A3961: Dual Full-Bridge PWM Motor Driver

3961
Data Sheet
29319.26
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
DUAL FULL-BRIDGE PWM MOTOR DRIVER
24
OUT2B
E1 2
23
E2
SENSE 1 3
22
SENSE 2
OUT1A 4
21
OUT2A
VBB1 5
20
V BB2
GROUND 6
19
GROUND
GROUND 7
18
GROUND
VREFOUT 8
17
I FULL/PD
VREFIN 9
16
V CC
OUT1B 1
Designed for pulse-width modulated (PWM) current control of
bipolar stepper motors, the A3961S— is capable of continuous output
currents to ±800 mA and operating voltages to 45 V. Internal fixed
off-time PWM current-control circuitry can be used to regulate the
maximum load current to a desired value. An internal precision voltage
reference is provided to improve motor peak current control accuracy.
The peak load current limit is set by the user’s selection of an external
resistor divider and current-sensing resistors.
T
C
U
Y
D
L
O
N
R
O
P E
D
C
E
N
U
E
N ER
I
T
F
N
E
O
R
C
S OR
I
D F
—
RC1 10
15 RC 2
PHASE1 11
14 PHASE 2
ENABLE1 12
13 ENABLE 2
Note the A3961SB (DIP) and the A3961SLB
(SOIC) are electrically identical and share a
common terminal number assignment.
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, VBB . . . . . . . . . . 45 V
Output Current, IOUT . . . . . . . . . . ±800 mA*
Logic Supply Voltage, VCC . . . . . . . . . 7.0 V
Logic Input Voltage Range,
VIN . . . . . . . . . . . -0.3 V to VCC + 0.3 V
Sense Voltage, VSENSE . . . . . . . . . . . . 1.0 V
Reference Output Current,
IREF OUT . . . . . . . . . . . . . . . . . . . 1.0 mA
Package Power Dissipation,
PD . . . . . . . . . . . . . . . . . . . . See Graph
Operating Temperature Range,
TA . . . . . . . . . . . . . . . . . -20˚C to +85˚C
Junction Temperature, TJ . . . . . . . +150˚C†
Storage Temperature Range,
TS . . . . . . . . . . . . . . . . -55˚C to +150˚C
* 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.
† Fault conditions that produce excessive
junction temperature will activate device
thermal shutdown circuitry. These conditions
can be tolerated but should be avoided.
The fixed off-time pulse duration is set by user-selected external
RC timing networks. The capacitor in the RC timing network also
determines a user-selectable blanking window that prevents false
triggering of the PWM current control circuitry during switching transitions. This eliminates the need for two external RC filter networks on
the current-sensing comparator inputs.
For each bridge the PHASE input controls load current polarity by
selecting the appropriate source and sink driver pair. For each bridge
the ENABLE input, when held high, disables the output drivers. Special
power-up sequencing is not required. Internal circuit protection includes
thermal shutdown with hysteresis, transient-suppression diodes, and
crossover-current protection.
The A3961S— is supplied in a choice of two power packages:
24-pin dual-in-line plastic package with copper heat-sink tabs and
24-lead plastic SOIC with copper heat-sink tabs. In both packages the
power tab is at ground potential and needs no electrical isolation.
