MM74C927 Output Drivers Datasheet

MM74C927 Datasheet, PDF, Equivalent


Part Number

MM74C927

Description

4-Digit Counters with Multiplexed 7-Segment Output Drivers

Manufacture

National

Total Page 8 Pages
Datasheet
Download MM74C927 Datasheet


MM74C927
March 1988
MM74C925 MM74C926 MM74C927 MM74C928
4-Digit Counters with Multiplexed
7-Segment Output Drivers
General Description
These CMOS counters consist of a 4-digit counter an inter-
nal output latch NPN output sourcing drivers for a 7-seg-
ment display and an internal multiplexing circuitry with four
multiplexing outputs The multiplexing circuit has its own
free-running oscillator and requires no external clock The
counters advance on negative edge of clock A high signal
on the Reset input will reset the counter to zero and reset
the carry-out low A low signal on the Latch Enable input will
latch the number in the counters into the internal output
latches A high signal on Display Select input will select the
number in the counter to be displayed a low level signal on
the Display Select will select the number in the output latch
to be displayed
The MM74C925 is a 4-decade counter and has Latch En-
able Clock and Reset inputs
The MM74C926 is like the MM74C925 except that it has a
display select and a carry-out used for cascading counters
The carry-out signal goes high at 6000 goes back low at
0000
The MM74C927 is like the MM74C926 except the second
most significant digit divides by 6 rather than 10 Thus if the
clock input frequency is 10 Hz the display would read
tenths of seconds and minutes (i e 9 59 9)
The MM74C928 is like the MM74C926 except the most sig-
nificant digit divides by 2 rather than 10 and the carry-out is
an overflow indicator which is high at 2000 and it goes back
low only when the counter is reset Thus this is a 3 -digit
counter
Features
Y Wide supply voltage range
3V to 6V
Y Guaranteed noise margin
1V
Y High noise immunity
0 45 VCC (typ )
Y High segment sourcing current
40 mA
VCC b 1 6V VCC e 5V
Y Internal multiplexing circuitry
Design Considerations
Segment resistors are desirable to minimize power dissipa-
tion and chip heating The DS75492 serves as a good digit
driver when it is desired to drive bright displays When using
this driver with a 5V supply at room temperature the display
can be driven without segment resistors to full illumination
The user must use caution in this mode however to prevent
overheating of the device by using too high a supply voltage
or by operating at high ambient temperatures
The input protection circuitry consists of a series resistor
and a diode to ground Thus input signals exceeding VCC
will not be clamped This input signal should not be allowed
to exceed 15V
Connection Diagrams
Dual-In-Line Package
Dual-In-Line Package
Top View
Order Number MM74C925
TL F 5919 – 1
C1995 National Semiconductor Corporation TL F 5919
Top View
Order Number MM74C926
MM74C927 or MM74C928
TL F 5919 – 2
RRD-B30M105 Printed in U S A

