TODX2960(F) Toshiba, TODX2960(F) Datasheet - Page 3

• Manufacturer Part Number: TODX2960(F)
• Description: TXRX FIBER OPTIC
• Manufacturer: Toshiba
• Series: -r

Specifications of TODX2960(F)

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

An optical fiber consists of a core surrounded by a cladding. An optical ray
entering the fiber is reflected back at the boundary between the core and
the cladding. In this manner, it travels along the length of the fiber.
There are three kinds of optical fiber:
All-plastic fiber, having a plastic core and plastic cladding, is used for
short-distance transmission. A plastic-clad silica fiber, which consists of a
silica core and plastic cladding, is used for mid-distance transmission. Silica
fiber consists of a pure silica core with silica cladding and is used for
long-distance transmission. Each optical fiber has a lower transmission loss
over a certain wavelength range and is used together with appropriate optical
modules.
Optical transmission module
The LED is driven by a differential circuit to reduce current transients
generated during the on-off switching of the LED so that the LED’s
switching does not affect peripheral ICs.
Optical receiving module
The receiving module employs an ATC (automatic threshold control)
circuit to reshape the waveform. The ATC circuit controls the comparator
reference voltage so that it is always automatically adjusted in accordance
with the input optical power. This minimizes pulse width distortion,
regardless of the length or bending of the optical fiber.
The transmission line (i.e. the optical cable) is not susceptible to
The optical cable does not radiate any electromagnetic noise.
The optical cable provides a complete galvanic isolation between
electromagnetic interference.
equipments.
a) All-plastic fiber (APF)
b) Plastic-clad silica fiber (PCF)
c) Silica fiber
Optical fiber
TOSLINK circuit configurations
3
Reference voltage
generating circuit
Optical ray
Amp circuit
I
F
-CONT 2
Input 4
GND 1
V
Structure of an optical fiber
CC
3
Transmitting module
Sheathing
Cladding
(low refractive index for confinement of light)
Core
(high refractive index for transmission of light)
Receiving module
ATC circuit
Receiving IC
Comparator
LED
4
3
2
1
GND 2
Output
V
GND 1
CC