FEATURES
■
■
■
■
■
■
■
±800 mA Continuous Output Current Rating
45 V Output Voltage Rating
Internal PWM Current Control, Saturated Sink Drivers
Internally Generated Precision 2.5 V Reference
Internal Transient-Suppression Diodes
Internal Thermal-Shutdown Circuitry
Crossover-Current Protection, UVLO Protection
Always order by complete part number:
PART NUMBER
PACKAGE
RθJA
RθJT
A3961SB
24-Pin DIP
40°C/W
6°C/W
A3961SLB
24-Lead SOIC
55°C/W
6°C/W
ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
5
TRUTH TABLE
RθJT = 6.0°C/W
4
ENABLE
PHASE
OUTA
OUTB
H
X
Off
Off
L
H
H
L
L
L
L
H
3
SUFFIX 'B', R θJA = 40°C/W
2
X = Irrelevant
1
SUFFIX 'LB', R θJA = 55°C/W
0
25
50
75
100
TEMPERATURE IN °C
125
150
Dwg. GP-049A
FUNCTIONAL BLOCK DIAGRAM AND TYPICAL
BIPOLAR STEPPER MOTOR APPLICATION
MOTOR SUPPLY 2
LOGIC SUPPLY
MOTOR SUPPLY 1
C BB
V BB1
GND
C cc
C BB2
V BB2
V cc
OUT 1A
OUT 2A
OUT 1B
OUT 2B
ENABLE 1
ENABLE 2
CONTROL LOGIC
AND LEVEL SHIFT
PHASE 1
RC1
BLANKING
TIME AND
SOURCE
DRIVER T OFF
CONTROL
CT1
UVLO
AND
TSD
+
VOLTAGE
REFERENCE
+
_
SENSE 1
RT1
CONTROL LOGIC
AND LEVEL SHIFT
_
E1
I FULL/PD REF
OUT
REFIN
E2
BLANKING
TIME AND
SOURCE
DRIVER T OFF
CONTROL
E2
R2
RC 2
SENSE 2
R1
RS1
PHASE 2
RS2
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright ©1995, 1996, Allegro MicroSystems, Inc.
CT2
RT2
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 45 V, VCC = 4.75 V to 5.25 V, VSENSE = 0
V, 30 kΩ & 1000 pF RC to Ground (unless noted otherwise)
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Output Drivers
Load Supply Voltage Range
VBB
Operating, IOUT = ±800 mA, L = 3 mH
5.0
—
45
V
Output Leakage Current
ICEX
VOUT = VBB
—
<1.0
50
µA
VOUT = 0 V
—
<-1.0
-50
µA
Source Driver, IOUT = -500 mA
—
1.0
1.2
V
Source Driver, IOUT = -750 mA
—
1.1
1.3
V
Source Driver, IOUT = -800 mA
—
—
1.4
V
Sink Driver, IOUT = +500 mA
—
0.3
0.6
V
Sink Driver, IOUT = +750 mA
—
0.5
0.9
V
Sink Driver, IOUT = +800 mA
—
—
1.0
V
IF = 500 mA
—
1.1
1.4
V
IF = 750 mA
—
1.3
1.6
V
IF = 800 mA
—
—
1.7
V
Output Saturation Voltage
Clamp Diode Forward Voltage
VCE(SAT)
VF
(Sink or Source)
Motor Supply Current
IBB(ON)
VENABLE = 0.8 V
—
5.0
7.0
mA
(No Load)
IBB(OFF)
VENABLE = 2.4 V
—
5.0
7.0
mA
4.75
—
5.25
V
Control Logic
Logic Supply Voltage Range
VCC
Logic Input Voltage
VIN(1)
2.4
—
—
V
VIN(0)
—
—
0.8
V
Logic Input Current
Reference Output Voltage
Operating
IIN(1)
VIN = 2.4 V
—
<1.0
20
µA
IIN(0)
VIN = 0.8 V
—
<-2.0
-200
µA
IFULL/PD = LOW
2.45
2.50
2.55
V
IFULL/PD = HIGH
1.49
1.67
1.84
V
VREF OUT
VCC = 5.0 V, IREF OUT = 90 to 900 µA:
Continued next page…
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 45 V, VCC = 4.75 V to 5.25 V, VSENSE = 0
V, 30 kW & 1000 pF RC to Ground (unless noted otherwise) (cont.)
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
90
—
900
µA
Control Logic (Continued)
Reference Output Current
I REF OUT
3 kΩ ≤ RD = R1 + R2 ≤ 15 kΩ
Ref. Input Offset Current
IOS
VREF IN = 1 V
-2.5
0
1.0
µA
Comparator Input Offset Volt.
