COM20019ILJP3V Standard Microsystems (SMSC), COM20019ILJP3V Datasheet - Page 3

• Manufacturer Part Number: COM20019ILJP3V
• Manufacturer: Standard Microsystems (SMSC)

Specifications of COM20019ILJP3V

• Number Of Transceivers: 1
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (min): 3V
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 28
• Lead Free Status / RoHS Status: Supplier Unconfirmed

SMSC COM20019I 3.3V Rev.C
Cost Competitive ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
General Description
SMSC's COM20019I 3V is a member of the family of Embedded ARCNET Controllers from Standard
Microsystems Corporation. The device is a general purpose communications controller for networking
microcontrollers and intelligent peripherals in industrial and embedded control environments using an
ARCNET protocol engine. The flexible microcontroller and media interfaces, eight-page message support,
and extended temperature range of the COM20019I 3V make it the only true network controller optimized
for use in industrial and embedded applications. Using an ARCNET protocol engine is the ideal solution
for embedded control applications because it provides a deterministic token-passing protocol, a highly
reliable and proven networking scheme, and a data rate of up to 312.5 Kbps when using the COM20019I
3V.
A token-passing protocol provides predictable response times because each network event occurs within a
predetermined time interval, based upon the number of nodes on the network. The deterministic nature of
ARCNET is essential in real time applications. The integration of the 2Kx8 RAM buffer on-chip, the
Command Chaining feature, the maximum data rate, and the internal diagnostics make the COM20019I
3V the highest performance embedded communications device available. With only one COM20019I 3V
and one microcontroller, a complete communications node may be implemented.
To accommodate transceivers with active high ENABLE pins, the COM20019I 3V contains a
programmable TXEN output. To program the TXEN pin for an active high pulse, the nPULSE2 pin should
be connected to ground. To retain the normal active low polarity, nPULSE2 should be left open. The
polarity determination is made at power on reset and is valid only for Backplane Mode operation. The
nPULSE2 pin should remain grounded at all times if an active high polarity is desired.
For more details on the ARCNET protocol engine and traditional dipulse signaling schemes,
please refer to the ARCNET Local Area Network Standard, available from Standard Microsystems
Corporation or the ARCNET Designer's Handbook, available from Datapoint Corporation.
For more detailed information on cabling options including RS485, transformer-coupled RS-485
and Fiber Optic interfaces, please refer to the following technical note which is available from
Standard Microsystems Corporation: Technical Note 7-5 - Cabling Guidelines for the COM20020
ULANC.
PRODUCT PREVIEW
Page 3
Rev. 11-07-08