Renesas R1Q2A7218ABB-40IB0

Overview

R1Q2A7218ABB from Renesas Electronics is a 4,194,304-word × 18-bit synchronous Quad Data Rate II (QDR-II) SRAM with burst-of-2 operation, 1.8 V core supply (VDD), 1.5 V I/O supply (VDDQ), and 165-pin FBGA (13 × 15 mm) packaging. It features dual clock pairs (K/̅K for input registration, C/̅C for output timing), HSTL I/O, programmable output impedance via ZQ pin, and JTAG 1149.1 test access - designed for high-bandwidth packet buffering in network switches and routers.

For engineers reviewing the R1Q2A7218ABB datasheet, R1Q2A7218ABB pinout, R1Q2A7218ABB application, or R1Q2A7218ABB equivalent, key selection criteria include its 250 MHz max operating frequency (4.0 ns cycle time), 1.5-cycle read latency, separate read/write ports enabling concurrent transactions, DLL/PLL-based data valid window control, and industrial temperature range (−40°C to +85°C) support.

Technical Context

The R1Q2A7218ABB implements a true synchronous architecture where all address, control, and data inputs are registered on rising edges of K and /K clocks. Its burst-of-2 operation delivers two words per transaction across independent read and write ports, achieving 100% bus utilization in DDR mode.

It integrates a DLL/PLL for precise output timing alignment with echo clocks CQ/̅CQ, supports clock-stop with microsecond restart, and uses HSTL-compatible I/O with user-programmable output impedance via external ZQ resistor - enabling robust signal integrity at 250 MHz in high-speed backplane and switch fabric applications.

Key Specifications

Pinout & Package

Package: 165-ball plastic FBGA (13 × 15 mm, 0.8 mm pitch), Pb-free, industrial temperature grade (−40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar QDR-II SRAM applications.

Compared with CY7C2663KV18-400BZI, the R1Q2A7218ABB offers smaller 13×15 mm FBGA and lower power at 250 MHz, while AS7C36256P-15TIN lacks QDR functionality entirely - making it unsuitable for high-speed packet buffering where deterministic latency and dual-port concurrency are mandatory.

Availability

R1Q2A7218ABB is available at Aetrix Electronics and suitable for network switch buffering, router packet memory, telecom baseband processing, and test equipment pattern memory requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for R1Q2A7218ABB 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

Renesas Electronics Corporation is a global semiconductor leader specializing in microcontrollers, analog, power, and memory solutions for automotive, industrial, and infrastructure markets.

The R1Q2A7218ABB belongs to Renesas' QDR-II SRAM product line, engineered specifically for high-bandwidth, low-latency data buffering in networking and communications equipment where deterministic timing and concurrent access are critical.

FAQ

What is the maximum operating frequency and corresponding cycle time for the R1Q2A7218ABB?

The R1Q2A7218ABB is rated for a maximum operating frequency of 250 MHz, corresponding to a minimum cycle time of 4.0 ns. This specification is guaranteed under industrial temperature conditions (−40°C to +85°C) with VDD = 1.8 V ±0.1 V and VDDQ = 1.5 V. The device achieves 500 million transfers per second (MT/s) on its 18-bit data bus using burst-of-2 QDR-II protocol.

Does the R1Q2A7218ABB support concurrent read and write operations on the same memory array?

Yes, the R1Q2A7218ABB features fully independent read and write data paths with separate address and control registers, enabling true concurrent read and write transactions to the same memory array without arbitration or pipeline stalls. This is implemented via dedicated /R and /W command inputs, both registered on the rising edge of the K clock, and is fundamental to its use in full-duplex packet buffering applications.

What are the power supply requirements for the R1Q2A7218ABB, and how do they differ between core and I/O domains?

The R1Q2A7218ABB requires two distinct power supplies: VDD (core) at 1.7–1.9 V nominal (1.8 V typical) for internal logic and memory array, and VDDQ (I/O) at 1.4–1.5 V for HSTL output drivers. VDDQ must never exceed VDD. Both supplies must be ramped in sequence (VSS → VDD → VDDQ → VREF → VIN) within 200 ms, with VDDQ applied after or simultaneously with VREF to ensure proper HSTL input buffer biasing.

How is output impedance calibrated on the R1Q2A7218ABB, and what resistor value yields 50 Ω drive strength?

Output impedance is calibrated via the ZQ pin, which must be connected to ground through an external precision resistor (RQ). The output driver impedance equals 0.2 × RQ. To achieve 50 Ω nominal output impedance, a 250 Ω resistor is used (0.2 × 250 Ω = 50 Ω). The RQ resistor tolerance must be ≤1% and total ZQ ball capacitance <7.5 pF to maintain ±15% impedance accuracy across voltage and temperature.

What is the function of the C and /C pins on the R1Q2A7218ABB, and can they be omitted in system design?

The C and /C pins on the R1Q2A7218ABB serve as user-controlled output timing reference clocks - their rising edges define when Q and CQ outputs are valid. These pins may be tied high (to VDDQ) to disable the C/̅C path and force the device to use K/̅K as the output reference instead, eliminating the need for a second clock source. When tied high, C and /C must remain static and never toggle during operation.