303.825 MHz

Transmitter Module

RF Monolithics, Inc.

Phone: (972) 233-2903

Fax: (972) 387-8148

E-mail: info@rfm.com

Page 2 of 2

RFM Europe

Phone: 44 1963 251383

Fax: 44 1963 251510

http://www.rfm.com

©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.

DR4103-121001

Pin Desciptions

Pin

Name

Description

1

VCC

5

TX IN

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

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

GND

8

NC

9

VCC

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.

10

GND

This is the supply voltage return pin.

11

CTR1

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.

12

CTR0

(T/S)

“T” =1 for transmission, “S” =0 for sleep mode

13

RFIO

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.

14

RF GND

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.

Da ta I n

3 Vd c

App li ca ti on OOK C ir cu i t

1

2

3

4

5

8

9

1 0

1 1

1 2

1 3

1 4

DR 400 0

T / S

7

6

3 .3 k

DR4103

Application OOK Circuit

Da ta I n

3 Vd c

App li ca ti on ASK C ir cu i t

DR 400 0

T /S

1

2

3

4

5

8

9

1 0

1 1

1 2

1 3

1 4

7

6

3 .3 k

Application ASK Circuit

DR4103