SYNCHRONOUS 4-BIT UP/DOWN COUNTER SN54/74LS669 The SN54 / 74LS669 is a synchronous 4-bit up/down counter. The LS669 is a 4-bit binary counter. For high speed counting applications, this presettable counter features an internal carry lookahead for cascading purposes. By clocking all flip-flops simultaneously so the outputs change coincident with each other .
an internal carry lookahead for cascading purposes. By clocking all flip-flops simultaneously so the outputs change coincident with each other (when instructed to do so by the count enable inputs and internal gating) synchronous operation is provided. This helps to eliminate output counting spikes, normally associated with asynchronous (ripple-clock) counters. The four master-slave flip-flops are triggered on the rising (positive-going) edge of the clock waveform by a buffered clock input. Circuitry of the load inputs allows loading with the carry-enable output of the cascaded counters. Becaus.
SN54LS668, SN54LS669, SN74LS668, SN74LS669 SYNCHRONOUS 4-BIT UP/DOWN COUNTERS SDLS192 – APRIL 1977 – REVISED MARCH 1988 .
No. | Partie # | Fabricant | Description | Fiche Technique |
---|---|---|---|---|
1 | SN74LS668 |
Texas Instruments |
SYNCHRONOUS 4-BIT UP/DOWN COUNTER | |
2 | SN74LS620 |
Texas Instruments |
Octal Bus Transceiver | |
3 | SN74LS621 |
Texas Instruments |
Octal Bus Transceiver | |
4 | SN74LS623 |
Motorola |
OCTAL BUS TRANSCEIVER | |
5 | SN74LS623 |
Texas Instruments |
Octal Bus Transceiver | |
6 | SN74LS624 |
Texas Instruments |
VOLTAGE-CONTROLLED OSCILLATOR | |
7 | SN74LS625 |
Texas Instruments |
VOLTAGE-CONTROLLED OSCILLATOR | |
8 | SN74LS626 |
Texas Instruments |
VOLTAGE-CONTROLLED OSCILLATOR | |
9 | SN74LS627 |
Texas Instruments |
VOLTAGE-CONTROLLED OSCILLATOR | |
10 | SN74LS628 |
Texas Instruments |
VOLTAGE-CONTROLLED OSCILLATOR | |
11 | SN74LS629 |
Texas Instruments |
VOLTAGE-CONTROLLED OSCILLATOR | |
12 | SN74LS640 |
ON Semiconductor |
Octal Bus Transceivers |