74HC_HCT238_15 Datasheet, PDF (8/18 Pages) NXP Semiconductors – 3-to-8 line decoder/demultiplexer

NXP Semiconductors
74HC238; 74HCT238
3-to-8 line decoder/demultiplexer
Table 7. Dynamic characteristics
GND = 0 V; test circuit see Figure 8.
Symbol Parameter
Conditions
Min
74HCT238
t_pd
propagation delay An to Yn; see Figure 6
V_CC = 4.5 V
V_CC = 5.0 V; C_L = 15 pF
E3 to Yn; see Figure 6
V_CC = 4.5 V
V_CC = 5.0 V; C_L = 15 pF
En to Yn or see Figure 7
V_CC = 4.5 V
V_CC = 5.0 V; C_L = 15 pF
t_t
transition time
V_CC = 4.5 V;
see Figure 6 and Figure 7
C_PD
power dissipation per package;
capacitance
V_I = GND to V_CC − 1.5 V
[1]
-
-
[1]
-
-
[1]
-
-
[2]
-
[3]
-
[1] t_pd is the same as t_PHL and t_PLH.
[2] t_t is the same as t_THL and t_TLH.
[3] C_PD is used to determine the dynamic power dissipation (P_D in µW):
P_D = C_PD × V_CC2 × f_i × N + ∑ (C_L × V_CC2 × f_o) where:
f_i = input frequency in MHz;
f_o = output frequency in MHz;
C_L = output load capacitance in pF;
V_CC = supply voltage in V;
N = number of inputs switching;
∑ (C_L × V_CC2 × f_o) = sum of outputs.
25 °C
Typ
19
18
20
20
20
21
7
76
−40 °C to +125 °C
Max Max
Max Unit
(85 °C) (125 °C)
35
44
-
-
37
46
-
-
35
44
-
-
15
19
-
-
53 ns
- ns
56 ns
- ns
53 ns
- ns
22 ns
- pF
11. Waveforms
An, E3 input
V_M
Yn output
t_PHL
V_Y
t_THL
V_M
V_X
t_PLH
t_TLH
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Measurement points are given in Table 8.
V_OL and V_OH are typical voltage output levels that occur with the output load.
Fig 6. Input (An, E3) to output (Yn) propagation delays and output transition times
74HC_HCT238_3
Product data sheet
Rev. 03 — 16 July 2007
© NXP B.V. 2007. All rights reserved.
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