TX 98-4
ASK Transmitter
Data Sheet
Revision 1.0, 2010-04-23
Wireless Sense & Control
Edition 2010-04-23
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2010 Infineon Technologies AG
All Rights Reserved.
Legal Disclaimer
The information given in this document shall in no event be regarded as a guarantee of conditions or
characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any
information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties
and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights
of any third party.
Information
For further information on technology, delivery terms and conditions and prices, please contact the nearest
Infineon Technologies Office (www.infineon.com).
Warnings
Due to technical requirements, components may contain dangerous substances. For information on the types in
question, please contact the nearest Infineon Technologies Office.
Infineon Technologies components may be used in life-support devices or systems only with the express written
approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure
of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support
devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain
and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may
be endangered.
TX 98-4
TX 98-4 ASK Transmitter
Revision History: 2010-04-23, Revision 1.0
Previous Revision: none
Page
Subjects (major changes since last revision)
Trademarks of Infineon Technologies AG
A-GOLD™, BlueMoon™, COMNEON™, CONVERGATE™, COSIC™, C166™, CROSSAVE™, CanPAK™,
CIPOS™, CoolMOS™, CoolSET™, CONVERPATH™, CORECONTROL™, DAVE™, DUALFALC™, DUSLIC™,
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EUPEC™, ELIC™, EPIC™, FALC™, FCOS™, FLEXISLIC™, GEMINAX™, GOLDMOS™, HITFET™,
HybridPACK™, INCA™, ISAC™, ISOFACE™, IsoPACK™, IWORX™, M-GOLD™, MIPAQ™, ModSTACK™,
MUSLIC™, my-d™, NovalithIC™, OCTALFALC™, OCTAT™, OmniTune™, OmniVia™, OptiMOS™,
OPTIVERSE™, ORIGA™, PROFET™, PRO-SIL™, PrimePACK™, QUADFALC™, RASIC™, ReverSave™,
SatRIC™, SCEPTRE™, SCOUT™, S-GOLD™, SensoNor™, SEROCCO™, SICOFI™, SIEGET™,
SINDRION™, SLIC™, SMARTi™, SmartLEWIS™, SMINT™, SOCRATES™, TEMPFET™, thinQ!™,
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X-PMU™, XPOSYS™, XWAY™.
Other Trademarks
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COLOSSUS™, FirstGPS™ of Trimble Navigation Ltd. EMV™ of EMVCo, LLC (Visa Holdings Inc.). EPCOS™ of
Epcos AG. FLEXGO™ of Microsoft Corporation. FlexRay™ is licensed by FlexRay Consortium.
HYPERTERMINAL™ of Hilgraeve Incorporated. IEC™ of Commission Electrotechnique Internationale. IrDA™ of
Infrared Data Association Corporation. ISO™ of INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.
MATLAB™ of MathWorks, Inc. MAXIM™ of Maxim Integrated Products, Inc. MICROTEC™, NUCLEUS™ of
Mentor Graphics Corporation. Mifare™ of NXP. MIPI™ of MIPI Alliance, Inc. MIPS™ of MIPS Technologies, Inc.,
USA. muRata™ of MURATA MANUFACTURING CO. OmniVision™ of OmniVision Technologies, Inc.
Openwave™ Openwave Systems Inc. RED HAT™ Red Hat, Inc. RFMD™ RF Micro Devices, Inc. SIRIUS™ of
Sirius Sattelite Radio Inc. SOLARIS™ of Sun Microsystems, Inc. SPANSION™ of Spansion LLC Ltd. Symbian™
of Symbian Software Limited. TAIYO YUDEN™ of Taiyo Yuden Co. TEAKLITE™ of CEVA, Inc. TEKTRONIX™
of Tektronix Inc. TOKO™ of TOKO KABUSHIKI KAISHA TA. UNIX™ of X/Open Company Limited. VERILOG™,
PALLADIUM™ of Cadence Design Systems, Inc. VLYNQ™ of Texas Instruments Incorporated. VXWORKS™,
WIND RIVER™ of WIND RIVER SYSTEMS, INC. ZETEX™ of Diodes Zetex Limited.
