The

Modulator

tab defines the configuration for high-level parameters of PWM instances.

Modulator tab in Voltage Control Mode​



Modulator tab in Peak Current Control Mode​



PWM instance table​

The

PWM instance

table displays information about allocated PWM resources.

High/Low side switch output

Corresponding pins assigned to the output.


PWM​

Enable high resolution

– This check box is active only for VCM.

The PWM group settings parameters are applied to all PWM instances.

Parameter

Description

Range

Default

Dead time rising

Dead time delay for HS

1-1e+09 ns

100 ns

Dead time falling

Dead time delay for LS

1-1e+09 ns

100 ns

Duty cycle min

Minimum modulation duty cycle

Read-only

0%

Duty cycle max*

Maximum modulation duty cycle

1-100%

90%

Passive level output

Behavior of PWM outputs with passive PWM

Low

High

High impedance

High impedance


Note:

*The calculated valid range forDuty cycle maximumdepends on the entered set of parameters. They display in the respective parameter tooltip.


Comparator (CMP)​

The

Comparator (CMP)

is available only in

PCCM

.

Parameter

Description

Range

Default

Blanking time

The time period when input is ignored to avoid switching transient

0-1000 ns

200 ns

DAC settings​

The

DAC settings

group is available only in

PCCM

.

Parameter

Description

Range

Default

Slope mode

Added by DAC current compensation slope

Stable (HW-based)

Responsive (HW-based)

Custom (editable)

Stable

Slope value

The decrease rate of the comparator reference voltage; active in custom Slope mode

-3300-0 mV/µs

-151.515 mV/µsec

DMA​

Enable transfer DMA

– This check box is active for VCM and PCCM.

The DMA is used to transfer the modulation value stored in the

mtb__stc_pwrconv_ctx_t.mod

structure to the modulator registers, which are PWM or DAC buffers.

PWM diagram​

The diagram on the right side illustrates the control loop operation replotted for VCM and PCCM. At the bottom, the dynamically-replotted PWM ON/OFF scheme for the HS and LS (high/low side) switches depending on the time scale with marked PWM period, Duty cycle, and dead times. The time change of the inductance current is on the top of the scheme. In PCCM, the slope generator curve, ADC and Controller blocks present the control loop operation.