74ACT11160 SYNCHRONOUS 4-BIT DECADE COUNTER

SCAS170 - D3624, AUGUST 1990 - REVISED APRIL 1993

features

Inputs Are TTL-Voltage Compatible
Internal Look-Ahead for Fast Counting
Carry Output for N-Bit Cascading
Fully Synchronous Operation for Counting
Synchronously Programmable
Flow-Through Architecture Optimizes PCB Layout
Center-Pin V_CC and GND Configurations Minimize High-Speed Switching Noise
EPIC ^TM (Enhanced-Performance Implanted CMOS) 1-m Process
500-mA Typical Latch-Up Immunity at 125°C
Package Options Include Plastic Small-Outline Packages and Standard Plastic 300-mil DIPs
EPIC is a trademark of Texas Instruments Incorporated.

description

This synchronous, presettable 4-bit decade counter features aninternal carry look-ahead circuitry for application in high-speedcounting designs. Synchronous operation is provided by having allflip-flops clocked simultaneously so that the outputs changecoincident with each other when so instructed by the count-enableinputs and internal gating. This mode of operation eliminates theoutput counting spikes that are normally associated with asynchronous(ripple-clock) counters. A buffered clock (CLK) input triggers thefour flip-flops on the rising (positive-going) edge of theclock-input waveform.

This counter is fully programmable; that is, it may be preset toany number between 0 and 9. As presetting is synchronous, setting upa low level at the load ()input disables the counter and causes the outputs to agree with thesetup data after the next clock rising edge regardless of the levelsof the enable inputs. The clear function for the 74ACT11160 isasynchronous, and a low level at the clear () input sets all four of theflip-flop outputs low regardless of the levels of the clock, load, orenable inputs.

The carry look-ahead circuitry provides for cascading counters forn-bit synchronous applications without additional gating.Instrumental in accomplishing this function are two count-enable (ENPand ENT) inputs and a ripple-carry (RCO) output. Both count-enableinputs must be held high to count, and ENT is fed forward to enableRCO. RCO thus enabled will produce a high-level pulse while the countis 9 (HLLH). This high-level overflow ripple-carry pulse can be usedto enable successive cascaded stages. Transitions at ENP or ENT areallowed regardless of the level of the clock input.

This counter features a fully independent clock circuit. Changesat control inputs (ENP, ENT, or )that will modify the operating mode have no effect on the contents ofthe counter until clocking occurs. The function of the counter(whether enabled, disabled, loading, or counting) is dictated solelyby the conditions meeting the setup and hold times.

The 74ACT11160 is characterized for operation from -40°C to85°C.

Title: SYNCHRONOUS 4-BIT DECADE COUNTER
Product Family: BINARY
Device Functionality: 4-BIT DECADE COUNTER
Orderable Devices: 74ACT11160DW, 74ACT11160N

View the complete PDF datasheet: scas170.pdf (106 K Bytes) (Requires Acrobat Reader 3.x)

View more information about generic part numbers:74ACT11160

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