LTC1535

7

1535fa

TEST CIRCUITS

Y

Z

R

R

1535 F02

RECEIVER

OUTPUT

1k

S1

S2

TEST POINT

1k

1535 F03

3V

DE

Y

Z

DI

R

R

1535 F04

OUTPUT

UNDER TEST

S1

S2

500

Ω

1535 F05

Figure 2. Driver DC Test Load

Figure 3. Receiver Timing Test Load

Figure 4. Driver Timing Test Circuit

Figure 5. Driver Timing Test Load

2

**

D

Y

Z

Y

Z

SLO

2

1

1

R

A

B

RO2

1535 F01

RO

RE

DE

DI

GND

LOGIC COMMON

2

2

FLOATING RS485 COMMON

** TRANSFORMER

COOPER (561) 241-7876

SLOW SLEW

RATE JUMPER

420kHz

28

27

26

25

4

17

15

16

18

12

13

14

11

1

+

+

GND2

1/2 BAT54C

1/2 BAT54C

ST1

ST2

3

2

RO

1

10

µF

10

µF

2

CTX02-14659

C2

50pF

2

C1

50pF

BAUD

RATE

Figure 1. Self-Oscillation at Maximum Data Rate

(Test Configuration for the First Six Typical Performance Characteristics Curves)