L6258EX
PWM controlled
high current DMOS universal motor driver
Features
■
■
■
■
■
■
■
■
■
Able to drive both windings of a bipolar stepper
motor or two DC motors
Output current up to 1.5A each winding
Wide voltage range: 12V to 40V
Four quadrant current control, ideal for
microstepping and DC motor control
Precision PWM control
No need for recirculation diodes
TTL/CMOS compatible inputs
Cross conduction protection
Thermal shutdow
The power stage is a dual DMOS full bridge
capable of sustaining up to 40V, and includes the
diodes for current recirculation.The output current
capability is 1.5A per winding in continuous mode,
with peak start-up current up to 2A. A thermal
protection circuitry disables the outputs if the chip
temperature exceeds the safe limits.
PowerSO36
Description
L6258EX is a dual full bridge for motor control
applications realized in BCD technology, with the
capability of driving both windings of a bipolar
stepper motor or bidirectionally control two DC
motors.
L6258EX and a few external components form a
complete control and drive circuit. It has high
efficiency phase shift chopping that allows a very
low current ripple at the lowest current control
levels, and makes this device ideal for steppers as
well as for DC motors.
Table 1.
Device summary
Order code
E-L6258EX
E-L6258EXTR
Package
PowerSO36
PowerSO36
Packing
Tube
Tape&Reel
December 2007
Rev 6
1/32
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1
Contents
L6258EX
Contents
1
2
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.1
2.2
2.3
2.4
2.5
2.6
2.7
Reference voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Input logic (I0 - I1 - I2 - I3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Phase input ( PH ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Triangular generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Charge pump circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Current control loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Current control loop compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3
PWM current control loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.1
3.2
3.3
3.4
3.5
Open loop transfer function analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Power amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Load attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Error amplifier and sense amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Effect of the Bemf on the current control loop stability . . . . . . . . . . . . . . . 22
4
Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.1
4.2
4.3
4.4
Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Motor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Unused inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Notes on PCB design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5
6
7
Operation mode time diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2/32
L6258EX
List of tables
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Absolute maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Pin functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Current levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Charge pump capacitor's values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3/32
List of figures
L6258EX
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
Figure 14.
Figure 15.
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Pin connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Thermal characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Power bridge configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Current control loop block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Output comparator waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Ax bode plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Aloop bode plot (uncompensated) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Aloop bode plot (compensated) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Electrical model of the load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Typical application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Full step operation mode timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Half step operation mode timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4 bit microstep operation mode timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
PowerSO36 mechanical data & package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4/32
L6258EX
Block diagram
1
Figure 1.
Block diagram
Block diagram
R
1
1M
R
C1
C
P
VCP1
VCP2
EA_IN1
C
C1
EA_OUT1
TRI_0
CHARGE
PUMP
V
R
VREF1
I3_1
I2_1
I1_1
I0_1
PH_1
SENSE1A
VR GEN
V
R
(V
DD
/2)
THERMAL
PROT.
DISABLE
VS
VREF1
I3_2
I2_2
I1_2
I0_2
PH_2
TRI_CAP
C
FREF
SENSE2A
TRIANGLE
GENERATOR
TRI_0
TRI_180
DAC
V
R
INPUT
&
SENSE
AMP
+
-
ERROR
AMP
TRI_0
DAC
+
INPUT
&
SENSE
AMP
-
ERROR
AMP
TRI_180
VS
C
BOOT
VBOOT
+
-
+
-
C
POWER
BRIDGE
1
OUT1A
C
OUT1B
SENSE1B
R
s
V
DD
(5V)
+
-
+
C
POWER
BRIDGE
2
OUT2A
TRI_180
-
C
OUT2B
SENSE2B
R
s
GND
EA_IN2
R
C2
R
2
1M
EA_OUT2
D96IN430D
C
C2
Table 2.
Absolute maximum rating
Description
Supply voltage
Logic supply voltage
Reference voltage
Output current (peak)
(1)
Output current (continuous)
Logic input voltage range
Bootstrap supply
Maximum Vgate applicable
Junction temperature
Storage temperature range
Value
45
7
2.5
2
1.5
-0.3 to 7
60
15
150
-55 to 150
Unit
V
V
V
A
A
V
V
V
°C
°C
Parameter
V
s
V
DD
V
ref1
/V
ref2
I
O
I
O
V
in
V
boot
V
boot
- V
s
T
j
T
stg
1. This current is intended as not repetitive current for max. 1 second.
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