Renesas UPD44645364AF5-E40-FQ1-A

Overview

UPD44645364AF5-E40-FQ1-A from Renesas Electronics is a 2,097,152-word × 36-bit synchronous Quad Data Rate II (QDR II) SRAM with HSTL interface, 4-word burst operation, and 1.8 V core supply. It delivers 250 MHz clock frequency (4.0 ns cycle time), supports concurrent read/write ports, and is packaged in a 165-pin plastic BGA (15 × 17 mm) for high-density memory subsystems in network packet buffers and baseband processing.

For engineers reviewing the UPD44645364AF5-E40-FQ1-A datasheet, UPD44645364AF5-E40-FQ1-A pinout, UPD44645364AF5-E40-FQ1-A application, or UPD44645364AF5-E40-FQ1-A equivalent, this page provides verified timing parameters, validated byte-write control logic, confirmed DLL/PLL-enabled output timing window, and precise HSTL I/O voltage compatibility per Renesas M19959EJ2V0DS.

Technical Context

This QDR II SRAM implements dual-clock architecture: K/K# registers address/control on rising edges, while C/C# govern output data timing with echo clocks CQ/CQ# tightly matched to data valid windows. Its internal burst counter and separate read/write data paths enable true 100% bus utilization in DDR mode.

The device integrates a programmable output impedance circuit (via ZQ pin), DLL/PLL for jitter-tolerant scaling up to 300 MHz, and IEEE 1149.1 JTAG test access. Byte write control uses four active-low BW0#–BW3# signals to select 9-bit subwords within the 36-bit data bus, with deterministic timing per burst phase.

Key Specifications

Pinout & Package

Package: 165-pin plastic BGA (15 mm × 17 mm, 0.8 mm pitch), RoHS-compliant, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C2663KV18-400BZXC and AS7C36256P-15JCIN, UPD44645364AF5-E40-FQ1-A uniquely balances HSTL compatibility, 250 MHz deterministic timing, and 36-bit subword write control-making it optimal for new designs requiring industrial-grade QDR II interoperability without redesigning termination or clocking.

Availability

UPD44645364AF5-E40-FQ1-A is available at Aetrix Electronics and suitable for network packet buffering, baseband signal processing, and medical imaging data pipelines requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant manufacturing.

Supply support for UPD44645364AF5-E40-FQ1-A 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 formed in 2010 through the merger of NEC Electronics and Renesas Technology, specializing in microcontrollers, analog, power, and memory solutions for industrial, automotive, and communications markets.

The UPD44645364AF5-E40-FQ1-A belongs to Renesas' QDR II SRAM product line, designed specifically for high-throughput, low-latency memory subsystems in networking infrastructure and real-time signal processing equipment.

FAQ

What is the maximum guaranteed clock frequency for UPD44645364AF5-E40-FQ1-A?

The UPD44645364AF5-E40-FQ1-A is rated for 250 MHz operation with a 4.0 ns clock cycle time, as specified in the Renesas datasheet M19959EJ2V0DS. This rating is guaranteed across the full industrial temperature range (0–70°C) and includes margin for setup/hold timing, DLL/PLL stability, and HSTL interface compliance. The device supports higher frequencies (e.g., 300 MHz) only in the -E33 variant (UPD44645364AF5-E33-FQ1-A).

Does UPD44645364AF5-E40-FQ1-A support true concurrent read and write operations?

Yes, UPD44645364AF5-E40-FQ1-A implements physically separate read and write data paths, enabling simultaneous access to the memory array. The block diagram (M19959EJ2V0DS p.9) confirms independent input registry/logic and output select/buffer stages. However, command arbitration prioritizes READ over WRITE if both R# and W# are asserted on the same K clock edge.

How is output impedance calibrated on UPD44645364AF5-E40-FQ1-A?

Output impedance calibration on UPD44645364AF5-E40-FQ1-A is performed via the ZQ pin, which connects to an external resistor to ground. The internal circuitry sets Q, CQ, and CQ# driver strength to 0.2 × RQ. Calibration occurs automatically every 20 μs after power-up and tracks supply voltage and temperature drift. Direct connection of ZQ to VDDQ minimizes impedance; grounding or leaving it floating is prohibited.

Can UPD44645364AF5-E40-FQ1-A operate without the DLL/PLL enabled?

Yes-asserting DLL# = LOW disables the DLL/PLL, allowing operation at frequencies below 120 MHz for debug or low-power modes. However, Renesas explicitly states that AC/DC electrical characteristics are not guaranteed in this mode. For production use at 250 MHz, DLL# must be tied HIGH (e.g., to VDDQ via ≤10 kΩ resistor) to ensure timing margin and data valid window integrity.

What are the power sequencing requirements for UPD44645364AF5-E40-FQ1-A?

UPD44645364AF5-E40-FQ1-A requires strict power sequencing: VSS first, then VDD, then VDDQ (or simultaneously with VDD if VDDQ ≤ VDD + 0.5 V), then VREF. During power-down, reverse the order. Violating this sequence risks undefined behavior or latch-up. The device enters high-impedance state during power-up and requires ≥20 μs of stable K clock after VDD/VDDQ stabilization to lock the DLL/PLL.