PHILIPS 74HC221

INTEGRATED CIRCUITS
DATA SHEET
For a complete data sheet, please also download:
• The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications
• The IC06 74HC/HCT/HCU/HCMOS Logic Package Information
• The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
74HC/HCT221
Dual non-retriggerable monostable
multivibrator with reset
Product specification
Supersedes data of April 1988
File under Integrated Circuits, IC06
December 1990
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
jitter-free triggering from inputs with slow transition rates,
providing the circuit with excellent noise immunity.
FEATURES
• Pulse width variance is typically less than ± 5%
Once triggered, the outputs (nQ, nQ) are independent of
further transitions of nA and nB inputs and are a function
of the timing components. The output pulses can be
terminated by the overriding active LOW reset inputs
(nRD). Input pulses may be of any duration relative to the
output pulse.
• Pin-out identical to “123”
• Overriding reset terminates output pulse
• nB inputs have hysteresis for improved noise immunity
• Output capability: standard (except for nREXT/CEXT)
• ICC category: MSI
Pulse width stability is achieved through internal
compensation and is virtually independent of VCC and
temperature. In most applications pulse stability will only
be limited by the accuracy of the external timing
components.
GENERAL DESCRIPTION
The 74HC/HCT221 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
The output pulse width is defined by the following
relationship:
The 74HC/HCT221 are dual non-retriggerable monostable
multivibrators. Each multivibrator features an active
LOW-going edge input (nA) and an active HIGH-going
edge input (nB), either of which can be used as an enable
input.
tW = CEXTREXTIn2
tW = 0.7CEXTREXT
Pin assignments for the “221” are identical to those of the
“123” so that the “221” can be substituted for those
products in systems not using the retrigger by merely
changing the value of REXT and/or CEXT.
Pulse triggering occurs at a particular voltage level and is
not directly related to the transition time of the input pulse.
Schmitt-trigger input circuitry for the nB inputs allow
QUICK REFERENCE DATA
GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns
TYPICAL
SYMBOL PARAMETER
CONDITIONS
UNIT
HC
propagation delay
tPHL
nA, nB, nRD to nQ, nQ
tPLH
nA, nB, nRD to nQ, nQ
CL = 15 pF; VCC = 5 V;
REXT = 5 kΩ; CEXT = 0 pF
HCT
29
32
ns
35
36
ns
CI
input capacitance
3.5
3.5
pF
CPD
power dissipation capacitance per package notes 1 and 2
90
96
pF
Notes
1. CPD is used to determine the dynamic power dissipation (PD in µW):
PD = CPD × VCC2 × fi + ∑ (CL × VCC2 × fo) + 0.33 × CEXT × VCC2 × fo + D × 28 × VCC where:
fi = input frequency in MHz; fo = output frequency in MHz
∑ (CL × VCC2 × fo) = sum of outputs
CEXT = timing capacitance in pF; CL = output load capacitance in pF
VCC = supply voltage in V; D = duty factor in %
2. For HC the condition is VI = GND to VCC
For HCT the condition is VI = GND to VCC − 1.5 V
December 1990
2
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
ORDERING INFORMATION
See “74HC/HCT/HCU/HCMOS Logic Package Information”.
PIN DESCRIPTION
PIN NO.
SYMBOL
NAME AND FUNCTION
1, 9
1A, 2A
trigger inputs (negative-edge triggered)
2, 10
1B, 2B
trigger inputs (positive-edge triggered)
3, 11
1RD, 2RD
direct reset inputs (active LOW)
4, 12
1Q, 2Q
outputs (active LOW)
7
2REXT/CEXT
external resistor/capacitor connection
8
GND
ground (0 V)
13, 5
1Q, 2Q
outputs (active HIGH)
14, 6
1CEXT, 2CEXT
external capacitor connection
15
1REXT/CEXT
external resistor/capacitor connection
16
VCC
positive supply voltage
Fig.1 Pin configuration.
December 1990
Fig.2 Logic symbol.
3
Fig.3 IEC logic symbol.
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
FUNCTION TABLE
INPUTS
OUTPUTS
nRD
nA
nB
L
X
X
nQ
nQ
L
H
(2)
H (2)
H (2)
X
H
X
L
X
X
L
L (2)
H
L
↑
H
↓
H
↑
L
H
(3)
(3)
Notes
1. H = HIGH voltage level
L = LOW voltage level
X = don’t care
↑ = LOW-to-HIGH level
↓ = HIGH-to-LOW level
= one HIGH-level output pulse
= one LOW-level output pulse
2. If the monostable was triggered before this condition
was established the pulse will continue as
programmed.
3. For this combination the reset input must be LOW and
the following sequence must be used:
pin 1 (or 9) must be set HIGH or pin 2 (or 10) set LOW;
then pin 1 (or 9) must be LOW and pin 2 (or 10) set
HIGH. Now the reset input goes from LOW-to-HIGH
and the device will be triggered.
