Si5351A/B/C

10. Si5351B Pin Descriptions (20-Pin QFN, 24-Pin QSOP)

Si5351B 20-QFN

Top View

 

VDD

CLK4

VDDOC

CLK5

CLK6

 

 

20

19

18

17

16

 

XA

1

 

 

 

15

CLK7

XB

2

 

 

 

14

VDDOD

VC

3

 

GND

 

13

CLK0

 

PAD

 

 

 

 

 

 

 

 

SCL

4

 

 

 

12

CLK1

SDA

5

 

 

 

11

VDDOA

 

6

7

8

9

10

 

 

SSEN

OEB

CLK3

CLK2

VDDOB

 

Si5351B 24-QSOP

Top View

CLK5

1

24

CLK6

VDDOC

2

23

CLK7

CLK4

3

22

VDD0D

VDD

4

21

CLK0

GND

5

20

CLK1

XA

6

19

GND

XB

7

18

VDDOA

GND

8

17

GND

VC

9

16

VDD0B

SCL

10

15

CLK2

SDA

11

14

CLK3

SSEN

12

13

OEB

Table 11. Si5351B Pin Descriptions

Pin Name

Pin Number

Pin Type*

Function

 

 

20-QFN

24-QSOP

 

 

 

 

 

 

 

 

XA

1

6

I

Input pin for external crystal

 

 

 

 

 

XB

2

7

I

Input pin for external crystal

 

 

 

 

 

CLK0

13

21

O

Output clock 0

 

 

 

 

 

CLK1

12

20

O

Output clock 1

 

 

 

 

 

CLK2

9

15

O

Output clock 2

 

 

 

 

 

CLK3

8

14

O

Output clock 3

 

 

 

 

 

CLK4

19

3

O

Output clock 4

 

 

 

 

 

CLK5

17

1

O

Output clock 5

 

 

 

 

 

CLK6

16

24

O

Output clock 6

 

 

 

 

 

CLK7

15

23

O

Output clock 7

 

 

 

 

 

VC

3

9

I

VCXO control voltage input

 

 

 

 

 

SCL

4

10

I

I2C bus serial clock input. Pull-up to VDD core with 1 kΩ.

SDA

5

11

I/O

I2C bus serial data input. Pull-up to VDD core with 1 kΩ.

SSEN

6

12

I

Spread spectrum enable. High = enabled, Low = disabled.

 

 

 

 

 

OEB

7

13

I

Output driver enable. Low = enabled, High = disabled.

 

 

 

 

 

VDD

20

4

P

Core voltage supply pin

 

 

 

 

 

VDDOA

11

18

P

Output voltage supply pin for CLK0 and CLK1. See 6.2

 

 

 

 

 

VDDOB

10

16

P

Output voltage supply pin for CLK2 and CLK3. See 6.2

 

 

 

 

 

VDDOC

18

2

P

Output voltage supply pin for CLK4 and CLK5. See 6.2

 

 

 

 

 

VDDOD

14

22

P

Output voltage supply pin for CLK6 and CLK7. See 6.2

 

 

 

 

 

GND

Center Pad

5, 8, 17, 19

P

Ground

 

 

 

 

 

*Note: I = Input, O = Output, P = Power

*Note: Input pins are not internally pulled up.

Preliminary Rev. 0.95

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Silicon Laboratories SI5351A/B/C specifications 10. Si5351B Pin Descriptions 20-Pin QFN, 24-Pin Qsop

SI5351A/B/C specifications

Silicon Laboratories SI5351A/B/C is a versatile, low-power clock generator and frequency synthesizer that has gained widespread popularity in various applications, including telecommunications, consumer electronics, and industrial control systems. These devices are primarily designed to provide precise clock frequency generation with low phase noise and jitter, making them ideal for high-performance applications.

One of the standout features of the SI5351 is its ability to generate multiple output frequencies simultaneously. Capable of producing up to three independent programmable outputs, the SI5351A/B/C can generate frequencies ranging from 8 kHz to 160 MHz. With its integrated phase-locked loop (PLL) technology, it achieves excellent frequency stability and accuracy, simplifying the design of frequency-dependent systems.

The device operates under a supply voltage range of 1.8V to 3.6V, allowing it to be used in battery-powered applications without excessive power consumption. The SI5351’s low current draw, typically as low as 25 mA, is especially beneficial in portable devices, extending battery life and enhancing overall efficiency. Furthermore, it features a programmable output driver, which can be set to various drive strengths, ensuring compatibility with a wide array of load requirements.

Configuration and control of the SI5351 are user-friendly, implemented via an I2C interface. This allows for straightforward integration into microcontroller-based designs. Moreover, the device includes an on-chip memory that stores settings, which streamlines the reconfiguration process when power cycling, minimizing setup time for developers.

Another significant advantage of the SI5351A/B/C is its output jitter performance, which is typically below 1 ps, resulting in clean output signals essential for high-speed data communications and precise timing applications. The SI5351’s integration of multiple synthesizer stages contributes to its impressive phase noise characteristics, making it suitable for demanding RF applications.

Additionally, the SI5351 devices offer programmable frequency stepping, allowing users to define custom frequency increments, which is particularly useful in applications requiring precise tuning or modulation. This flexibility, combined with its compact size and simple interface, makes the SI5351A/B/C an ideal choice for engineers seeking a reliable, cost-effective solution for generating clock signals in a myriad of electronic systems.

In summary, Silicon Laboratories SI5351A/B/C provides a robust, low-power solution for high-precision clock generation, characterized by its programmable outputs, low jitter, easy configurability, and broad frequency range, making it an excellent choice for both commercial and industrial applications across various sectors.