Silicon Laboratories SI5351A/B/C manual

Preliminary Rev. 0.95 8/11 Copyright © 2011 by Silicon Labo ratories Si5351A/B/C This information applies to a product under dev elopment. Its characteristics and specifications are s ubject to change without n otice. Si5351A/B/C I 2 C-P ROGRAMMABL E A NY -F REQUENCY CMOS C LOCK G ENERATOR + VCXO Features Applications Description The Si5351 is an [...]

Si5351A/B/C 2 Preliminary Rev. 0.95[...]

Si5351A/B/C Preliminary Rev. 0.95 3 T ABLE OF C ONTENT S Section Page 1. Electrical Specificat ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Detailed Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 3. Functional De[...]

Si5351A/B/C 4 Preliminary Rev. 0.95 1. Electrical S pecifications T able 1. Recommended Operating Conditions Parameter Symbol T est Condition Min T yp Max Unit Ambient T emperature T A – 4 0 2 58 5° C Core Supply V oltage V DD 3.0 3.3 3.60 V 2.25 2.5 2.7 5 V Output Buffer V oltage V DDOx 1.71 1.8 1.8 9 V 2.25 2.5 2.7 5 V 3.0 3.3 3.60 V Notes: Al[...]

Si5351A/B/C Preliminary Rev. 0.95 5 T able 3. AC Characteristics (V DD = 2.5 V ±10%, or 3.3 V ±10%, T A = –40 to 85 °C) Parameter Symbol T est Condition Min T yp Max Unit Power-up T ime T RDY From V DD =V DDmin to valid output clock, C L =5p F , f CLKn >1M H z —1 1 0 m s Output Enable T ime T OE From OEB pulled low to valid clock output, [...]

Si5351A/B/C 6 Preliminary Rev. 0.95 T able 5. Output Clock Characteristics (V DD = 2.5 V ±10%, or 3.3 V ±10%, T A =– 4 0 t o 8 5° C ) Parameter Symbol T est Condition Min T yp Max Units Frequency Range F CLK 0.008 — 160 MHz Load Cap acitance C L —5 1 5 p F Duty Cycle DC Measured at V DD /2, f CLK =5 0M H z 45 50 55 % Rise/Fall T ime t r 20[...]

Si5351A/B/C Preliminary Rev. 0.95 7 T able 7. I 2 C Specifica tions (SCL,SDA) 1 Parameter Symbol T es t Co nd ition St and ard Mode 100 kbp s Fast Mode 400 kbps Unit Min Max Min Max LOW Level Input V oltage V ILI2C –0.5 0.3 x V DDI2 C –0.5 0.3 x V DDI2C 2 V HIGH Level Input V oltage V IHI2C 0.7 x V DDI2 C 3.63 0.7 x V DDI2C 2 3.63 V Hysteresis [...]

Si5351A/B/C 8 Preliminary Rev. 0.95 T able 9. Absolute Maximum Ratings 1 Parameter Symbol T est Condition V alue Unit DC Supply V o ltage V DD_max –0.5 t o 3.8 V Input V oltage V IN_CLKIN CLKIN, SCL, SDA –0.5 to 3.8 V V IN_VC VC –0.5 to (VDD+0.3) V V IN_XA/B Pins XA, XB –0.5 to 1.3 V V Junction T emperature T J –55 to 150 °C Soldering T [...]

Si5351A/B/C Preliminary Rev. 0.95 9 2. Det ailed Block Diagrams Figure 1. Block Diagrams of 3-Output and 8-Output Si5351A Devices PLL B PLL A SDA SCL OSC XA XB VDDO R0 R1 CLK0 CLK1 R2 CLK2 M ult iS yn th 0 M ult iS yn th 1 M ult iS yn th 2 VDD GND 10- M SO P Si5351A 3-Outpu t R0 R1 CLK0 CLK1 VDDOA R2 R3 CLK2 CLK3 VDDOB R4 R5 CLK4 CLK5 VDDOC R6 R7 C[...]