VIO
VREF = 0 V
-5.0
0
5.0
mV
Comparator Input Volt. Range
VREF
Operating
-0.3
—
1.0
V
CT = 1000 pF, R T = 30 kΩ
27
30
33
µs
Comparator Trip to Source OFF
—
1.2
2.0
µs
CT = 1000 pF ± 5%, RT ≥ 15 kΩ, V CC = 5 V
—
2.5
3.6
µs
ENABLE ON to Source ON
—
3.2
—
µs
ENABLE OFF to Source OFF
—
1.2
—
µs
ENABLE ON to Sink ON
—
3.2
—
µs
ENABLE OFF to Sink OFF
—
0.7
—
µs
PHASE Change to Sink ON
—
3.2
—
µs
PHASE Change to Source ON
—
3.2
—
µs
PHASE Change to Sink OFF
—
0.7
—
µs
PHASE Change to Source OFF
—
1.2
—
µs
PWM RC Fixed Off-time
PWM Propagation Delay Time
tOFF RC
tPWM
PWM Minimum On Time
tON(min)
Propagation Delay Times
tpd
IOUT = ±800 mA, 50% to 90%:
Thermal Shutdown Temp.
TJ
—
165
—
˚C
Thermal Shutdown Hysteresis
∆TJ
—
15
—
˚C
UVLO Disable Threshold
2.5
2.7
2.9
V
UVLO Hysterisis
0.7
0.9
1.1
V
mA
Logic Supply Current
Logic Supply Current
Temperature Coefficient
ICC(ON)
VENABLE1 = VENABLE2 = 0.8 V
—
65
85
ICC(OFF)
VENABLE1 = VENABLE2 = 2.4 V
—
11
15
∆ICC(ON)
VENABLE1 = VENABLE2 = 0.8 V
—
0.18
—
NOTES: 1. Typical Data is for design information only.
2. Negative current is defined as coming out of
(sourcing) the specified device terminal.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
mA/˚C
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
FUNCTIONAL DESCRIPTION
Internal PWM Current Control. The A3961S— contains
a fixed off-time pulse-width modulated (PWM) currentcontrol circuit that can be used to limit the load current to
a desired value. The peak value of the current limiting
(ITRIP) is set by the selection of an external current-sensing
resistor (RS ) and reference input voltage (VREF IN).
The internal circuitry compares the voltage across the
external sense resistor to the voltage on the reference
input terminal (VREF IN), resulting in a transconductance
function approximated by:
ITRIP ≈
VREF IN
RS
The reference input voltage is typically set with a
resistor divider from VREF OUT. The value of VREF OUT
can be switched from a nominal value of 2.5 V to 1.67 V
by applying a low or high logic signal respectively to the
I FULL/PD terminal. To ensure proper operation of the
voltage reference, the resistor divider (RD = R1+R2) should
have an impedance of 3 kΩ to 15 kΩ. Within this range, a
low impedance will minimize the effect of the REF IN input
offset current.
The current-control circuitry limits the load current as
follows: when the load current reaches ITRIP, the comparator resets a latch that turns off the selected source driver.
The load inductance causes the current to recirculate
through the sink driver and flyback diode.
For each bridge, the user selects an external resistor
(RT) and capacitor (CT) to determine the time period
(tOFF = RTCT) during which the source driver remains disabled (see “RC Fixed Off-time” below). The range of recommended values for CT and RT are 1000 pF to
1500 pF and 15 kΩ to 100 kΩ respectively. For optimal
load current regulation, CT is normally set to 1000 pF (see
“Load Current Regulation” below). At the end of the RC interval, the source driver is enabled allowing the load current to increase again. The PWM cycle repeats, maintaining the peak load current at the desired value.
internal current-control circuitry (or by the PHASE or
ENABLE inputs). The comparator output is blanked to
prevent false over-current detections due to reverserecovery currents of the clamp diodes, and/or switching
transients related to distributed capacitance in the load.
