# 1st Order PLL

The First Order PLL clock recovery method models the response of an ideal first-order hardware PLL.

You can specify the PLL's response in terms of either the JTF's 3 dB bandwidth or the OJTF's 3 dB bandwidth. JTF and OJTF 3 dB bandwidths are the same because it is first order.

When the 1st Order PLL clock recovery mode is selected, the dialog box has these controls:

- Symbol Rate — Enter the signal's expected baud rate.

  The Select From List drop-down menu lets you select typical rates for standard communication interface technologies. The Auto Set Symbol Rate button runs a data rate measurement and populates the Symbol Rate field with the data rate measured on the input signal.

- Clock Skew — For PAM type signals, this can be used to center the eye opening at the clock locations by shifting the clocks relative to the data.

- Loop Bandwidth — You can specify the PLL's loop bandwidth either by entering it directly in the Loop Bandwidth field (also known as the -3 dB BW) or by entering the Loop Bandwidth Divisor value.

- Loop Bandwidth Divisor — Enter a number that you divide the Symbol Rate by to get the loop bandwidth.

## Advanced Settings

- Deemphasis Removal
- Edge Direction
- Transition Density Dependent
- Settling Time
- Idle Clock Count
- Apply SSC Correction
- Use Advanced Clock Recovery for Closed Eyes