KK74HC221A Datasheet, PDF (1/7 Pages) KODENSHI KOREA CORP. – Dual Monostable Multivibrator

TECHNICAL DATA
Dual Monostable Multivibrator
KK74HC221A
The KK74HC221A is identical in pinout to the LS/ALS221. The device
inputs are compatible with standard CMOS outputs; with pullup resistors,
they are compatible with LS/ALSTTL outputs.
There are two trigger inputs, A INPUT (negative edge) and
B INPUT (positive edge). These inputs are valid for rising/falling signals
The device may also be triggered by using the RESET input (positive-
edge) because of the Schmitt-trigger input; after triggering the output
maintains the MONOSTABLE state for the time period determined by the
external resistor R_EXT and capacitor C_EXT. Taking RESET low breaks this
MONOSTABLE STATE. If the next trigger pulse occurs during the
MONOSTABLE period it makes the MONOSTABLE period longer.
• Outputs Directly Interface to CMOS, NMOS, and TTL
• Operating Voltage Range: 3.0 to 6.0 V
• Low Input Current: 1.0 µA
• High Noise Immunity Characteristic of CMOS Devices
N SUFFIX
PLASTIC
16
1
D SUFFIX
16
SOIC
1
ORDERING INFORMATION
KK74HC221AN Plastic
KK74HC221AD SOIC
T_A = -55° to 125° C for all packages
PIN ASSIGNMENT
LOGIC DIAGRAM
C_EXT
D_EXT
R_EXT
C_EXT
D_EXT
R_EXT
1A 1
1B 2
1RESET 3
1Q 4
2Q 5
2C_EXT
6
2R_EXT/C_EXT 7
GND 8
16 VCC
15 1R_EXT/C_EXT
14 1C_EXT
13 1Q
12 2Q
11 2RESET
10 _2B
9 2A
PIN 16 =V_CC
PIN 8 = GND
Note
(1) C_EXT, R_EXT, D_EXT are external components.
(2) D_EXT is a clamping diode.
The external capacitor is charged to V_CC in the stand-by
state, i.e. no trigger. When the supply voltage is turned off
C_X is discharged mainly through an internal parasitic diode.
If C_X is sufficiently large and V_CC decreases rapidy, there
will be some possibility of damaging the I.C. with a surge
current or latch-up. If the voltage supply filter capacitor is
large enough and V_CC decrease slowly, the surge current is
automatically limited and damage the I.C. is avoided. The
maximum forward current of the parasitic diode is
approximately 20 mA.
FUNCTION TABLE
Inputs
Outputs
A B RESET Q Q
HH
XL
H
L^* H^*
HX
H
L^* H^*
L
H
LH
XX L
LH
X = don’t care
* _{- except for monostable period}
Note
Output
Enable
Inhibit
Inhibit
Output
Enable
Output
Enable
Inhibit
1