SN75LPE185

LOW-POWER MULTIPLE RS-232 DRIVERS/RECEIVERS

WITH ENABLE

SLLS256D – DECEMBER 1996 – REVISED OCTOBER 1998

10

POST OFFICE BOX 655303

PARAMETER MEASUREMENT INFORMATION

VOH

VOL

From Output

Under Test

CL = 50 pF

(see Note A)

LOAD CIRCUIT

S1

4 V

Open

GND

5k

Ω

VI

VO

Waveform 1

(see Note B)

VO

Waveform 2

(see Note B)

tPZL

tPZH

tPLZ

tPHZ

50%

50%

0 V

50%

VOL + 0.3 V

50%

VOH – 0.3 V

0 V

3 V

4 V

VOLTAGE WAVEFORMS

ENABLE AND DISABLE TIMES

tPHL/tPLH

tPLZ/tPZL

tPHZ/tPZH

Open

4 V

GND

TEST

S1

NOTES: A. CL includes probe and jig capacitance.

B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.

Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.

C. All input pulses are supplied by generators having the following characteristics: PRR = 250 kbit/s, ZO = 50 Ω, tr = tf < 50 ns.

D. The outputs are measured one at a time with one transition per measurement.

Figure 7. Receiver 3-State Parameter Test Circuit and Voltage Waveforms