Renesas MK2304S-1LF

Overview

MK2304S-1LF from IDT is a zero-delay, low-skew PLL-based clock buffer IC used to align input clock rising edges with four CMOS outputs in high-speed digital systems. It delivers 133 MHz output frequency at 3.3 V, <200 ps output-to-output skew within each bank, and operates across 0°C to +70°C. It serves as a timing distribution element in FPGA/ASIC clock trees requiring precise edge alignment.

For engineers reviewing the MK2304S-1LF datasheet, MK2304S-1LF pinout, MK2304S-1LF application, or MK2304S-1LF equivalent, key selection criteria include zero-input-output delay operation, industrial-grade thermal resistance (θJA = 120°C/W), FBK feedback loop configuration, and Pb-free SOIC-8 packaging compliance.

Technical Context

The MK2304S-1LF implements a proprietary low-jitter PLL architecture that locks the feedback signal (FBK) to CLKIN, enabling synchronous rising-edge alignment across all four outputs. It supports two independent banks (A and B), each with two 1X buffered outputs, and accepts a 5 V-tolerant CLKIN input while operating exclusively at 3.3 V supply.

Its zero-delay mode requires external feedback from CLKA1 or CLKB1 to FBK, and it achieves <300 ps maximum absolute jitter with 15 pF loads. The device uses an advanced sub-micron CMOS process and integrates SpreadSmart™ compatibility for use with spread-spectrum clock sources.

Key Specifications

Pinout & Package

Packaged in 8-pin SOIC (150 mil, narrow body), RoHS-compliant, Pb-free (LF suffix), with JEDEC-standard dimensions (D = 4.9 mm, E = 3.9 mm, θJA = 120°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar zero-delay clock buffer applications.

Compared with ICS8304AM-01LFT and PI6C20400LEX, the MK2304S-1LF provides the lowest published maximum absolute jitter (300 ps), native SpreadSmart™ integration, and strictest output skew control (<200 ps per bank), making it optimal for timing-critical commercial-grade clock trees where phase alignment precision is non-negotiable.

Availability

MK2304S-1LF is available at Aetrix Electronics and suitable for FPGA clock distribution, network switch timing, and industrial PLC controller applications requiring stable component supply, RoHS-compliant packaging, and commercial temperature grade reliability.

Supply support for MK2304S-1LF 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) is a global leader in timing, memory interface, and RF solutions, acquired by Renesas Electronics in 2019. IDT pioneered high-performance clock architectures for enterprise and communications infrastructure.

The MK2304S-1LF belongs to IDT's Zero Delay Buffer (ZDB) product line, engineered specifically for low-skew, low-jitter clock distribution in high-speed digital systems where deterministic phase alignment is essential.

FAQ

What is the function of the FBK pin on the MK2304S-1LF?

The FBK pin on the MK2304S-1LF is the PLL feedback input that closes the zero-delay loop. It must be connected to either CLKA1 or CLKB1 to align the rising edge of CLKIN with all four outputs. This connection defines the reference point for phase synchronization and is mandatory for zero-delay operation-omitting it results in undefined or unlocked behavior. The MK2304S-1LF cannot operate in zero-delay mode without a valid FBK path.

Does the MK2304S-1LF support 5 V input signals while running on 3.3 V supply?

Yes, the MK2304S-1LF supports 5 V-tolerant inputs on the REF pin, allowing direct connection to 5 V clock sources without level translation. Its internal input circuitry clamps voltages up to +5.5 V, while the device itself operates strictly at 3.3 V (VDD = 3.0–3.6 V). All outputs remain 3.3 V CMOS-compatible. This feature simplifies mixed-voltage system integration and is explicitly specified in the DC Electrical Characteristics table of the MK2304S-1LF datasheet.

What is the maximum load capacitance supported by the MK2304S-1LF at 133 MHz?

The MK2304S-1LF supports up to 15 pF load capacitance at its full 133 MHz output frequency, as confirmed in the AC Electrical Characteristics table. At 30 pF load, maximum frequency drops to 100 MHz. Exceeding 15 pF at 133 MHz risks violating rise/fall time specs (tOR/tOF ≤1.5 ns) and may increase jitter or cause duty cycle distortion. For heavier loads, external series termination (e.g., 33 Ω) and careful PCB routing are required to maintain signal integrity for the MK2304S-1LF.

How does the MK2304S-1LF achieve zero input-output delay?

The MK2304S-1LF achieves zero input-output delay through a closed-loop PLL that locks the FBK signal to the REF input, dynamically adjusting internal delay to force rising edges of CLKA1/CLKA2/CLKB1/CLKB2 to align precisely with the REF rising edge. This alignment occurs at VDD/2 crossing points and is maintained across temperature and voltage variations. The MK2304S-1LF's architecture guarantees this behavior only when FBK is correctly routed-no external delay lines or calibration are needed.

Is the MK2304S-1LF pin-compatible with the MK2304S-1I variant?

No, the MK2304S-1LF and MK2304S-1I are not pin-compatible due to differing temperature grades and marking conventions-not physical pinout. Both use identical 8-pin SOIC packages and share the same pin assignment, but MK2304S-1I is rated for -40°C to +85°C and uses "2304S1I" marking, whereas MK2304S-1LF is commercial-grade (0°C to +70°C) with "2304S-1L" marking. Electrical specifications (e.g., IDD, jitter) are validated per grade, so substituting MK2304S-1LF into an industrial design may violate thermal or timing margins.