74HC/HCT173

General description

The 74HC/HCT173 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A.

The 74HC/HCT173 are 4-bit parallel load registers with clock enable control, 3-state buffered outputs (Q₀ to Q₃) and master reset (MR).

When the two data enable inputs (E₁ and E₂) are LOW, the data on the Dn inputs is loaded into the register synchronously with the LOW-to-HIGH clock (CP) transition. When one or both E_n inputs are HIGH one set-up time prior to the LOW-to-HIGH clock transition, the register will retain the previous data. Data inputs and clock enable inputs are fully edge-triggered and must be stable only one set-up time prior to the LOW-to-HIGH clock transition.

The master reset input (MR) is an active HIGH asynchronous input. When MR is HIGH, all four flip-flops are reset (cleared) independently of any other input condition.

The 3-state output buffers are controlled by a 2-input NOR gate. When both output enable inputs (OE₁ and OE₂) are LOW, the data in the register is presented to the Q_n outputs. When one or both OE_n inputs are HIGH, the outputs are forced to a high impedance OFF-state. The 3-state output buffers are completely independent of the register operation; the OE_n transition does not affect the clock and reset operations.

Features

• Gated input enable for hold (do nothing) mode
• Gated output enable control
• Edge-triggered D-type register
• Asynchronous master reset
• Output capability: bus driver
• I_CC category: MSI

Products/packages

Pricing/ordering/availability

Applications

• High-speed disc or tape controller
• Communications buffer.

Technical documents

Support Documents

HCT_USER_GUIDE; HC/T User Guide (1997-11-01)

Parametrics/similar products

Similar products

74HC/HCT173 links to the similar products page containing an overview of products that are similar in function or related to the type number(s) as listed on this page. The similar products page includes products from the same catalog tree(s), relevant selection guides and products from the same functional category.

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