Datasheet

R
1
R
F
T1
2N2923
+
+5V
V+
V-
I
SET
I
SET
I
OUT
V
OUT
V
IN
V
SET
R
LOAD
OPA564
OPA333
R
5k
SET
W
C
100pF
1
V
100mV
SET
V (1 + )
IN
R
R
F
1
R
LOAD
I =
OUT
£ I
LIM
I I
LIM SET
20,000
@ ´
I
SET
@
I
20,000
LIM
I
SET
(0.4A to 1.5A) = 20 A to 75 Am m
V
SET
(0.4A to 1.5A) = 100mV to 375mV
and
G= - = -4
R
2
R
1
V
IN
V+
V
DIG
V-
R
1
5kW
R
2
20kW
OPA564
10W
(Non-
inductive)
Motor
0.01 Fm
Z
1
(1)
Z
2
S
2
S
1
(1)
(2)
(2)
C
0.1 F
1
m
C
0.1 F
1
m
C
47 F
2
m
C
47 F
2
m
Note(3)
Note(3)
OPA564
SBOS372E –OCTOBER 2008– REVISED JANUARY 2011 www.ti.com
PROGRAMMABLE POWER SUPPLY For more information on this circuit, see the
Application Bulletin DC Motor Speed Controller:
Figure 53 shows the OPA333 used to control I
SET
in
Control a DC Motor without Tachometer Feedback
order to adjust the current limit of the OPA564.
(SBOA043), available for download at the TI web site.
Figure 54 shows a basic motor speed driver but does
Figure 56 shows two examples of generating the
not include any control over the motor speed. For
signal for V
DIG
. Figure 56a uses an 1N4732A zener to
applications where good control of the speed of the
bias the V
DIG
to precisely 4.7V above V–. Figure 56b
motor is desired, but the precision of a tachometer
uses a high-voltage subregulator to derive the V
DIG
control is not required, the circuit in Figure 55
voltage. Figure 58 illustrates a detailed powerline
provides control by using feedback of the current
communication circuit.
consumption to adjust the motor drive.
Figure 53. Programmable Current Limit Option
(1) Z
1
, Z
2
= zener diodes (IN5246 or equivalent). Select Z
1
and Z
2
diodes that are capable of the maximum anticipated surge current.
(2) S
1
, S
2
= Schottky diodes (STPS1L40 or equivalent).
(3) C
1
= high-frequency bypass capacitors; C
2
= low-frequency bypass capacitors (minimum of 10mF for every 1A peak current)
Figure 54. Motor Drive Circuit
26 Submit Documentation Feedback © 2008–2011, Texas Instruments Incorporated
Product Folder Link(s): OPA564