A system for tissue sealing including first and second electrodes, a drive circuit, a measurement component, a rate component, and a slope regulation component is disclosed. The drive circuit is configured to provide RF energy to the first and second electrodes for application to a load. The measurement component is configured to periodically measure an impedance of the load. The rate component is configured to determine a rate of change for the impedance. The slope regulation component is configured to provide impedance slope regulation. The slope regulation may include adjusting, based on the determined rate of change for the impedance, the RF energy provided by the drive circuit to cause the rate of change for the impedance to follow a predetermined impedance rate.