DC1746A-A Linear Technology, DC1746A-A Datasheet - Page 16

• Manufacturer Part Number: DC1746A-A
• Description: EVALUATION KIT LOW EMI LTM2881-3
• Manufacturer: Linear Technology
• Series: µModuler

Specifications of DC1746A-A

• Main Purpose: Interface, Transceiver RS-422/RS-485
• Embedded: No
• Utilized Ic / Part: LTM2881
• Primary Attributes: 3V Supply, Isolated, Transceiver + Power
• Kit Contents: Board, Datasheet
• Tool / Board Applications: Interface-Backplane, PCI, PCI Express, RS-XXX, Digital & Opto Isolator
• Mcu Supported Families: LTM2881
• Development Tool Type: Hardware - Eval/Demo Board
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Secondary Attributes: -

LTM2881
APPLICATIONS INFORMATION
Cable Length versus Data Rate
For a given data rate, the maximum transmission distance
is bounded by the cable properties. A typical curve of
cable length versus data rate compliant with the RS485
standard is shown in Figure 16. Three regions of this
curve reflect different performance limiting factors in data
transmission. In the flat region of the curve, maximum
distance is determined by resistive loss in the cable. The
downward sloping region represents limits in distance and
rate due to the AC losses in the cable. The solid vertical
line represents the specified maximum data rate in the
RS485 standard. The dashed line at 250kbps shows the
maximum data rate when SLO is low. The dashed line at
20Mbps shows the maximum data rate when SLO is high.
16
100
10k
10
Figure 16. Cable Length vs Data Rate
1k
10k
100k
DATA RATE (bps)
RS485 MAX
DATA RATE
1M
MAX DATA RATE
LOW-EMI MODE
10M
MODE MAX
DATA RATE
NORMAL
2881 F16
100M
RF , Magnetic Field Immunity
The LTM2881 has been independently evaluated and has
successfully passed the RF and magnetic field immunity
testing requirements per European Standard EN 55024,
in accordance with the following test standards:
EN 61000-4-3 Radiated, Radio-Frequency,
EN 61000-4-8 Power Frequency Magnetic Field
EN 61000-4-9 Pulsed Magnetic Field Immunity
Tests were performed using an unshielded test card de-
signed per the data sheet PCB layout recommendations.
Specific limits per test are detailed in Table 1.
Table 1. Test Frequency Field Strength
EN 61000-4-3, Annex D 80MHz to 1GHz
EN61000-4-8, Level 4 50Hz and 60Hz
EN61000-4-8, Level 5 60Hz
EN61000-4-9, Level 5 Pulse
*Non IEC Method
1.4MHz to 2GHz
2GHz to 2.7GHz
Electromagnetic Field Immunity
Immunity
100A/m*
1000A/m
10V/m
30A/m
3V/m
1V/m
2881fb