Fig.4 Functional diagram.
December 1990
4
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
Fig.5 Logic diagram.
Note
It is recommended to ground pins 6 (2CEXT) and 14 (1CEXT) externally to pin 8 (GND).
Fig.6 Timing component connections.
December 1990
5
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
DC CHARACTERISTICS FOR 74HC
For the DC characteristics see “74HC/HCT/HCU/HCMOS Logic Family Specifications”.
Output capability: standard (except for nREXT/CEXT)
ICC category: MSI
AC CHARACTERISTICS FOR 74HC
GND = 0 V; tr = tf = 6 ns; CL = 50 pF
Tamb (°C)
TEST CONDITIONS
74HC
SYMBOL PARAMETER
+25
−40 to +85
min typ max. min max.
−40 to +125
min.
UNIT
VCC WAVEFORMS
(V)
max.
tPLH
propagation delay (trigger)
nA, nB to nQ
72
26
21
220
44
37
275
55
47
330
66
56
ns
2.0
4.5
6.0
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.10
tPLH
propagation delay (trigger)
nRD to nQ
80
29
23
245
49
42
305
61
52
370
74
63
ns
2.0
4.5
6.0
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.10
tPHL
propagation delay (trigger)
nA, nB to nQ
58
21
17
180
36
31
225
45
38
270
54
46
ns
2.0
4.5
6.0
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.10
tPHL
propagation delay (trigger)
nRD to nQ
63
23
18
195
39
33
245
49
42
295
59
50
ns
2.0
4.5
6,0
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.10
tPLH
propagation delay (reset)
nRD to nQ
66
24
19
200
40
34
250
50
43
300
60
51
ns
2.0
4.5
6.0
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.11
tPLH
propagation delay (reset)
nRD to nQ
58
21
17
180
36
31
225
45
38
270
54
46
ns
2.0
4.5
6.0
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.11
tTHL/
tTLH
output transition time
19
7
6
75
15
13
95
19
16
110
22
19
ns
2.0
4.5
6.0
Fig.10
tW
trigger pulse width
nA = LOW
75
15
13
25
9
7
95
19
16
110
22
19
ns
2.0
4.5
6.0
Fig.7
tW
trigger pulse width
nB = HIGH
90
18
15
30
11
9
115
23
20
135
27
23
ns
2.0
4.5
6.0
Fig.7
tW
trigger pulse width
nRD = LOW
75
15
13
25
9
7
95
19
16
110
22
19
ns
2.0
4.5
6.0
Fig.8
tW
output pulse width
nQ = LOW
nQ = HIGH
630
700 770
602
µs
5.0
CEXT = 100 nF;
REXT = 10 kΩ;
Fig.10
December 1990
6
798
595
805
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
Tamb (°C)
TEST CONDITIONS
74HC
SYMBOL PARAMETER
+25
−40 to +85
min typ max. min max.
−40 to +125
min.
UNIT
VCC WAVEFORMS
(V)
max.
tW
output pulse width
nQ or nQ
140
−
−
ns
2.0
4.5
6.0
CEXT = 28 nF;
REXT = 2 kΩ;
Fig.10
tW
output pulse width
nQ or nQ
1.5
−
−
µs
2.0
4.5
6.0
CEXT = 1 nF;
REXT = 2 kΩ;
Fig.10
tW
output pulse width
nQ or nQ
7
−
−
µs
2.0
4.5
6.0
CEXT = 1 nF;
REXT = 10 kΩ;
Fig.10
tW
pulse width match
between circuits
in the package
±2
−
−
%
4.5
to
5.5
CEXT = 1000 pF;
REXT = 10 kΩ
trem
removal time
nRD to nA
or nB
100
20
17
30
11
9
125
25
21
150
30
26
ns
2.0
4.5
6.0
Fig.9
REXT
external timing resistor
10
2
−
−
kΩ
2.0
5.0
Fig.12
Fig.13
CEXT
external timing capacitor
no limits
pF
2.0
5.0
Fig.12
Fig.13
December 1990
1000 −
1000 −
7
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
DC CHARACTERISTICS FOR 74HCT
For the DC characteristics see “74HC/HCT/HCU/HCMOS Logic Family Specifications”.
Output capability: standard (except for nREXT/CEXT)
ICC category: MSI
Note to HCT types
The value of additional quiescent supply current (∆ICC) for a unit load of 1 is given in the family specifications.
To determine ∆ICC per input, multiply this value by the unit load coefficient shown in the table below.
INPUT
UNIT LOAD COEFFICIENT
nB
0.30
nA
0.50
nRD
0.50
December 1990
8
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
AC CHARACTERISTICS FOR 74HCT
GND = 0 V; tr = tf = 6 ns; CL = 50 pF
Tamb (°C)
TEST CONDITIONS
74HCT
SYMBOL
PARAMETER
+25
−40 to +85
min typ max min max.
