MAX3221

3V TO 5.5V SINGLECHANNEL RS232 LINE DRIVER/RECEIVER

WITH ±15kV ESD PROTECTION

SLLS348M − JUNE 1999 − REVISED MARCH 2004

9

POST OFFICE BOX 655303

PARAMETER MEASUREMENT INFORMATION

TEST CIRCUIT

50

Ω

Generator

(see Note B)

FORCEOFF

ROUT

FORCEON

Auto-

powerdown

INVALID

DOUT

DIN

CL = 30 pF

(see Note A)

2.7 V

−2.7 V

0.3 V

−0.3 V

0 V

Valid RS-232 Level, INVALID High

Indeterminate

Indeterminate

If Signal Remains Within This Region

For More Than 30

µs, INVALID Is Low†

Valid RS-232 Level, INVALID High

† Auto-powerdown disables drivers and reduces supply

current to 1

µA.

NOTES: A. CL includes probe and jig capacitance.

B. The pulse generator has the following characteristics: PRR = 5 kbit/s, ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns.

VOLTAGE WAVEFORMS

3 V

2.7 V

−2.7 V

INVALID

Output

Receiver

Input

tvalid

0 V

0 V

−3 V

VCC

0 V

≈V+

0 V

≈V−

V+

VCC

ten

V−

50% VCC

50% VCC

2.7 V

−2.7 V

0.3 V

0.3 V

tinvalid

Supply

Voltages

Figure 5. INVALID Propagation Delay Times and Driver Enabling Time