Si5351A/B/C 10 Preliminary Rev. 0.95 Figure 2. Block Diagrams of Si5351B and Si5351C 8-Output Devices OSC XA XB PLL VCXO R0 R1 CLK0 CLK1 VDDOA R2 R3 CLK2 CLK3 VDDOB R4 R5 CLK4 CLK5 VDDOC R6 R7 CLK6 CLK7 VDDOD MultiSynth 0 MultiSynth 1 MultiSynth 2 MultiSynth 3 MultiSynth 4 MultiSynth 5 MultiSynth 6 MultiSynth 7 VC VDD GND Si5351B SCL SDA Control Lo[...]

Si5351A/B/C Preliminary Rev. 0.95 11 3. Functional Description The Si5351 is a ve rsatile I 2 C progr ammable clock ge nerator that is ide ally suited for repla cing crystals, crystal oscillators, VCXOs, PLLs, and buffers. A block diagram sho wing the general architecture of the Si5351 is shown in Figure 3. The device consists of an input st age, t[...]

Si5351A/B/C 12 Preliminary Rev. 0.95 3.1.2. Exte rnal Clock I nput (C LKIN) The external clock input is used as a clock reference for the PLLs when gene rating synchronous clock outputs. CLKIN can accept any frequency from 10 to 10 0 MHz. A divider at the input stag e limit s the PLL input frequency to 30 MHz. 3.1.3. V oltage Control Input (VC ) Th[...]

Si5351A/B/C Preliminary Rev. 0.95 13 3.4. Spread S pectrum S pread spectrum can be enabl ed on any of the clock output s that use PLL A as its reference. S p read spectr um is useful for reducin g el ectromag netic interf er ence (EMI). E nabling sp read spectru m on a n output clo ck modulates it s frequency , which effectivel y reduces the overal[...]

Si5351A/B/C 14 Preliminary Rev. 0.95 4. I 2 C Interface Many of the functions and features of th e Si5351 are controlled by reading and writing to the RAM sp ace using the I 2 C interface. The following is a list of the common features that ar e controllable through the I 2 C interface. A summary of register function s is shown in Section 7.  Re[...]

Si5351A/B/C Preliminary Rev. 0.95 15 Figure 9. I 2 C W rite Operation A read operation is performed in two st ages. A data writ e is used to set the register addre ss, then a data read is performed to retr ieve the data fr om the set address. A read bur st operation is also su pported. This is shown in Figure 10. Figure 10. I 2 C Read Operation AC [...]

Si5351A/B/C 16 Preliminary Rev. 0.95 5. Configuring the Si5351 The Si5351 is a highly flexible clock generato r which is entirely conf igurable through its I 2 C interface. The device’s default configuration is stored in non-vola tile memory (NVM) as shown in Figure 1 1. The NVM is a one time programm able memo ry (OTP) w hich can st ore a cus to[...]

Si5351A/B/C Preliminary Rev. 0.95 17 Figure 12. I 2 C Programming Proce dure Disable Out puts Set CLKx_DI S high; Reg. 3 = 0xFF Powerdown all output drivers Reg. 16, 17, 18, 19, 20, 21, 22 , 23 = 0x80 Se t in terrup t m a s k s (see regist er 2 description) Write new conf igurat ion to device usi ng the cont ents of t he register map generated by C[...]

Si5351A/B/C 18 Preliminary Rev. 0.95 5.2. Si5351 Appl ication Examples The Si5351 is a versatile clock generator which serves a wide variety of applications. The following ex amples show how it can be used to replace crystals, crystal oscillators, VCXOs, and PLLs. 5.3. Replacing Cryst als and Cryst al Oscillators Using an inexpensive external cryst[...]

