ls7260 LSI Computer Systems, Inc., ls7260 Datasheet - Page 5

• Manufacturer Part Number: ls7260
• Description: Brushless Dc Motor Commutator/controller
• Manufacturer: LSI Computer Systems, Inc.

7260-012703-5
For controlled acceleration and deceleration of motors in
the forward or reverse directions, a motor control pulse
width modulator circuit such as the SG1731 or UC1637
can be interfaced with the LS7260 or LS7262.
The logical OR gate made up of the resistor-diode net-
work permits the LS7260 or LS7262 to be enabled when
either the forward or reverse input is high. By applying
For four phase commutation (See Fig. 4), the COMMUTA-
TION SELECT inputs must both be tied low. The S1 input
is driven from one motor position sensor while the S2 and
S3 inputs are connected together and driven by the
second position sensor. The COMMON input must be
L S 7 2 6 2
COMMON
BRAKE
INPUT
S1
0
1
1
0
TABLE 4. OUTPUT COMMUTATION SEQUENCE FOR FOUR PHASE OPERATION
O4
O5
O6
FORWARD
9
R E V E R S E
6
7
5
8
FIGURE 3. PRECISION CONTROL BRUSHLESS DC MOTOR DRIVE
Vss
S2,S3
Inputs from SG1731
or UC1637
0
1
1
0
CS1 = CS2 = 0 OUTPUTS ENABLED
MOTOR
SUPPLY
the forward input directly to Pin 19, the motor can only
operate in the forward direction when the forward input is
high and only in the reverse direction when the reverse
input is high. Motor direction is determined by relative
pulse widths of the forward and reverse inputs while ac-
celeration or deceleration is determined by variations of
these widths.
connected to Vss. The sensors have an electrical separa-
tion of 90°. Figure 4A indicates the use of Bipolar Tran-
sistors. Figure 4B indicates the use of FETs. In both
cases, the LS7262 is used.
FWD/REV = 1
O1
O3
O4
O6
BRAKE
I N 9 1 4
I N 9 1 4
2 . 2 K
This configuration requires only
one base current limiting resistor
connected from the COMMON
pin to Vss.
19
10
L S 7 2 6 0
or
L S 7 2 6 2
ENABLE
F/R
DRIVER CIRCUIT
SINGLE-ENDED
FIGURE 2A.
FWD/REV = 0
O4
O6
O1
O3