SN74V3660-15PEU

Overview

The SN74V3660-15PEU is a 3.3-V CMOS first-in, first-out (FIFO) memory featuring a 4096 × 36 bit organization and a 128-pin TQFP package. It supports 166-MHz operation with a 6-ns read/write cycle time. The device provides user-selectable bus sizing for input and output ports, configurable big-endian or little-endian byte representation, and 5-V tolerant inputs. It includes programmable almost-empty and almost-full flags, selectable standard or first-word fall-through timing modes, and independent read and write clocks.

Feature Summary

• Supports flexible bus matching with user-selectable input and output port widths of 36-bit, 18-bit, or 9-bit.
• Features zero-latency retransmit capability allowing data to be reread from the FIFO without disturbing write operations.
• Includes programmable almost-empty and almost-full flags that can be configured via serial or parallel methods.
• Offers selectable first-word fall-through or standard timing modes for optimized data access latency.

Applications

• Network buffering and packet processing
• Video signal processing systems
• Telecommunications data communications
• Signal processing applications requiring bus size matching

Procurement Notes

Verify the specific ordering suffix '-15PEU' against the manufacturer's current production status, as availability may vary. Confirm that the 128-pin Thin Quad Flat Pack (TQFP) package matches your PCB footprint requirements. Ensure the 3.3-V supply voltage aligns with your system design. Check for any updated datasheet revisions that might affect pin configurations or electrical characteristics before finalizing procurement.

Selection Notes

Select this component when deep memory depth combined with high-speed synchronous operation is required. It is suitable for applications needing to buffer large amounts of data between buses of unequal sizes. Consider its programmable flag offsets and retransmit features if complex data handling logic is needed. Verify that the 5-V tolerant inputs are compatible with upstream interface voltages.

Part Context

This part belongs to the SN74V36xx series of high-speed CMOS FIFO memories from Texas Instruments. The series includes variants with different memory depths, ranging from 1024 to 32768 words, all sharing a 36-bit word width. These devices are designed for high-performance digital systems requiring efficient data flow management and bus interfacing capabilities.

Replacement Considerations

Direct substitutes within the same family include SN74V3640, SN74V3650, SN74V3670, SN74V3680, and SN74V3690. Note that these alternatives differ in memory depth but share identical pinouts and functional specifications. Ensure the selected replacement meets the required storage capacity for your application.

FAQ

How is the bus width configured on the SN74V3660?

The input and output bus widths are configured during the master reset cycle using the BM, IW, and OW pins. This allows for combinations such as 36-bit input to 18-bit output or 9-bit input to 36-bit output.

What is the difference between standard mode and FWFT mode?

In standard mode, every word read requires a specific read enable signal. In First-Word Fall-Through (FWFT) mode, the first word written to an empty FIFO appears at the outputs automatically after three clock cycles without requiring a read enable signal.

Can the read and write clocks operate at different frequencies?

Yes, the SN74V3660 supports independent read and write clocks. The frequencies of RCLK and WCLK can vary from 0 to the maximum operating frequency without restrictions on their relationship.