Renesas MK3722GLFTR

Overview

MK3722GLFTR from Renesas Electronics (formerly IDT) is a VCXO-plus-PLL audio clock synthesizer for set-top box applications, replacing discrete VCXOs and multipliers. It accepts a 27 MHz pullable crystal, delivers ±115 ppm tuning range via 0–3.3 V control voltage, and provides selectable audio clocks (8.192–24.576 MHz) plus a 27 MHz reference output.

For engineers reviewing the MK3722GLFTR datasheet, MK3722GLFTR pinout, MK3722GLFTR application, or MK3722GLFTR equivalent, key selection criteria include VCXO pull range, audio clock frequency selectability, 3.3 V operation, 16-pin TSSOP package compatibility, and low-jitter (<150 ps short-term) performance in consumer STB timing systems.

Technical Context

The MK3722GLFTR integrates a patented on-chip voltage-controlled crystal oscillator with analog/digital PLL synthesis. It uses an external 27 MHz fundamental-mode pullable crystal connected to X1/X2 pins and generates two synchronized outputs: a fixed 27 MHz reference (27M) and a programmable audio clock (ACLK) selected by S2:S0 inputs.

VCXO frequency adjustment is achieved via high-impedance VIN (0–3.3 V), enabling direct drive from PWM+RC integrators. The device operates at 3.3 V ±5% across 0–70 °C, features internal pull-up resistors (150 kΩ) on S0/S1/S2, and supports tri-state power-down via PDTS.

Key Specifications

Pinout & Package

Package: 16-pin TSSOP (4.40 mm body width, 0.65 mm lead pitch), RoHS-compliant, Pb-free (LF suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar audio clock synthesizer applications.

Compared with Si5338A-D-GM and ICS552GI-01LFT, the MK3722GLFTR offers optimal balance of simplicity, jitter performance, and cost for volume STB production-requiring no configuration, supporting real-time VCXO tuning, and delivering eight audio rates in a compact 16-pin TSSOP.

Availability

MK3722GLFTR is available at Aetrix Electronics and suitable for set-top box audio timing, digital TV subsystems, and home media gateway designs requiring stable component supply, RoHS compliance, and commercial temperature grade operation.

Supply support for MK3722GLFTR 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 consumer applications.

The MK3722GLFTR belongs to Renesas' legacy IDT timing portfolio, specifically engineered for cost-sensitive, high-volume consumer audio clocking-replacing discrete VCXOs and multipliers in STB and DTV platforms.

FAQ

What is the primary function of the MK3722GLFTR in a set-top box design?

The MK3722GLFTR serves as an integrated VCXO-plus-PLL audio clock synthesizer, generating both a stable 27 MHz reference clock and a selectable audio clock (8.192–24.576 MHz) from a single low-cost pullable crystal. In STB designs, it replaces discrete VCXOs and multipliers to correct broadcast timing drift and synchronize audio output with video streams. Its ±115 ppm VCXO tuning range enables precise lip-sync alignment without external compensation circuitry, making MK3722GLFTR ideal for cost-sensitive, high-volume consumer deployments.

How does the MK3722GLFTR achieve VCXO frequency tuning, and what voltage range is supported?

The MK3722GLFTR achieves VCXO frequency tuning through its high-impedance VIN pin, which accepts a 0–3.3 V analog control voltage to adjust the on-chip oscillator frequency by ±115 ppm. This voltage directly modulates the internal variable load capacitors coupled to the external 27 MHz crystal. Because VIN presents high input impedance, it can be driven directly from a simple PWM-to-DC integrator circuit-eliminating the need for op-amp buffers. The MK3722GLFTR's VCXO gain is specified at 80 ppm/V, ensuring predictable and linear tuning behavior across the full 0–3.3 V range.

Which audio clock frequencies does the MK3722GLFTR support, and how are they selected?

The MK3722GLFTR supports eight discrete audio clock frequencies: 8.192, 11.2896, 12.288, 16.9344, 18.432, 16.384, 22.5792, and 24.576 MHz. These are selected via the 3-bit binary input S2:S0, with internal 150 kΩ pull-up resistors eliminating the need for external bias. Each combination corresponds to a specific ACLK output frequency per the Audio Clock Select Table in the datasheet. This hardware-based selection enables deterministic, glitch-free switching-critical for real-time audio applications where firmware-controlled I²C reconfiguration would introduce latency or timing uncertainty in the MK3722GLFTR's operation.

What are the power supply and decoupling requirements for reliable MK3722GLFTR operation?

The MK3722GLFTR requires a clean 3.3 V ±5% supply delivered across four dedicated VDD pins (3, 4, 7, 14) and three GND pins (6, 7, 11). To ensure low-jitter performance, 0.01 µF ceramic decoupling capacitors must be placed between each VDD–GND pair-specifically at pins 3–6, 4–7, and 11–14-as close to the MK3722GLFTR as possible, mounted on the component side with no vias in the decoupling path. Operating current is 11 mA (no load, two outputs), and the device includes thermal protection with θJA = 78 °C/W in still air. Failure to follow these decoupling guidelines will degrade MK3722GLFTR's jitter specification and may cause output instability.

Is the MK3722GLFTR pin-compatible with earlier IDT audio clock devices like the MK3721 or ICS552?

No, the MK3722GLFTR is not pin-compatible with the MK3721 or ICS552 series. It uses a unique 16-pin TSSOP pinout optimized for its dual-output (27M + ACLK), VCXO-tuning, and tri-state power-down functionality-including dedicated X1/X2 crystal connections, three GND pins, and separate S2:S0 select lines. The MK3721 uses a different package and fewer select bits; the ICS552 employs a 20-pin SOIC with distinct pin assignments and no VIN or PDTS capability. Board-level replacement requires layout revision. Engineers evaluating migration should verify signal routing, decoupling placement, and crystal layout compliance per MK3722GLFTR's datasheet-especially the requirement for zero-via crystal traces and no adjacent signal routing near X1/X2.