Active Clamp Forward-Flyback

A block diagram and input parameters for the Active Clamp Forward-Flyback converter are given in Table 1.

Table 1. Active Clamp Forward-Flyback converter component in the Schematic Editor core library

component	component dialog window	component properties
		General Control (Digital inputs, Model) S1 (digital input selection for switch S1) S2 (digital input selection for switch S2) gate_logic (active high, active low) Gate control enabling (enables usage of external digital signal to enable the switching) Sen (digital input selection for PWM enable) Sen_logic (active high, active low) Transformer n1 (number of turns of the primary transformer winding) n2 (number of turns of the secondary transformer winding) L1 (total leakage inductance - sum of leakage inductances of both transformers) Lm (magnetizing inductance of both transformers) R1 (primary winding resistance) R2 (secondary winding resistance) Rm (core losses resistance) Weight = 2

In order to optimize the model execution for high switching frequencies, Switch-level GDS oversampling is used in this converter block. Global GDS oversampling is not currently supported, meaning that this converter block can be used only in firmware configurations that support the switch-level GDS oversampling.

Digital inputs, when selected as the Control parameter, enables you to assign gate drive inputs to any of the digital input pins. For example, if S1 is assigned to 1, the digital input pin 1 will be routed to the S1 switch gate drive. In addition, the S1_logic parameter is set to either active high (i.e. high-level input voltage VIH which turns on the switch), or active low (i.e. low-level input voltage VIL which turns on the switch). The gate drive logic depends on your external controller design.

Selecting Internal modulator as the Control parameter, enables use of the internal PWM modulator for driving the switches instead of the digital input pins. In this configuration, two additional component inputs will be present. The En input is used to enable/disable the internal PWM modulator, while In is used as the reference signal input. Overall, 1 PWM channel is used to drive the main switch and the active clamp switch. The input reference signal is set in a range from 0.0 to 1.0.

Model, when selected as the Control parameter, enables you to set the switch gate drive signals directly from signal processing model. The input pin gates appears on the component. It is a single vector input of four gate drive signals in the following order: [S1, S2]. When controlled from the model, logic is always set to active high.

Gate control enabling, when checked, enables using an external PWM enabling digital signal.

Analog output variable naming for the active clamp forward-flyback switching block (internal to the component)

Digital Alias

If a converter is controlled by digital inputs, an alias for every digital input used by the converter will be created. Digital input aliases will be available under the Digital inputs list alongside existing Digital input signals. The alias will be shown as Converter_name.Switch_name, where Converter_name is name of the converter component and Switch_name is name of the controllable switch in the converter.