MM74C927
Absolute Maximum Ratings (Note 1)
If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
Office Distributors for availability and specifications
Voltage at Any Output Pin
Voltage at Any Input Pin
GND b 0 3V to VCC a 0 3V
GND b 0 3V to a15V
Operating Temperature
Range (TA)
b40 C to a85 C
Storage Temperature Range
b65 C to a150 C
Power Dissipation (PD)
Operating VCC Range
VCC
Lead Temperature
(Soldering 10 seconds)
Refer to PD(MAX) vs TA Graph
3V to 6V
6 5V
260 C
DC Electrical Characteristics Min Max limits apply at b40 C s Tj s a85 C unless otherwise noted
Symbol
Parameter
Conditions
Min Typ Max Units
CMOS TO CMOS
VIN(1) Logical ‘‘1’’ Input Voltage
VCC e 5V
35 V
VIN(0) Logical ‘‘0’’ Input Voltage
VCC e 5V
15 V
VOUT(1)
Logical ‘‘1’’ Output Voltage
(Carry-Out and Digit Output
Only)
VCC e 5V IO e b10 mA
45
V
VOUT(0) Logical ‘‘0’’ Output Voltage
VCC e 5V IO e 10 mA
05 V
IIN(1)
Logical ‘‘1’’ Input Current
VCC e 5V VIN e 15V
0 005
1 mA
IIN(0)
ICC
Logical ‘‘0’’ Input Current
Supply Current
CMOS LPTTL INTERFACE
VCC e 5V VIN e 0V
VCC e 5V Outputs Open Circuit
VIN e 0V or 5V
b1 b0 005
mA
20 1000 mA
VIN(1) Logical ‘‘1’’ Input Voltage
VCC e 4 75V
VCC b 2
V
VIN(0) Logical ‘‘0’’ Input Voltage
VCC e 4 75V
08 V
VOUT(1)
Logical ‘‘1’’ Output Voltage
(Carry-Out and Digit
Output Only)
VCC e 4 75V
IO e b360 mA
24 V
VOUT(0) Logical ‘‘0’’ Output Voltage
VCC e 4 75V IO e 360 mA
04 V
OUTPUT DRIVE
VOUT
Output Voltage (Segment
Sourcing Output)
IOUT e b65 mA VCC e 5V Tj e 25 C
IOUT e b40 mA VCC e 5V
Tj e 100 C
Tj e 150 C
VCC b 2
VCC b 1 6
VCC b 2
VCC b 1 3
VCC b 1 2
VCC b 1 4
V
V
V
RON
Output Resistance (Segment
Sourcing Output)
Output Resistance (Segment
Output) Temperature Coefficient
IOUT e b65 mA VCC e 5V Tj e 25 C
IOUT e b40 mA VCC e 5V
Tj e 100 C
Tj e 150 C
20 32 X
30 40 X
35 50 X
06 08 % C
ISOURCE Output Source Current
(Digit Output)
VCC e 4 75V VOUT e 1 75V Tj e 150 C
b1
b2
mA
ISOURCE Output Source Current
(Carry-Out)
VCC e 5V VOUT e 0V Tj e 25 C
b1 75
b3 3
mA
ISINK
Output Sink Current
(All Outputs)
VCC e 5V VOUT e VCC Tj e 25 C
1 75 3 6
mA
ijA Thermal Resistance
MM74C925
(Note 4)
MM74C926 MM74C927 MM74C928
75 100 C W
70 90 C W
Note 1 ‘‘Absolute Maximum Ratings’’ are those values beyond which the safety of the device cannot be guaranteed Except for ‘‘Operating Temperature Range’’
they are not meant to imply that the devices should be operated at these limits The table of ‘‘Electrical Characteristics’’ provides conditions for actual device
operation
Note 2 Capacitance is guaranteed by periodic testing
Note 3 CPD determines the no load AC power consumption of any CMOS device For complete explanation see 54C 74C Family Characteristics application note
AN-90
Note 4 ijA measured in free-air with device soldered into printed circuit board
2


Features MM74C925 MM74C926 MM74C927 MM74C928 4-Di git Counters with Multiplexed 7-Segment Output Drivers March 1988 MM74C925 M M74C926 MM74C927 MM74C928 4-Digit Count ers with Multiplexed 7-Segment Output D rivers General Description These CMOS c ounters consist of a 4-digit counter an internal output latch NPN output sourc ing drivers for a 7-segment display and an internal multiplexing circuitry wit h four multiplexing outputs The multipl exing circuit has its own free-running oscillator and requires no external clo ck The counters advance on negative edg e of clock A high signal on the Reset i nput will reset the counter to zero and reset the carry-out low A low signal o n the Latch Enable input will latch the number in the counters into the intern al output latches A high signal on Disp lay Select input will select the number in the counter to be displayed a low l evel signal on the Display Select will select the number in the output latch t o be displayed The MM74C925 is a 4-decade counter and has Latch.
Keywords MM74C927, datasheet, pdf, National, 4-Digit, Counters, with, Multiplexed, 7-Segment, Output, Drivers, M74C927, 74C927, 4C927, MM74C92, MM74C9, MM74C, Equivalent, stock, pinout, distributor, price, schematic, inventory, databook, Electronic, Components, Parameters, parts, cross reference, chip, Semiconductor, circuit, Electric, manual, substitute




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