Si53xx-RM

3.7. Si5326

The Si5326 is a jitter-attenuating precision clock multiplier for applications requiring sub 1 ps jitter performance. The Si5326 accepts dual clock inputs ranging from 2 kHz to 710 MHz and generates two independent, synchronous clock outputs ranging from 2 kHz to 945 MHz and select frequencies to 1.4 GHz. The device provides virtually any frequency translation combination across this operating range. The Si5326 input clock frequency and clock multiplication ratios are programmable through an I2C or SPI interface. The DSPLL loop bandwidth is digitally programmable from 60 Hz to 8 kHz, providing jitter performance optimization at the application level. Operating from a single 1.8, 2.5, or 3.3 V supply, the Si5326 is ideal for providing clock multiplication and jitter attenuation in high-performance timing applications. See "7. Microprocessor Controlled Parts (Si5319, Si5324, Si5325, Si5326, Si5327, Si5367, Si5368, Si5369, Si5374, Si5375)" on page 76 for a complete description.

Xtal or Refclock

 

 

 

 

RATE[1:0]

 

 

 

 

 

 

 

 

 

XB

XA

 

 

 

 

 

 

 

0

3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

DSPLL

 

BYPASS

 

 

CKIN_1 +

2

÷ N31

 

 

 

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

CKIN_1 –

 

 

f3

 

 

 

 

 

2

 

 

 

 

 

 

 

CKIN_2 +

÷ N32

1

®

fOSC

÷ NC1

1

2 /

CKOUT_1 +

 

DSPLL

0

CKIN_2 –

 

 

 

 

 

 

 

CKOUT_1 –

INT_C1B

 

 

Signal

 

 

÷ N1_HS

 

 

 

 

 

 

 

 

 

 

 

C2B

 

 

Detect

÷ N2

 

÷ NC2

1

2

CKOUT_2 +

 

 

 

 

 

0

/

 

 

 

 

 

 

 

 

CKOUT_2 –

 

 

 

 

 

 

 

 

 

LOL

CS_CA

CMODE

SDA_SDO

SCL

SDI Control

A[2]/SS

 

 

 

 

 

 

 

A[1:0]

 

 

 

 

 

 

 

INC

 

 

 

 

 

 

 

 

VDD

 

 

 

 

 

 

DEC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RST

 

 

 

 

 

 

 

GND

 

 

 

 

 

 

 

 

 

 

 

 

Figure 7. Si5326 Clock Multiplier and Jitter Attenuator Block Diagram

Rev. 0.5

23

Page 23
Image 23
Silicon Laboratories SI5319, SI5369, SI5365, SI5366, SI5367 Si5326 Clock Multiplier and Jitter Attenuator Block Diagram