841602AGILFT vs SI5340D-D-GM
| Part Number |
|
|
| Category | Clock/Timing - Clock Generators, PLLs, Frequency Synthesizers | Clock/Timing - Clock Generators, PLLs, Frequency Synthesizers |
| Manufacturer | Renesas Electronics America Inc | Skyworks Solutions Inc. |
| Description | IC CLOCK GENERATOR 28-TSSOP | IC JITTER ATTENUATOR/MULTIPLEXER |
| Package | Tube | Tape & Reel (TR) |
| Series | FemtoClock® | - |
| Type | Clock Generator, Multiplexer | - |
| Voltage - Supply | 3.135V ~ 3.465V | 1.71V ~ 3.47V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Package / Case | 28-TSSOP (0.240\", 6.10mm Width) | 44-VFQFN Exposed Pad |
| Supplier Device Package | 28-TSSOP | 44-QFN (7x7) |
| Output | HCSL | CML, HCSL, LVCMOS, LVDS, LVPECL |
| Frequency - Max | 125MHz | 350MHz |
| Number of Circuits | 1 | 1 |
| Input | LVCMOS, LVTTL, Crystal | LVCMOS, LVDS, LVPECL, Crystal |
| PLL | Yes with Bypass | Yes |
| Ratio - Input:Output | 2:2 | 4:4 |
| Differential - Input:Output | No/Yes | Yes/Yes |
| Divider/Multiplier | Yes/No | Yes/No |
-
1. What is a PLL clock generator?
A PLL clock generator (Phase-Locked Loop Clock Generator) is an electronic circuit used to generate and adjust a clock signal. It automatically adjusts the frequency of the internal oscillator by comparing the phase difference between the input signal and the output signal of the internal oscillator so that the phase of the output signal is synchronized with the input signal. PLL clock generator is mainly used to generate high-speed and stable clock signal to provide timing reference for communication system.
The key components of PLL clock generator include:
Phase detector: compare the phase difference between input signal and feedback signal.
Charge pump: adjust the voltage to control the frequency of VCO according to the output of phase detector.
Loop filter: smooth the output of charge pump and reduce noise.
Voltage controlled oscillator (VCO): change the oscillation frequency according to the control voltage to generate output clock signal.
-
2. How does Phase-locked loops（PLL） work?
PLL (phase locked loop) is a feedback control circuit that continuously adjusts the frequency and phase of the internal oscillation signal to synchronize with the input reference signal by comparing the phase difference between the input signal and the feedback signal. PLL is mainly composed of phase detector (PD), loop filter (LF), voltage controlled oscillator (VCO) and optional divider (Divider).
When PLL starts working, the frequency of input reference signal is always different from the inherent oscillation frequency of voltage controlled oscillator, resulting in constant phase difference. The error voltage output by the phase detector is converted into a control voltage through a loop filter and added to the voltage-controlled oscillator, so that its frequency is gradually adjusted to synchronize with the input reference signal and enter the "locked" state. If the frequency and phase of the input reference signal change, the PLL controls the frequency and phase of the voltage-controlled oscillator to track the changes of the input reference signal and re-enter the locked state. -
3. How does PLL increase frequency?
PLL (phase-locked loop) is usually used to increase or decrease the frequency of a signal. Increasing the frequency usually involves increasing the value of the feedback divider, while decreasing the frequency involves increasing or adjusting the gain followed by a divider.
-
4. Why do clocks use PLL?
The reason why clocks use PLL is because PLL can provide a stable high-frequency clock signal to ensure the precise operation and synchronization of electronic systems. PLL (Phase Locked Loop) compares the phase difference between the input signal and the output signal generated by the voltage-controlled oscillator (VCO) and adjusts the frequency of the VCO so that the phase of the output signal is synchronized with the phase of the input signal. This synchronization process is achieved through a closed-loop feedback system, which ensures the stability and accuracy of the clock signal.
The main functions of PLL include:
Providing a stable high-frequency clock signal: PLL generates a stable high-frequency clock based on the reference clock provided by the oscillator to ensure stable circuit timing.
Frequency synthesis: PLL can multiply or divide the frequency of the input signal to generate a clock signal of the required frequency.
Phase control: By adjusting the phase of the output signal, it ensures synchronization with the input signal and reduces phase deviation.
In modern electronic systems, the role of clock signals is very important. It is not only used to synchronize the operation of various components and ensure that key time parameters are within the allowable range, but also regulates the connection speed of data transmission in communication systems. The application of PLL ensures the accuracy and stability of the clock signal and improves the performance and reliability of the entire system.
