DEVELOPMENT KIT
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TX5002
•
•
•
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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 TX5002 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 TX5002 includes provisions for both on-off keyed (OOK) and
amplitude-shift keyed (ASK) modulation. The TX5002 employs SAW filtering to suppress output harmonics,
facilitating compliance with FCC Part 15 and similar regulations.
418.00 MHz
Hybrid
Transmitter
Rating
Power Supply and All Input/Output Pins
Non-Operating Case Temperature
Soldering Temperature (10 seconds / 5 cycles max.)
Value
-0.3 to +4.0
-50 to +100
260
Units
V
°C
°C
SM-20L Case
Electrical Characteristics
Characteristic
Operating Frequency
Modulation Types
OOK Data Rate
ASK Data Rate
Transmitter Performance
Peak RF Output Power, 250 µA TXMOD Current
Peak Current, 250 µA TXMOD Current
OOK Turn On/Turn Off Times
ASK Output Rise/Fall Times
2nd - 4th Harmonic Outputs
5th - 10th Harmonic Outputs
Non-harmonic Spurious Outputs
Sleep Mode Current
Sleep to Transmit Switch Time
Transmit to Sleep Switch Time
Control Input Logic Low Level
Control Input Logic High Level
Power Supply Voltage Range
Operating Ambient Temperature
V
CC
T
A
1
Vcc - 300
2.2
-40
3.7
+85
I
S
t
TOR
t
RTO
0.7
21
15
200
P
O
I
TP
t
ON
/t
OFF
t
TR
/t
TF
0
7.5
20/15
1.1/1.1
-50
-55
-50
dBm
mA
µs
µs
dBm
dBm
dBm
µA
µs
µs
mV
mV
Vdc
°C
Sym
f
o
Notes
Minimum
417.80
Typical
Maximum
418.20
Units
MHz
OOK & ASK
10
115.2
kbps
kbps
www.RFM.com
E-mail: info@rfm.com
©2008 by RF Monolithics, Inc.
Page 1 of 6
TX5002 - 4/3/08
Transmitter OOK Configuration
Transmitter ASK Configuration
+3
C
RFB2
VDC C
DCB
+
+3
C
RFB2
VDC C
DCB
+
T/S
T/S
17
CNT
RL1
16
VCC
2
15
14
13
12
THLD
2
RREF
19
18
CNT
RL0
L
AT
20
GND
3
RFIO
P
P
THLD
WIDTH RATE
1
19
18
CNT
RL0
17
CNT
RL1
16
VCC
2
15
14
13
12
THLD
2
RREF
L
AT
11
TOP VIEW
GND1
VCC
1
2
AGC
CAP
3
PK
DET
4
BB
OUT
5
CMP
IN
6
RX
DATA
7
GND2
10
TX
LPF
MOD
ADJ
8
9
20
GND
3
RFIO
P
P
THLD
WIDTH RATE
1
11
L
ESD
TOP VIEW
GND1
VCC
1
2
AGC
CAP
3
PK
DET
4
BB
OUT
5
CMP
IN
6
RX
DATA
7
TX
MOD
8
GND2
10
LPF
ADJ
9
1
L
ESD
1
L
RFB
R
TXM
+3
VDC
C
RFB1
Modulation Input
L
RFB
R
TXM
+3
VDC
C
RFB1
Modulation Input
Transmitter Set-Up, 3.0 Vdc, -40 to +85 °C
Item
Nominal NRZ Data Rate
Minimum Signal Pulse
Maximum Signal Pulse
TXMOD Resistor
DC Bypass Capacitor
RF Bypass Capacitor 1
RF Bypass Capacitor 2
RF Bypass Bead
Series Tuning Inductor
Shunt Tuning/ESD Inductor
Symbol
DR
NOM
SP
MIN
SP
MAX
R
TXM
C
DCB
C
RFB1
C
RFB2
L
RFB
L
AT
L
ESD
OOK
2.4
416.67
1666.68
8.2
4.7
27
100
Fair-Rite
56
220
ASK
19.2
52.08
208.32
8.2
4.7
27
100
Fair-Rite
56
220
ASK
115.2
8.68
34.72
8.2
4.7
27
100
Fair-Rite
56
220
Units
kbps
µs
µs
K
µF
pF
pF
vendor
nH
nH
Notes
see page 1
single bit
4 bits of same value
±5%, for 0 dBm output
tantalum
±5% NPO
±5% NPO
2506033017YO or equivalent
50 ohm antenna
50 ohm antenna
CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.
