MAX490C/D Maxim Integrated, MAX490C/D Datasheet - Page 9

• Manufacturer Part Number: MAX490C/D
• Description: RS-422/RS-485 Interface IC
• Manufacturer: Maxim Integrated

Specifications of MAX490C/D

• Data Rate: 2.5 Mbps
• Operating Supply Voltage: 5 V
• Supply Current: 0.5 mA
• Operating Temperature Range: 0 C to + 70 C
• Number Of Drivers: 1
• Number Of Receivers: 1
• Product: RS-422/RS-485 Combination

Maxim Integrated
Figure 4. Driver DC Test Load
Figure 6. Driver/Receiver Timing Test Circuit
The MAX483 and MAX487–MAX489 are slew-rate limit-
ed, minimizing EMI and reducing reflections caused by
improperly terminated cables. Figure 12 shows the dri-
ver output waveform and its Fourier analysis of a
150kHz signal transmitted by a MAX481, MAX485,
MAX490, MAX491, or MAX1487. High-frequency har-
_________________________________________________________________Test Circuits
DI
DE
MAX483/MAX487/MAX488/MAX489:
3V
Y
Z
Y
Z
Reduced EMI and Reflections
V
V
OD
ID
R
C
C
DIFF
L1
L2
R
R
V
OC
A
B
Low-Power, Slew-Rate-Limited
RE
RO
RS-485/RS-422 Transceivers
MAX487–MAX491/MAX1487
monics with large amplitudes are evident. Figure 13
shows the same information displayed for a MAX483,
MAX487, MAX488, or MAX489 transmitting under the
same conditions. Figure 13’s high-frequency harmonics
have much lower amplitudes, and the potential for EMI
is significantly reduced.
Figure 5. Receiver Timing Test Load
Figure 7. Driver Timing Test Load
UNDER TEST
RECEIVER
OUTPUT
OUTPUT
15pF
C
TEST POINT
RL
C
L
500Ω
1kΩ
S1
S2
S1
S2
1kΩ
V
CC
V
CC
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