07XSF517 Datasheet, PDF (22/72 Pages) Freescale Semiconductor, Inc – Triple 7.0 mOhm and Dual 17 mOhm High Side Switch

6 Functional Block Requirements and Behaviors
6.1 Self-protected High Side Switches Description and Application
Information
6.1.1 Features
Up to five power outputs are foreseen to drive light as well as DC motor applications. The outputs are optimized for driving bulbs,
but also HID ballasts, LEDs, and other resistive or low inductive loads.
The smart switches are controlled by use of high sophisticated gate drivers. The gate drivers provide:
• output pulse shaping
• output protections
• active clamps
• output diagnostics
6.1.2 Output Pulse Shaping
The outputs are controlled with a closed loop active pulse shaping to provide the best compromise between:
• low switching losses
• low EMC emission performance
• minimum propagation delay time
Depending on the programming of the prescaler setting register #12-1, #12-2, the switching speeds of the outputs are adjusted
to the output frequency range of each channel.
The edge shaping shall be designed according the following table:
divider
fa c tor
4
2
1
PWM freq [Hz]
min
ma x
25
100
50
200
100
400
PWM period [m s]
m in
max
10
40
5
20
2, 5
10
d.c. range [hex]
min
max
03
FB
07
F7
07
F7
d.c. range [LSB]
min
max
4
252
8
248
8
248
min. on/off duty
cycle time [µs]
156
156
78
The edge shaping provides full symmetry for rising and falling transition:
• the slopes for the rising and falling edge are matched to provide the best EMC emission performance
• the shaping of the upper edges and the lower edges are matched to provide the best EMC emission performance
• the propagation delay time for the rising edge and the falling edge is matched to provide true duty cycle control
of the output duty cycle error, < 1 LSB at max. frequency
• a digital regulation loop is used to minimize the duty cycle error of the output signal
MC07XSF517
22
Analog Integrated Circuit Device Data
Freescale Semiconductor