MAX3221

3V TO 5.5V SINGLECHANNEL RS232 LINE DRIVER/RECEIVER

WITH ±15kV ESD PROTECTION

SLLS348M − JUNE 1999 − REVISED MARCH 2004

7

POST OFFICE BOX 655303

PARAMETER MEASUREMENT INFORMATION

50

Ω

TEST CIRCUIT

VOLTAGE WAVEFORMS

−3 V

−3 V

3 V

3 V

0 V

3 V

Output

Input

VOL

VOH

tTLH

Generator

(see Note B)

RL

3 V

FORCEOFF

RS-232

Output

tTHL

CL

(see Note A)

SR(tr)

+

6V

t

NOTES: A. CL includes probe and jig capacitance.

B. The pulse generator has the following characteristics: PRR = 250 kbit/s, ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns.

Figure 1. Driver Slew Rate

50

Ω

TEST CIRCUIT

VOLTAGE WAVEFORMS

0 V

3 V

Output

Input

VOL

VOH

tPLH

Generator

(see Note B)

RL

3 V

FORCEOFF

RS-232

Output

tPHL

CL

(see Note A)

NOTES: A. CL includes probe and jig capacitance.

B. The pulse generator has the following characteristics: PRR = 250 kbit/s, ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns.

50%

50%

1.5 V

1.5 V

Figure 2. Driver Pulse Skew

TEST CIRCUIT

VOLTAGE WAVEFORMS

50

Ω

−3 V

3 V

Output

Input

VOL

VOH

tPHL

Generator

(see Note B)

tPLH

Output

CL

(see Note A)

3 V or 0 V

FORCEON

NOTES: A. CL includes probe and jig capacitance.

B. The pulse generator has the following characteristics: ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns.

3 V

FORCEOFF

1.5 V

1.5 V

50%

50%

Figure 3. Receiver Propagation Delay Times