Last Trademarks Update 2009-10-19
Data Sheet
3
Revision 1.0, 2010-04-23
TX 98-4
Table of Contents
Table of Contents
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1
1.1
1.2
1.3
Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
2.1
2.2
2.3
2.4
2.4.1
2.4.2
2.4.3
2.4.4
2.4.4.1
2.4.4.2
2.4.4.3
2.4.4.4
2.4.5
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin Definition and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Functional Block Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
PLL Synthesizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Crystal Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
PLL Enable Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Transmit Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Power mode control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Recommended Timing Diagrams for ASK-Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3
3.1
3.2
3.3
Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Application Hints on the Crystal Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Hints on the Clock Output (CLKOUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Application Hints on the Power-Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
13
13
14
4
4.1
4.1.1
4.2
4.3
4.3.1
Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC/DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC/DC Characteristic at 3 V, 25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16
16
16
16
17
17
5
Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Data Sheet
4
5
5
5
5
Revision 1.0, 2010-04-23
TX 98-4
Product Description
1
Product Description
1.1
Overview
The TX 98-4 is a single chip ASK transmitter for operation in the frequency band from 433 to 435 MHz. The IC
offers a high level of integration and needs only a few external components. The device contains a fully integrated
PLL synthesizer and a high efficiency power amplifier to drive a loop antenna. A special circuit design and an
unique power amplifier design are used to save current consumption and therefore to save battery life. Additional
features are a power down mode and a divided clock output.
1.2
•
•
•
•
•
•
•
•
•
•
•
•
Features
Frequency range 433 ... 435 MHz
Low supply current
Power down mode
High efficiency power amplifier (typically 10 dBm)
Fully integrated frequency synthesizer
VCO without external components
ASK modulation
Voltage supply range 2.1... 4 V
Low external component count
Divided clock output for µC
Temperature range -40... +85°C
Crystal oscillator 13.56 MHz
1.3
Application
TX 98-4 is suitable for any kind of remote control system, especially for low data rate wireless applications where
low current consumption is important and where the line-of-sight limitation is driving the infra-red to RF
replacement.
Main applications:
•
•
•
•
Home Automation
- Lighting Control
- Curtain, Roller Blind Control
- Air Condition Control
Garage Door Openers
Wireless Toys
Remote Keyless Entry Systems
TX 98-4 is defined and qualified to meet low-cost consumer product requirements.
Data Sheet
5
Revision 1.0, 2010-04-23
TX 98-4
Product Description
1.4
Ordering Information
Table 1
Order Information
Type
Package1)
Ordering Code
TX 98-4
SP000743714
1) Available on tape and reel
Data Sheet
PG-TSSOP-10
6
Revision 1.0, 2010-04-23
TX 98-4
Functional Description
2
Functional Description
2.1
Pin Configuration
CLKOUT
1
10
PDWN
VS
2
9
PAOUT
GND
3
8
PAGND
N.U.1
4
7
N.U.2
COSC
5
6
ASKDTA
TX 98-4
Figure 1
IC Pin Configuration
2.2
Pin Definition and Functions
Table 2
Pin Definition and Functions - Overview
Pin No.
Symbol
Function
1
CLKOUT
Clock Driver Output (847.5 kHz)
2
VS
Voltage Supply
3
GND
Ground
4
N.U.1
Not used 1
5
COSC
Crystal Oscillator Input (13.56 MHz)
6
ASKDTA
Amplitude Shift Keying Data Input
7
N.U.2
Not used 2
8
PAGND
Power Amplifier Ground
9
PAOUT
Power Amplifier Output (434 MHz)
10
PDWN
Power Down Mode Control
Data Sheet
6
Revision 1.0, 2010-04-23
TX 98-4
Functional Description
Table 3
Pin Definition and Function
Ball No.
Name
1
CLKOUT
Pin
Type
Buffer Type
Function
Clock output to supply an external device
An external pull-up resistor has to be added
in accordance to the driving requirements of
the external device.
The clock frequency is 847.5 kHz.
VS
1
300 Ω
2
VS
This pin is the positive supply of the
transmitter electronics
An RF bypass capacitor should be
connected directly to this pin and returned to
GND (pin 3) as short as possible.
3
GND
General ground connection
4
N.U.1
This pin must be left open
5
COSC
VS
This pin is connected to the reference
oscillator circuit
The reference oscillator is working as a
negative impedance converter. It presents a
negative resistance in series to an
inductance at the COSC pin.