During internal PWM operation, at the end of the tOFF
time, the comparator’s output is blanked and CT begins to
be charged from approximately 1.1 volts by an internal
current source of approximately 1 mA. The comparator
output remains blanked until the voltage on CT reaches
approximately 3.0 volts.
When a transition of the PHASE input occurs, CT
is discharged to near ground during the crossover delay
time (The crossover delay time is present to prevent
simultaneous conduction of the source and sink drivers).
After the crossover delay, CT is charged by an internal current source of approximately 1 mA. The comparator output remains blanked until the voltage on C T reaches
approximately 3.0 volts.
When the device is disabled, via the ENABLE input,
CT is discharged to near ground. When the device is
re-enabled, CT is charged by an internal current source
of approximately 1 mA. The comparator output remains
blanked until the voltage on CT reaches approximately
3.0 volts.
The minimum recommended value for CT is
1000 pF. This value ensures that the blanking time is sufficient to avoid false trips of the comparator under normal
operating conditions. For optimal regulation of the load
current, the above value for CT is recommended and the
value of RT can be sized to determine tOFF. For more information regarding load current regulation, see below.
Load Current Regulation. Because the device operates
in a slow decay mode (2-quadrant PWM mode), there is a
limit to the lowest level that the PWM current control circuitry can regulate load current. The limitation is due to the
minimum PWM duty cycle, which is a function of the userselected value of tOFF and the minimum on-time pulse
tON(min)max that occurs each time the PWM latch is reset.
RC BLANKING. In addition to determining the fixed offIf the motor is not rotating, as in the case of a stepper motime of the PWM control circuit, the CT component sets the
tor in hold/detent mode, a brush dc motor when stalled or
comparator blanking time. This function blanks the output
at startup, the worst case value of current regulation can
of the comparator when the outputs are switched by the
be approximated by:
[(VBB - V SAT(SOURCE+SINK)) tON(min) max] – (1.05 (VSAT(SINK) + VF) tOFF)
I AVG ≈
1.05 (tON(min) max + tOFF) RLOAD
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
where tOFF = RTCT, RLOAD is the series resistance of the
load, VBB is the motor supply voltage and t ON(min)max is
specified in the electrical characteristics table. When the
motor is rotating, the back EMF generated will influence
the above relationship. For brush dc motor applications,
the current regulation is improved. For stepper motor
applications when the motor is rotating, the effect is
dependent on the polarity and magnitude of the motor’s
back EMF.
The following procedure can be used to evaluate the
worst-case internal PWM load current regulation in the
system:
Set VREF to 0 volts. With the load connected and
the PWM current control operating in slow decay mode,
use an oscilloscope to measure the time the output is
low (sink ON) for the output that is chopping. This is the
typical minimum on time (tON(min)typ) for the device. The
CT then should be increased until the measured value of
tON(min) is equal to tON(min)max as specified in the electrical
characteristics table. When the new value of CT has been
set, the value of RT should be decreased so the value for
tOFF = R TCT (with the artificially increased value of CT)
is equal to the nominal design value. The worst-case loadcurrent regulation then can be measured in the system
under operating conditions.
PWM of the Phase and Enable Inputs. The PHASE and
ENABLE inputs can be pulse width modulated to regulate
load current. Typical propagation delays from the PHASE
and ENABLE inputs to transitions of the power outputs are
specified in the electrical characteristics table. If the internal PWM current control is used, the comparator blanking
function is active during phase and enable transitions. This
eliminates false tripping of the over-current comparator
caused by switching transients (see “RC Blanking” above).
Enable PWM. Toggling the ENABLE input turns ON and
OFF the selected source and sink drivers. The corresponding pair of flyback and ground clamp diodes conduct
after the drivers are disabled, resulting in fast current decay. When the device is enabled the internal current-control circuitry will be active and can be used to limit the load
current in a slow decay mode.
Phase PWM. Toggling the PHASE terminal selects which
sink/source pair is enabled, producing a load current that
varies with the duty cycle and remains continuous at all
times. This can have added benefits in bidirectional brush
dc servo motor applications as the transfer function be-
tween the duty cycle on the PHASE input and the average
voltage applied to the motor is more linear than in the case
of ENABLE PWM control (which produces a discontinuous
current at low current levels).
