TFBS5700
Document Number 84670
Rev. 2.1, 25-Sep-06
Vishay Semiconductors
www.vishay.com
219
Functional Block Diagram
Pin Description
Pinout
TFBS5700, bottom view
weight 33 mg
Definitions:
In the Vishay transceiver data sheets the following nomenclature is
used for defining the IrDA operating modes:
SIR: 2.4 kbit/s to 115.2 kbit/s, equivalent to the basic serial infrared
standard with the physical layer version IrPhY 1.0
MIR: 576 kbit/s to 1152 kbit/s
FIR: 4 Mbit/s
VFIR: 16 Mbit/s
MIR and FIR were implemented with IrPhY 1.1, followed by IrPhY
1.2, adding the SIR Low Power Standard. IrPhY 1.3 extended the
Low Power Option to MIR and FIR and VFIR was added with IrPhY
1.4. A new version of the standard in any case obsoletes the former
version.
Pin Number Function Description I/O Active
1 IRED A IRED anode, V
CC2
2 TXD This Schmitt-Trigger input is used to transmit serial data when SD is low. An
on-chip protection circuit disables the LED driver if the TXD pin is asserted
for longer than 80 µs. When used in conjunction with the SD pin, this pin is
also used to control receiver output pulse duration. The input threshold
voltage adapts to and follows the internal logic voltage reference of 1.8 V
IHIGH
3 RXD Received Data Output, push-pull CMOS driver output capable of driving
standard CMOS or TTL loads. No external pull-up or pull-down resistor is
required. Floating with a weak pull-up of 500 kΩ (typ.) in shutdown mode.
The voltage swing is defined by the internal Vlogic voltage of 1.8 V
OLOW
4 SD Shutdown. Also used for setting the output pulse duration. Setting this pin
active for more than 1.5 ms places the module into shutdown mode. Before
that (t < 0.7 ms) on the falling edge of this signal, the state of the TXD pin
is sampled and used to set the receiver output to long pulse duration (2 µs)
or to short pulse duration (0.4 µs) mode. The input threshold voltage adapts
to and follows the internal logic voltage reference of 1.8 V
IHIGH
5V
CC
Power Supply. Receives power supply 2.4 V to 3.6 V. This pin provides
power for the receiver and transmitter drive section.
6 GND Ground
IRED Driver
TXD
SD
GND
V
CC
IREDA
RXD
Amplifier Comparator
Tri-state
Driver
Mode
Control
PD
IRED
ASIC
19291
19290
