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74HC237

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Product data sheet

Rev. 7 — 29 January 2016

8 of 17

Nexperia

74HC237

3-to-8 line decoder, demultiplexer with address latches

[1]

tpd is the same as tPLH and tPHL.

[2]

tt is the same as tTHL and tTLH.

[3]

CPD is used to determine the dynamic power dissipation (PD in W).

PD =CPD  VCC2  fi  N+ (CL  VCC2  fo) where:

fi = input frequency in MHz;

fo = output frequency in MHz;

CL = output load capacitance in pF;

VCC = supply voltage in V;

N = number of inputs switching;

(C

L  VCC

2

 f

o) = sum of outputs.

11. Waveforms

th

hold time

An to LE; see Figure 9

-

VCC = 2.0 V

30

3

-

40

-

45

-

ns

VCC = 4.5 V

6

1

-

8

-

9

-

ns

VCC = 6.0 V

5

1

-

7

-

8

-

ns

CPD

power

dissipation

capacitance

CL =50pF;f= 1 MHz;

VI =GND to VCC

[3]

-60

-

-

-

-

-

pF

Table 7.

Dynamic characteristics …continued

Voltages are referenced to GND (ground = 0 V); CL = 50 pF unless otherwise specified; for test circuit see Figure 10.

Symbol Parameter

Conditions

Tamb = 25 C

Tamb = 40 C

to +85

C

Tamb = 40 C

to +125

C

Unit

Min

Typ

Max

Min

Max

Min

Max

Measurement points are given in Table 8.

VOL and VOH are typical voltage output levels that occur with the output load.

Fig 7.

Propagation delay input (An) and enable inputs (E2, LE) to output (Yn) and output transition time