TOIM3232

Vishay Telefunken

Not for new designs

Rev. A1.1, 02-Apr-01

2 (9)

www.vishay.com

Document Number 82521

Pin Assignment and Description

Pin

Symbol

Function

I/O

Active

1

RESET

Resets all internal registers. Initially must be HIGH (“1”) to reset internal

registers. When HIGH, the TOIM3232 sets the IrDA default bit rate of

9600, sets pulse width to 1.627

ms. Then the TOIM3232 enters the

therefore switching off the transceiver. When RESET returns to LOW,

the TOIM3232 sets VCC_SD HIGH switching on the front-end device,

and sets the new baud rate in the 1.627

ms pulse width mode. In the

application the RESET pin can be controlled by either the RTS or DTR

line through RS232 level converter. Minimum hold time for reset: 1

ms.

I

HIGH

2

BR/ D

Baud Rate control/ Data.

When BR/ D = 0, RD_232 data is transmitted to the IrDA transmitter pin

TD_IR, while RD_IR is routed to the transmitter pin TD_232. When

BR/ D = 1, data received from the RS232 port is interpreted as the

Control Word. The Control Word programs the baud rate and pulse

width will be effective as soon as BR/ D return to LOW.

I

3

RD_232

Received signal data output of stretched signal to the RS232 port

(using level converter).

O

HIGH

4

TD_232

Input of the signal to be transmitted from the RS232 port (passing the

level converter).

I

HIGH

5

transceiver (e.g., TFDx4xxx). Output polarity: Inverted RESET input.

O

LOW

6

X1

Crystal input clock, 3.6864 MHz nominal. Input for external clock *)

I

7

X2

Crystal *)

I

8

GND

Ground in common with the RS232 port and IrDA transceiver ground

9

TD_LED

Transmit LED indicator driver. Use 270

W current limiting resistor in

O

LOW

10

RD_LED

Receive LED indicator driver. Use 270

W current limiting resistor in

O

LOW

11

NC

No connection

12

S1

User Programmable Bit. Can be used to turn ON/ OFF a front-end

infrared transceiver (e.g., an infrared module at the adapter front)

O

LOW

13

S2

User Programmable Bit. Can be used to turn ON/ OFF a front-end

infrared transceiver (e.g., an infrared module at the adapter back)

O

LOW

14

TD_IR

Data output of shortened signal to the infrared transceiver TFDx4xxx

O

HIGH

15

RD_IR

Data input from the infrared transceiver TFDx4xxx

I

LOW

16

Supply voltage

I

*)

Crystal should be connected as shown in figure 2. In addition connect a 100 k

W resistor from

Pin 6 to Pin 7 and from Pin 6 and Pin 7 a 22 pF capacitor to ground, respectively. When an

external clock is available connect it to Pin 6 leaving Pin 7 open.