−40 to +125
min.
UNIT
VCC
(V)
WAVEFORMS
max.
tPLH
propagation delay (trigger)
nA, nRD to nQ
30
50
63
75
ns
4.5
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.10
tPLH
propagation delay (trigger)
nB to nQ
24
42
53
63
ns
4.5
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.10
tPHL
propagation delay (trigger)
nA to nQ
26
44
55
66
ns
4.5
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.10
tPHL
propagation delay (trigger)
nB to nQ
21
35
44
53
ns
4.5
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.10
tPHL
propagation delay (trigger)
nRD to nQ
26
43
54
65
ns
4.5
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.10
tPHL
propagation delay (reset)
nRD to nQ
26
43
54
65
ns
4.5
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.11
tPLH
propagation delay (reset)
nRD to nQ
31
51
64
77
ns
4.5
CEXT = 0 pF;
REXT = 5 kΩ;
Fig.11
tTHL/ tTLH
output transition time
7
15
19
22
ns
4.5
Fig.10
tW
trigger pulse width
nA = LOW
20
13
25
30
ns
4.5
Fig.10
tW
trigger pulse width
nB = HIGH
20
13
25
30
ns
4.5
Fig.10
tW
pulse width
nRD = LOW
22
13
28
33
ns
4.5
Fig.8
tW
output pulse width
nQ = LOW
nQ = HIGH
630
700 770
602
µs
5.0
CEXT = 100 nF;
REXT = 10 kΩ;
Fig.10
tW
trigger pulse width
nQ or nQ
140
−
−
ns
4.5
CEXT = 28 pF;
REXT = 2 kΩ;
Fig.10
tW
trigger pulse width
nQ or nQ
1.5
−
−
µs
4.5
CEXT = 1 nF;
REXT = 2 kΩ;
Fig.10
December 1990
9
798
595
805
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
Tamb (°C)
TEST CONDITIONS
74HCT
SYMBOL
PARAMETER
+25
−40 to +85
min typ max min max.
min.
UNIT
VCC
(V)
WAVEFORMS
max.
7
−
−
µs
4.5
CEXT = 1 nF;
REXT = 10 kΩ;
Fig.10
12
25
30
ns
4.5
Fig.9
−
kΩ
5.0
Fig.13
pF
5.0
Fig.13
tW
trigger pulse width
nQ or nQ
trem
removal time
nRD to nA or nB
20
REXT
external timing resistor
2
CEXT
external timing capacitor
no limits
December 1990
−40 to +125
1000 −
10
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
AC WAVEFORMS
Fig.7 Output pulse control; nRD = HIGH.
(1) HC : VM = VM = 50%; VI = GND to VCC.
HCT : VM = VM = 1.3 V; VI = GND to 3 V.
Fig.8
Fig.10 Waveforms showing the triggering of One
Shot by input nA or input nB for one period
(tW) and minimum pulse widths of the trigger
inputs nA and nB.
Output pulse control using reset input nRD;
nA = LOW.
(1) HC : VM = VM = 50%; VI = GND to VCC.
HCT : VM = VM = 1.3 V; VI = GND to 3 V.
(1) HC : VM = VM = 50%; VI = GND to VCC.
HCT : VM = VM = 1.3 V; VI = GND to 3 V.
Fig.9
Fig.11 Waveforms showing the reset to nQ and nQ
output propagation delays.
Waveforms showing the removal times;
nRD to nA or nB.
December 1990
11
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
Fig.12 HC typical output pulse width as a function of timing capacitance (VCC = 2 V).
December 1990
12
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
Fig.13 HC/HCT typical output pulse width as a function of timing capacitance (VCC = 4.5 V).
December 1990
13
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
Fig.14 HC typical output pulse width as a function of timing capacitance (VCC = 6 V).
December 1990
14
Philips Semiconductors
Product specification
Dual non-retriggerable monostable
multivibrator with reset
74HC/HCT221
Fig.15 Typical output pulse width as a function of
temperature; CX = 0.1 µF; RX = 10 KΩ;
VCC = 5 V.
Fig.16 k factor as a function of supply voltage;
RX = 10 KΩ; Tamb = 25 °C.
Power-down consideration
PACKAGE OUTLINES
A large capacitor (CX) may cause problems when
powering-down the monostable due to the energy stored
in this capacitor. When a system containing this device is
powered-down or a rapid decrease of VCC to zero occurs,
the monostable may substain damage, due to the
capacitor discharging through the input protection diodes.
To avoid this possibility, use a damping diode (DX)
preferably a germanium or Schottky type diode able to
withstand large current surges and connect as shown in
Fig.17.
See “74HC/HCT/HCU/HCMOS Logic Package Outlines”.
Fig.17 Power-down protection circuit.
December 1990
15