Philips Semiconductors
Product specification
Hex inverter
74HCU04
C
1
= 47 pF (typ.)
C
2
= 33 pF (typ.)
R
1
= 1 to 10 MΩ (typ.)
R
2
optimum value depends on the frequency and required
stability against changes in V
CC
or average minimum I
CC
(I
CC
is typically 5 mA at V
CC
= 5 V and f = 10 MHz).
1
1
f
=
--
≈
-----------------
-
-
T 2.2 RC
R
S
≈
2
×
R.
The average I
CC
(mA) is approximately
3.5 + 0.05
×
f (MHz)
×
C (pF) at V
CC
= 5.0 V
(for more information refer to
“DESIGNERS GUIDE”).
Fig.13 Crystal oscillator configuration.
Fig.14 HCU04 used as an astable multivibrator
OPTIMUM VALUE FOR R
2
FREQUENCY
(MHz)
3
R
2
(kΩ)
2
8
1
4.7
0.5
2
0.5
1
OPTIMUM FOR
minimum required I
CC
minimum influence due to
change in V
CC
minimum I
CC
minimum influence by V
CC
minimum I
CC
minimum influence by V
CC
minimum I
CC
minimum influence by V
CC
6
10
14
>
14
replace R
2
by C
3
with a typical
value of 35 pF
EXTERNAL COMPONENTS FOR RESONATOR
(f
<
1 MHz)
FREQUENCY
(kHz)
10 to 15.9
16 to 24.9
25 to 54.9
55 to 129.9
130 to 199.9
200 to 349.9
350 to 600
Note
1. All values given are typical and must be used as an
initial set-up.
R
1
(MΩ)
22
22
22
22
22
10
10
R
2
(kΩ)
220
220
100
100
47
47
47
C
1
(pF)
56
56
56
47
47
47
47
C
2
(pF)
20
10
10
5
5
5
5
Note to Application information
All values given are typical unless otherwise specified.
PACKAGE OUTLINES
See
“74HC/HCT/HCU/HCMOS Logic Package Outlines”.
(1) V
CC
= 2.0 V.
(2) V
CC
= 3.0 V.
(3) V
CC
= 4.0 V.
(4) V
CC
= 5.0 V.
(5) V
CC
= 6.0 V.
Fig.15 Typical input capacitance as a function of
input voltage.
September 1993
7
PHILIPS [ NXP SEMICONDUCTORS ]
