TLE72422GXT Infineon Technologies, TLE72422GXT Datasheet - Page 7

• Manufacturer Part Number: TLE72422GXT
• Manufacturer: Infineon Technologies

Specifications of TLE72422GXT

• Operating Temperature (max): 150C
• Operating Temperature (min): -40C
• Pin Count: 28
• Mounting: Surface Mount
• Screening Level: Automotive
• Lead Free Status / Rohs Status: Compliant

measurement amplifiers. If the autozero function is enabled in SPI message #7, then the measured offset will be
subtracted from the A/D converter output as shown in
Dither
A triangular dither waveform can be superimposed on the current set point by setting the Dither Enable bit in SPI
message #3. The amplitude and frequency of the dither waveform are programmed for each channel via SPI
messages #3 and #4. See the SPI message section for details.
The first programmed value is the step size of the dither waveform which is the number of bits added or subtracted
from the setpoint per PWM period. One LSb of the dither step size is 1/16 the magnitude of the nominal setpoint
current value. The second programmed value is the number of steps in one quarter of the dither waveform.
When dither is enabled, a new average current set point will not be activated until the current dither cycle has
completed. The dither cycle is completed on the positive zero crossing of the dither waveform. A new dither
amplitude setting, a new dither frequency setting, or a dither disable command will also not be activated until the
current dither cycle has completed see
Figure 4
Note: the actual dither waveform is attenuated and phase shifted according to the frequency response of the
control loop.
If a channel enters transient mode operation while the dither waveform is active, the dither wave-form will pause
until transient mode is exited.
Transient Mode
When a large change in the current set point occurs, the device can be programmed to enter transient mode of
operation. The setpoint change threshold required to initiate transient mode can be programmed in
SPI message #6. The purpose of this mode of operation is to reduce the transition time of the load current after a
large change in setpoint. In this mode of operation the OUTx pin signal is controlled by the state machine shown
in
low based on the immediate value of the measured output current. The PWM frequency is not fixed in this mode
of operation. The device will automatically switch from transient mode of operation to steady state operation at the
start of the first PWM period after the new set point has been reached.
Data Sheet
Figure
5. The control method in this mode is similar to hysteretic control, the OUTx signal transitions high or
New Dither Values Programmed and the Resultant Waveform Timing
PWM_START
Parameter
Dither
Change
Dither
Figure
4.
Figure 3
7
when the current set point is greater than 0.
Rev. 1.0, 2008-07-09
TLE7242-2G
Overview