3936
A3936-DS Rev. 1
Designed for pulse-width modulated (PWM) current control of three-
phase brushless dc motors, the A3936SED is capable of peak output currents
to
3 A and operating voltages to 50 V. Internal fixed off-time PWM current-
control timing circuitry can be configured to operate in slow-, fast- and mixed-
decay modes.
Internal synchronous rectification control circuitry is provided to
improve power dissipation during PWM operation.
Internal circuit protection includes thermal shutdown with
hysteresis, and crossover current protection. Special power up sequencing is
not required.
The A3936 is supplied in a 44-pin plastic PLCC with a copper
batwing tabs (suffix `ED'). The power tabs are at ground potential and need
no electrical isolation. This device is also available in a lead-free version
(100% matte tin leadframe).
Features
3 A, 50 V Continuous Output Rating
Low
r
DS(on)
Outputs (typically 500 m
source, 315 m
sink)
Configurable Mixed, Fast and Slow Current-Decay Modes
Synchronous Rectification for Low Power Dissipation
Internal UVLO and Thermal Shutdown Circuitry
Crossover-Current Protection
Tachometer Output for External Speed Control Loop
Always order by complete part number
Part Number
Package
A3936SED 44-pin
PLCC
A3936SED-T
44-pin PLCC, Lead-free
ABSOLUTE MAXIMUM RATINGS
at TA = +25C
Load Supply Voltage, V
BB
........................... 50 V
Output Current, I
OUT
...................................
3 A*
Logic Supply Voltage, V
DD
......................... 7.0 V
Logic Input Voltage Range, V
IN
(t
W
>30 ns) .......... -0.3 V to V
DD
+ 0.3 V
(t
W
<30 ns) ................ -1.0V to V
DD
+1V
Sense Voltage, V
SENSE
................................. 0.5 V
Reference Voltage, V
REF
................................ V
DD
Package Power Dissipation,
P
D
............................................... 3.9 W
Operating Temperature Range,
T
A
................................ -20
C to +85C
Junction Temperature, T
J
......................... +150
C
Storage Temperature Range,
T
S
............................... -55
C to +150C
* Output current rating may be limited by duty cycle,
ambient temperature, and heat sinking. Under any set of
conditions, do not exceed the specified current rating or a
junction temperature of 150
C.
DMOS THREE-PHASE
PWM MOTOR DRIVER
3936 Three Phase PWM Motor Driver
ELECTRICAL CHARACTERISTICS at TJ = +25C, VBB = 50 V, V
DD
= 5.0 V,
f
PWM
< 50KHz (unless noted otherwise)
Limits
Characteristics
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Output Drivers
Load Supply Voltage Range
VBB
Operating
9
50
V
During Sleep Mode
0
50
V
Output Leakage Current
I
DSS
V
OUT
= V
BB
<1.0
20
A
V
OUT
= 0 V
<1.0
-20
A
Output On Resistance
R
DSON
Source Driver, I
OUT
= -3A
.55
Sink Driver, I
OUT
= 3A
.35
Body Diode Forward Voltage
V
F
Source Diode, I
F
= -3A
1.4
V
Sink Diode, I
F
= 3A
1.3
V
Motor Supply Current
I
BB
f
PWM
< 50 kHz
4
7
mA
Charge Pump On, Outputs Disabled
2
5
mA
Sleep Mode
20
uA
I
DD
f
PWM
< 50 kHz
10
mA
Outputs Off
8
mA
Logic Supply Current
Sleep Mode (Inputs below .5V)
100
A
Control Logic
Logic Supply Voltage Range
V
DD
Operating
3
5.0
5.5
V
Logic Input Voltage
V
IN(1)
V
DD
*.5
V
V
IN(0)
V
DD
*.2
V
Logic Input Current
I
IN(1)
V
IN
= V
DD
*.5
-20
<1.0
20
A
(except ENABLE)
I
IN(0)
V
IN
= V
DD
*.2
-20
<-1.0
20
A
Logic Input Current
I
IN(1)
V
IN
= V
DD
*.5
100
A
ENABLE Input
I
IN(0)
V
IN
= V
DD
*.2
30
A
OSC shorted to GND
3
4
5
MHz
Internal Oscillator
f
OSC
R
OSC
= 51K
3.4
4
4.6
MHz
3936 Three Phase PWM Motor Driver
ELECTRICAL CHARACTERISTICS at T
J
= +25C, V
BB
= 50 V, V
DD
= 5.0 V, f
PWM
< 50KHz (unless noted
otherwise)
Limits
Characteristics
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Control Logic
Buffer Input Offset Volt.
V
IO
10
mV
V
REF
Input Voltage Range
Operating
0.0
V
DD
V
Reference Input Current
I
REF
V
REF
= V
DD
,V
BB
=0 to 50V
-.5
0
0.5
A
Comparator Input Offset Volt.
V
IO
V
REF
= 0 V
5
mV
V
REF
= V
DD
-4
4
%
G
M
Error
V
ERR
(Note 3)
V
REF
= .5V
-14
14
%
Propagation Delay Times
tpd
50% TO 90%, SR Enabled
PWM CHANGE TO SOURCE ON
600
750
1000
ns
PWM CHANGE TO SOURCE OFF
50
150
350
ns
PWM CHANGE TO SINK ON
600
750
1000
ns
PWM CHANGE TO SINK OFF
50
100
150
ns
Crossover Delay
t
COD
SR Enabled
300
600
1000
ns
Thermal Shutdown Temp.
T
J
165
C
Thermal Shutdown Hysteresis
T
J
15
C
UVLO Enable Threshold
Rising V
DD
2.45
2.7
2.95
V
UVLO Hysteresis
0.05
0.10
V
NOTES:
1.
Typical Data is for design information only.
2.
Negative current is defined as coming out of (sourcing) the specified device pin.
3.
V
ERR
=((V
REF
/10) V
SENSE
)/(V
REF
/10)
PDF 
ZIP
