TLE6288R_10 Datasheet, PDF (11/32 Pages) Infineon Technologies AG – Smart 6 Channel Peak & Hold Switch

TLE6288R
Description
4.1.2 Current Regulator: Peak Current Control with Fixed Off-Time
• Hold only: When the channel is turned on externally (SPI or parallel input) the current rises to the programmed
hold current level. Then the channel is internally turned off and a timer is started for a fixed off-time (e.g.
200 μs). After this time the channel is internally turned on again until the hold current level is reached again
and so on. This regulation works automatically until the channel is turned of externally.
• Peak and hold mode with minimum peak time: When the channel is turned on the current rises to the
programmed peak current level. Then the channel is internally turned off, the current regulator changes to hold
current values and a timer is started for a constant off-time. After this time the channel is internally turned on
again until the hold current value is reached and then again turned off for the fixed off time. This regulation
works automatically until the channel is turned of externally.
• Peak and hold mode with programmed peak time: When the channel is turned on the current rises to the
programmed peak current level. Then the channel is internally turned off and a timer is started for a fixed off-
time. After this time the channel is internally turned on again until the peak current value is reached and then
again turned off. This works until the programmed peak time is over. Then the current regulator changes to
hold current values and works as described under “hold only”.
Peak Current, Peak Time, Hold Current and fixed Off-Time can be set via SPI.
To avoid regulation disturbances by current transients during switching (e.g. caused by ESD capacitors at the
outputs) the current regulator has a “leading edge blanking” of typical 20 μs in all three regulation modes. After
turning on the DMOS (internally or externally) the current regulation circuit is deactivated for the first 20 μs. This
guarantees that switching of the DMOS itself or charging of small capacitors at the output (e.g. ESD) is not
disturbing the current regulation.
To detect shorted loads or low inductance loads in all three regulation modes a timer is started when a channel is
turned on (t_li). If the first rising edge of the load current reaches the programmed current level (peak or hold current
depending on the configured current control mode) within this time a overload fault is reported (see Chapter 7.3).
Figure 5 Simplified Functional Block Diagram
Data Sheet
11
Rev. 2.5, 2010-10-11