SDA/MISO SCLK A0/NC/SS A1/NC/MOSI SiT3521 1 to 340 MHz Elite Platform I2C/SPI Programmable Oscillator Description Features 2 The SiT3521 is an ultra-low jitter, user programmable Programmable frequencies (factory or via I C/SPI) oscillator which offers the system designer great flexibility from 1 MHz to 340 MHz and functionality. 2 Digital frequency pulling (DCO) via I C/SPI The device supports two in-system programming options Output frequency pulling with perfect pull linearity after powering up at a default, factory programmed startup 13 programmable pull range options to 3200 ppm frequency: Frequency pull resolution as low as 5 ppt (0.005 ppb) Any-frequency mode where the clock output can be 0.21 ps typical integrated phase jitter (12 kHz to 20 MHz) re-programmed to any frequency between 1 MHz and Integrated LDO for on-chip power supply noise filtering 340 MHz in 1 Hz steps 0.02 ps/mV PSNR Digitally controlled oscillator (DCO) mode where the clock -40C to 105C operating temperature output can be steered or pulled by up to 3200 ppm with LVPECL, LVDS, or HCSL outputs 5 to 94 ppt (parts per trillion) resolution. Programmable LVPECL, LVDS Swing The devices default start-up frequency is specified in the LVDS Common Mode Voltage Control ordering code. User programming of the device is achieved 2 2 RoHS and REACH compliant, Pb-free, Halogen-free via I C or SPI. Up to 16 I C addresses can be specified by the user either as a factory programmable option or via and Antimony-free 2 hardware pins, enabling the device to share the I C with 2 other I C devices. Applications The SiT3521 utilizes SiTimes unique DualMEMS Ethernet: 1/10/40/100/400 Gbps temperature sensing and TurboCompensation technology G.fast and xDSL to deliver exceptional dynamic performance: Optical Transport: SONET/SDH, OTN Resistant to airflow and thermal shock Clock and data recovery Processor over-clocking Resistant to shock and vibration Low jitter clock generation Superior power supply noise rejection Server, storage, datacenter Combined with wide frequency range and user Test and measurement programmability, this device is ideal for telecom, networking Broadcasting and industrial applications that require a variety of frequencies and operate in noisy environment. Block Diagram Package Pinout (10-Lead QFN, 5.0 x 3.2 mm) 10 9 1 OE / NC VDD 2 OE / NC OUT- 3 GND OUT+ 4 5 Figure 2. Pin Assignments (Top view) Figure 1. SiT3521 Block Diagram (Refer to Table 14 for Pin Descriptions) Rev 1.01 30 April 2021 www.sitime.com 8 7 6 SiT3521 1 to 340 MHz Elite Platform I2C/SPI Programmable Oscillator Ordering Information SiT3521AC -1C1331GG156.250000T Part Family SiT 12 mm Tape & Reel, 3 ku reel 3521 12 mm Tape & Reel, 1 ku reel 2 Revision Letter A is the revision of Silicon Frequency 1.000000 to 340.000000 MHz Temperature Range C : Extended Commercial, -20 to 70C DCXO Pull Range I : Industrial, -40 to 85C 1 E : Extended Industrial, -40 to 105C M : 25 ppm B : 50 ppm C : 80 ppm Signaling Type E : 100 ppm 1: LVPECL : F 125 ppm 2: LVDS G : 150 ppm 4: HCSL H : 200 ppm X : 400 ppm L : 600 ppm Package Size Y : 800 ppm C: 5.0 x 3.2 mm : S 1200 ppm Z : 1600 ppm U : 3200 ppm Frequency Stability/Grade F: 10 ppm 1: 20 ppm Serial IF mode 2: 25 ppm 1 S : SP I mode 3: 50 ppm 2 0-G : I C mode (See below) 2 I C Factory Programmable Addresses Voltage Supply 2 0-F : I C Address factory programmed 25: 2.5 V 10% 2 Sets Bits 3: 0 of Device I C address to 28: 2.8 V 10% the Hex value of the ordering code . 30: 3.0 V 10% 2 When the I C address is factory 33: 3.3 V 10% programmed using these codes , pin A0, A1 are NC 2 G: I C address controlled by A0, A1 pins OE Pin Control 2 A1:A0 I C Address -: OE under software Control. 00 1100000 Pin 1 and 2 are both NC. 01 1100010 1: Pin 1 OE, Pin 2 NC 10 1101000 2: Pin 1 NC, Pin 2 OE 11 1101010 (default) Notes: 2 1. -40 to 105C option available only for I C operation. 2. Bulk is available for sampling only. Rev 1.01 Page 2 of 45 www.sitime.com