Renesas 72205LB10PFG

Overview

72205LB10PFG from Integrated Device Technology (IDT) is a 256 × 18-bit synchronous FIFO memory IC with dual-clock operation, 10 ns read/write cycle time, and industrial temperature range (–40°C to +85°C). It provides programmable Almost-Empty/Almost-Full flags, Half-Full flag, and depth/width expandability for buffering in LAN controllers, interprocessor communication, and optical disk interfaces.

For engineers reviewing the 72205LB10PFG datasheet, 72205LB10PFG pinout, 72205LB10PFG application, or 72205LB10PFG equivalent, this page delivers verified timing parameters, flag behavior under dual-clock skew, offset register programming sequence, and TQFP-64 package compatibility for real-time data flow synchronization.

Technical Context

The 72205LB10PFG implements a dual-port zero fall-through time architecture with independent read/write pointers, enabling true asynchronous clock domain crossing. Its flag logic synchronizes EF to RCLK and FF to WCLK, while PAF/PAE operate asynchronously with configurable offsets loaded via LD/WEN/RCLK sequences.

It supports single-clock (RCLK = WCLK) or dual-clock operation with tSKEW1 ≥ 5 ns and tSKEW2 ≥ 5 ns minimum clock edge separation to guarantee reliable Full/Empty flag updates. The device uses high-performance submicron CMOS and features output enable (OE) for three-state bus control.

Key Specifications

Pinout & Package

72205LB10PFG is housed in a 64-lead thin quad flatpack (TQFP) per order code PF, with seven ground pins and multiple VCC pins distributed for noise reduction and signal integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FIFO memory applications.

Compared with 72205L10PF and 72205LA10PFG, the 72205LB10PFG uniquely balances industrial temperature operation, RoHS compliance, and proven 10 ns timing-making it the preferred choice for long-lifecycle embedded systems where reliability outweighs marginal AC performance gains.

Availability

72205LB10PFG is available at Aetrix Electronics and suitable for LAN controllers, interprocessor communication links, optical disk interfaces, real-time data acquisition systems, and industrial motion control requiring stable component supply across multi-year production cycles.

Supply support for 72205LB10PFG includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Integrated Device Technology (IDT) was a fabless semiconductor company specializing in timing, memory interface, RF, and sensor solutions before its acquisition by Renesas Electronics in 2019. IDT pioneered high-speed SyncFIFO architectures for system-level data coherency.

The IDT72205 family was designed specifically for deterministic, low-latency buffering in mixed-clock-domain systems-targeting telecom infrastructure, storage controllers, and industrial automation where predictable flag timing and expandability are critical.

FAQ

What is the default Almost-Empty offset value for 72205LB10PFG?

The 72205LB10PFG has a default Almost-Empty offset of 31 words. After reset, the PAE flag asserts LOW when the FIFO contains 31 or fewer words, providing early warning before underflow. This value is stored in the Empty Offset register and can be reprogrammed via the LD/WEN sequence using D0–D11 inputs.

Does 72205LB10PFG support single-clock operation?

Yes, 72205LB10PFG supports single-clock operation by tying RCLK and WCLK together. In this configuration, the device behaves as a unified-clock FIFO with EF synchronized to RCLK and FF to WCLK (same edge), maintaining deterministic flag timing while simplifying clock tree design.

How is the Half-Full flag (WXO/HF) used in single-device mode?

In single-device mode with WXI and RXI grounded, the WXO/HF pin functions as a Half-Full flag: it goes LOW when exactly 128 words (half of 256) are stored and remains LOW until the word count drops to 127 or below. This provides a hardware-based midpoint occupancy signal for flow control without software polling.

What happens to output data during reset on 72205LB10PFG?

During reset (RS = LOW), the 72205LB10PFG initializes its output register to all zeros. If OE = LOW, Q0–Q17 drive logic 0; if OE = HIGH, outputs enter high-impedance state. The reset recovery time tRSF is ≤25 ns, after which EF = LOW and FF = HIGH, ready for first write.

Can 72205LB10PFG be used in depth-expansion daisy-chain configurations?

Yes, 72205LB10PFG supports depth expansion via WXI/WXO and RXI/RXO pins. In daisy chain, FL = LOW on the first device and HIGH on subsequent devices. WXO of each device drives WXI of the next, propagating write-complete pulses; similarly, RXO drives RXI for read-complete signaling across the chain.