MCP2122-E/SNG Microchip Technology, MCP2122-E/SNG Datasheet - Page 3

• Manufacturer Part Number: MCP2122-E/SNG
• Description: Infrared Encoder/Decoder
• Manufacturer: Microchip Technology

1.0
The MCP2122 is a stand-alone IrDA standard encoder/
decoder device that is pinout-compatible with the
Agilent
The MCP2122 has two interfaces: the host UART
interface and the IR interface (see Figure 1-1). The host
UART interfaces to the UART of the host controller. The
host controller is the device in the embedded system
that transmits and receives the data. The IR interface
connects to an infrared (IR) optical transceiver circuit,
which converts electrical pulses into IR light (encode)
and converts IR light into electrical pulses (decode).
This IR optical transceiver circuit could be either a stan-
dard infrared (IR) optical transceiver (such as a Vishay
TFDU 4100) or it could be implemented with discrete
components. For additional information, please refer to
Application Note 243, “Fundamentals of the Infrared
Physical Layer” (DS00243).
When the host controller transmits the UART format
data, the MCP2122 receives this UART data and
encodes (modulates) the data bit by bit. This encoded
data is then output as electrical pulses to the IR Trans-
ceiver. The IR transceiver will then convert these
electrical pulses to IR light pulses.
The IR Transceiver also receives IR light pulses (data),
which are outputted as electrical pulses. The MCP2122
decodes (demodulates) these electrical pulses, with
the data then transmitted by the MCP2122 UART. This
modulation and demodulation method is performed in
accordance with the IrDA standard.
Table 1-1 shows an overview of some of the device
features. Figure 1-1 shows a typical application block
diagram. Table 1-2 shows the pin definitions of the
MCP2122 in normal operation.
FIGURE 1-1:
 2004 Microchip Technology Inc.
Host Controller
®
PICmicro
HSDL-7000 Encoder/Decoder.
DEVICE OVERVIEW
MCU
Clock
®
(I/O)
SO
SYSTEM BLOCK DIAGRAM
SI
Host UART
Interface
16XCLK
RESET
TX
RX
Protocol Handler
Preliminary
®
Reset
Logic
MCP2122
Decode
Encode
Clock
Logic
TABLE 1-1:
Infrared Technology Features:
• Universal standard for connecting portable
• Easy, effortless implementation
• Economical alternative to other connectivity
• Reliable, high speed connection
• Safe to use in any environment; can even be used
• Eliminates the hassle of cables
• Allows PC’s and non-PC’s to communicate to
• Enhances mobility by allowing users to easily
1.1
Some applications where an IR interface (MCP2122)
could be used include:
• Data Logging/Data Exchange
• System Setup
• System Diagnostic Read Out
• Manufacturing Configuration
• Host Controller Firmware Updates
• System Control
Serial Communications:
Baud Rate Selection:
Low Power Mode:
Resets: (and Delays)
Packages:
computing devices
solutions
during air travel
each other
connect
RXIR
TXIR
Applications
Features
Interface
MCP2122 FEATURES
OVERVIEW
IR
Transceiver
TFDU 4100
MCP2122
TXD
RXD
Optical
RESET pin (none)
8-pin SOIC
8-pin PDIP
MCP2122
UART, IR
16XCLK
DS21894A-page 3
Yes