Renesas R1Q4A7236ABG-40IA0

Overview

R1Q4A7236ABG-40IA0 from Renesas Electronics is a 72-Mbit DDR II synchronous SRAM with 2,097,152-word × 36-bit organization, fabricated in advanced CMOS using full six-transistor memory cells. It operates at 1.8 V core and 1.4–1.5 V I/O supply, supports 250 MHz max frequency (4 ns cycle time), features HSTL I/O, burst-of-two operation, and is packaged in a 165-pin FBGA (15 × 17 × 1.4 mm) for high-speed networking buffer applications.

For engineers reviewing the R1Q4A7236ABG-40IA0 datasheet, R1Q4A7236ABG-40IA0 pinout, R1Q4A7236ABG-40IA0 application, or R1Q4A7236ABG-40IA0 equivalent, key selection criteria include DDR II burst timing, dual clock pair (K/̅K and C/̅C) synchronization, programmable output impedance via ZQ, DLL/PLL-enabled data valid window, and industrial temperature support (−40°C to +85°C).

Technical Context

This device implements a synchronous double-data-rate architecture where all inputs-including address (SAx), control (/LD, R/̅W, /BWx), and clocks (K, /K, C, /C)-are registered on rising edges. It uses pipelined DDR I/O with common DQ bus and echo clocks (CQ, /CQ) for precise data capture in high-bandwidth systems.

The internal burst counter and self-timed write control enable deterministic two-tick burst transactions. Clock-stop capability with microsecond restart and /DOFF pin allow low-power operation without loss of state, while JTAG 1149.1 support enables boundary-scan testability in complex PCB assemblies.

Key Specifications

Pinout & Package

Package: 165-pin plastic FBGA (15 mm × 17 mm × 1.4 mm, ball pitch 0.8 mm), Pb-free, RoHS-compliant (6/6).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1551KV18-250BZI and IS42S32800J-6BLI, R1Q4A7236ABG-40IA0 uniquely balances deterministic DDR II timing, industrial temperature reliability, and minimal control complexity-making it optimal for telecom buffers and switch fabrics where burst predictability and echo-clock–assisted capture are essential.

Availability

R1Q4A7236ABG-40IA0 is available at Aetrix Electronics and suitable for telecom packet buffering, high-speed switch fabric, and industrial control data logging requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for R1Q4A7236ABG-40IA0 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 R1Q4A7236ABG-40IA0 belongs to Renesas' DDR II SRAM product line, designed specifically for high-bandwidth, low-latency buffering in networking equipment, telecom infrastructure, and real-time embedded systems demanding deterministic timing and industrial-grade reliability.

FAQ

What is the maximum operating frequency and corresponding cycle time for R1Q4A7236ABG-40IA0?

R1Q4A7236ABG-40IA0 is rated for a maximum operating frequency of 250 MHz, corresponding to a minimum cycle time of 4 ns. This specification is validated under industrial temperature conditions (−40°C to +85°C) with VDD = 1.8 V ±0.1 V and VDDQ = 1.5 V, and reflects guaranteed performance across the full speed bin defined by the "-40" suffix in the part number.

Does R1Q4A7236ABG-40IA0 support both DDR II and QDR II protocols?

No, R1Q4A7236ABG-40IA0 is a DDR II SRAM only. It does not support QDR II functionality such as separate read/write ports or quad data rate operation. The "Q" in the part number denotes membership in Renesas' broader QDR/DDR SRAM family naming convention, but this specific variant implements DDR II timing with common DQ bus, burst-of-two, and dual clock pairs (K/̅K and C/̅C) as defined in the R1Q4A7236ABG datasheet.

How is output impedance calibrated on R1Q4A7236ABG-40IA0?

Output impedance on R1Q4A7236ABG-40IA0 is calibrated via the ZQ pin, which must be connected to ground through an external precision resistor (RQ). The device sets DQ and CQ output impedance to 0.2 × RQ; for example, a 250 Ω RQ yields ~50 Ω driver impedance. Total ZQ net capacitance must remain below 7.5 pF to ensure accurate calibration, and RQ tolerance should be ≤1% for ±15% impedance matching accuracy.

What is the function of the /DOFF pin on R1Q4A7236ABG-40IA0?

The /DOFF (DLL/PLL Disable) pin on R1Q4A7236ABG-40IA0 disables the internal DLL/PLL when driven low, forcing the device into a bypass mode with fixed delay paths. This enables stable operation at frequencies below 120 MHz and supports low-power clock-stop modes with microsecond restart. When /DOFF is high, the DLL/PLL is active, providing jitter-reduced output timing and scalable data valid windows for high-frequency operation.

Is R1Q4A7236ABG-40IA0 pin-compatible with other members of the R1Q4A72xxABG series?

Yes, R1Q4A7236ABG-40IA0 shares identical pinout and package (165-pin FBGA) with R1Q4A7218ABG-40IA0 and other R1Q4A72xxABG variants in the same generation. However, functional differences exist: R1Q4A7236ABG-40IA0 uses all 36 DQ lines (DQ0–DQ35), whereas R1Q4A7218ABG-40IA0 uses only DQ0–DQ17 and treats DQ18–DQ35 as NC. Address and control pin assignments are fully compatible across the series.