Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.NET

X  

Preview PDF Download HTML

3968 Datasheet(PDF) 5 Page - Allegro MicroSystems

Part No. 3968
Description  DUAL FULL-BRIDGE PWM MOTOR DRIVER WITH BRAKE
Download  10 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  ALLEGRO [Allegro MicroSystems]
Direct Link  http://www.allegromicro.com
Logo ALLEGRO - Allegro MicroSystems

3968 Datasheet(HTML) 5 Page - Allegro MicroSystems

  3968_03 Datasheet HTML 1Page - Allegro MicroSystems 3968_03 Datasheet HTML 2Page - Allegro MicroSystems 3968_03 Datasheet HTML 3Page - Allegro MicroSystems 3968_03 Datasheet HTML 4Page - Allegro MicroSystems 3968_03 Datasheet HTML 5Page - Allegro MicroSystems 3968_03 Datasheet HTML 6Page - Allegro MicroSystems 3968_03 Datasheet HTML 7Page - Allegro MicroSystems 3968_03 Datasheet HTML 8Page - Allegro MicroSystems 3968_03 Datasheet HTML 9Page - Allegro MicroSystems Next Button
Zoom Inzoom in Zoom Outzoom out
 5 / 10 page
background image
3968
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
WITH BRAKE
www.allegromicro.com
Internal PWM Current Control. The A3968SA and
A3968SLB dual H-bridges are designed to bidirectionally
control two dc motors. An internal fixed-frequency PWM
current-control circuit controls the load current in each
motor. The current-control circuitry works as follows:
when the outputs of the H-bridge are turned on, current
increases in the motor winding. The load current is sensed
by the current-control comparator via an external sense
resistor (RS). Load current continues to increase until it
reaches the predetermined value, set by the selection of
external current-sensing resistors and reference input
voltage (VREF) according to the equation:
ITRIP = IOUT + ISO = VREF/(4RS)
where ISO is the sense-current error (typically 18 mA) due
to the base-drive current of the sink driver transistor.
At the trip point, the comparator resets the source-
enable latch, turning off the source driver of that H-bridge.
The source turn off of one H-bridge is independent of the
other H-bridge. Load inductance causes the current to
recirculate through the sink driver and ground-clamp
diode. The current decreases until the internal clock
oscillator sets the source-enable latches of both H-bridges,
turning on the source drivers of both bridges. Load current
increases again, and the cycle is repeated.
The frequency of the internal clock oscillator is set by
FUNCTIONAL DESCRIPTION
the external timing components RTCT. The frequency
can be approximately calculated as:
fosc = 1/(RT CT + tblank)
where tblank is defined below.
The range of recommended values for RT and CT are
20 k
Ω to 100 kΩ and 470 pF to 1000 pF respectively.
Nominal values of 56 k
Ω and 680 pF result in a clock
frequency of 25.4 kHz.
Current-Sense Comparator Blanking. When the
source driver is turned on, a current spike occurs due to
the reverse-recovery currents of the clamp diodes and
switching transients related to distributed capacitance in
the load. To prevent this current spike from erroneously
resetting the source enable latch, the current-control
comparator output is blanked for a short period of time
when the source driver is turned on. The blanking time is
set by the timing component CT according to the equa-
tion:
tblank = 1900 CT (µs).
A nominal CT value of 680 pF will give a blanking
time of 1.3 µs.
The current-control comparator is also blanked when
the load current changes polarity (direction or phase
change). This internally generated blank time is approxi-
mately 1.8 µs.
+
0
Dwg. WM-003-2
VPHASE
I
OUT
td
ITRIP
t
blank
INTERNAL
OSCILLATOR
BRIDGE
ON
SOURCE
OFF
BRIDGE
ON
R C
T T
ALL
OFF
Enlargement A
See Enlargement A
Dwg. EP-006-16
RS
BB
V
BRIDGE ON
SOURCE OFF
ALL OFF


Html Pages

1  2  3  4  5  6  7  8  9  10 


Datasheet Download

Go To PDF Page

Related Electronics Part Number

Part No.DescriptionHtml ViewManufacturer
L6219 DUAL FULL-BRIDGE PWM MOTOR DRIVER 1  2  3  4  5  More Unisonic Technologies
A3969 Dual Full-Bridge PWM Motor Driver 1  2  3  4  5  More Allegro MicroSystems
3974_1 DMOS DUAL FULL-BRIDGE PWM MOTOR DRIVER 1  2  3  4  5  More Allegro MicroSystems
3964_00 DUAL FULL-BRIDGE PWM MOTOR DRIVER 1  2  3  4  5  More Allegro MicroSystems
3966_03 DUAL FULL-BRIDGE PWM MOTOR DRIVER 1  2  3  4  5  More Allegro MicroSystems
2916_07 DUAL FULL-BRIDGE PWM MOTOR DRIVER 1  2  3  4  5  More Allegro MicroSystems
2919_06 DUAL FULL-BRIDGE PWM MOTOR DRIVER 1  2  3  4  5  More Allegro MicroSystems
A1441_06 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Element Commutation 1  2  3  4  Allegro MicroSystems
3953_05 FULL-BRIDGE PWM MOTOR DRIVER 1  2  3  4  5  More Allegro MicroSystems

Link URL




Privacy Policy
ALLDATASHEET.NET
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn