Features
- Compliant with the requirements outlined in Telcordia GR-253-CORE (SONET) and ITU-T G.813/G.8262 (SDH/SONET & SyncE) when paired with a Synchronous Equipment Timing Source (SETS) device
- Generates up to 4 LVPECL/LVDS/HCSL or 16 LVCMOS output clocks ranging from 8kHz up to 1.0GHz (diff.), 8kHz to 250MHz (LVCMOS), that meet jitter limits for 10G up to 25G Ethernet applications
- 0.276ps RMS (including spurs), 12kHz to 20MHz
- Accepts up to two LVPECL, LVDS, LVHSTL, HCSL, or LVCMOS input clocks ranging from 8kHz up to 875MHz
- Auto and manual input clock selection with hitless switching
- Clock input monitoring, including support for gapped clocks
- Phase-Slope Limiting and Fully Hitless Switching options to control output phase transients
- Operates from a 10MHz to 50MHz fundamental-mode crystal
- Register programmable through I2C or via external I2C EEPROM
- 8T49N242-998 "Boot from EEPROM"
- 8T49N242-999 "powers up disabled"
- Supported by the Timing Commander™ software
Description
The 8T49N242 has one fractional-feedback PLL that can be used as a frequency translator with jitter attenuation or a frequency synthesizer. It is equipped with four integer output dividers, allowing the generation of up to four different output frequencies, ranging from 8kHz to 1GHz. Output frequencies can be completely independent of the input frequencies. The four outputs may be selected among LVPECL, LVDS, HCSL, or LVCMOS output levels.
The 8T49N242 is ideal for use in a wide range of equipment, including 10G/40G/100G SONET/SDH and Ethernet network line cards, wireless base station baseband units, broadcast video, carrier Ethernet switches, OTN, or in test and measurement applications. For example, the 8T49N242 can be used in GbE/10GbE/100GbE Synchronous Ethernet line card applications to preserve the G.8262 compliance from the Synchronous Equipment Timing Source (SETS) on the timing card.
Renesas’ third-generation Universal Frequency Translator family also includes the 8T49N241 (2-in/1-PLL/4-out), the 8T49N285 (2-in/1-PLL/8-out), the 8T49N286 (4-in/2-PLL/ 8-out) and the 8T49N287 (2-in/2-PLL/8-out). These devices are complemented by the 82P33714 and 82P33731 synchronous equipment timing source for Synchronous Ethernet (SyncE) and 10G-40G SyncE, respectively.
To see other devices in this product family, visit the Universal Frequency Translators page.
Parameters
| Attributes | Value |
|---|---|
| Inputs (#) | 2 |
| Input Type | LVCMOS, HCSL, LVHSTL, LVDS, LVPECL, LVTTL |
| Product Category | FemtoClock NG, IEEE 1588, Ultra-Low Jitter Clocks (<300 fs RMS), Jitter Attenuators, Network Synchronization, PDH and SONET/SDH Clocks, Programmable Clocks, Universal Frequency Translators, FemtoClock NG, Ultra-Low Jitter Clocks (<300 fs RMS), IEEE 1588, Jitter Attenuators, Network Synchronization, PDH and SONET/SDH Clocks, Programmable Clocks, Universal Frequency Translators |
| Diff. Outputs | 4 |
| Output Type | LVCMOS, LVDS, LVPECL, HCSL |
| Output Voltage (V) | 2.5V, 3.3V, 1.8V |
| Input Freq (MHz) | 0.008 - 875 |
| Phase Jitter Typ RMS (ps) | 0.276 |
| Output Freq Range (MHz) | 0.008 - 1000 |
| Fractional Output Dividers (#) | 0 |
| Core Voltage (V) | 2.5V, 3.3V |
| Output Banks (#) | 4 |
| Loop Bandwidth Range (Hz) | 0.2 - 6400 |
| Xtal Freq (KHz) | 10000 - 50000 |
| Advanced Features | Programmable Hitless Reference Switching, Fractional-N PLL, OTP, External Feedback |
Package Options
| Pkg. Type | Pkg. Dimensions (mm) | Lead Count (#) | Pitch (mm) |
|---|---|---|---|
| VFQFPN | 6.0 x 6.0 x 0.9 | 40 | 0.5 |
Applications
- OTN or SONET/SDH equipment
- Gigabit and Terabit IP switches/routers including Synchronous Ethernet
- Video broadcast
Renesas Boards & Kits
Evaluation Kit for 8T49N242
The 8T49N242-EVK is designed to help the customer evaluate the 8T49N242 Universal Frequency Translator (UFT 3G). When the board is connected to a PC running Timing CommanderTM software through USB, the device can be configured and programmed through a graphical interface or through register... Read More
Support Communities
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Clarification on VCCA Pin Grouping and Filtering – 8T49N242
Hello, I am currently implementing the 8T49N242 (3.3 V supply, Q0 configured as ~400 MHz LVDS output) and would like clarification regarding the recommended VCCA supply topology. In the datasheet, pins 1, 30, and 39 are described as PLL supply pins. However, in the Renesas design checklist (Excel document ...
Feb 20, 2026 -
8T49N242 PLL lock time in Synthesizer mode
Hello, I am using 8T49N242 in Synthesizer mode with external crystal 32.768MHz. When I am changing APLL frequency by setting new dividers values, I see that it takes quite long time for PLL to lock. It takes about 100~200mS to PLL lock. I suspect it should be much ...
Nov 30, 2022 -
VCO tuning for 8T49N242
I am planning on using an 8T49N242 Clock generator in a design I am working on, but have a few questions about its limitations and uses. First, how do I tune the VCO frequency, I can see via the app note about programming the 8T49N24X that its VCO can be ...
Oct 6, 2021
Knowledge Base
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Can 8T49N242 use different voltages for VCC and VCCA?
Last Updated: 05/21/2026 Question: Can 8T49N242 use different voltages for VCC and VCCA? Answer: 8T49N242 was never intended to be operated with different voltages for VCC and VCCA. It must operate with VCC = VCCA = 2.5V or VCC = VCCA = 3.3V. Suitable Products 8T49N242
May 21, 2026
Support Communities
