74AHC_AHCT123A All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 4 — 8 November 2011 12 of 22
NXP Semiconductors
74AHC123A; 74AHCT123A
Dual retriggerable monostable multivibrator with reset
[1] Typical values are measured at nominal supply voltage (V
CC
= 3.3 V and V
CC
= 5.0 V).
[2] t
pd
is the same as t
PLH
and t
PHL
; C
EXT
= 0 pF; R
EXT
=5 k.
[3] For C
EXT
10 nF the typical value of the pulse width t
W
(s) = C
EXT
(nF) R
EXT
(k).
[4] C
PD
is used to determine the dynamic power dissipation P
D
(W).
P
D
=C
PD
V
CC
2
f
i
+ (C
L
V
CC
2
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.
[5] C
EXT
has no limits.
t
rtrig
retrigger
time
nA to nB; C
EXT
= 100 pF;
R
EXT
=1k; C
L
=50pF;
see Figure 8 and Figure 10
V
CC
= 4.5 V to 5.5 V - 60 - - - - - ns
nA
to nB; C
EXT
= 0.01 F;
R
EXT
=1k; C
L
=50pF;
see Figure 8 and Figure 10
V
CC
= 4.5 V to 5.5 V - 1.5 - - - - - s
C
PD
power
dissipation
capacitance
C
L
=50pF; f
i
= 1 MHz;
V
I
=GNDtoV
CC
[4]
-58- - - - -pF
External components
R
EXT
external
resistance
V
CC
= 2.0 V 5 - - - - - - k
V
CC
> 3.0 V 1 - - - - - - k
C
EXT
external
capacitance
V
CC
= 2.0 V
[5]
---- - - -pF
V
CC
> 3.0 V
[5]
---- - - -pF
Table 7. Dynamic characteristics …continued
GND = 0 V; For test circuit see Figure 12.
Symbol Parameter Conditions 25 C 40 C to +85 C 40 C to +125 C Unit
Min Typ
[1]
Max Min Max Min Max