Miscellaneous Information. An internally generated dead
time prevents crossover currents that can occur when
switching phase.
Thermal protection circuitry turns OFF all drivers
should the junction temperature reach 165°C (typical).
This is intended only to protect the device from failures
due to excessive junction temperatures and should not
imply that output short circuits are permitted. The hysteresis of the thermal shutdown circuit is approximately 15°C.
APPLICATION NOTES
Current Sensing. The actual peak load current (IPEAK)
will be above the calculated value of ITRIP due to delays in
the turn off of the drivers. The amount of overshoot can be
approximated by:
IOS ≈
(VBB – [(ITRIP R LOAD) + VBEMF]) tPWM
L LOAD
where VBB is the motor supply voltage, VBEMF is the
back-EMF voltage of the load, RLOAD and LLOAD are the
resistance and inductance of the load respectively, and
t PWM is specified in the electrical characteristics table.
To minimize current sensing inaccuracies caused by
ground trace IR drops, each current-sensing resistor
should have a separate return to the ground terminal of the
device. For low-value sense resistors, the IR drops in the
PCB can be significant and should be taken into account.
The use of sockets should be avoided as their contact
resistance can cause variations in the effective value of
RS .
Generally, larger values of RS reduce the aforementioned effects but can result in excessive heating and
power loss in the sense resistor. The selected value of RS
should not cause the absolute maximum voltage rating of
1.0 V, for the SENSE terminal, to be exceeded. The
recommended value of RS is in the range of:
RS ≈
0.5
ITRIPmax
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
± 50%
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
If desired, the reference input voltage can be filtered
by placing a capacitor from REFIN to ground. The ground
return for this capacitor as well as R2 should be independent from the high-current power-ground trace to avoid
changes in REFIN due to IR drops.
Thermal Considerations. For reliable operation it is
recommended that the maximum junction temperature be
kept below 110 to 125°C. The junction temperature can
be measured best by attaching a thermocouple to the
power tab/batwing of the device and measuring the tab
temperature, TTAB . The junction temperature can then be
approximated by using the formula:
TJ ≈ TTAB + (ILOAD 2 V F RθJT)
where VF can be chosen from the electrical specification
table for the given level of ILOAD. The value for RθJT is
given in the package thermal resistance table for the
appropriate package.
The power dissipation of the batwing packages can
be improved by 20 to 30% by adding a section of printed
circuit board copper (typically 6 to 18 square centimeters)
connected to the batwing terminals of the device.
The thermal performance in applications that run at
high load currents and/or high duty cycles can be improved by adding external diodes from each output to
ground in parallel with the internal diodes. Fast recovery
(≤ 200 ns) diodes should be used to minimize switching
losses.
The load supply terminal, VBB, should be decoupled
with an electrolytic capacitor (≥ 47 µF is recommended)
placed as close to the device as is physically practical.
To minimize the effect of system ground IR drops on the
logic and reference input signals the system ground should
have a low-resistance return to the motor supply voltage.
See also “Current Sensing” and “Thermal Considerations” above.
Fixed Off-Time Selection. With increasing values of tOFF,
switching losses will decrease, low-level load current
regulation will improve, EMI will be reduced, the PWM
frequency will decrease, and ripple current will increase.
The value of tOFF can be chosen for optimization of these
parameters. For applications where audible noise is a
concern, typical values of tOFF are chosen to be in the
range of 15 to 35 µs.
