TOIM5232

www.vishay.com

Vishay Semiconductors

Rev. 1.3, 04-Jul-12

2

Document Number: 81749

THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT

BLOCK DIAGRAM

Notes

 resistor from pin

4 to pin 5 and from pin 4 and pin 5 a 22 pF capacitor to ground, respectively. When an external clock is available connect it to pin 4 leaving

pin 5 open. The external resistor of 100 k

 is used to accelerate the start of the oscillation after reset or power-on. The value depends on

the “Q” of the resonator. With low Q resonators no resistor is needed. The start-up time of the oscillator is between 30 μs (with piezo

resonators) and above 2 ms with high Q quartzes.

PIN ASSIGNMENT AND DESCRIPTION

PIN NUMBER

SYMBOL

DISCRIPTION

I/O

ACTIVE

1

RD_232

Received signal data output of stretched signal to the RS232 RXD line (using level

converter).

OHigh

2

TD_232

Input of the signal to be transmitted from the RS232 port TXD line

(passing the level converter).

IHigh

3

This pin can be used to shut down a transceiver (e.g., TFDx4xxx).

Output polarity: Inverted RESET input.

OLow

4X1

Crystal input clock, 3.6864 MHz nominal for 9.6 kbit/s default setting. Input for external

I

5X2

I

7

GND

Ground in common with the RS232 port and IrDA transceiver ground

9

TD_LED

Transmit LED indicator driver. Use 180

 current limiting resistor in series to LED to

OLow

10

RD_LED

Receive LED indicator driver. Use 180

 current limiting resistor in series to LED to connect

OLow

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).

OLow

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).

OLow

14

TD_IR

Data output of shortened signal to the infrared transceiver.

O

High

16

RD_IR

ILow

17

Supply voltage

I

18

RESET

Resets all internal registers. Initially must be high (“1”) to reset internal registers. When high,

the TOIM5232 sets the IrDA default bit rate of 9600 bit/s, sets pulse width to 1.627 μs.

transceiver when applying the reset signal to the TOIM5232. When using devices with

external SD like TFDU4101, the reset line can be used directly as shutdown signal.

RESET pin can be controlled by either the RTS or DTR line through RS232 level converter.

Minimum hold time for resetting is 1 μs.

Disables the oscillator when active.

High

19

BR/D

Baud rate control/data

BR/D = 0, data communication mode:

RS232 TXD data line is connected (via a level shifter) to TD_232 input pin. The TXD - signal

is appropriately shortened and applied to the output TD_IR, driving the TXD input of the IR

transceiver. The RXD line of the transceiver is connected to the RD_IR input. This signal is

stretched to the correct bit length according to the programmed bit rate and is routed to the

RS232 RXD line at the RD_232 pin.

BR/D = 1, programming mode:

Data received from the RS232 port is interpreted as control word. The control word

programs the baud rate width will be effective as soon as BR/D return to low.

6, 8, 11, 15, 20

NC

TD_232

RD_232

BR/D

RESET

TD_IR

RD_IR

TD_LED

RD_LED

V

CC_SD

S2

S1

GND

X1

X2

V

CC

Oscillator

Endec

Baud

generator

Logic

18079