Renesas 72245LB10PFG8

Overview

IDT72245LB10PFG8 from Integrated Device Technology (IDT) is a high-speed 4,096 × 18-bit synchronous FIFO memory IC used for clock-domain bridging and data buffering in dual-clock systems. It supports 10 ns read/write cycle time, programmable Almost-Empty/Almost-Full flags with default 127-word offsets, and operates across –40°C to +85°C industrial temperature range. It is deployed in optical disk controllers and LAN interface subsystems requiring deterministic latency and depth-expandable buffering.

For engineers reviewing the IDT72245LB10PFG8 datasheet, IDT72245LB10PFG8 pinout, IDT72245LB10PFG8 application, or IDT72245LB10PFG8 equivalent, key selection criteria include its 4,096-word depth, dual-port zero fall-through architecture, asynchronous clock support (WCLK/RCLK), TQFP-64 package compatibility, and industrial-grade reliability for embedded communications interfaces.

Technical Context

This device implements a dual-ported, clocked RAM array with independent read/write pointer logic, offset register programming via LD/WEN/RCLK control, and flag generation synchronized to respective clocks (FF to WCLK, EF to RCLK). Its architecture enables true concurrent read/write operations without metastability risk when clocks are asynchronous.

The FIFO supports three operational modes: single-device (FL/WXI/RXI grounded), width expansion (parallel data bus widening), and daisy-chained depth expansion using WXO/RXO signals. Programmable PAE/PAF flags use 12-bit offset registers loaded via dedicated state-machine sequencing on WCLK/RCLK edges.

Key Specifications

Pinout & Package

Package: 64-lead thin quad flatpack (TQFP), order code PF, RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NB3N502DG and 72V2115L10PF, IDT72245LB10PFG8 uniquely delivers 4,096-word depth at 10 ns with industrial-temp 5 V operation, Half-Full flag, and seamless daisy-chain expansion-making it optimal for legacy 5 V embedded systems requiring maximum buffering headroom.

Availability

IDT72245LB10PFG8 is available at Aetrix Electronics and suitable for optical disk controllers, LAN interface modules, interprocessor communication links, and industrial sensor aggregation systems requiring stable component supply and long-term industrial temperature support.

Supply support for IDT72245LB10PFG8 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 signal conditioning solutions before its acquisition by Renesas Electronics in 2019.

IDT72245LB10PFG8 belongs to the SyncFIFO™ family designed specifically for high-reliability, low-latency data buffering in mixed-clock-domain systems such as storage controllers, networking equipment, and real-time industrial controllers.

FAQ

What is the maximum operating frequency of the IDT72245LB10PFG8?

The IDT72245LB10PFG8 supports a 10 ns clock cycle time, enabling operation up to 100 MHz on both WCLK and RCLK inputs. This specification is guaranteed over the full industrial temperature range (–40°C to +85°C) and 4.5 V to 5.5 V supply voltage. The device maintains timing integrity even with asynchronous clock sources, provided minimum skew requirements (tSKEW1/tSKEW2 ≥ 5 ns) are met.

Does the IDT72245LB10PFG8 support depth expansion, and how is it implemented?

Yes, the IDT72245LB10PFG8 supports depth expansion via daisy-chain configuration using WXO/RXO and WXI/RXI pins. In this mode, FL is grounded on the first device and set HIGH on subsequent devices. A pulse on WXO signals the next device to accept a write; RXO pulses trigger reads in cascade. This allows building FIFOs larger than 4,096 words without external control logic, preserving the IDT72245LB10PFG8's native timing and flag behavior.

What are the default values for the programmable Almost-Empty and Almost-Full offsets in the IDT72245LB10PFG8?

The IDT72245LB10PFG8 defaults to 127-word offsets for both PAE and PAF flags after reset. This means PAE asserts LOW when 127 words remain before empty, and PAF asserts LOW when 127 words remain before full. These values are stored in the offset registers and can be reprogrammed via LD/WEN sequence using D0–D11 inputs, with new values taking effect on the next clock edge.

Is the Half-Full flag (HF) available in all configurations of the IDT72245LB10PFG8?

The Half-Full flag (HF) is available only in single-device or width-expansion configurations where WXI and RXI are grounded. In these modes, HF goes LOW when exactly half the FIFO (2,048 words) is filled and remains active until the word count drops to ≤2,047. During depth expansion, the HF function is disabled and WXO serves exclusively as a write-expansion pulse output.

What is the purpose of the Load (LD) pin on the IDT72245LB10PFG8, and how is it used?

The LD pin enables access to internal 12-bit offset registers for PAE and PAF configuration. When LD = LOW and WEN = LOW, D0–D11 data is written to the offset registers on successive WCLK edges; when LD = LOW and REN = LOW, Q0–Q11 reflects current offset values on RCLK edges. This allows runtime adjustment of flow-control thresholds without resetting the FIFO or interrupting data flow.