Si5351A/B/C Preliminary Rev . 0. 95 19 5.4. Replacing Cryst als, Cr yst al Oscillators, and VCXOs The Si5351B combines fre e-running clock generation an d a VCXO in a single packag e fo r cost sensi tive video applications. An example is shown in Figure 14. Figure 14. Using the Si5351B to Replace Cryst als, Cryst al Oscillators, VCXOs, and PLLs 5.5[...]

Si5351A/B/C 20 Preliminary Rev . 0.95 5.6. Replacing a Cr ystal with a Clock The Si5351 can be driven with a clock signal through the XA i nput pin. Figure 16. Si5351 Driven by a Clock Signal 5.7. HCSL Comp atible Outputs The Si5351 can be co nfigured to suppor t HCSL comp atible swing when the VDDO of th e output pair of interest is set to 2.5 V ([...]

Si5351A/B/C Preliminary Rev . 0. 95 21 6. Design Considerations The Si5351 is a self-cont ained clock generator that re qui res very few external component s. The following general guidelines are recommended to ensure op timum pe rforman c e. Refer to “AN55 4: Si5350/51 PCB Layout Guide” for additional layout recommendations. 6.1. Power Supply [...]

Si5351A/B/C 22 Preliminary Rev . 0.95 6.6. T race Characteristics The Si5351A/B/C features various output current drives ranging from 2 to 8 mA (default). It is recommended to configure t he trace char acteristics as shown in F igu re 18 when an output drive setting of 8 m A is used. Figure 18. Recommended T race Characteristics with 8 mA Drive Str[...]

Si5351A/B/C Preliminary Rev . 0. 95 23 7. Register Map Summary The following is a summary of the re gister map used to read st atus, control, and configure th e Si535 1. Register 7 6 5 4 3 2 1 0 0 SYS_INIT LOL_B LOL_A LOS REVID[1:0] 1 SYSCAL_ STKY LOS_B_ STKY LOL_A_ STKY LOS_ STKY 2 SYSCAL_ MASK LOS_B_ MASK LOL_A _ MASK LOS_ MASK 3 CLK7_EN CLK6_EN [...]

Si5351A/B/C 24 Preliminary Rev . 0.95 66 MS3_P3[15:8] 67 MS3_P3[7:0] 68 R3_DIV[2:0] MS3_P1[17:16] 69 MS3_P1[15:8] 70 MS3_P1[7:0] 71 MS3_P3[19:16] MS3_P2[19:16] 72 MS3_P2[15:8] 73 MS3_P2[7:0] 74 MS4_P3[15:8] 75 MS4_P3[7:0] 76 R4_DIV[2:0] MS4_P1[17:16] 77 MS4_P1[15:8] 78 MS4_P1[7:0] 79 MS4_P3[19:16] MS4_P2[19:16] 80 MS4_P2[15:8] 81 MS4_P2[7:0] 82 MS5[...]

Si5351A/B/C Preliminary Rev . 0. 95 25 8. Register Descriptions Reset value = 0000 0000 Register 0. Device St atus B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name SYS_INIT LO L_B LOL_A LOS REVID[1:0] Ty p e RRRRRR R Bit Name Function 7S Y S _ I N I T System Initialization St atus. During power up the device copies the content of the NVM into RAM and performs a[...]

Si5351A/B/C 26 Preliminary Rev . 0.95 Reset value = 0000 0000 Register 1. Interrupt S tatus S ticky B i t D 7 D 6 D 5 D 4 D 3D 2D 1D 0 Name SYS_INIT_STKY LOL_B_STKY LOL_A_STKY LOS_STKY Ty p e R/W R/W R/W R/W R/W R/W R/W R/W Bit Name Function 7 SYS_INIT_STKY System Calibration St atus Sticky Bit. The SYS_INIT_STKY bit is trig gered when the SYS_INIT[...]

Si5351A/B/C Preliminary Rev . 0. 95 27 Reset value = 0000 0000 Register 2. Interrupt St atus Mask B i t D 7 D 6 D 5 D 4 D 3D 2D 1D 0 Name SYS_INIT_MASK LOL_B_MASK LOL_A_MASK LOS_MASK Ty p e R/W R/W R/W R/W R/W R/W R/W R/W Bit Name Function 7 SYS_INIT_MASK System Initialization S t atus Mask. Use this mask bit to prevent the INTR pin (Si5351C only) [...]

Si5351A/B/C 28 Preliminary Rev . 0.95 Reset value = 0000 0000 Reset value = 0000 0000 Register 3. Output Enable Control B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK7_OEB CLK6_OEB CLK5_OEB CLK4_OEB CLK3_OEB CLK2_OEB CLK1_OEB CLK0_OEB Ty p e R/W R/W R/W R/W R/W R/W R/W R/W Bit Name Function 7:0 CLKx_OEB Output Disable for CLKx. Where x = 0, 1, 2, 3, 4, 5,[...]

Si5351A/B/C Preliminary Rev . 0. 95 29 Reset value = 0000 0000 Register 15. PLL Input Source B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name PLLB_SRC PLLA_SRC Ty p e R/W R/W R/W R/W R/W R/W R/W R/W Bit Name Functi on 7:4 Reserved Leave as default. 3 PLLB_SRC Input Source Select for PLLB. 0: Select the XT AL input as the refe rence clock for PLLB (Si5351A/C onl[...]

Si5351A/B/C 30 Preliminary Rev . 0.95 Reset value = 0000 0000 Register 16. CLK0 Control B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK0_PDN MS0_INT MS0_SRC CLK0_INV CLK0_SRC[1:0] CLK0_IDRV[1:0] Ty p e R/W R/W R/W R/W R/W R/W Bit Name Funct ion 7 CLK0_PDN Clock 0 Power Down. This bit allows powering down the CLK0 outp ut driver to conserve power when the o[...]

Si5351A/B/C Preliminary Rev . 0. 95 31 Reset value = 0000 0000 Register 17. CLK1 Control B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK1_PDN MS1_INT MS1_SRC CLK1_INV CLK1_SRC[1:0] CLK1_IDRV[1:0] Ty p e R/W R/W R/W R/W R/W R/W Bit Name Function 7 CLK1_PDN Clock 1 Power Down. This bit allows powering down the CLK1 output driver to conser ve power when the o[...]

Si5351A/B/C 32 Preliminary Rev . 0.95 Reset value = 0000 0000 Register 18. CLK2 Control B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK2_PDN MS2_INT MS2_SRC CLK2_INV CLK2_SRC[1:0] CLK2_IDRV[1:0] Ty p e R/W R/W R/W R/W R/W R/W Bit Name Function 7 CLK2_PDN Clock 2 Power Down. This bit allows powe ring down the CLK2 output driver to conserve power when th e o[...]

Si5351A/B/C Preliminary Rev . 0. 95 33 Reset value = 0000 0000 Register 19. CLK3 Control B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK3_PDN MS3_INT MS3_SRC CLK3_INV CLK3_SRC[1:0] CLK3_IDRV[1:0] Ty p e R/W R/W R/W R/W R/W R/W Bit Name Function 7C L K 3 _ P D N Clock 3 Pow e r Do wn . This bit allows powering down the CLK3 output driver to co nserve po wer[...]

Si5351A/B/C 34 Preliminary Rev . 0.95 Reset value = 0000 0000 Register 20. CLK4 Control B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK4_PDN MS4_INT MS4_SRC CLK4_INV CLK4_SRC[1:0] CLK4_IDRV[1:0] Ty p e R/W R/W R/W R/W R/W R/W Bit Name Function 7 CLK4_PDN Clock 4 Power Down. This bit allows powering down the CLK4 output dr iver to conserve power when the ou[...]

Si5351A/B/C Preliminary Rev . 0. 95 35 Reset value = 0000 0000 Register 21. CLK5 Control B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK5_PDN MS5_INT MS5_SRC CLK5_INV CLK5_SRC[1:0] CLK5_IDRV[1:0] Ty p e R/W R/W R/W R/W R/W R/W Bit Name Function 7 CLK5_PDN Clock 5 Power Down. This bit allows powering down the CLK5 output dr iver to conserve power when the o[...]

Si5351A/B/C 36 Preliminary Rev . 0.95 Reset value = 0000 0000 Register 22. CLK6 Control B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK6_PDN FBA_INT MS6_SRC CLK6_INV CLK6_SRC[1:0] CLK6_IDRV[1:0] Ty p e R/W R/W R/W R/W R/W R/W Bit Name Function 7 CLK6_PDN Clock 7 Power Down. This bit allows powering down the CLK6 output dr iver to conserve power when the ou[...]

Si5351A/B/C Preliminary Rev . 0. 95 37 Reset value = 0000 0000 Register 23. CLK7 Control B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK7_PDN FBB_INT MS7_SRC CLK7_INV CLK7_SRC[1:0] CLK7_IDRV[1:0] Ty p e R/W R/W R/W R/W R/W R/W Bit Name Function 7 CLK7_PDN Clock 7 Power Down. This bit allows powering down the CLK7 output dr iver to conserve power when the o[...]

Si5351A/B/C 38 Preliminary Rev . 0.95 Reset value = 0000 0000 Reset value = 0000 0000 Register 24. CLK3–0 Disable St ate B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK3_DIS_ST A TE CLK2_DIS_ST A TE CLK1_DIS_ST A TE CLK0_DIS_ST A TE Ty p e R/W R/W R/W R /W Bit Name Function 7:0 CLKx_DIS_ST A TE Clock x Disable St ate. Where x = 0, 1, 2, 3. Th ese 2 bits [...]

Si5351A/B/C Preliminary Rev . 0. 95 39 Reset value = xxxx xxxx Reset value = xxxx xxxx Register 42 . Multisynth0 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS0_P3[15:8 ] Type R/W Bit Name Function 7:0 MS0_P 3[15:8] Multisynth0 Parameter 3. This 20-bit number is an en coded represent ation of the denominator for the frac- tional part of the Mult[...]

Si5351A/B/C 40 Preliminary Rev . 0.95 Reset value = xxxx xxxx Reset value = xxxx xxxx Register 44 . Multisynth0 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name R0_DIV[2:0] MS0_P1[17:16] Type R/W R/ W R/W R /W R/W Bit Name Function 7 Unused 6:4 R0_DIV[2:0] R0 Output Divider . 000b: Divide by 1 001b: Divide by 2 010b: Divide by 4 01 1b: Divide by 8 10[...]

Si5351A/B/C Preliminary Rev . 0. 95 41 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 46 . Multisynth0 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS0_P1[7:0] Ty p e R/W Bit Name Function 7:0 MS0_P1[7:0] Multisynth0 Paramet er 1. This 18-bit number is an encoded r epresentation o f the intege r part of the Multi[...]

Si5351A/B/C 42 Preliminary Rev . 0.95 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 49 . Multisynth0 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS0_P2[7:0] Ty p e R/W Bit Name Function 7:0 MS0_P2[7:0] Multisynth0 Paramet er 2. This 20-bit number is an enco ded repre sent ation of the numerator for the fraction[...]

Si5351A/B/C Preliminary Rev . 0. 95 43 Reset value = xxxx xxxx Reset value = xxxx xxxx Register 52 . Multisynth1 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name R1_DIV[2:0] MS1_P1[17:16] Type R/W R/ W R/W R /W R/W Bit Name Function 7 Unused 6:4 R1_DIV[2:0] R1 Output Divider . 000b: Divide by 1 001b: Divide by 2 010b: Divide by 4 01 1b: Divide by 8 1[...]

Si5351A/B/C 44 Preliminary Rev . 0.95 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 54 . Multisynth1 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS1_P1[7:0] Ty p e R/W Bit Name Function 7:0 MS1_P1[7:0] Multisynth1 Paramet er 1. This 18-bit number is an encoded r epresentation o f the intege r part of the MultiS[...]

