Phase H Bridge (Phase A Shown) - Motorola M68HC08 Manual

Hardware Design
PWM_AT
PWM_AB
Optional filter
Phase B Input
GND
0R C36 Phase C Input
R43
Fault
0.5V @ (Imax=10A)
R21
+12V
82k - 1%
+
R22 GND C24
8k2 - 1% 100uF/25V
GND
5.2.6 Current Sensing
Designer Reference Manual
42
Freescale Semiconductor, Inc.
D7
MURS160T3
+12V
U2
2
HIN1 VB1
5
LIN1 HO1
VS1
3
HIN2 LO1
6
LIN2
4
HIN3 VB2
7
LIN3 HO2
VS2
8
FAULT LO2
9
ITRIP
10
CA0
11
CA- VB3
HO3
1
VCC
VS3
12
VSS LO3
13
VS0
IR2132S
C25 C35
100nF 100nF
+12V
Figure 5-6. 3-Phase H Bridge (Phase A Shown)
As mentioned, the 3-phase driver IR2132 contains cycle-by-cycle
current limit feature with over-current detection and fault generation. An
on-chip ground-referenced operational amplifier provides analog
feedback of bridge current via an external current sense resistor. A
current trip function, which terminates all six outputs is also derived from
this resistor. An open drain /FAULT signal indicates if an over-current or
under-voltage shutdown has occurred.
Figure 5-7. Current Sensing - Detail illustrates the detailed topology of
the circuitry derived from Figure 5-6. 3-Phase H Bridge (Phase A
Shown). Both operational amplifier and comparator are available within
IR2132, so just resistors R21 and R22 are needed externally. The
resistors R21 and R22 define the gain of the on-chip operational
amplifier. The gain is set to -10. The over-current trip is set internally to
0.5V. It corresponds to 10A for DC-Bus sensing resistor 0.005 ohms and
Hardware Design
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D6
MBRS240LT3
C21
470nF/25V
28
27
26
16
D8
MBRS240LT3
24
23 Phase B
22
Output
15
20
19 Phase C
18
Output
14
GND
+48V
R29
4R7
Q1
IRF3710
R15 R44
24R
47k
D18
MMSZ5248BT1
Motor Ph A
R30
4R7
Q4
IRF3710
R16
R47
24R
47k
D21
MMSZ5248BT1
R13
0R010 - SBL4
R14
0R010 - SBL4
DC Bus cureent
sensing resistors
DRM046 — Rev 0
MOTOROLA