xed off-time pulse duration. For added
鏗?/div>
exibility, the
PWM input can provide speed/torque control where the internal current
control circuit sets a limit on the maximum current.
The A3938 includes a synchronous recti鏗乧ation feature. This shorts out
the current path through the power MOSFET reverse body diodes dur-
ing PWM off-cycle current decay. This can minimize power dissipation
in the MOSFETs, eliminate the need for external power clamp diodes,
and potentially allow a more economical choice for the MOSFET drivers.
The A3938 provides commutation logic for Hall sensors con鏗乬ured for
120-degree spacing. The Hall input pins are pulled-up to an internally-
generated 5 V reference. Power MOSFET protection features include:
bootstrap capacitor charging current monitor, regulator undervoltage
monitor, motor lead short-to-ground, and thermal shutdown.
The LD package is available in a lead-free version (100% matte tin
plated leadframe).
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, V
BB
...................................50
V
VREG (Transient) ...............................................15
V
Logic Input Voltage Range, V
IN
...鈥?.3
V to V
LCAP
+0.3 V
Sense Voltage, V
SENSE
...........................
鈥? V to 1.5 V
Pins: SA, SB, SC...................................
鈥? V to 50 V
Pins: GHA, GHB, GHC ..................
鈥? V to V
BB
+ 17 V
Pins: CA, CB, CC ...........................SA/SB/SC
+ 17 V
Operating Temperature Range
Ambient Temperature, T
A
.............鈥?0擄C
to +85擄C
Junction Temperature, T
J
............................+150擄C
Storage Temperature, T
S
..........鈥?5擄C
to +150擄C
Thermal Impedance (Typical), at T
A
= +25潞C;
measured on a JEDEC-standard "High-K" PCB
A3938EQ, R
胃JA
........................................37擄C/W
A3938LD, R
胃JA
........................................38擄C/W
A3938LQ, R
胃JA
........................................44擄C/W
26301.104B
Data Sheet
A3938EQ, 32-pin PLCC
A3938LQ, 36-pin QSOP
A3938LD, 38-pin TSSOP
FEATURES
Drives wide range of N-channel MOSFETs
Low-side synchronous recti鏗乧ation
Power MOSFET protection
Adjustable dead time for cross-con-
duction protection
Selectable coast or dynamic brake on
power-down or RESET input
Fast/slow current decay modes
Internal PWM current control
Motor lead short-to-ground
protection
Internal 5 V regulator
Fault diagnostic output
Thermal shutdown
Undervoltage protection
Use the following complete part numbers when ordering:
Part Number
A3938SEQ
A3938SLQ
A3938SLD
A3938SLD-T
Pins
32
36
38
38
Package
PLCC
QSOP
TSSOP
TSSOP, Lead-free