RFM products are now
Murata products.
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TX5003 (R) 4/24/15 Page 1 of 6 www.murata.com
• Designed for Short-Range Wireless Data Communications
• Supports RF Data Transmission Rates Up to 115.2 kbps
• 3 V, Low Current Operation plus Sleep Mode
• Stable, Easy to Use, Low External Parts Count
• Complies with Directive 2002/95/EC (RoHS)
The TX5003 hybrid transmitter is ideal for short-range wireless data applications where robust
operation, small size, low power consumption and low cost are required. All critical RF functions
are contained in the hybrid, simplifying and speeding design- in. The TX5003 includes provisions
for both on-off keyed (OOK) and amplitude-shift keyed (ASK) modulation. The TX5003 employs
SAW filtering to suppress output harmonics, facilitating compliance with FCC Part 15 and similar
regulations.
Absolute Maximum Ratings
Rating Value Units
Power Supply and All Input/Output Pins -0.3 to +4.0 V
Non-Operating Case Temperature -50 to +100 °C
Soldering Temperature (10 seconds / 5 cycles max.) 260 °C
303.825 MHz
Hybrid Transmitter
TX5003
SM-20L Case
Electrical Characteristics
Characteristic Sym Notes Minimum Typical Maximum Units
Operating Frequency fo303.625 304.025 MHz
Modulation Types OOK & ASK
OOK Data Rate 10 kbps
ASK Data Rate 115.2 kbps
Transmitter Performance
Peak RF Output Power, 250 µA TXMOD Current PO1.5 dBm
Peak Current, 250 µA TXMOD Current ITP 9.5 mA
OOK Turn On/Turn Off Times tON/tOFF 20/15 µs
ASK Output Rise/Fall Times tTR/tTF 1.1/1.1 µs
2nd - 4th Harmonic Outputs -50 dBm
5th - 10th Harmonic Outputs -55 dBm
Non-harmonic Spurious Outputs -50 dBm
Sleep Mode Current IS0.7 µA
Sleep to Transmit Switch Time tTOR 21 µs
Transmit to Sleep Switch Time tRTO 15 µs
Control Input Logic Low Level 200 mV
Control Input Logic High Level 1 Vcc - 300 mV
Power Supply Voltage Range VCC 2.2 3.7 Vdc
Operating Ambient Temperature TA-40 +85 °C
©2010-2015 by Murata Electronics N.A., Inc.
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1. Do not allow the voltage applied to a control input pin to exceed Vcc + 200 mV.
2. The companion receiver to the TX5003 is the RX5003. Please see RFM’s web site at www.rfm.com for details.
Transmitter Set-Up, 3.0 Vdc, -40 to +85 °C
Item Symbol OOK ASK ASK Units Notes
Nominal NRZ Data Rate DRNOM 2.4 19.2 115.2 kbps see page 1
Minimum Signal Pulse SPMIN 416.67 52.08 8.68 µs single bit
Maximum Signal Pulse SPMAX 1666.68 208.32 34.72 µs 4 bits of same value
TXMOD Resistor RTXM 8.2 8.2 8.2 K ±5%, for 0 dBm output
DC Bypass Capacitor CDCB 4.7 4.7 4.7 µF tantalum
RF Bypass Capacitor 1 CRFB1 27 27 27 pF ±5% NPO
RF Bypass Capacitor 2 CRFB2 100 100 100 pF ±5% NPO
RF Bypass Bead LRFB Fair-Rite Fair-Rite Fair-Rite vendor 2506033017YO or equivalent
Series Tuning Inductor LAT 82 82 82 nH 50 ohm antenna
Shunt Tuning/ESD Inductor LESD 33 33 33 nH 50 ohm antenna
Modulation Input
TOP VIEW
GND
3
CNT
RL0
CNT
RL1
P
WIDTH
P
RATE
THLD
1
THLD
2
RREF
GND2
TX
MOD
RX
DATA
LPF
ADJ
CMP
IN
BB
OUT
PK
DET
AGC
CAP
VCC
1
VCC
2
RFIO
GND1
+ 3
VDC
Transmitter OOK Configuration
1
20
23456789
10
11
1213141516171819
+ 3
VDC
RTXM
CRFB2 CDCB
LAT
LESD
CRFB1
LRFB
+
T/S
Modulation Input
TOP VIEW
GND
3
CNT
RL0
CNT
RL1
P
WIDTH
P
RATE
THLD
1
THLD
2
RREF
GND2
TX
MOD
RX
DATA
LPF
ADJ
CMP
IN
BB
OUT
PK
DET
AGC
CAP
VCC
1
VCC
2
RFIO
GND1
+ 3
VDC
Transmitter ASK Configuration
1
20
23456789
10
11
1213141516171819
+ 3
VDC
RTXM
CRFB2 CDCB
LAT
LESD
CRFB1
LRFB
+
T/S
CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.
NOTES:
©2010-2015 by Murata Electronics N.A., Inc.
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Figure 1
Transmitter Theory of Operation
Introduction
RFM’s TX-series hybrid transmitters are specifically designed for
short-range wireless data communication applications. These
transmitters provide robust operation, very small size, low power
consumption and low implementation cost. All critical RF functions
are contained in the hybrid, simplifying and speeding design-in.
