MOTOROLA Manuals

The MC74AC138/74ACT138 is a high-speed 1-of-8 decoder/demultiplexer. This device is ideally suited for high-speed bipolar memory chip select address decoding. The multiple input enables allow parallel expansion to a 1-of-24 decoder using just three MC74AC138/74ACT138 devices or a 1-of-32 decoder using four MC74AC138/74ACT138 devices and one inverter.

The MC74AC14/74ACT14 is a device that contains six logic inverters which accept standard CMOS input signals (TTL levels for MC74ACT14) and provide standard CMOS output levels. They are capable of transforming slowly changing input signals into sharply defined, jitter-free output signals. In addition, they have a greater noise margin than conventional inverters. The MC74AC14/74ACT14 has hysteresis between the positive-going and negative-going input thresholds (typically 1.0V) which is determined internally by transistor ratios and is essentially insensitive to temperature and supply voltage variations.

MC74AC151/74ACT151 is a high-speed 8-input digital multiplexer. It provides, in one package, the ability to select one line of data from up to eight sources. The MC74AC151/74ACT151 can be used as a universal function generator to generate any logic function of four variables. Both true and complementary outputs are provided.

The MC74AC153/74ACT153 is a high-speed dual 4-input multiplexer with common select inputs and individual enable inputs for each section. It can select two lines of data from four sources. The two buffered outputs present data in the true (non-inverted) form. In addition to multiplexer operation, the MC74AC153/ 74ACT153 can act as a function generator and generate any two functions of three variables.

The MC74AC157/74ACT157 is a high-speed quad 2-input multiplexer. Four bits of data from two sources can be selected using the common Select and Enable inputs. The four outputs present the selected data in the true (noninverted) form. The MC74AC157/74ACT157 can also be used as a function generator.

The MC74AC158/74ACT158 is a high-speed quad 2-input multiplexer. It selects four bits of data from two sources using the common Select and Enable inputs. The four buffered outputs present the selected data in the inverted form. The MC74AC158/74ACT158 can also be used as a function generator.

MC74AC160/74ACT160 and MC74AC162/74ACT162 are high-speed synchronous decade counters operating in the BCD (8421) sequence. They are synchronously presettable for application in programmable dividers and have two types of Count Enable inputs plus a Terminal Count output for versatility in forming synchronous multistage counters. The MC74AC160/74ACT160 has an asynchronous Master Reset input that overrides all other inputs and forces the outputs LOW. The MC74AC162/74ACT162 has a Synchronous Reset input that overrides counting and parallel loading and allows all outputs to be simultaneously reset on the rising edge of the clock.

The MC74AC/ACT175 is a high-speed quad D flip-flop. The device is useful for general flip-flop requirements where clock and clear inputs are common. The information on the D inputs is transferred to storage during the LOW-to-HIGH clock transition. The device has a Master Reset to simultaneously clear all flip-flops, when MR is low. The MC74AC/ACT175 consists of four edge-triggered D flip-flops with individual D inputs and Q and Q outputs. The Clock (CP) and Master Reset (MR) are common to all flip-flops. Each D input’s state is transferred to the corresponding flip-flop’s output following the LOW-to-HIGH Clock (CP) transition. A LOW input to the Master Reset (MR) will force all Q outputs LOW and Q outputs HIGH independent of Clock or Data inputs. The MC74AC/ACT175 is useful for applications where the Clock and Master Reset are common to all storage elements.

The MC74AC190 is a reversible BCD (8421) decade counter which features synchronous counting and asynchronous presetting.

MC74AC194/74ACT194 is a high-speed 4-bit bidirectional universal shift register. As a high-speed multifunctional, sequential building block, it is useful in a wide variety of applications. It may be used in serial-serial, shift left, shift right, serial-parallel, parallel-serial, and parallel-parallel data register transfers. The ′AC/ACT194 is similar in operation to the ′AS195 universal shift register, with added features of shift left without external connections and hold (do nothing) modes of operation.

MC74AC20/MC74ACT20 is a dual 4-input NAND gate. The two models differ in that MC74ACT20 has TTL compatible inputs. The device operates over a supply voltage range of -0.5~+7V, with input current of -20mA and output current of 24mA.

The MC74AC241/74ACT241 is an octal buffer and line driver designed to be employed as a memory address driver, clock driver and bus oriented transmitter or receiver which provides improved PC board density.

The MC74AC244/74ACT244 is an octal buffer and line driver designed to be employed as a memory address driver, clock driver and bus oriented transmitter/receiver which provides improved PC board density.