Analog Devices Inc./Maxim Integrated DS1080CLU+T

Overview

DS1080CLU+T from Maxim Integrated is a spread-spectrum crystal multiplier IC with integrated PLL, generating low-jitter clock outputs from 8MHz to 64MHz via 1x/2x/4x multiplication of an 8–16MHz crystal or clock input. It supports selectable ±0.5%/±1.0%/±1.5% center-spread dithering and operates from 3.0V to 3.6V across –40°C to +125°C in an 8-pin µSOP package. Used in PC peripherals and infotainment systems to reduce EMI.

For engineers reviewing the DS1080CLU+T datasheet, DS1080CLU+T pinout, DS1080CLU+T application, or DS1080CLU+T equivalent, key selection criteria include spread-spectrum dither magnitude configurability, power-down mode with high-impedance output, cycle-to-cycle jitter ≤75ps at 8MHz, and compatibility with parallel-resonant crystals ≤90Ω ESR.

Technical Context

The DS1080CLU+T implements a center-spread PLL architecture where dither rate is fixed at f_IN/512 (e.g., ~15.6kHz for 8MHz input), ensuring modulation remains above audible frequencies. Clock multiplication is controlled by trilevel CMSEL (1x/2x/4x), while SMSEL sets dither magnitude (±0.5%/±1.0%/±1.5%) and PDN enables power-down or spread-spectrum disable modes.

It accepts either a fundamental-mode parallel-resonant crystal (8–16MHz, ESR <90Ω) across X1/X2 or a single-ended clock applied to X1 only (X2 open). Output SSO drives 15pF load with 45–55% duty cycle, 1.6ns rise/fall times, and guaranteed low cycle-to-cycle jitter performance over full temperature range.

Key Specifications

Pinout & Package

DS1080CLU+T is housed in an 8-pin lead-free µSOP package (package code U8+1, outline 21-0036), with 0.65mm pitch and exposed pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar spread-spectrum clock generator applications.

Compared with IDT 8T49N241 and Silicon Labs Si5351A, DS1080CLU+T offers simpler, pin-strapped configuration with guaranteed center-spread compliance out-of-box, lower BOM count, and direct crystal interface-ideal for cost-sensitive, fixed-frequency EMI reduction without microcontroller overhead.

Availability

DS1080CLU+T is available at Aetrix Electronics and suitable for PC peripherals, automotive infotainment systems, and industrial printers requiring stable component supply with guaranteed long-term availability and RoHS-compliant packaging.

Supply support for DS1080CLU+T 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, automotive, and communications applications.

The DS1080CLU+T belongs to Maxim's spread-spectrum clock generator product line, engineered specifically to simplify EMI compliance in space-constrained digital systems using crystal-based timing sources.

FAQ

What is the function of the PDN pin on the DS1080CLU+T?

The PDN pin on the DS1080CLU+T controls power-down and spread-spectrum enable/disable states. When pulled low, DS1080CLU+T enters power-down mode with SSO in high-impedance state and ICCQ ≤200μA. When open, DS1080CLU+T operates with active SSO but spread-spectrum dithering disabled. When pulled high, DS1080CLU+T runs with full spread-spectrum functionality enabled. This trilevel behavior allows flexible system-level EMI and power management without additional logic.

Can the DS1080CLU+T accept an external clock instead of a crystal?

Yes, the DS1080CLU+T can accept an 8MHz to 16MHz single-ended clock signal applied directly to the X1 pin, with X2 left unconnected. In this configuration, the DS1080CLU+T uses the external clock as its reference input and applies the selected multiplication factor (1x/2x/4x) and spread-spectrum dither to generate the SSO output. Input logic thresholds follow standard CMOS levels (VIH ≥0.8×VCC, VIL ≤0.2×VCC), and input leakage remains within ±1μA.

What is the maximum allowable crystal ESR for reliable operation of the DS1080CLU+T?

The DS1080CLU+T requires a parallel-resonant crystal with ESR ≤90Ω to ensure reliable startup and stable PLL lock across –40°C to +125°C. Crystals exceeding this ESR may cause intermittent locking, increased jitter, or failure to start under temperature extremes. The DS1080CLU+T datasheet specifies this limit explicitly in the DC Electrical Characteristics table and reinforces it in the Applications Information section for crystal selection.

How does the DS1080CLU+T achieve EMI reduction?

The DS1080CLU+T achieves EMI reduction through center-spread spectrum modulation, dithering the output clock frequency around its nominal value at a fixed rate of f_IN/512 (e.g., ~15.6kHz for 8MHz input). This spreads spectral energy over a narrow bandwidth, reducing peak radiated emissions by up to 15.6dB as shown in the typical frequency spectrum plot (toc06). The dither magnitude is configurable via SMSEL (±0.5%/±1.0%/±1.5%), allowing optimization for specific regulatory test margins.

Is the DS1080CLU+T compatible with 3.3V-only systems?

Yes, the DS1080CLU+T operates fully within a 3.0V to 3.6V supply range, making it directly compatible with standard 3.3V systems. All input logic thresholds scale with VCC (VIH ≥0.8×VCC, VIL ≤0.2×VCC), and output VOH/VOL specifications (≥2.4V/≤0.4V at ±4mA) meet 3.3V CMOS interface requirements. Supply current varies predictably with VCC, as confirmed in the Typical Operating Characteristics (toc01), supporting robust operation across the entire 3.3V ±10% tolerance band.