Si5351A/B/C Preliminary Rev . 0. 95 45 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 57 . Multisynth1 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS1_P2[7:0] Ty p e R/W Bit Name Function 7:0 MS1_P2[7:0] Multisynth1 Paramet er 2. This 20- bit numbe r is an en coded re presen tation of the numerator for the fract[...]

Si5351A/B/C 46 Preliminary Rev . 0.95 Reset value = xxxx xxxx Reset value = xxxx xxxx Register 60 . Multisynth2 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name R2_DIV[2:0] M S2_P1[17:1 6] Ty p e R/W R/W R/W R/W R/W Bit Name Function 7 Unused 6:4 R2_DIV[2:0] R2 Output Divider . 000b: Divide by 1 001b: Divide by 2 010b: Divide by 4 01 1b: Divide by 8 [...]

Si5351A/B/C Preliminary Rev . 0. 95 47 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 62 . Multisynth2 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS2_P1[7:0] Ty p e R/W Bit Name Function 7:0 MS2_P1[7:0] Multisynth2 Paramet er 1. This 18-bit number is an encoded r epresenta tion of the integer part of the Multis[...]

Si5351A/B/C 48 Preliminary Rev . 0.95 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 65 . Multisynth2 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS2_P2[7:0] Ty p e R/W Bit Name Function 7:0 MS2_P2[7:0] Multisynth2 Paramet er 2. This 20- bit numbe r is an en coded re presen tation of the numerator for the fracti[...]

Si5351A/B/C Preliminary Rev . 0. 95 49 Reset value = xxxx xxxx Reset value = xxxx xxxx Register 68 . Multisynth3 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name R3_DIV[2:0] M S3_P1[17:1 6] Ty p e R/W R/W R/W R/W R/W Bit Name Function 7 Unused 6:4 R3_DIV[2:0] R3 Output Divider . 000b: Divide by 1 001b: Divide by 2 010b: Divide by 4 01 1b: Divide by 8[...]

Si5351A/B/C 50 Preliminary Rev . 0.95 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 70 . Multisynth3 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS3_P1[7:0] Ty p e R/W Bit Name Function 7:0 MS3_P1[7:0] Multisynth3 Paramet er 1. This 18-bit number is an encoded r epresenta tion of the integer part of the Multisy[...]

Si5351A/B/C Preliminary Rev . 0. 95 51 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 73 . Multisynth3 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS3_P2[7:0] Ty p e R/W Bit Name Function 7:0 MS3_P2[7:0] Multisynth3 Paramet er 2. This 20- bit numbe r is an en coded re presen tation of the numerator for the fract[...]

Si5351A/B/C 52 Preliminary Rev . 0.95 Reset value = xxxx xxxx Reset value = xxxx xxxx Register 76 . Multisynth4 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name R4_DIV[2:0] M S4_P1[17:1 6] Ty p e R/W R/W R/W R/W R/W Bit Name Function 7 Unused 6:4 R4_DIV[2:0] R4 Output Divider . 000b: Divide by 1 001b: Divide by 2 010b: Divide by 4 01 1b: Divide by 8 [...]

Si5351A/B/C Preliminary Rev . 0. 95 53 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 78 . Multisynth4 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS4_P1[7:0] Ty p e R/W Bit Name Function 7:0 MS4_P1[7:0] Multisynth4 Paramet er 1. This 18-bit number is an encoded r epresenta tion of the integer part of the Multis[...]

Si5351A/B/C 54 Preliminary Rev . 0.95 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 81 . Multisynth4 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS4_P2[7:0] Ty p e R/W Bit Name Function 7:0 MS4_P2[7:0] Multisynth4 Paramet er 2. This 20- bit numbe r is an en coded re presen tation of the numerator for the fracti[...]