The transmitters can be readily configured to support a wide
range of data rates and protocol requirements. TX-series
transmitters feature excellent suppression of output harmonics and
virtually no other RF emissions, making them easy to certify to
short- range (unlicensed) radio regulations.
Transmitter Block Diagram
Figure 1 is the general block diagram of the transmitter. Please
refer to Figure 1 for the following discussions.
Antenna Port
The only external RF components needed for the transmitter are
the antenna and its matching components. Antennas presenting
an impedance in the range of 35 to 72 ohms resistive can be
satisfactorily matched to the RFIO pin with a series matching coil
and a shunt matching/ESD protection coil. Other antenna
impedances can be matched using two or three components. For
some impedances, two inductors and a capacitor will be required.
A DC path from RFIO to ground is required for ESD protection.
Transmitter Chain
The transmitter chain consists of a SAW coupled-resonator
oscillator followed by a modulated buffer amplifier. The SAW
coupled resonator output filter suppresses transmitter harmonics
to the antenna.
Transmitter operation supports two modulation formats, on-off
keyed (OOK) modulation, and amplitude-shift keyed (ASK)
modulation. When OOK modulation is chosen, the transmitter
output turns completely off between “1” data pulses. When ASK
modulation is chosen, a “1” pulse is represented by a higher
transmitted power level, and a “0” is represented by a lower
transmitted power level. OOK modulation provides compatibility
with first-generation ASH technology, and provides for power
conservation. ASK modulation must be used for high data rates
(data pulses less than 200 µs). ASK modulation also reduces the
effects of some types of interference and allows the transmitted
pulses to be shaped to control modulation bandwidth.
The modulation format is chosen by the state of the CNTRL0 and
the CNTRL1 mode control pins, as discussed below. In the OOK
mode, the oscillator amplifier TXA1 and buffer amplifier TXA2 are
turned off when the voltage to the TXMOD input falls below 220
mV. In the OOK mode, the data rate is limited by the 20/15 µs turn-
on and turn-off time of the oscillator. In the ASK mode TXA1 is
biased ON continuously, and the output of TXA2 is modulated by
the TXMOD input current. Minimum output power occurs in the
ASK mode when the modulation driver sinks about 10 µA of
current from the TXMOD pin.
Transmitter Block Diagram
TXA1 TXA2
Antenna
SAW
Coupled
Resonator
SAW
CR
Filter
Modulation
& Bias Control
TX
IN
CN
TRL1
CN
TRL0
Tune/ESD
Ant
Tune
RTXM
©2010-2015 by Murata Electronics N.A., Inc.
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The transmitter RF output power is proportional to the input current
to the TXMOD pin. A series resistor is used to adjust the peak
transmitter output power. 0 dBm of output power requires about
250 µA of input current.
Transmitter Mode Control
The three transmitter operating modes – transmit ASK, transmit
OOK, and power-down (sleep), are controlled by the Modulation &
Bias Control function, and are selected with the CNTRL1 and
CNTRL0 control pins. Setting CNTRL1 high and CNTRL0 low
place the unit in the ASK transmit mode. Setting CNTRL1 low and
CNTRL0 high place the unit in the OOK transmit mode. Setting
CNTRL1 and CNTRL0 both low place the unit in the power-down
mode. (Note that the resistor driving TXMOD must also be low in
the power-down mode to minimize power-down current.) CNTRL1
and CNTRL0 are CMOS compatible inputs. These inputs must be
held at a logic level; they cannot be left unconnected.
Turn-On Timing
The maximum time required for either the OOK or ASK transmitter
mode to become operational is 5 ms after the supply voltage
reaches 2.2 Vdc. The total turn-on time to stable transmitter
operation for a 10 ms power supply rise time is 15 ms.
Sleep and Wake-Up Timing
The maximum transition time from either transmit mode to the
sleep mode (tTOS and tTAS) is 15 µs after CNTRL1 and CNTRL0
are both low (1 µs fall time).
The maximum time required to switch from the sleep mode to
either transmit mode (tSTO and tSTA) is 21 µs. Most of this time is
due to the start-up of the transmitter oscillator.