Notes:
1.
2.
Do not allow the voltage applied to a control input pin to exceed Vcc + 200 mV.
The companion receiver to the TX5002 is the RX5002. Please see RFM’s web site at www.rfm.com for details.
www.RFM.com
E-mail: info@rfm.com
©2008 by RF Monolithics, Inc.
Page 2 of 6
TX5002 - 4/3/08
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
Transmitter Block Diagram
Antenna
SAW
Coupled
Resonator
SAW
CR
Filter
Ant
Tune
TXA1
TXA2
Tune/ESD
Modulation
& Bias Control
R
TXM
TX
IN
CN
TRL1
CN
TRL0
Figure 1
www.RFM.com
E-mail: info@rfm.com
©2008 by RF Monolithics, Inc.
Page 3 of 6
TX5002 - 4/3/08
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 (t
TOS
and t
TAS
) 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 (t
STO
and t
STA
) is 21 µs. Most of this time is
due to the start-up of the transmitter oscillator.
Transmitter Pin Out
GND1
1
VCC1 2
NC 3
NC 4
NC 5
NC 6
NC 7
TXMOD 8
NC 9
10
GND2
11
NC
20
RFIO
B
SM-20L Package Drawing
C
D
E
19 GND3
18 CNTRL0
17 CNTRL1
16 VCC2
15 NC
14 NC
13 NC
H
A
F
12 NC
G
mm
SM-20L PCB Pad Layout
.1975
.2125
.2375
.1725
Inches
Max
11.049
9.779
2.032
3.302
0.635
1.143
3.429
2.032
Dimension
Min
A
B
.3825
.3575
.3175
Nom
10.922
9.652
1.905
3.175
0.508
1.016
3.302
1.905
Min
.425
.375
.070
.120
.015
.035
.125
.070
Nom
.430
.380
.075
.125
.020
.040
.130
.075
Max
.435
.385
.080
.130
.025
.045
.135
0.80
10.795
9.525
1.778
3.048
0.381
0.889
3.175
1.778
.4600
C
D
E
.2775
.2375
.1975
.1575
.1175
.1025
.0775
.140
0.000
.270
.410
F
G
H
0.000
Dimensions in inches
www.RFM.com
E-mail: info@rfm.com
©2008 by RF Monolithics, Inc.
Page 4 of 6
TX5002 - 4/3/08
Pin
1
2
3
4
5
6
7
Name
GND1
VCC1
NC
NC
NC
NC
NC
Description
GND1 is the RF ground pin. GND2 and GND3 should be connected to GND1 by short, low-inductance traces.
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.
No connection. Printed circuit board pad may be grounded or floating.
No connection. Printed circuit board pad may be grounded or floating.
No connection. Printed circuit board pad may be grounded or floating.
No connection. Printed circuit board pad may be grounded or floating.
No connection. Printed circuit board pad may be grounded or floating.
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. 0 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 P
O
for a 3 Vdc supply voltage is approximately:
8
TXMOD
P
O
= 16*(I
TXM
)
2
, where P
O
is in mW, and the peak modulation current I
TXM
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.
No connection. Printed circuit board pad may be grounded or floating.
GND2 is an IC ground pin. It should be connected to GND1 by a short, low inductance trace.
No connection. Printed circuit board pad may be grounded or floating.
No connection. Printed circuit board pad may be grounded or floating.
No connection. Printed circuit board pad may be grounded or floating.
No connection. Printed circuit board pad may be grounded or floating.
No connection. Printed circuit board pad may be grounded or floating.
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.
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.
CNTRL0 is used with CNTRL1 to control the operating modes of the transmitter. See the description of CNTRL1 for more
information.
GND3 is an IC ground pin. It should be connected to GND1 by a short, low inductance trace.
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.
9
10
11
12
13
14
15
16
NC
GND2
NC
NC
NC
NC
NC
VCC2
17
CNTRL1
18
19
20
CNTRL0
GND3
RFIO
www.RFM.com
E-mail: info@rfm.com
©2008 by RF Monolithics, Inc.
Page 5 of 6
TX5002 - 4/3/08
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