VS
6 kΩ
5
100 μA
6
ASKDTA
VS
+1.2 V
60 kΩ
6
+1.1 V
90 kΩ
2.3 pF
7
30 μA
N.U.2
Data Sheet
Digital amplitude modulation can be
imparted to the Power Amplifier through
this pin
A logic high (ASKDTA > 1.5 V or open)
enables the Power Amplifier.
A logic low (ASKDTA < 0.5 V) disables the
Power Amplifier.
This pin must be left open
7
Revision 1.0, 2010-04-23
TX 98-4
Functional Description
Table 3
Pin Definition and Function (cont’d)
Ball No.
Name
8
PAGND
Pin
Type
Buffer Type
Function
Ground connection of the power amplifier
The RF ground return path of the power
amplifier output PAOUT (pin 9) has to be
concentrated to this pin.
9
9
PAOUT
RF output pin of the transmitter
A DC path to the positive supply VS has to be
supplied by the antenna matching network.
8
10
PDWN
VS
40 μA ∗ (ASKDT)
5 kΩ
10
Disable pin for the complete transmitter
circuit
A logic low (PDWN < 0.7 V) turns off all
transmitter functions.
A logic high (PDWN > 1.5 V) gives access to
all transmitter functions.
"ON"
150 kΩ
250 kΩ
Data Sheet
8
Revision 1.0, 2010-04-23
Data Sheet
Crystal
13.56 MHz
5
9
Ground
Clock
Output
LF
VCO
3
:64
1
:16
PFD
XTAL
Osc
Power
Supply
:2
Power
AMP
On
6
Power
Am plifier
Output
Power
Am plifier
Ground
9
8
Functional Block Diagram
2
Figure 2
10
ASK
Data
Input
Functional Block Diagram
7
N.U.2
Power
Supply
VS
2.3
4
N.U.1
Power
Down
Control
TX 98-4
Functional Description
Revision 1.0, 2010-04-23
TX 98-4
Functional Description
2.4
Functional Block Description
2.4.1
PLL Synthesizer
The Phase Locked Loop synthesizer consists of a Voltage Controlled Oscillator (VCO), an asynchronous divider
chain, a phase detector, a charge pump and a loop filter. It is fully implemented on chip. The tuning circuit of the
VCO consisting of spiral inductors and varactor diodes is on chip, too. Therefore no additional external
components are necessary. The nominal center frequency of the VCO is 868 MHz. The oscillator signal is fed both,
to the synthesizer divider chain and (via 1:2 divider) to the power amplifier. The overall division ratio of the
asynchronous divider chain is 64. The phase detector is a Type IV PD with charge pump. The passive loop filter
is realized on chip.
2.4.2
Crystal Oscillator
The crystal oscillator operates at 13.56 MHz.
The crystal frequency is divided by 16. The resulting 847.5 kHz are available at the clock output CLKOUT (pin1)
to drive the clock input of a micro controller.
2.4.3
Power Amplifier
The VCO frequency is divided by 2 and fed to the Power Amplifier.
The Power Amplifier can be switched on and off by the signal at ASKDTA (pin 6).
Table 4
ASKDTA - Power Amplifier
ASKDTA (pin6)
Low
1)
Power Amplifier
OFF
2)
3)
Open , High
1) Low: Voltage at pin < 0.5 V
ON
2) Open: Pin open
3) High: Voltage at pin > 1.5 V
The Power Amplifier has an Open Collector output at PAOUT (pin 9) and requires an external pull-up coil to
provide bias. The coil is part of the tuning and matching LC circuitry to get best performance with the external loop
antenna. To achieve the best power amplifier efficiency, the high frequency voltage swing at PAOUT (pin 9) should
be twice the supply voltage.
The power amplifier has its own ground pin PAGND (pin 8) in order to reduce the amount of coupling to the other
circuits.
2.4.4
Power Modes
The IC provides three power modes, the POWER DOWN MODE, the PLL ENABLE MODE and the TRANSMIT
MODE.
2.4.4.1
Power Down Mode
In the POWER DOWN MODE the complete chip is switched off.
The current consumption is typically 0.3 nA @ 3 V and 25°C.
This current doubles every 8°C. The values for higher temperatures is typically 14 nA @ 85°C.