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
A3961SB
Dimensions in Inches
(controlling dimensions)
24
0.014
0.008
13
NOTE 1
0.430
MAX
0.280
0.240
0.300
BSC
1
0.070
0.045
6
7
0.100
1.280
1.230
12
BSC
0.005
MIN
0.210
MAX
0.015
0.150
0.115
MIN
0.022
0.014
Dwg. MA-001-25A in
Dimensions in Millimeters
(for reference only)
24
0.355
0.204
13
NOTE 1
10.92
MAX
7.11
6.10
7.62
BSC
1
1.77
1.15
6
7
2.54
32.51
31.24
BSC
12
0.13
MIN
5.33
MAX
3.81
2.93
0.39
MIN
0.558
0.356
Dwg. MA-001-25A mm
NOTES: 1. Webbed lead frame. Leads 6, 7, 18, and 19 are internally one piece.
2. Lead thickness is measured at seating plane or below.
3. Lead spacing tolerance is non-cumulative.
4. Exact body and lead configuration at vendor’s option within limits shown.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
A3961SLB
Dimensions in Inches
(for reference only)
24
13
0.0125
0.0091
0.491
0.394
0.2992
0.2914
0.050
0.016
0.020
0.013
1
2
3
0.050
0.6141
0.5985
0° TO 8°
BSC
NOTE 1
NOTE 3
0.0926
0.1043
0.0040 MIN.
Dwg. MA-008-25 in
Dimensions in Millimeters
(controlling dimensions)
24
13
0.32
0.23
10.65
10.00
7.60
7.40
1.27
0.40
0.51
0.33
1
2
3
15.60
15.20
1.27
BSC
0° TO 8°
NOTE 1
NOTE 3
2.65
2.35
0.10 MIN.
NOTES: 1. Webbed lead frame. Leads 6, 7, 18, and 19 are internally one piece.
2. Lead spacing tolerance is non-cumulative.
3. Exact body and lead configuration at vendor’s option within limits shown.
Dwg. MA-008-25A mm
3961
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
BRIDGE & HALF-BRIDGE DRIVERS
SELECTION GUIDE
IN ORDER OF 1) OUTPUT CURRENT AND 2) OUTPUT VOLTAGE
Features
Output Ratings *
Internal
Diodes
Outputs
Internal
Protection
Dual PWM Full Bridge
Dual PWM Full Bridge
X
X
Bipolar
Bipolar
X
X
3966
3968
45
45
45
Dual PWM Full Bridge
Dual PWM Full Bridge
Dual PWM Full Bridge
X
X
X
Bipolar
Bipolar
Bipolar
X
X
X
2916
2919
6219
±800
33
Dual PWM Full Bridge
X
Bipolar
X
3964
±900
14
3-Ø Back-EMF Controller/Driver
X
DMOS
X
8902-A
±1000
7.0
3-Ø Back-EMF Controller/Driver
X
NMOS
X
8984
±1300
50
PWM Full Bridge
X
Bipolar
X
3953
±1500
45
45
50
50
Dual PWM Full Bridge
Dual PWM Full Bridge
PWM Microstepping Full Bridge
PWM Microstepping Full Bridge
X
X
X
X
Bipolar
Bipolar
Darlington/Satlington™
Darlington/Satlington™
X
X
X
X
2917
2918
3955
3957
±2000
45
50
50
50
3-Ø Brushless Controller/Driver
Dual Full Bridge
PWM Full-Bridge
PWM Full-Bridge
X
X
X
X
Darlington
Darlington
Darlington
Darlington
X
X
X
X
2936
2998
3951
3952
±3000
45
PWM Control
X
Darlington
–
2962
±3400
45
PWM Control
X
Bipolar
X
2961
±4000
14
3-Ø Brushless Controller/Driver
X
DMOS
X
8925
mA
V
Description
±650
30
30
±750
Part
Number †
* Current is maximum specified test condition, voltage is maximum rating. See specification for sustaining voltage limits or overcurrent protection voltage limits.
†
Complete part number includes additional characters to indicate operating temperature range and package style.
Allegro MicroSystems, Inc. reserves the right to make, from time to
time, such departures from the detail specifications as may be required to
permit improvements in the design of its products.
The information included herein is believed to be accurate and
reliable. However, Allegro MicroSystems, Inc. assumes no responsibility
for its use; nor for any infringements of patents or other rights of third
parties which may result from its use.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
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