Si5351A/B/C Preliminary Rev . 0. 95 55 Reset value = xxxx xxxx Reset value = xxxx xxxx Register 84 . Multisynth5 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name R5_DIV[2:0] M S5_P1[17:1 6] Ty p e R/W R/W R/W R/W R/W Bit Name Function 7 Unused 6:4 R5_DIV[2:0] R5 Output Divider . 000b: Divide by 1 001b: Divide by 2 010b: Divide by 4 01 1b: Divide by 8[...]

Si5351A/B/C 56 Preliminary Rev . 0.95 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 86 . Multisynth5 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS5_P1[7:0] Ty p e R/W Bit Name Function 7:0 MS5_P1[7:0] Multisynth5 Paramet er 1. This 18-bit number is an encoded r epresenta tion of the integer part of the Multisy[...]

Si5351A/B/C Preliminary Rev . 0. 95 57 Reset value = xxxx xxxx Reset value = xxxx xxxx Reset value = xxxx xxxx Register 89 . Multisynth5 Parameters B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name MS5_P2[7:0] Ty p e R/W Bit Name Function 7:0 MS5_P2[7:0] Multisynth5 Paramet er 2. This 20- bit numbe r is an en coded re presen tation of the numerator for the fract[...]

Si5351A/B/C 58 Preliminary Rev . 0.95 Reset value = xxxx xxxx Register 92 . Clock 6 a nd 7 Out put Divider B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name R7_DIV[2:0] R6_DIV[2:0] Ty p e R/W R/W R/W R/W Bit Name Function 7 Reserved Leave as default. 6:4 R7_DIV[2:0] R7 Output Divider . 000b: Divide by 1 001b: Divide by 2 010b: Divide by 4 01 1b: Divide by 8 100b[...]

Si5351A/B/C Preliminary Rev . 0. 95 59 Reset value = 0000 0000 Reset value = 0000 0000 Reset value = 0000 0000 Register 165. CLK0 Initial Phase Offset B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK0_PHOFF[6:0] Ty p e R/W R/W R/W R/W R/W R/W R/W R/W Bit Name Function 7 Reserved Only write 0 to this bit. 6:0 CLK0_PHOFF [6:0] Clock 0 Initial Phase Offset. CL[...]

Si5351A/B/C 60 Preliminary Rev . 0.95 Reset value = 0000 0000 Reset value = 0000 0000 Reset value = 0000 0000 Register 168. CLK3 Initial Phase Offset B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name CLK3_PHOFF[6:0] Ty p e R/W R/W R/W R/W R/W R/W R/W R/W Bit Name Function 7 Reserved Only write 0 to this bit. 6:0 CLK3_PHOFF[ 6:0] Clock 3 Initial Pha se Offset. CL[...]

Si5351A/B/C Preliminary Rev . 0. 95 61 Reset value = 0000 0000 Reset value = 1 1xx xx xx Register 177. PLL Reset B i t D 7D 6D 5D 4D 3D 2D 1D 0 Name PLLB_RST PLLA_RST Ty p e R/W R/W R/W R/W R/W R/W R/W R/W Bit Name Function 7P L L B _ R S T PLLB_Reset. Writing a 1 to this bit will reset PLLB. This is a self clearing bit (Si5351A/C only). 6 Reserved[...]

Si5351A/B/C 62 Preliminary Rev . 0.95 9. Si5351A Pin Descriptions (20-Pin QFN, 24-Pin QSOP) T able 10. Si5351A Pin Descriptions Pin Name Pin Number Pin T ype* 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 clo ck 0. CLK1 12 20 O Output clo ck 1. CLK2 9 15 O Output clock[...]

Si5351A/B/C Preliminary Rev . 0. 95 63 10. Si5351B Pin Descriptions (20-Pin QFN, 24-Pin QSOP) T able 1 1. Si5351B Pin Descriptions Pin Name Pin Number Pin T ype* 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 [...]

Si5351A/B/C 64 Preliminary Rev . 0.95 1 1. Si5351C Pin Descriptions (20-Pin QFN, 24-Pin QSOP) T able 12. Si5351C Pin Descriptions Pin Name Pin Number Pin T ype* 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[...]

