Renesas 8T49N203A-027NLGI

Overview

8T49N203A-027NLGI from IDT is a universal frequency translator IC supporting three operating modes-frequency synthesizer, high-bandwidth translator (up to 710MHz input), and low-bandwidth jitter-attenuating translator (down to 8kHz input)-with dual LVPECL/LVDS programmable outputs, 0.98–1300MHz output range, and factory-configurable OTP defaults for telecom line cards.

For engineers reviewing the 8T49N203A-027NLGI datasheet, 8T49N203A-027NLGI pinout, 8T49N203A-027NLGI application, or 8T49N203A-027NLGI equivalent, this device delivers precise zero-ppm frequency translation, RMS phase jitter as low as 285fs (synthesizer mode), configurable PLL bandwidths (10Hz–580Hz or high-bandwidth tracking), and real-time alarm monitoring (CLK0BAD, XTALBAD, HOLDOVER) for mission-critical timing in networking infrastructure.

Technical Context

The 8T49N203A-027NLGI implements a dual-loop architecture in low-bandwidth translator mode: a low-frequency integer-N loop (8kHz–16kHz PFD) for exact ratio translation and a digitally controlled crystal oscillator (DCXO) upper loop for jitter attenuation using an external 16–40MHz crystal. In synthesizer and high-bandwidth modes, it uses a single delta-sigma fractional-N feedback loop with VCO range 1.995–2.6GHz.

It supports two independent factory-programmed OTP configurations selected via the CONFIG pin, each defining distinct input/output ratios, PLL bandwidths, output types (LVPECL/LVDS), and supply voltages (VCCO = 2.5V or 3.3V). Input clock selection (CLK0/nCLK0 or CLK1/nCLK1) is controlled by CLK_SEL, with automatic/manual switchover and holdover behavior fully configurable via I²C registers.

Key Specifications

Pinout & Package

8T49N203A-027NLGI is housed in a 40-lead VFQFN package (6 mm × 6 mm × 0.925 mm, K package), RoHS-compliant and lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5341-A01AGM and LMK04828BISQE/NOPB, the 8T49N203A-027NLGI uniquely combines factory-programmable OTP defaults, dedicated hardware alarm outputs, and dual-mode PLL flexibility in a compact 40-pin VFQFN - making it optimal for telecom line cards requiring deterministic, pin-level fault signaling and rapid hardware-based configuration switching.

Availability

8T49N203A-027NLGI is available at Aetrix Electronics and suitable for OC-12 line cards, Gigabit Ethernet switches, and PCIe Gen3 server platforms requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for 8T49N203A-027NLGI 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 power management ICs for communications and computing markets.

The 8T49N203A-027NLGI belongs to IDT's FemtoClock® NG family, engineered specifically for carrier-grade networking equipment requiring programmable, low-jitter, multi-mode clock generation with hardware-based fault monitoring and field-upgradable configurations.

FAQ

What are the supported input clock types for 8T49N203A-027NLGI?

The 8T49N203A-027NLGI accepts LVPECL, LVDS, LVHSTL, and HCSL differential inputs on CLK0/nCLK0 and CLK1/nCLK1 pins, covering 8 kHz to 710 MHz. It also supports 16–40 MHz fundamental-mode parallel-resonant crystals on XTAL_IN/XTAL_OUT for low-jitter DCXO operation. Single-ended inputs are not supported.

How does the CONFIG pin affect the default behavior of 8T49N203A-027NLGI at power-up?

The CONFIG pin selects between two factory-programmed OTP configurations stored in the 8T49N203A-027NLGI. When CONFIG = 0, Configuration 0 loads (e.g., 622.08 MHz OC-12 profile); when CONFIG = 1, Configuration 1 loads (e.g., 125 MHz GigE profile). These settings define output frequency, PLL bandwidth, output type, and alarm thresholds - all active before I²C access.

Can 8T49N203A-027NLGI generate both LVPECL and LVDS outputs simultaneously?

Yes. The 8T49N203A-027NLGI allows independent programming of Q0/nQ0 and Q1/nQ1 as either LVPECL or LVDS via I²C register bits Q0_TYPE and Q1_TYPE. Both outputs share the same VCCO supply (2.5V or 3.3V), and LVPECL operation requires VCCO = 2.5V with VCC = 3.3V, as specified in the datasheet's output supply voltage modes.

What is the purpose of the HOLDOVER pin on 8T49N203A-027NLGI?

The HOLDOVER pin on 8T49N203A-027NLGI is a dedicated LVCMOS output that asserts high when the device loses lock to both input references (automatic mode) or the selected reference (manual mode). In low-bandwidth translator mode, it indicates crystal-based holdover; in high-bandwidth mode, it signals free-run. This enables immediate system-level failover without polling registers.

Does 8T49N203A-027NLGI support I²C write operations after power-up without disrupting ongoing clock output?

Yes. The 8T49N203A-027NLGI supports full I²C register reconfiguration post-power-up. While output behavior may be unpredictable during register writes and settling, the device maintains continuous clock output. For glitch-sensitive systems, IDT recommends completing reconfiguration before enabling downstream logic or performing a controlled reset after write completion.