908E625_07 Datasheet, PDF (32/48 Pages) Freescale Semiconductor, Inc – Integrated Quad Half H-Bridge with Power Supply, Embedded MCU, and LIN Serial Communication

FUNCTIONAL DEVICE OPERATION
LOGIC COMMANDS AND REGISTERS
HALF-BRIDGE OUTPUT REGISTER (HBOUT)
Register Name and Address: HBOUT - $01
Bits 7
6
5
4
3
2
1
0
Read HB4_ HB4_ HB3_ HB3_ HB2_ HB2_ HB1_ HB1_
H
L
H
L
H
L
H
L
Write
Reset 0
0
0
0
0
0
0
0
Low-Side On/Off Bits (HBx_L)
These read/write bits turn on the low-side MOSFETs.
Reset clears the HBx_L bits.
• 1 = Low-side MOSFET turned on for half-bridge output
x
• 0 = Low-side MOSFET turned off for half-bridge output
x
High-Side On/Off Bits (HBx_H)
These read/write bits turn on the high-side MOSFETs.
Reset clears the HBx_H bits.
• 1 = High-side MOSFET turned on for half-bridge output
x
• 0 = High-side MOSFET turned on for half-bridge output
x
HALF-BRIDGE CURRENT LIMITATION
Each low-side MOSFET offers a current limit or constant
current feature. This features is realized by a pulse width
modulation on the low-side MOSFET. The pulse width
modulation on the outputs is controlled by the FGEN input
and the load characteristics. The FGEN input provides the
PWM frequency, whereas the duty cycle is controlled by the
load characteristics.
The recommended frequency range for the FGEN and the
PWM is 0.1 kHz to 20 kHz.
Functionality
Each low-side MOSFET switches off if a current above the
selected current limit was detected. The 908E625 offers five
different current limits. Refer to Table 10 for current limit
values. The low-side MOSFET switches on again if a rising
edge on the FGEN input was detected (Figure 18).
908E625
32
Analog Integrated Circuit Device Data
Freescale Semiconductor