Adaptive Gate Control (AGC)

The Infineon’s Motor System ICs (TLE956x) and Multi MOSFET driver ICs (TLE9210x) include a MOSFET driver with multi-stage current source gate control which is configured over SPI. Over this interface, the turn-on (tDONx) and turn-off (tDOFFx) delay can be controlled in PWM operation, as well as the rise (tRISEx) and fall (tFALLx) times. Therefore the algorithms explained in Rise fall time regulation with current source MOSFET gate drivers were implemented in this library.

../_images/AGC_animated.gif

Example codes

There are two software examples available, that directly execute the regulation like shown in the animated GIF.

For optimal results it’s recommended to use TLE9562_DCM_rise-and-fall-time-regulation.ino with an ideal R-L- Load instead of a real motor to avoid side effects. This code can be used on both TLE956x boards despite the specific name.

#define HALFBRIDGE              PHASE1      // [PHASE1;Phase4] Select the phase on which you want to regulate Rise/Fall time
#define SPEED_INCREASE_STEP     100         // [1;511] speed step increase/decrease when pressing a key
#define CONTROL_LOOP_DELAY      400         // [ms] time between regulation executions

First choose the phase on which you want to apply the AGC algorithm.

enum Tle9xxx::_Halfbridges

Values:

enumerator PHASE1
enumerator PHASE2
enumerator PHASE3
enumerator PHASE4

All other phases will be always connected to ground. In practice it’s usually sufficient to execute the algorithm on one phase, as the other MOSFETS should meet the same specifications and come from the same charge.

uint8_t trise_tg = 11;                      // [0;63] Initial Risetime target. Can be changed via keyboard input.
uint8_t tfall_tg = 11;                      // [0;63] Initial Falltime target. Can be changed via keyboard input.

Here you can define your initial target Rise- and Falltime, which will be set by

void DCMcontrol::setTrisefallTarget(uint8_t trise_tg, uint8_t tfall_tg)

Set the T_Rise and T_Fall target times where the regulation loop should go to.

Parameters

  • trise_tg – rise time target [0;63]

  • tfall_tg – fall time target [0;63]

If this function is not used (like in normal motor operation) the values from the defines will be taken as described below. The entered values in the examples are suited as a starting point for the DC and BLDC shield. However if other MOSFETS are used, refer to the TLE9560/1/2 Gate Driver Setting Guide in order to estimate start values for rise and fall times, turn-on and turn-off delay times and recommendations for the settings of the cross-current protection time and of the blank times.

void DCMcontrol::riseFallTimeRegulation(uint8_t hb, uint8_t *iCharge, uint8_t *iDischarge, uint8_t *risetime, uint8_t *falltime)

reads out the actual MOSFET rise-time (fall-time) and compares it to the desired rise-(fall-)time. The algorithm then adjusts the charge current ICHG for the active MOSFET of the selected halfbridge.

Parameters

  • hb – on which halfbridge should the algorithm be applied. Must be the same halfbridge where the PWM is routed to.

  • risetime – hands over the actual rise-time

  • falltime – hands oder the actual fall-time

This function executes the algorithm one time and hands over the variables to read back the actual rise- / falltimes and charge-/discharge currents.

Parameter defines

In order to constantly change the initial charge current (ICHG) / initial discharge current (IDCHG) go to /src/corelib/TLE9xxx.hpp. There you find the defines listed below. Just replace the values there by the values you found out experimentally.

CONF_TRISE_TG

[0;63] initial Target tRISE (CONF_TRISE_TG * 53.3 ns). The variable can be changed afterwards.

CONF_INIT_ICHG

[0;63] Starting charge current that will be first used by the algorithm

CONF_TFALL_TG

[0;63] initial Target tFALL (CONF_TFALL_TG * 53.3 ns). The variable can be changed afterwards.

CONF_INIT_IDCHG

[0;63] Starting discharge current that will be first used by the algorithm