SN74V245-7PAG

Overview

The SN74V245-7PAG is a synchronous FIFO memory with a 4096 x 18-bit organization. It supports clock frequencies up to 133 MHz and features read-access times as fast as 5 ns. The device operates on a 3.3-V VCC supply and includes 5-V input tolerant capabilities. It is packaged in a 64-pin Thin Quad Flat Package (TQFP) and is characterized for operation from 0°C to 70°C.

Feature Summary

• Supports asynchronous or coincident read and write clocks for flexible interface control.
• Features programmable almost-empty and almost-full flags with default settings.
• Provides single or double register-buffered empty and full flags.
• Capable of depth expansion using daisy-chain techniques or FWFT mode.

Applications

• DSP-to-processor communication
• DSP-to-analog front end buffering
• Network communications
• Video data handling
• Data communications

Procurement Notes

Verify the specific suffix '7PAG' against the manufacturer's current production status, as datasheets may list generic variants like SN74V245. Confirm the operating temperature range matches the 0°C to 70°C specification for commercial applications. Ensure the 64-pin TQFP package dimensions align with your PCB footprint requirements before finalizing procurement.

Selection Notes

Select this component when interfacing high-speed DSPs or microprocessors requiring 18-bit wide data paths. It is suitable for applications needing glueless interfaces to Texas Instruments TMS320 DSPs. Choose this part if you require synchronous FIFO buffering with programmable flag offsets and support for both standard and first-word fall-through timing modes.

Part Context

This device belongs to the SN74V215, SN74V225, SN74V235, and SN74V245 family of DSP-SYNC FIFO memories. While sharing core architecture, the SN74V245 specifically offers a 4096 x 18 array depth, distinguishing it from the smaller capacities of the SN74V215 (512), SN74V225 (1024), and SN74V235 (2048).

Replacement Considerations

Direct substitutes within the same family include SN74V215, SN74V225, and SN74V235, though they differ in memory depth. Verify compatibility if swapping between these variants due to differing flag offset defaults and capacity constraints.

FAQ

What are the two timing modes supported by the SN74V245?

The SN74V245 supports Standard mode and First-Word Fall-Through (FWFT) mode. In FWFT mode, the first word appears on outputs automatically after three RCLK transitions, whereas Standard mode requires a specific read operation.

How are the programmable flags configured?

The almost-empty (PAE) and almost-full (PAF) flags are programmable via internal offset registers. These values are loaded using the LD pin and data inputs D0-D11 during initialization.