1 Features

? Ultra-low jitter BAW VCO based Ethernet clocks

– 13fs typical RMS jitter at 625MHz with 4MHz 1st

order high-pass filter (HPF)

– 24fs typical RMS jitter at 312.5MHz with 4MHz

1st order HPF

– 42fs typical/ 60fs maximum RMS jitter at

312.5MHz

– 47fs typical/ 65fs maximum RMS jitter at

156.25MHz

? 1 high-performance Digital Phase Locked Loop

(DPLL) with 2 Analog Phase Locked Loops

(APLLs)

– Programmable DPLL loop filter bandwidth from

1mHz to 4kHz

– < 1ppt DCO frequency adjustment step size

? 2 differential or single-ended DPLL inputs

– 1Hz (1PPS) to 800MHz input frequency

– Digital Holdover and Hitless Switching

? 12 differential outputs with programmable HSDS,

AC-LVPECL, LVDS and HSCL formats

– Up to 16 total frequency outputs when

configured with 6 LVCMOS frequency outputs

on OUT0_P/N, OUT1_P/N, GPIO1 and GPIO2

and 10 differential outputs on OUT2_P/N to

OUT11_P/N

– 1Hz (1PPS) to 1250MHz output frequency with

programmable swing and common mode

– PCIe Gen 1 to 6 compliant

? I2C or 3-wire/4-wire SPI

2 Applications

? Wired networking

– Inter/Intra DC interconnect

– Timing card, line card, fixed card (pizza box)

? SyncE (G.8262), SONET/SDH (Stratum 3/3E,

G.813, GR-1244, GR-253), IEEE-1588 PTP

secondary clock

? Jitter cleaning, wander attenuation, and reference

clock generation for 112G/224G PAM-4 SerDes

? 100G-800G data center switches, core routers,

edge routers, WLAN

? Data center and enterprise computing

– Smart Network Interface Card (NIC)

? Optical Transport Networks (OTN G.709)

? Broadband fixed line access

? Industrial

– Test and measurement

– Medical imaging

3 Description

The LMK5B12212 is a high-performance network

synchronizer and jitter cleaner designed to meet the

stringent requirements of ethernet-based networking

applications with < 5ns timing accuracy (class D).

The network synchronizer integrates a DPLL to

provide hitless switching and jitter attenuation with

programmable loop bandwidth (LBW) and no external

loop filters, maximizing flexibility and ease of use. The

DPLL phase locks an integrated APLL to the provided

reference input.

APLL1 features an ultra high performance PLL

with TI's proprietary Bulk Acoustic Wave (BAW)

technology (known as the BAW APLL) and can

generate 312.5MHz output clocks with 42fs typical /

60fs maximum RMS jitter irrespective of the DPLL

reference input frequency and jitter characteristics.

APLL2 provides for a second frequency and/or

synchronization domain.

Reference validation circuitry monitors the DPLL

reference clocks and performs a hitless switch

between inputs upon detecting a switchover event.

Zero-Delay Mode (ZDM) and phase cancellation can

be enabled to control the phase relationship from

input to outputs.

The device is fully programmable through I2C or SPI.

The integrated EEPROM can be used to customize

system start-up clocks. The device also features

factory default ROM profiles as fallback options.