Description

The 8V19N470 is a fully integrated FemtoClock® NG jitter attenuator

and clock synthesizer designed as a high-performance clock solution

for conditioning and frequency/phase management of wireless base

station radio equipment boards.

The device is optimized to deliver excellent phase noise

performance as required in GSM, WCDMA, LTE, LTE-A radio board

implementations. A two-stage PLL architecture supports both jitter

attenuation and frequency multiplication. The first stage PLL is the

jitter attenuator and uses an external VCXO for best possible phase

noise characteristics. The second stage PLL locks on the VCXO-PLL

output signal and synthesizes the target frequency. This PLL has two

VCO circuits at 2949.12MHz and 2400MHz–2500MHz, respectively,

for enhanced frequency flexibility.

The device generates the output clock signals from the selected

VCO by frequency division. Four independent integer frequency

dividers are available. Delay circuits can be used for achieving

alignment and controlled phase delay between clock signals. The

two redundant inputs are monitored for activity. Four selectable clock

switching modes are provided to handle clock input failure scenarios.

Auto-lock, individually programmable output frequency dividers and

phase adjustment capabilities are added for flexibility.

The device is configured through an SPI interface and reports PLL

lock and signal loss status in internal registers, PLL lock status is

also reported via two lock detect outputs. Internal status bit changes

can also be reported via the nINT output. The device is ideal for

driving converter circuits in wireless infrastructure, radar/imaging

and instrumentation/medical applications. The device is a member of

the high-performance clock family from IDT.

Features

▪ High-performance clock RF-PLL

▪ Optimized for low phase noise: ≤150dBc/Hz (1MHz offset;

245.76MHz clock)

▪ Dual-PLL architecture

— 1st-PLL stage with external VCXO for clock jitter attenuation

— 2nd-PLL stage with internal FemtoClock NG PLL at selectable

2949.12MHz and 2400MHz  2500MHz VCO

▪ Five output channels with a total of 11 outputs, organized in:

— Two clock channels with two differential outputs

— Two clock channels with three differential outputs

— One VCXO-PLL channel with one selectable LVDS/ two

LVCMOS outputs

▪ Each clock channel contains an integer output divider and a

phase delay circuit with 512 steps of half of the VCO period

▪ Supported clock output frequencies include:

— From VCO-0: 2949.12MHz, 1474.56MHz, 983.04MHz,

491.52MHz, 368.64MHz, 122.88MHz

— From VCO-1: 2457.6MHz, 1228.8MHz, 614.4MHz, 307.2MHz,

153.6, 76.8MHz or 625MHz, 500MHz, 312.5MHz, 250MHz,

156.25MHz, and 125MHz

▪ Low-power LVPECL/LVDS outputs support configurable signal

amplitude, DC and AC coupling and LVPECL, LVDS line

terminations techniques

▪ Redundant input clock architecture

— Two inputs

— Individual input signal monitor

— Digital holdover

— Manual and automatic clock selection

— Hitless switching

▪ Status monitoring and fault reporting

— Input signal status

— Lock status of each individual PLL (two status pins)

— Hold-over and reference loss status

— Mask-able status interrupt pin

▪ Voltage supply:

— Device core supply voltage: 3.3V

— Output supply voltage: 3.3V, 2.5V or 1.8V

— Digital control I/O voltage: 1.8V (3.3V tolerant)

— SPI control I/O voltage: 1.8V or 3.3V (selectable), 3.3V

tolerant inputs when set to 1.8V

▪ Package: 81-FPBGA (8  8  1.35 mm, 0.8mm ball pitch)

▪ Temperature range: -40°C to +85°C