Si5351A/B/C Preliminary Rev . 0. 95 65 12. Si5351A Pin Descri ptions (10-Pin MSOP) T able 13. Si5351A 10-MSOP Pin Descriptions Pin Name Pin Number Pin T ype* Function 10-MSOP XA 2 I Input pin for external crystal. XB 3 I Input pin for external crystal. CLK0 10 O Output clock 0. CLK1 9 O Output clock 1. CLK2 6 O Output clock 2. SCL 4 I Serial clock [...]

Si5351A/B/C 66 Preliminary Rev . 0.95 13. Ordering Information Figure 19. Device Part Numbers An evaluation kit cont aining ClockBuilder Desktop sof twa re and hardware enable easy evaluatin of the Si5351A/B/C. The ordera ble part numbers for the evaluati on kits are pr ovided in F igure 20. Figure 20. Si5351A/B/C Evaluation Kit Si5351X XX A A = Pr[...]

Si5351A/B/C Preliminary Rev . 0. 95 67 14. Package Out line (24-Pin QSOP) T able 14. 24-QSOP Package Dimensions Dimension Min Nom Max A— — 1 . 7 5 A1 0.10 — 0.2 5 b 0.19 — 0.30 c 0.1 5 — 0.25 D 8 . 5 58 . 6 58 . 7 5 E 6.00 BSC E1 3.81 3.90 3.99 e 0.635 BSC L 0.40 — 1.27 L2 0.25 BSC q0 — 8 aaa 0.10 bbb 0.17 ccc 0.10 Notes: 1. All dimen[...]

Si5351A/B/C 68 Preliminary Rev . 0.95 15. Package Out line (20-Pin QFN) T able 15. Package Dimensions Dimension Min Nom Max A 0 . 8 00 . 8 50 . 9 0 A1 0.00 0.02 0.05 b 0 . 1 80 . 2 50 . 3 0 D 4.00 BSC D2 2.65 2.70 2.75 e 0.50 BSC E 4.00 BSC E2 2.65 2.70 2.75 L 0 . 3 00 . 4 00 . 5 0 aaa 0.10 bbb 0.10 ccc 0.08 ddd 0.10 eee 0.10 Notes: 1. All dimensio[...]

Si5351A/B/C Preliminary Rev . 0. 95 69 16. Package Out line (10-Pin MSOP) T able 16. 24-QSOP Pa ckage Dimensions Dimension Min Nom Max A— — 1 . 1 0 A1 0.00 — 0.1 5 A2 0.75 0.85 0.95 b 0.17 — 0.33 c 0.0 8 — 0.23 D 3.00 BSC E 4.90 BSC E1 3.00 BSC e 0.50 BSC L 0 . 4 00 . 6 00 . 8 0 L2 0.25 BSC q0 — 8 aaa — — 0.20 bbb — — 0.25 ccc ?[...]

Si5351A/B/C 70 Preliminary Rev . 0.95 D O CUM EN T C HA NGE L IST Revision 0.1 to Revision 0.9  Updated max output freque ncy .  Updated kV values in T able 3 on page 5.  Updated "3.4. S pread S pectrum" on page 13.  Added "5.1. Writing a Custom Configuration to RAM" on page 16.  Added "5.7. HCSL Comp atible [...]

Si5351A/B/C Preliminary Rev . 0. 95 71 N OTES :[...]

Si5351A/B/C 72 Preliminary Rev . 0.95 C ONT AC T I NF ORMATION Silicon La boratories Inc. 400 West Cesar Chavez Austin, TX 78701 T el: 1+(512) 416-8500 Fax: 1+(512) 416-9669 T oll Free: 1 +(877) 444-3032 Please visit the Silicon Labs T echnical Support web page: https://www .silabs.com/support/pages/contacttechnicalsupport.aspx and register to subm[...]