74HC20 Dual 4-input NAND Gate IC (7420 IC) DIP-14 Package

The 74HC137 decoder utilizes advanced silicon-gate CMOS technology and is well suited to memory address decoding or data routing applications. The circuit features high noise immunity and low power consumption usually associated with CMOS circuitry, yet has speeds comparable to low power Schottky TTL logic. The 74HC137 has 3 binary select inputs (A, B, and C). If the device is enabled, these inputs determine which one of the eight normally HIGH outputs will go LOW. Two active LOW and one active HIGH enables (G1, G2A and G2B) are provided to ease the cascading of decoders. The decoder’s outputs can drive 10 low power Schottky TTL equivalent loads, and are functionally and pin equivalent to the 74LS137. All inputs are protected from damage due to static discharge by diodes to VCC and ground.

Features:-

• Combines 3-to-8 decoder with 3-bit latch
• Multiple input enable for easy expansion or independent controls
• Active LOW mutually exclusive outputs
• Low-power dissipation
• Complies with JEDEC standard no. 7A
• Multiple package options

The 74F393 is a Dual Ripple Counter with separate Clock (CPn) and Master Reset (MR) inputs to each counter. The two counters are identified by the “a” and “b” suffixes in the pin configuration. The operation of each half of the 74F393 is the same. The counters are triggered by a High-to-Low transition of the Clock (CPa and CPb)inputs. The counter outputs are internally connected to provide Clock inputs to succeeding stages. The outputs of the ripple counter do not change synchronously and should not be used for high speed address decoding. The Master Resets (MRa and MRb) are active High asynchronous inputs; one for each 4-bit counter. A High level in the MR input overrides the Clock and sets the outputs Low

Features :-

• Two 4-bit binary counters
• Two Master Resets to clear each 4-bit counter individually

This 8-bit flip-flop features 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. It is particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers. The eight flip-flops of the SN74F574 are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the Q outputs will be set to the logic levels that were set up at the data (D) inputs. A buffered output enable (OE) input can be used to place the eight outputs in either a normal logic state (high or low logic levels) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components. The output enable (OE) does not affect the internal operations of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state. The SN74F574 is characterized for operation from 0°C to 70°C.

Features :-

• Eight D-Type Flip-Flops in a Single Package
• 3-State Bus-Driving True Outputs
• Full Parallel Access for Loading
• Buffered Control Inputs
• Package Options Include Plastic Small-Outline Packages and Standard Plastic 300-mil DIPs

The 74F521 is an expandable 8-bit comparator. It compares two words of up to eight bits each and provides a LOW output when the two words match bit for bit. The expansion input IA=B also serves as an active LOW enable input

Features :-

• Compares two 8-bit words in 6.5 ns typ
• Expandable to any word length
• 20-pin package