A3977SEDTR-T Allegro Microsystems Inc, A3977SEDTR-T Datasheet - Page 10

• Manufacturer Part Number: A3977SEDTR-T
• Description: LEAD FREE A3977SEDTR
• Manufacturer: Allegro Microsystems Inc

Specifications of A3977SEDTR-T

• Rohs Compliant: YES
• Applications: Stepper Motor Driver
• Number Of Outputs: 1
• Current - Output: ±2.5A
• Voltage - Load: 8 V ~ 35 V
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 44-LCC (J-Lead)
• Motor Type: Stepper
• No. Of Outputs: 2
• Output Current: 2.5A
• Output Voltage: 35V
• Supply Voltage Range: 3V To 5.5V
• Driver Case Style: LCC
• No. Of Pins: 44
• Operating Temperature Range: -20°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 620-1146-2; A3977SEDTR-T

A3977
Layout.
plane.
driver should be soldered directly onto the board.
with an electrolytic capacitor (>47 μF is recommended)
placed as close to the device as possible.
high dv/dt switching transients, route the bridge-output
traces away from the sensitive logic-input traces. Always
drive the logic inputs with a low source impedance to in-
crease noise immunity.
Grounding. A star ground system located close to the
driver is recommended.
power ground internally bonded to the power tabs of the
package (leads 44, 1, 2, 11 – 13, 22 – 24, and 33 – 35).
(lead 7) and the power ground (lead 21) must be con-
The printed wiring board should use a heavy ground
The load supply terminal, V
To avoid problems due to capacitive coupling of the
The 44-lead PLCC has the analog ground and the
On the 28-lead TSSOP package, the analog ground
For optimum electrical and thermal performance, the
BB
, should be decoupled
Microstepping DMOS Driver with Translator
Applications Information
nected together externally. The copper ground plane located
under the exposed thermal pad is typically used as the star
ground.
Current Sensing. To minimize inaccuracies caused by
ground-trace IR drops in sensing the output current level,
the current-sense resistor (R
ground return to the star ground of the device. This path
should be as short as possible. For low-value sense resis-
tors the IR drops in the printed wiring board sense resistor’s
traces can be signifi cant and should be taken into account.
The use of sockets should be avoided as they can introduce
variation in R
given by
Thermal Protection. Circuitry turns off all drivers when
the junction temperature reaches 165°C, typically. It is
intended only to protect the device from failures due to
excessive junction temperatures and should not imply that
output short circuits are permitted. Thermal shutdown has a
hysteresis of approximately 15°C.
Allegro MicroSystems recommends a value of R
S
due to their contact resistance.
R
S
= 0.5/I
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
S
) should have an independent
TRIP
max
S
10