TLE8242-2 Datasheet, PDF (32/78 Pages) Infineon Technologies AG – 8 Channel Fixed Frequency Constant Current Control With Current Profile Detection

OUTx Voltage
TLE8242-2
Functional Description and Electrical Characteristics
Measured Current
(Differential Voltage )
Time Out Timer
A/D Samples
Detect Interrupt
Time Out
PASS
Zone 1
Zone 2
Timeout for Failure
Figure 17 Current Profile Diagram - Time Out Failure
OUTx Voltage
Measured Current
(Differential Voltage )
Zone 1
Time Out Timer
Timeout for Failure
A/D Samples
Detect Interrupt
Time Out
PASS
Figure 18 Current Profile Diagram - Detection Interrupted Failure
The Current Profile Detection feature is active only in Direct PWM mode. The method employed is to look for three
specific "patterns" of the current in 3 zones. This detection method is generally used for on/off valves. The on/off
control of the valve is achieved by selecting the PWM period desired and setting to a 0% or 100% duty cycle via
SPI, however the detection may work within a single PWM on-time with a duty cycle less than 100% if the profile
completes before the gate turns off.
The PWM period (N and M values) are critical as these values set the A/D sample rate used in the current profile
detection. The full 10-bit result of the A/D converter is used for the CPD function. Using a 200 mOhm sense
resistor, this translates into a resolution of 1.56 mA.
Data Sheet
32
Rev. 1.0, 2010-02-09