L6258EP_07 STMICROELECTRONICS [STMicroelectronics], L6258EP_07 Datasheet - Page 13

• Manufacturer Part Number: L6258EP_07
• Description: PWM controlled high current DMOS universal motor driver
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

L6258EP
2.3
2.4
2.5
Table 5.
Phase input ( PH )
The logic level applied to this input determines the direction of the current flowing in the
winding of the motor.
High level on the phase input causes the motor current flowing from OUT_A to OUT_B
through the load.
Triangular generator
This circuit generates the two triangular waves TRI_0 and TRI_180 internally used to
generate the duty cycle variation of the signals driving the output stage in bridge
configuration.
The frequency of the triangular wave defines the switching frequency of the output, and can
be adjusted by changing the capacitor connected at TR1_CAP pin:
where: K = 1.5 x 10
Charge pump circuit
To ensure the correct driving of the high side drivers a voltage higher than Vs is supplied on
the Vboot pin. This boostrap voltage is not needed for the low side power DMOS transistors
because their sources terminals are grounded. To produce this voltage a charge pump
method is used. It is made by using two external capacitors; one connected to the internal
oscillator (CP) and the other (Cboot) to storage the overvoltage needed for the driving the
gates of the high side DMOS. The value suggested for the capacitors are:
Table 6.
Component name
I3
L
L
L
L
L
C
C
boot
P
Current levels (continued)
Charge pump capacitor's values
-5
I2
H
L
L
L
L
Component's function
Storage capacitor
Pump capacitor
I1
H
H
L
L
L
F
ref
=
--- -
C
K
I0
H
H
L
L
L
Value
100
10
Functional description
Current level
% of IMAX
88.9
92.1
95.2
98.4
100
Unit
nF
nF
13/32