3

I/O Pins Configuration Table

Pin

Symbol

I/O

Description

Notes

1

LEDA

I

IR and Remote

Tied through external resistor, R1, to VLED from 2.4 to 4.5 Volt

Control LED Driver

2

N.C.

–

No Connection

No Connection

3

TxD_IrDA

I

IrDA Transmitter Data

Logic high turns on the IrDA LED. If held HIGH longer than

Input. Active High

~50

µs, the IrDA LED is turned off. TxD_IrDA must be driven either

HIGH or LOW. Do not leave the pin floating

4

RxD_IrDA

O

IrDA Receiver Data

Output is at LOW pulse response when light pulse is seen

Output. Active Low

5

SD

I

Shutdown. Active High

Complete shutdown TxD_IrDA, RxD_IrDA, and PIN diode. Do not

leave the pin floating

I

Supply Voltage

Regulated, 2.4 to 3.6 Volt

7

TxD_RC

I

Remote Control

Logic high turns on the RC LED. If held HIGH longer than ~50

µs,

Transmission Input.

the RC LED is turned off. TxD_RC must be driven either HIGH or

Active High

LOW. Do not leave the pin floating

8

GND

I

Connect to System

Tie this pin to system ground

Ground

–

Shield

–

EMI Shield

Tie to system ground via a low inductance trace. For best

performance, do not tie it to the HSDL-3003 GND pin directly

Recommended Application Circuit Components

Component

Recommended Value

R1

1.8

Ω ± 5%, 0.25 Watt for 2.4 ≤ VLED ≤ 2.7 V

2.7

Ω ± 5%, 0.25 Watt for 2.7 ≤ VLED ≤ 3.3 V

3.3

Ω ± 5%, 0.25 Watt for 3.0 ≤ VLED ≤ 3.6 V

4.7

Ω ± 5%, 0.25 Watt for 3.6 ≤ VLED ≤ 4.5 V

0.47

µF ± 20%, X7R Ceramic

6.8

µF ± 20%, Tantalum

CX3

6.8

µF ± 20%, Tantalum

Notes:

1. CX1 must be placed within 0.7 cm of HSDL-3003 to obtain optimum noise immunity.

2. The supply rejection performance can be enhanced by including CX2, as shown in Figure 1, in

environment with noisy power supplies.