Data Sheet
10
Revision 1.0, 2010-04-23
TX 98-4
Functional Description
2.4.4.2
PLL Enable Mode
In the PLL ENABLE MODE the PLL is switched on but the power amplifier is turned off to avoid undesired power
radiation during the time the PLL needs to settle. The turn on time of the PLL is determined mainly by the turn on
time of the crystal oscillator and is less than 1 msec when the specified crystal is used.
The current consumption is typically 4mA.
2.4.4.3
Transmit Mode
In the TRANSMIT MODE the PLL is switched on and the power amplifier is turned on too.
The current consumption of the IC is typically 14.2 mA when using a proper transforming network at PAOUT, see
Figure 3.
2.4.4.4
Power mode control
The bias circuitry is powered up via a voltage V > 1.5 V at the pin PDWN (pin10).
When the bias circuitry is powered up, the pin ASKDTA is pulled up internally.
Forcing the voltage at the pins low overrides the internally set state.
The principle schematic of the power mode control circuitry is shown in Figure 3
PDWN
ASKDTA
On
Bias Voltage
Bias
Source
120 kΩ
On
434
MHz
PLL
PA
PAOUT
IC
Figure 3
Power mode control circuitry
Table 5 provides a listing of how to get into the different power modes
Table 5
PDWN
Power Modes
ASKDTA
MODE
Low, Open
POWER DOWN
Low
POWER DOWN
High
Low
PLL ENABLE
Open
High
TRANSMIT
Low
1)
2)
Open
3)
High
Open, High
TRANSMIT
1) Low: Voltage at pin < 0.7 V (PDWN), Voltage at pin < 0.5 V (ASKDTA)
2) Open: Pin open
3) High: Voltage at pin > 1.5 V
Data Sheet
11
Revision 1.0, 2010-04-23
TX 98-4
Functional Description
Other combinations of the control pins PDWN and ASKDTA are not recommended.
To avoid spurious radiation it is strongly recommended to switch not directly from PDWN-mode to TRANSMITmode, but to PLL-ENABLE-mode first!
2.4.5
Recommended Timing Diagrams for ASK-Modulation
Modes:
Power Down
PLL Enable
Transmit
High
PDWN
Low
to
t
DATA
Open, High
ASKDTA
Low
to
t
min. 1 msec.
Figure 4
Data Sheet
ASK Modulation
12
Revision 1.0, 2010-04-23
TX 98-4
Application
3
Application
3.1
Application Hints on the Crystal Oscillator
The crystal oscillator achieves a turn on time less than 1 msec when the specified crystal is used. To achieve this,
a NIC oscillator type is implemented in the TX 98-4. The input impedance of this oscillator is a negative resistance
in series to an inductance. Therefore the load capacitance of the crystal CL (specified by the crystal supplier) is
transformed to the capacitance Cv.
-R
L
f, CL
Cv
IC
Figure 5
Cv =
Application Hints
1
1
+ ω 2L
CL
(1)
CL
Crystal load capacitance for nominal frequency
ω
Angular frequency
L
Inductance of the crystal oscillator
Example
The inductance L at 13.56 MHz is about 4.6 μH. Assuming a crystal frequency of 13.56 MHz and a crystal load
capacitance of CL = 12 pF, the value of Cv is calculated to ~ 8,6 pF.
C v =
1
1
+ ω
C L
2
L
(2)
3.2
Design Hints on the Clock Output (CLKOUT)
The CLKOUT pin is an open collector output. An external pull up resistor (RL) should be connected between this
pin and the positive supply voltage. The value of RL is depending on the clock frequency and the load capacitance
CLD (PCB board plus input capacitance of the micro controller). RL can be calculated to:
RL =
1
fCLKOUT * 8 * CLD
Data Sheet
(3)
13
Revision 1.0, 2010-04-23
TX 98-4
Application
Table 6
Clock Output fCLKOUT=847.5 kHz
CL[pF]
RL[kOhm]
5
27
10
12
20
6.8
Note: To achieve a low current consumption and a low spurious radiation, the largest possible RL should be
chosen.
Even harmonics of the signal at CLKOUT can interact with the crystal oscillator input COSC preventing the startup of oscillation. Care must be taken in layout by sufficient separation of the signal lines to ensure sufficiently small
coupling.
3.3
Application Hints on the Power-Amplifier
The power amplifier operates in a high efficient class C mode. This mode is characterized by a pulsed operation
of the power amplifier transistor at a current flow angle of Θ
