Renesas 849N202CKI-009LF

Overview

849N202CKI-009LF from Integrated Device Technology is a dual-output universal frequency translator/synthesizer IC supporting 0.98MHz–1300MHz output frequencies, three operating modes (synthesizer, high-bandwidth translator, low-bandwidth translator), and factory-programmed dual OTP configurations. It delivers <510fs RMS phase jitter at 125MHz (low-bandwidth mode) and features LVPECL/LVDS programmable outputs with independent enable control, used in telecom line cards for OC-12 and Gigabit Ethernet clock translation.

For engineers reviewing the 849N202CKI-009LF datasheet, 849N202CKI-009LF pinout, 849N202CKI-009LF application, or 849N202CKI-009LF equivalent, key selection considerations include input reference flexibility (8kHz–710MHz), crystal-based jitter attenuation (10Hz–580Hz PLL bandwidth), I²C reconfigurability, and dual-alarm monitoring (CLK0BAD/CLK1BAD/XTALBAD/HOLDOVER).

Technical Context

The 849N202CKI-009LF implements a dual-loop architecture in low-bandwidth translator mode-using a low-frequency integer-divider loop (8kHz–16kHz PFD) for precise ratio control and a digitally controlled crystal oscillator (DCXO) upper loop for stability-enabling sub-ppb frequency translation accuracy with external crystal jitter filtering. Its VCO operates from 1.995GHz to 2.6GHz, paired with 11-bit integer output dividers (N = 2–2046) and fractional-N feedback for synthesizer mode.

In high-bandwidth translator mode, it uses a single high-loop-bandwidth PLL (no external crystal required) to track spread-spectrum modulation without attenuating input jitter, while the synthesizer mode relies solely on delta-sigma fractional feedback from a 16MHz–40MHz fundamental-mode crystal. All modes support two differential inputs (LVPECL/LVDS/LVHSTL/HCSL) and two independently configurable LVPECL/LVDS outputs.

Key Specifications

Pinout & Package

40-pin Very Thin Quad Flat No-Lead (VFQFN) package, 6mm × 6mm body, 0.925mm height, exposed thermal pad, lead-free (RoHS 6) compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar universal frequency translator applications.

Compared with 849N204CKI-009LF and Si5338A-A-GM, the 849N202CKI-009LF uniquely balances dual-output flexibility, factory-configurable OTP states, five dedicated alarm outputs, and external crystal–based jitter attenuation-making it optimal for telecom line cards where reliability, configurability, and hardware-fault visibility are critical.

Availability

849N202CKI-009LF is available at Aetrix Electronics and suitable for OC-12 line cards, Gigabit Ethernet switches, and PCIe server motherboards requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant timing solutions.

Supply support for 849N202CKI-009LF 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), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor signal conditioning ICs for communications, computing, and industrial markets.

The 849N202CKI-009LF belongs to IDT's FemtoClock® NG family-designed specifically for high-reliability, multi-standard timing in telecom infrastructure, where zero-ppm translation, dual-input redundancy, and hardware alarm visibility are essential.

FAQ

What are the supported input clock types for the 849N202CKI-009LF?

The 849N202CKI-009LF accepts LVPECL, LVDS, LVHSTL, and HCSL differential inputs across an 8kHz–710MHz range, plus 16MHz–40MHz fundamental-mode crystals on XTAL_IN/XTAL_OUT. Single-ended CMOS inputs are not supported; all clock inputs must be differential and terminated per datasheet guidelines to ensure proper lock and jitter performance.

How does the CONFIG pin affect the 849N202CKI-009LF power-up behavior?

The CONFIG pin selects between two factory-programmed OTP configurations stored in the 849N202CKI-009LF at manufacture-e.g., Configuration 0 may deliver 622.08MHz for OC-12, while Configuration 1 delivers 125MHz for Gigabit Ethernet. The selected configuration loads automatically at power-up; no I²C interaction is needed unless runtime reprogramming is required.

Can the 849N202CKI-009LF generate exactly 100MHz for PCIe Gen3 reference clocking?

Yes-the 849N202CKI-009LF supports 100MHz output in high-bandwidth translator mode using a 25MHz input reference, achieving zero-ppm translation with RMS phase jitter under 600fs (12kHz–20MHz). Its PLL bypass capability preserves spread-spectrum modulation, meeting PCIe Gen3 specification requirements without external filtering.

What is the function of the HOLDOVER pin on the 849N202CKI-009LF?

The HOLDOVER pin on the 849N202CKI-009LF is an active-high LVCMOS/LVTTL output that asserts when the device loses lock to both input references (in automatic mode) or the selected input (in manual mode). In low-bandwidth translator mode, it indicates holdover using the local crystal; in high-bandwidth mode, it signals free-run from the internal VCO.

Does the 849N202CKI-009LF require external loop filter components?

Only in low-bandwidth frequency translator mode: pins LF0 and LF1 connect to external RC loop filter components to set PLL bandwidth (10Hz–580Hz). In synthesizer and high-bandwidth translator modes, the 849N202CKI-009LF operates without external filters-reducing BOM count and layout complexity for simpler clock generation tasks.