................................................................................................................................... 5
Electrical Specifications......................................................................................................................... 5
General description............................................................................................................................. 7
Frequency synthesizer........................................................................................................................... 7
General Structure .................................................................................................................................. 7
Crystal Oscillator ................................................................................................................................... 8
VCO....................................................................................................................................................... 8
Charge Pump ...................................................................................................................................... 10
Loop Filter............................................................................................................................................ 10
Lock Detect.......................................................................................................................................... 11
Modulator............................................................................................................................................. 11
Introduction.......................................................................................................................................... 11
Data Interface ...................................................................................................................................... 11
Bit Rate Setting for MW1 and MW2 .................................................................................................... 12
Deviation Setting for MW1 and MW2 .................................................................................................. 12
Shaping for MW1 and MW2 ................................................................................................................ 13
Modulator Saturation for MW1 and MW2............................................................................................ 13
Summary of Modulator Settings for MW1 and MW2........................................................................... 13
Frequency deviation setting for MW3.................................................................................................. 13
Power Amplifier ................................................................................................................................... 14
Voltage regulators ............................................................................................................................... 14
Serial Interface definition and Principles of operation .................................................................. 15
Serial Control Interface........................................................................................................................ 15
Configuration and Status registers ...................................................................................................... 16
Operating Modes ................................................................................................................................. 16
Other Settings...................................................................................................................................... 17
Optional and Test Parameters ............................................................................................................ 19
Application Information .................................................................................................................... 21
Matching network of the transmitter .................................................................................................... 21
Reference crystal for the frequency synthesizer ................................................................................. 22
Loop filter components ........................................................................................................................ 22
Recommended modulation conditions ................................................................................................ 22
TYPICAL APPLICATION SCHEMATICS ............................................................................................ 23
Packaging information...................................................................................................................... 24
© Semtech 2007
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2
SX1223
The SX1223 is a single chip transmitter operating in the 433, 868 and 915MHz license free ISM (Industrial Scientific
and Medical) frequency bands; the frequency range is selectable between 425-475 MHz and 850-950 MHz. The
modulation scheme is 2-FSK. The circuit has 4 functional modes: sleep mode, where all the blocks are switched off,
standby mode, where only the crystal oscillator is on, synthesizer mode, where the frequency synthesizer is running,
and transmission mode, where all the blocks are on, including the power amplifier. It complies with European (ETSI
EN 300-220-1) and North American (FCC part 15) regulations.
There are three different methods of modulation:
- (mw1) pulling the VCO in closed loop: all the specified bit rates can be implemented, but a DC-free coding
scheme is needed (e.g. Manchester), which means that the real information rate is half the bit rate,
- (mw2) pulling the VCO in open loop: all the specified bit rates can be implemented, and NRZ coding is
allowed; but, since the control voltage of the VCO will drift due to leakage currents, the duration of the
transmission is limited,
- (mw3) switching between two frequency divider ratios in closed loop; bit rates from 1.2 to 19.2 kbit/s are
achievable with this method.
The circuit works on two selectable supply voltage ranges:
- (sv1) the high range (2.2 V to 3.6 V), where the on-chip regulators are activated,
- (sv2) the low range (2.0 V to 2.5 V), where the on-chip regulators are off.
A 3-wire bi-directional bus is used to communicate with SX1223 and gives access to the configuration register. An
output clock of 1 MHz is user selectable for driving an external micro-controller.
SX1223 comes in a RoHS green TQFN-24 package (body size: 4 mm x 4 mm).
