Texas Instruments Technology for Innovators 4Q 2006, Руководство пользователя, Страница: 18 / 49

Interface Selection Guide Texas Instruments 4Q 2006
Design Considerations
Bus Protection — Features such as
short-circuit protection, thermal shutdown
protection, glitch-free power-up and power-
down protection, high-ESD protection,
wide common-mode range that provides for
common-mode noise rejection, and current-
limiting circuitry to protect the transceivers
and system from damage during a fault
condition have been incorporated into
these devices.
CAN Transceiver Selection Guide
Supply I
CC
ESD Bus Fault Operating
Voltage Device Description Max (mA) (kV) Protection (V) Temp Range Price *
5.0 SN65HVD251 Improved Drop-In Replacement for the PCA82C250 and PCA82C251 65 ±14 ±36 –40 to 125° C 0.90
SN65HVD1050 Improved Drop-In Replacement for the TJA1050 with Better ESD 70 ±8 –27 to 40 –40 to 125° C 0.55
3.3 SN65HVD230 3.3-V CAN Bus Transceiver, Standby Mode 67 ±16 –4 to 16 –40 to 85° C 1.35
SN65HVD231 3.3-V CAN Bus Transceiver, Sleep Mode 67 ±16 –4 to 16 –40 to 85° C 1.35
SN65HVD232 3.3-V CAN Bus Transceiver, Cost Effective 67 ±16 –4 to 16 –40 to 85° C 1.30
SN65HVD233 3.3-V CAN Bus Transceiver, Standby Mode, Diagnostic Loop-back 56 ±16 ±36 –40 to 125° C 1.50
SN65HVD234 3.3-V CAN Bus Transceiver, Standby Mode, Sleep Mode 56 ±16 ±36 –40 to 125° C 1.45
SN65HVD235 3.3-V CAN Bus Transceiver, Standby Mode, Autobaud Loop-back 56 ±16 ±36 –40 to 125° C 1.50
All devices have a signaling rate of 1 Mbps. New products are listed in bold red .
*Suggested resale price in U.S. dollars in quantities of 1,000.
3.3
5.0
Electromagnetic Compatibility — An
important requirement for products intended
for networking applications is that they
behave in a way that does not interfere with
the operation of other nearby components or
systems. TI offers specially designed and
tested transceivers for EM compatibility
without malfunction or degradation of
performance in rugged EM environments.
Compatibility in this definition means both
immunity to external EM fields, and the
limited strength of generated EM fields.
Supply Voltage — In addition to 5-V
transceivers, TI offers 3.3-V transceivers
that accomplish the same tasks with less
than half the power and save on the cost of
an additional voltage regulator in 3.3-V
powered applications.
Technical Information
• ISO11898 specifies the physical-layer
implementation of CAN.
• This specification describes a twisted
wire pair bus with 120-W characteristic
impedance (Zo) and differential signaling
rate of up to 1 Mbps on a 40-meter bus
with multi-drop topology.
Selection Guide
Standard Compliant Protocols
CAN is a serial communications bus for robust
real-time control applications that is rapidly
gaining the attention of industrial process,
test, measurement and control engineers
worldwide. It has excellent error detection
and confinement capabilities, and has the
flexibility to operate either as a primary
backbone data communications network, as a
secondary local embedded system, or as both.
The engineering community is just now
exploring the limits of what this bus can do
when coupled with newly developed intelligent
sensing technologies.
Besides CAN’s high reliability, another of the
main advantages of CAN when compared to
alternative networks, is the availability of
higher layer protocols (HLPs). There are many
CAN-related system development packages
prepared for these HLPs – hardware interface
cards and easy-to-use software packages that
provide system designers with a wide range of
design and diagnostic tools. These compo-
nents provide for the rapid development of
complex control applications without building
each node of a system network from scratch.
The HLP relieves a developer from the burden
of dealing with CAN-specific details such as
bit-timing and implementation functions. It
provides standardized communication objects
for real-time data with Process Data Objects
(PDOs) and Service Data Objects (SDOs), and
provides special functions such as a time
stamp, a sync message, and emergency
shut-down procedures as well as network
management, boot-up commands, and error
management.
Among the most popular HLPs are CANopen,
CANkingdom and DeviceNet with applications
ranging from medical equipment to process
control and assembly line coordination.
Device
DSPs with CAN Controllers (3.3-V Supply Voltage)
TMS320LF2403A TMS320F2802-60 TMS320LC2403A TMS320F2806 TMS320LF2406A TMS320F2808 TMS320LC2406A TMS320F2809
TMS320LF2407A TMS320F2810 TMS320LF2407A TMS320C2810 TMS320F2801 TMS320F2811 TMS320F2801-100 TMS320R2811
TMS320F2801-60 TMS320C2811 TMS320F28016 TMS320F2812 TMS320C2802 TMS320C2812 TMS320F2802-100 TMS320R2812
ARM7 Microprocessors with CAN Controllers (3.3-V Supply Voltage)
TMS470R1A64 TMS470R1A384 TMS470R1A128 TMS470R1B512 TMS470R1A256 TMS470R1B768 TMS470R1A288 TMS470R1B1M
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CAN (3.3-V and 5-V High-Speed CAN Transceivers)
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