6 Parameter Measurement Information

Phase relationships between waveforms were chosen arbitrarily. All input pulses are supplied by generators

having the following characteristics: PRR ≤ 1 MHz, ZO = 50 Ω, tt < 6 ns.

For clock inputs, fmax is measured when the input duty cycle is 50%.

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

CL

(1)

From Output

Under Test

Test

Point

(1) CL includes probe and test-fixture capacitance.

Figure 6-1. Load Circuit for Push-Pull Outputs

1.3V

tw

Input

1.3V

3V

0 V

Figure 6-2. Voltage Waveforms, TTL-Compatible

CMOS Inputs Pulse Duration

Clock

Input

1.3V

3V

0 V

1.3V

1.3V

3V

0 V

tsu

Data

Input

th

Figure 6-3. Voltage Waveforms, TTL-Compatible

CMOS Inputs Setup and Hold Times

1.3V

Input

1.3V

3V

0 V

50%

50%

VOH

VOL

tPLH

(1)

tPHL

(1)

VOH

VOL

tPHL

(1)

tPLH

(1)

Output

Waveform 1

Output

Waveform 2

50%

50%

(1) The greater between tPLH and tPHL is the same as tpd.

Figure 6-4. Voltage Waveforms, TTL-Compatible CMOS Inputs Propagation Delays

CD74HC390, CD54HCT390, CD74HCT390

SCHS185E – SEPTEMBER 1997 – REVISED APRIL 2022

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