HEF4737VP Просмотр технического описания (PDF) - Philips Electronics
Номер в каталоге
Компоненты Описание
Список матч
HEF4737VP Datasheet PDF : 9 Pages
| |||
Philips Semiconductors
Quadruple static decade counters
Product specification
HEF4737B
HEF4737V
multiplexer. A LOW level at this input disables the BCD
outputs making them floating (high impedance off-state).
Digit select inputs (SA, SB, SC)
SA
SB
SC
L
L
L selects D1 (LSD)
H
L
L selects D2
L
H
L selects D3
H
H
L selects D4
X
X
H selects D5 (MSD)
Notes
1. H = HIGH state (the more positive voltage)
2. L = LOW state (the less positive voltage)
3. X = state is immaterial
4. When D5 is selected, the contents of D5 is available at
O0 and O1, O2 and O3 are LOW.
5. LSD = least significant divider
6. MSD = most significant divider
Output signals
The carry outputs are active LOW outputs.
Carry output CO2
When the contents of the first two decades of the counter
are both 9 then the CO2 output becomes LOW. It remains
LOW until the next LOW to HIGH transition of the count
input, i.e. until the contents of the first two decades are
zero. CO2 is LOW when the contents of the counter are: 00
099, 00 199, 00 299 etc.
Carry output CO3
When the contents of the first three decades of the counter
are all 9 then the CO3 output becomes LOW. It remains
LOW until the next LOW to HIGH transition of the count
input, i.e. until the contents of the first three decades are
zero. CO3 is LOW when the contents of the counter are
00 999, 01 999, 02 999 etc.
Carry output CO4
When the contents of the first four decades of the counter
are all 9 then the CO4 output becomes LOW. It remains
LOW until the next LOW to HIGH transition of the count
input, i.e. until the contents of the first four decades are
zero. CO4 is LOW when the contents of the counter are
09 999 and 19 999.
The carry signals CO2 , CO3 and CO4 are suppressed
while the preset is active. A HIGH to the preset input sets
the counter to 19 999 but the carry signals remain HIGH
until preset input returns to LOW, then the carry outputs
will also become LOW.
Carry output CO5
When the content of the counter is 10 000 the CO5 output
becomes LOW. It returns to HIGH when the content of the
counter is zero.
Digit outputs (O0 to O3)
The digit outputs give the contents of the selected latch.
The output is in the form of BCD, positive logic.
January 1995
4
Share Link: 