0.000
0.000
.140
.270
.410
.0775
.1025
.1175
.1575
.1975
.2375
.2775
.3175
.3575
.3825
.4600
.1975
.1725
.2125
.2375
Dimensions in inches
SM-20L PCB Pad Layout
Dimension
mm Inches
Min Nom Max Min Nom Max
A 10.795 10.922 11.049 .425 .430 .435
B 9.525 9.652 9.779 .375 .380 .385
C 1.778 1.905 2.032 .070 .075 .080
D 3.048 3.175 3.302 .120 .125 .130
E 0.381 0.508 0.635 .015 .020 .025
F 0.889 1.016 1.143 .035 .040 .045
G 3.175 3.302 3.429 .125 .130 .135
H 1.778 1.905 2.032 .070 .075 0.80
SM-20L Package Drawing
CD
E
F
G
A
B
H
3
4
5
6
7
9
11
12
13
14
15
16
17
19
Transmitter Pin Out
RFIO
8
2
10
201
18
NC
NC
NC
NC
NC
NC
NC
NC
TXMOD NC
NC
NC
GND1
VCC1
GND2
VCC2
GND3
CNTRL0
CNTRL1
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Pin Name Description
1 GND1 GND1 is the RF ground pin. GND2 and GND3 should be connected to GND1 by short, low-inductance traces.
2 VCC1
VCC1 is the positive supply voltage pin for the transmitter output amplifier and the transmitter base-band circuitry. VCC1 is
usually connected to the positive supply through a ferrite RF decoupling bead which is bypassed by an RF capacitor on the
supply side. See the description of VCC2 (Pin 16) for additional information.
3 NC No connection. Printed circuit board pad may be grounded or floating.
4 NC No connection. Printed circuit board pad may be grounded or floating.
5 NC No connection. Printed circuit board pad may be grounded or floating.
6 NC No connection. Printed circuit board pad may be grounded or floating.
7 NC No connection. Printed circuit board pad may be grounded or floating.
8TXMOD
The transmitter RF output voltage is proportional to the input current to this pin. A series resistor is used to adjust the peak
transmitter output voltage. 1.5 dBm of output power requires 250 µA of input current. In the ASK mode, minimum output
power occurs when the modulation driver sinks about 10 µA of current from this pin. In the OOK mode, input signals less than
220 mV completely turn the transmitter oscillator off. Internally, this pin appears to be a diode in series with a small resistor.
Peak transmitter output power PO for a 3 Vdc supply voltage is approximately:
PO = 24*(ITXM)2, where PO is in mW, and the peak modulation current ITXM is in mA
A ±5% resistor value is recommended. In the OOK mode, this pin is usually driven with a logic-level data input (unshaped
data pulses). OOK modulation is practical for data pulses of 200 µs or longer. In the ASK mode, this pin accepts analog mod-
ulation (shaped or unshaped data pulses). ASK modulation is practical for data pulses 8.7 µs or longer. This pin must be low
in the power-down (sleep) mode. Please refer to the ASH Transceiver Designer’s Guide for additional information on modula-
tion techniques.
9 NC No connection. Printed circuit board pad may be grounded or floating.
10 GND2 GND2 is an IC ground pin. It should be connected to GND1 by a short, low inductance trace.
11 NC No connection. Printed circuit board pad may be grounded or floating.
12 NC No connection. Printed circuit board pad may be grounded or floating.
13 NC No connection. Printed circuit board pad may be grounded or floating.
14 NC No connection. Printed circuit board pad may be grounded or floating.
15 NC No connection. Printed circuit board pad may be grounded or floating.
16 VCC2
VCC2 is the positive supply voltage pin for the transmitter oscillator. Pin 16 must be bypassed with an RF capacitor, and must
also be bypassed with a 1 to 10 µF tantalum or electrolytic capacitor. Power supply voltage ripple should be limited to 10 mV
peak-to-peak. See the ASH Transceiver Designer’s Guide for additional information.
17 CNTRL1
CNTRL1 and CNTRL0 select the transmit modes. CNTRL1 high and CNTRL0 low place the unit in the ASK transmit mode.
CNTRL1 low and CNTRL0 high place the unit in the OOK transmit mode. CNTRL1 and CNTRL0 both low place the unit in
the power-down (sleep) mode. CNTRL1 is a high-impedance input (CMOS compatible). An input voltage of 0 to 300 mV is
interpreted as a logic low. An input voltage of Vcc - 300 mV or greater is interpreted as a logic high. An input voltage greater
than Vcc + 200 mV should not be applied to this pin. A logic high requires a maximum source current of 40 µA. A logic low
requires a maximum sink current of 25 µA (1 µA in sleep mode). This pin must be held at a logic level; it cannot be left uncon-
nected.
18 CNTRL0 CNTRL0 is used with CNTRL1 to control the operating modes of the transmitter. See the description of CNTRL1 for more
information.
19 GND3 GND3 is an IC ground pin. It should be connected to GND1 by a short, low inductance trace.
20 RFIO
RFIO is the transmitter RF output pin. This pin is connected directly to the SAW filter transducer. Antennas presenting an
impedance in the range of 35 to 72 ohms resistive can be satisfactorily matched to this pin with a series matching coil and a
shunt matching/ESD protection coil. Other antenna impedances can be matched using two or three components. For some
impedances, two inductors and a capacitor will be required. A DC path from RFIO to ground is required for ESD protection.
©2010-2015 by Murata Electronics N.A., Inc.
TX5003 (R) 4/24/15 Page 6 of 6 www.murata.com
Note: Specifications subject to change without notice.
0 0.030.060.090.120.150.180.210.240.270.30
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
RF Output Power vs ITXM
ITXM in mA
Output Power in mW
3 V
0 0.030.060.090.120.150.180.210.240.270.30
ITXM in mA
VTXM vs ITXM
0.85
0.90
0.95
1.00
1.05
1.10
1.15
1.20
V
TXM
in V