1
FUNCTIONAL BLOCK DIAGRAM
CRYSTAL
LOOP FILTER
VDDF
XTA
XTB
LD
CPOUT
VARIN
OSCILLATOR
LOCK
DETECT
VDD
SO
LDO
CLOCK
GEN
LDO
M
PFD
PFD
Open Loop
OPAMP
DATA & CONTROL INTERFACE
÷
SI
EN
SCK
VDDP
÷
N,A
N,A
÷
2
2
÷
2
2
MOD
BIAS
LDO
VCO
RFOUT
PA
VCO
DATAIN
DCLK
CLKOUT
SX1223
VDDD
VDD
Figure 1: SX1223 block diagram
© Semtech 2007
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3
SX1223
2
PIN DESCRIPTION
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Name
VDD
VSSP
VDDP
RFOUT
VSSP
PTATBIAS/PAC
XTB
XTA
VDDD
VSSD
VDD
LD
CLKOUT
DCLK
DATAIN
SCK
EN
SI
SO
CPOUT
VARIN
VSSF
VDDF
CIBIAS
I/O
-
-
-
OUT
-
IN/OUT
IN/OUT
IN/OUT
-
-
-
OUT
OUT
OUT
IN
IN
IN
IN
OUT
OUT
IN
-
-
OUT
Function
Main analog power supply
Max 3.6V in sv1-mode
Max 2.5V in sv2-mode
PA ground
In sv1-mode: PA LDO output, capacitor needed
In sv2-mode: PA power supply, max 2.5 V
RF output
PA ground
PTAT source bias resistor / PA start-up control capacitor
Crystal oscillator pin & input for external reference
Crystal oscillator pin
In sv1-mode: Digital LDO output, capacitor needed
In sv2-mode: Digital power supply, max 2.5V
Digital ground
Main digital power supply
Max 3.6V in sv1-mode
Max 2.5V in sv2-mode
Lock detect output
Output clock (1 MHz)
Data clock output
Data input
3-wire interface clock input
Enable signal for the 3-wire interface
3-wire interface data input
3-wire interface data output
PLL charge pump output
VCO varactor input
Analog ground
In sv1-mode: Analog LDO output, capacitor needed
In sv2-mode: Analog power supply max 2.5 V
CI source bias resistor
Note: Thermal Pad on the bottom of the package must be connected to ground.
Thermal
Pad
24
1
bottom view
© Semtech 2007
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4
SX1223
3
ELECTRICAL CHARACTERISTICS
3.1
ABSOLUTE MAXIMUM OPERATING RANGES
Stresses above the values listed below may cause permanent device failure. Exposure to absolute maximum
ratings for extended periods may affect device reliability.
Symbol
VDDmax
Tmax
Description
Supply voltage
Storage temperature
Min.
-0.4
-55
Max.
3.9
125
Unit
V
°
C
The device is ESD sensitive and should be handled with precaution.
3.2
3.2.1
SPECIFICATIONS
Operating Range
Description
Supply voltage (*)
Temperature
Load capacitance on digital ports
Min.
2.0
-40
-
Max.
3.6
85
25
Unit
V
°
C
pF
Symbol
VDD
T
CLop
(*) Divided in two ranges:
- (sv1) high range, 2.2 V – 3.6 V, using on-chip regulators,
- (sv2) low range, 2.0 V – 2.5 V, without using the regulators.
3.2.2
Electrical Specifications
The table below gives the electrical specifications of the transmitter under the following conditions:
Supply Voltage = 3.3 V, temperature = 25 ° 2-leve l FSK, fc = 915 MHz, Output power = 10 dBm, Bit rate = 38.4
C,
kb/s,
∆f
= 100 kHz, XTAL = 16 MHz, modulation by pulling the VCO in open loop (mw2), and conditions as defined
in section 6, unless otherwise specified.
Symbol
IDDSL
IDDST
IDDFS
IDDT
FR
FDA
FDA_L
∆FDA
BR
BR_3
SPICLK
© Semtech 2007
Description
Supply current in sleep
mode
Supply current in standby
mode
Supply current in FS mode
Supply current during
transmission
Frequency range
Frequency deviation
Frequency deviation
Variation of frequency
deviation
Bit rate
Bit rate for mw3 mode
SPI clock frequency (SCK)
Conditions
Min
-
Typ
0.3
0.2
5
25.8
14
-
-
-
-
-
-
-
Max
1
0.3
6
-
-
475
950
255
200
+ 15
153.6
19.2
1
Unit
µA
mA
mA
mA
mA
MHz
MHz
kHz
kHz
%
kbit/s
kbit/s
MHz
Crystal oscillator running,
CLKOUT off
Frequency synthesizer
running
10 dBm
0dBm
-
-
-
-
425
850
For FR from 850 to 950 MHz
For FR from 425 to 475 MHz
5
5
- 15
Modulation modes mw1 mw2
Modulation mode mw3
SCK duty cycle 50% +/-10%
1.2
1.2
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5
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