FUNCTION
V+ A
PIN #
11
7
DESCRIPTION
High Voltage D.C. Bus, Phase A
High Voltage D.C. Bus, Phase B
High Voltage D.C. Bus, Phase C
V+ B
V+ C
3
+15V
12
+15 VDC input required to power gate drive supply and gate drive circuitry of all
three phases.
GND
RTN A
RTN B
RTN C
PHASE A
PHASE B
PHASE C
UA
19,22,26
Reference for LOGIC supply, +15V supply, and digital inputs.
Return for High Voltage Bus, Phase A.
Return for High Voltage Bus, Phase B
Return for High Voltage Bus, Phase C
Output to motor winding Phase A
8
5
1
9
6
Output to motor winding Phase B
2
Output to motor winding Phase C
18
Digital input to Phase A upper transistor
Digital input to Phase A lower transistor
Digital input to Phase B upper transistor
Digital input to Phase B lower transistor
Digital input to Phase C upper transistor
Digital input to Phase C lower transistor
Digital shut-down input to enable / disable all six gate drives
No connection Internally
LA
17
UB
21
LB
20
UC
25
24
LC
SD
23
N/C
4,10,13-16
DIGITAL INPUT STAGE
The ACT5101-1 offers complete flexibility by allowing the user to turn on/off each of the 6 IGBTS in any order
or combination desired which enables the hybrid to be commutated in a 6 step trapezoidal mode. The only
unacceptable combination would be to turn on an upper and lower transistor of the same phase. This is not
a desirable condition for normal operation and is therefore not allowed. The ACT5101-1 has a digital lockout
feature that prevents turn-on of two in-line transistors. Damage to one or both of the transistors would occur
if this protection circuitry was not present in the hybrid. As a safety precaution, it is still recommended that a
500 nsec dead time be installed between commands at the inputs of the upper and lower transistors of the
same phase. This will compensate for any lag in transistor turn-off due to the inductive load.
The SD input allows the user to enable/disable the drive stage of the ACT5101-1 on demand. This input can
be incorporated into the user's temperature or current monitoring circuitry to shutdown the hybrid if
excessive current or case temperatures are sensed.
The digital input circuits are of the Schmitt trigger type with hystersesis of at least 1.6 volts, thus greatly
enhancing the input noise immunity. The inputs are internally pulled up to 15 volts so that an uncommitted
input is sensed as "OFF", providing a measure of protection against an accidental input disconnect.
GATE DRIVE
The ACT5101-1 includes a gate drive supply which provides a floating voltage for each upper and lower
transistor. This constant voltage allows the motor to be operated at very low duty cycles or driven into a stall
without any loss of upper or lower gate drive. This performance could not be obtained with only a
conventional boot strap design.
5
Aeroflex Circuit Technology
SCD5101-1 REV D 5/14/01 Plainview NY (516) 694-6700
AEROFLEX [ AEROFLEX CIRCUIT TECHNOLOGY ]
