TC7MBL3245BFT/FK

2007-10-19

5

Rise and Fall Times (tr / tf) of the TC7MBL3245B I/O Signals

The tr(out) and tf(out) values of the output signals are affected by the CR time constant of the input, which consists of

In practice, the tr(out) and tf(out) values are also affected by the circuit’s capacitance and resistance components other

than those of the TC7MBL3245B.

The tr / tf (out) values can be approximated as follows. (Figure 4 shows the test circuit.)

Calculation example:

tr out (approx) = - ( 19+ 15 )E-12 ･ ( 120 + 4) ･ ln ( ( ( 3.0 - 0 ) – 1.5 ) / ( 3.0 – 0 ) )

≈ 3.0ns

Calculation conditions:

Parameter

3.3 ± 0.3 V

2.5 ± 0.2 V

1.8 ± 0.15 V

Figure 3 Test Circuit

Measure

An/Bn

(Switch On)

TC7MBL3245B

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Bn/An

tr out

Measure

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GND

Waveform generated without the TC7MBL3245B

tf out

Waveform generated with the TC7MBL3245B added