TFDS4500 データシートの表示（PDF） - Vishay Semiconductors

部品番号

コンポーネント説明

メーカー

TFDS4500

2.7–5.5V Serial Infrared Transceiver Module Family (SIR, 115.2 kbit/s)

Vishay Semiconductors 

TELEFUNKEN TFDU4100/TFDS4500/TFDT4500

Semiconductor

Optoelectronic Characteristics (Cont’d)

Parameter

Symbol

Test Conditionsa

Minb Typc

Transmitter

IRED Operating Currentd

ID

Current limiting resistor is series to

IRED: R1 = 8.2 Ω, VCC2 = 5V

0.3

Logic Low Transmitter Input Voltage

VIL (Txd)

0

Logic High Transmitter Input Voltage

VIH (Txd)

2.4

Output Radiant Intensitye

Current limiting resistor in series to

IeH

IRED: R1 = 8.2Ω @ VCC2 = 5V, α =

45

140

±15_

Output Radiant Intensity

IeL

Logic Low Level

Angle of Half Intensity

α

±24

Peak Wavelength of Emission

λP

Halfwidth of Emission Spectrum

880

60

Optical Rise Time, Fall Time

tR, tF

115.2 kHz square wave signal, duty

cycle 1:1

200

Optical Overshoot

Rising Edge Peak–to–Peak Jitter

tj

Over a period of 10 bits, independent

of information content

Notes

a. Tamb = 25_C, VCC = 2.7 – 5.5 V unless otherwise noted.

b. The algebraic convention whereby the most negative value is a minimum and the most positive a maximum.

c. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing.

d. IRED Operating Current can be adjusted by variation of R1

e. In agreement with IEC 825 eye safety limit

Maxb

0.4

0.8

VCC1+0.5

200

0.04

900

600

25

0.2

Unit

A

V

mW/sr

mW/sr

_

nm

ns

%

µs

Recommended Circuit Diagram

The only required components for designing an IrDA 1.2

compatible design using TEMIC SIR transceivers are a

current limiting resistor to the IRED. However,

depending on the entire system design and board layout,

additional components may be required (see Figure 1).

given by the absolute maximum ratings on the data sheet

and the eye safety limitations given by IEC825–1.

VCC2

VCC1/SD

TFDx4x00

R1

It is recommended that the capacitors C1 and C2 are

positioned as near as possible to the transceiver power

Rxd

supply pins, as in the proposed layout in Figure 1. A

tantalum capacitor should be used for C1, while a ceramic

capacitor should be used for C2 to suppress RF noise.

Txd

Also, when connecting the described circuit to the power

supply, low impedance wiring should be used.

GND

R2

IRED IRED

Cathode Anode

Rxd

Txd

C1

C2 VCC1/SD SC

GND

NC

R1 is used for controlling the current through the IR

emitter. For increasing the output power of the IRED, the

value of the resistor should be reduced. Similarly, to

reduce the output power of the IRED, the value of the

resistor should be increased. For typical values of R1 see

Fig 2. For IrDA compliant operation, a current control

resistor of 8–12 Ω is recommended. The upper drive

current limitation is dependent on the duty cycle and is

SC

Note: Outlined components are optional depending on quality of

power supply.

Figure 1. Recommended Application Circuit

R2, C1 and C2 are optional and dependent on the quality

of the supply voltage VCC1 and injected noise. An

Pending—Rev. A, 03-Apr-98

5

Pre-Release Information

Share Link: