HSDL-3021 Datasheet, PDF (17/26 Pages) AVAGO TECHNOLOGIES LIMITED – IrDA® Data Compliant Low Power 4.0 Mbit/s with Remote Control Infrared Transceiver

Appendix C: General Application
Guide for the HSDL-3021 infrared
IrDA Compliant 4 Mb/s Transceiver
Description
The HSDL-3021, a wide-voltage
operating range infrared
transceiver is a low-cost and small
form factor device that is
designed to address the mobile
computing market such as PDAs,
as well as small embedded mobile
products such as digital cameras
and cellular phones. It is
spectrally suited to universal
remote control transmission
function at 940 nm typically. It is
fully compliant to IrDA 1.4 low
power specification up 4Mb/s and
support most remote control
codes. The design of HSDL-3021
also includes the following unique
features :
• Spectrally suited to universal
remote control transmission
function at 940 nm typically
• Low passive component count
• Shutdown mode for low power
consumption requirement
• Direct interface with I/O logic
circuit
Selection of Resistor R2
Resistor R2 should be selected to
provide the appropriate peak
pulse IR and RC LED current
respectively at different ranges of
V_CC as shown on page 3 under
“Recommended Application
circuit components.”
Interface to the Recommended I/O
Chip
The HSDL-3021’s TXD data input
is buffered to allow for CMOS
drive levels. No peaking circuit or
capacitor is required. Data rate
from 9.6 kb/s to 4 Mb/s is
available at RXD pin. The
TXD_RC, pin 7, together with
LEDA, pin1, is used to select the
remote control transmit mode.
Alternatively, the TXD_IR, pin 3,
together with LEDA, pin 1, is used
for infrared transmit selection.
Following shows the hardware
reference design with HSDL-3021.
*Detailed configuration of HSDL-
3021 with the controller chip is
shown in Figure 3.
STN/TFT
LCD PANEL
KEY PAD
TOUCH PANEL
LCD CONTROL
A/D
PERIPHERIAL INTERFACE
PWM
MEMORY
EXPANSION
LOGIC BUS
DRIVER
ROM
FLASH
SDRAM
MOBILE
APPLICATION
CHIPSET
IrDA
INTERFACE
MEMORY I/F
AC97
SOUND
BASEBAND I2S
CONTROLLER
POWER
MANAGEMENT
ANTENNA
Figure 2: Mobile application platform.
LCD BACKLIGHT
PANEL
*HSDL-3021
PCM SOUND
AUDIO INPUT
The use of the infrared tech-
niques for data communication
has increased rapidly lately and
almost all mobile application
processors have built in the IR
port. This does away with the
external Endec and simplifies the
interfacing to a direct connection
between the processor and the
transceiver. The next section
discusses interfacing
configuration with a general
processor.
17