Renesas 85222AMLFT

Overview

85222AMLFT from Renesas Electronics (formerly IDT) is a dual-channel LVCMOS/LVTTL-to-differential LVHSTL clock translator IC used for high-speed clock distribution in memory interfaces and FPGA timing systems. It accepts two single-ended LVCMOS or LVTTL clock inputs (CLK0, CLK1), delivers two differential LVHSTL output pairs (Q0/nQ0, Q1/nQ1), supports 350 MHz maximum output frequency, operates from 2.5 V or 3.3 V supply, and features ≤1.3 ns max propagation delay.

For engineers reviewing the 85222AMLFT datasheet, 85222AMLFT pinout, 85222AMLFT application, or 85222AMLFT equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, application-specific implementation guidance, and confirmed alternative parts for clock translation in DDR memory subsystems, FPGA I/O banks, and high-speed serial interface timing chains.

Technical Context

The 85222AMLFT implements a dual independent translation path: each input channel (CLK0/CLK1) drives a dedicated LVHSTL differential driver stage with internal 51 kΩ pulldown resistors and compatible LVCMOS/LVTTL input thresholds (VIL ≤ 1.3 V, VIH ≥ 2 V). Output stages are designed for 50 Ω termination to GND and deliver controlled LVHSTL swing (0.45–1.2 V peak-to-peak) with duty cycle stability across 350 MHz operation.

Its architecture targets low-skew clock fanout in space-constrained applications: part-to-part skew is specified at ≤350 ps (3.3 V) or ≤450 ps (2.5 V), and propagation delay variation is tightly bounded (750–1150 ps at 3.3 V). The device requires external 50 Ω terminations on all active and unused differential outputs to maintain signal integrity and minimize reflections.

Key Specifications

Pinout & Package

85222AMLFT is housed in an 8-pin SOIC package (M suffix), measuring 3.90 mm × 4.92 mm × 1.37 mm, with lead-free RoHS-compliant finish per JEDEC MS-012 outline.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LVCMOS/LVTTL-to-LVHSTL translation applications.

Compared with ICS85222AMLF, 85222AMLFT offers identical functionality in tape-and-reel format for high-volume manufacturing; compared with PI6C557-03LEX, it delivers true LVHSTL compliance, dual-channel operation, and integrated input termination-making it the only drop-in solution for DDR memory clocking where JEDEC LVHSTL specification adherence is mandatory.

Availability

85222AMLFT is available at Aetrix Electronics and suitable for DDR2/DDR3 memory subsystems, FPGA-based data acquisition systems, and industrial PLC timing modules requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for 85222AMLFT 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 delivering microcontrollers, analog power, and timing solutions for automotive, industrial, and infrastructure markets.

The 85222AMLFT belongs to Renesas' high-performance clock translation portfolio, engineered specifically for bridging legacy single-ended clock sources to modern differential memory and FPGA interfaces with minimal board space and zero external biasing.

FAQ

What is the function of the internal 51 kΩ pulldown resistors on CLK0 and CLK1 of the 85222AMLFT?

The internal 51 kΩ pulldown resistors on CLK0 and CLK1 ensure defined logic-low states during power-up, reset, or floating input conditions-eliminating the need for external pull-down components. This simplifies PCB layout and reduces BOM cost in LVTTL-driven systems where input drivers may not guarantee rail-to-rail behavior. The 85222AMLFT relies on these resistors to meet VIH/VIL thresholds without external biasing, maintaining compatibility across both LVCMOS and LVTTL logic families.

Can the 85222AMLFT operate with only one output pair enabled while the other remains unused?

Yes, but the unused differential output pair (e.g., Q1/nQ1) must still be terminated with 50 Ω to GND per the 85222AMLFT datasheet. Leaving either Q0/nQ0 or Q1/nQ1 unterminated causes signal reflections, degraded waveform integrity, and potential crosstalk into the active channel. The device's internal design assumes matched termination on both outputs-even if only one is connected to a load-to preserve common-mode noise rejection and output stage stability.

What is the maximum junction temperature of the 85222AMLFT under full-load operation at 3.3 V?

At 3.3 V supply and ambient temperature of 70°C with both outputs switching, the calculated junction temperature of the 85222AMLFT is 102.4°C-well below the 125°C maximum limit. This assumes a multi-layer PCB with 200 LFPM airflow and uses θJA = 103.3°C/W. Total power dissipation reaches 313.7 mW (155.9 mW core + 157.8 mW outputs), confirming safe thermal operation in typical industrial environments without forced cooling.

Does the 85222AMLFT support 2.5 V and 3.3 V supplies simultaneously on the same device?

No-the 85222AMLFT has a single VDD pin and must operate from either 2.5 V ±5% or 3.3 V ±5%, not both concurrently. Its internal circuitry is optimized for one supply voltage at a time; mixing voltages would violate absolute maximum ratings and risk latch-up or parametric failure. Designers must select the appropriate supply based on system-level voltage rails and output swing requirements-3.3 V yields higher VOH (1.2 V max) and lower tPD, while 2.5 V reduces power consumption and heat generation.

How does the part-to-part skew specification of the 85222AMLFT impact multi-device clock tree designs?

The 85222AMLFT's guaranteed ≤350 ps part-to-part skew (at 3.3 V) enables predictable phase alignment across multiple devices in parallel clock distribution networks-critical for DDR memory rank expansion or multi-FPGA synchronization. When used with matched trace lengths and identical termination, this spec ensures that clock edges arriving at different receivers deviate by no more than 350 ps, preserving setup/hold margins and avoiding timing violations in high-speed synchronous systems relying on the 85222AMLFT.