1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

______________________________________________________________________________________

11

Figure 10. Loopback Test Result at 235kbps

T1IN

R1OUT

C1–C4 = 0.1µF

T1OUT

5V/div

5V/div

2µs/div

5V/div

MAX3221

MAX3223

MAX3243

5kΩ

R_ IN

R_ OUT

EN (MAX3221/3)

C2-

C2+

C1-

C1+

V-

V+

C4

C3

C1

C2

0.1µF

FORCEOFF

T_ OUT

T_ IN

GND

0V

1000pF

Figure 8. Loopback Test Circuit

Figure 9. Loopback Test Result at 120kbps

T1IN

R1OUT

C1–C4 = 0.1µF

T1OUT

5V/div

5V/div

5V/div

5µs/div

Table 4. Logic Family Compatibility with

Various Supply Voltages

Table 3. Required Capacitor Values

VOLTAGE

(V)

COMPATIBILITY

3.3

3.3

Compatible with all CMOS

families.

5

5

Compatible with all TTL and

CMOS-logic families.

SYSTEM

POWER-

SUPPLY

VOLTAGE

(V)

5

3.3

Compatible with ACT and

HCT CMOS, and with TTL.

Incompatible with AC, HC,

or CD4000 CMOS.

(V)

C1

(µF)

C2, C3, C4

(µF)

3.0 to 3.6

0.1

0.1

4.5 to 5.5

0.047

0.33

3.0 to 5.5

0.1

0.47