High CMRR RS-485 Transceiver

with ±50V Isolation

_______________________________________________________________________________________

7

DE

5V/div

VY

10V/div

100

µs/div

0

+50V

POWER-UP DELAY

MAX3157toc19

0

20

10

40

30

50

60

0.1

1

10

MAXIMUM COMMON-MODE PEAK VOLTAGE TO

GROUND vs. COMMON-MODE FREQUENCY

COMMON-MODE FREQUENCY (kHz)

MAXIMUM COMMON PEAK

VOLTAGE TO ISOCOM

COMMON-MODE VOLTAGE TO

ISOCOM = 7V PEAK

Typical Operating Characteristics (continued)

Test Circuits and Timing Diagrams

R

R

Y

Z

Figure 1. Driver DC Test Load

DI

DE

3V

Y

Z

Figure 3. Driver Timing Test Circuit

RECEIVER

OUTPUT

TEST POINT

1k

Ω

1k

Ω

S1

S2

100pF

OUTPUT

UNDER TEST

500

Ω

S1

S2

Figure 2. Receiver Enable/Disable Timing Test Load

Figure 4. Driver Enable/Disable Timing Test Load