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AN1899 Rev 0.00
Page 7 of 24
January 8, 2014
HIP2103-4DEMO1Z
HIP2103_4 Circuit Description
The simplified schematic of Figure 8 illustrates the three power
phases of the motor driver. Each phase has identical components
(except for the one HIP2104 and two HIP2103s). For specific
component values and complete circuit details, please refer to
the BOM and schematic found at the end of this application note.
The HIP2104 (red) provides the Vcc (3.3V) bias for the controller
and the Vdd bias (12V) for itself and for the two HIP2103s (green
and blue).
Series connected gate resistors on each bridge FET are used to
reduce the switching speed to help minimize EMI radiating from
the power leads to the motor. The diodes in parallel with the FET
gate resistors are used to provide rapid turn off of the FETs. The
customer may change the resistor values or even remove the
diodes to suit the customer’s application needs.
The HIP2103/4 drivers do not have internal dead time features.
A dead time is provided by the controller and can be adjusted by
the SW6 dip switch settings.
Current Monitor and Current Limit
There are two current control features in the HIP2103-4DEMO1Z.
A linear current monitor op amp, U2, amplifies the voltage across
R21 and R22. This op amp is configured as a true differential
amplifier to allow Kelvin connections across the current sensing
resistors (see Figure 9). R3 and R4, each 32.4k
Ω
, have a
Thevenin equivalent value that is the parallel value of R3 and R4
(or 1/2 of 32.4k
Ω
). The Thevenin equivalent voltage also is 1/2
of the bias voltage of 3.3V. Consequently, the output of the
differential amplifier is offset by +1.65V (see Figure 10).
FIGURE 7. SEQUENCE STEPS 4 TO 6
S
N
S
N
S
N
S
N
S
N
S
N
4
Z
L
P
5
L
Z
P
6
L
P
Z
S
S
N
N
N
N
S
S
S
N
S
N
N
S
N
S
N
S
N
S
N
S
N
S
6
4
5
HC
HB
HA
MB
MA
MC
HC
HB
HA
MB
MA
MC
HC
HB
HA
MB
MA
MC
L
Z
P
L
L
P
P
Z
Z
Z
Z
Z
P
P
P
L
L
L
neutral
neutral
neutral
neutral
neutral
neutral
neutral
neutral
neutral
neutral
neutral
neutral
FIGURE 8. SIMPLIFIED 3-PHASE BRIDGE
HB
HO
LO
HS
VSS
Vdd
HI
LI
mo
to
r
Vbat
current
sense
HB
HO
LO
HS
Vbat
VSS
VCen
VDen
Vcc
Vdd
HI
LI
HB
HO
LO
HS
VSS
Vdd
HI
LI
HIP2103
HIP2104
HIP2103
A
B
C
C
o
n
tr
o
ller
FIGURE 9. DIFFERENTIAL CURRENT MONITOR AMPLIFIER
U2
R14
R17
R15
R18
R4
R3
R11
R12
3.3V
ISL28246FUZ
32.4K
32.4K
32.4K
32.4K
511
511
1.15K
1.15K
filter capacitors
are not shown.
R21
R22
from
bridge
.015
.015
I
motor
+
-