868.35 MHz
Pin Desciptions
Pin
1
Name
VCC
Transmitter Module
Description
The TX IN pin is connected to the transmitter TXMOD pin through a 4.7 K resistor on the circuit board. Additional series
resistance will often be required between the modulation source and the TX IN pin, depending on the desired output power
and peak modulation voltage (3.3 K typical for a peak modulation voltage of 3 volts). Saturated output power requires about
450 µA of drive current. Peak output power P
O
for a 3 Vdc supply is approximately:
5
TX IN
P
O
= 4.8*((V
TXH
- 0.9)/(R
M
+ 4.7))
2
, where P
O
is in mW, peak modulation voltage V
TXH
is in volts and external modulation
resistor R
M
is in kilohms
This pin must be held low in the receive and sleep modes. Please refer to section 2.9 of the ASH Transceiver Designer's
Guide for additional information.
6, 7
8
9
10
GND
NC
VCC
GND
This is the positive supply voltage pin for the module. The operating voltage range is 2.7 to 3.5 Vdc. It is also possible to use
Pin 1 as the Vcc input. Please refer to the Pin 1 description above.
This is the supply voltage return pin.
CTR1 and CTR0 select the transmit modes. CTR1 high and CTR0 low place the unit in the ASK transmit mode. CTR1 low
and CTR0 high place the unit in the OOK transmit mode. CTR1 and CTR0 both low place the unit in the power down (sleep)
mode. CTR1 is a high-impedance input (CMOS compatible). An input voltage of 0 to 200 mV is interpreted as a logic low. An
input voltage of Vcc - 200 mV or greater is interpreted as a logic high. An input voltage greater than Vcc + 200 mV should not
be applied to this pin. This pin must be held at a logic level; it cannot be left unconnected.
“T” =1 for transmission, “S” =0 for sleep mode
11
CTR1
12
CTR0
(T/S)
RFIO
13
RFIO is the RF output pin. A matching circuit for a 50 ohm load (antenna) is implemented on the circuit board between this
pin and the transceiver SAW filter transducer.
This pin is the RF ground (return) to be used in conjunction with the RFIO pin. For example, when connecting the module to
an external antenna, the coaxial cable ground is connected this pin and the coaxial cable center conductor is connected to
RFIO.
14
RF GND
A
Application
n O O K C i r c u it
p p lic a t i o
OOK Circuit
A p p lic a t i o n A S K C i r c u i t
Application ASK Circuit
T /S
3 Vdc
T /S
3 Vdc
12
13
14
1
11
10
9
8
7
6
12
13
14
1
D a ta In
3 .3k
11
10
9
8
7
6
DR4001
0
D R 400
2
3
4
5
DR4001
0
D R 400
2
3
4
5
D a ta In
3 .3 k
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: info@rfm.com
http://www.rfm.com
DR4001-121001
Page 2 of 2
RFM [ RF MONOLITHICS, INC ]
