DESCRIPTION
Oscillator.
The output current at ROSC pin is mirrored to
COSC pin with a proper direction according to its
voltage slope.
The triangular wave form at COSC pin, being
compared with a threshold, defines the PWM duty
cycle at the motor driver output M+ and M-.
The oscillator also supplies the time base for the
switch off and switch on delays and the Time Out
Counter.
The typical oscillator period is:
Tosc = 7.04 x Rosc x Cosc
February 2001
150K
150K
OP1
COMP1
+
-
-
+
0 1
0
1
375K
1
2
+
-
V
R3
=6.6% Vcc
COMP7
+
switch on
DELAY
VR7 =
7.5% Vcc
switch off
D ELAY
35V
35V
V
R3
=
6.6% Vcc
VR2 =
56.6% Vcc
COMP2
COMP3
I
I
curr.
sense
I
OSCILLATOR
OP8
+
-
VR8 =
14.2% Vcc
COMP4
pwm
DELAY
+
VR4 = 1.5V
COUN TER
Tck
RES
TIME OUT
Vcc
Tck
FF
S
R
Tck
Tck
Vcc
Tck
Vcc
ROSC
GND
M+
M-
VR2=56.6%Vcc
VR3=6.6%Vcc
TEMP.
SENSE
Current ratio = 1 : 2
VR5 = 6.6% Vcc
| 5 Verr|
curr.
limit
curr.
limit
Vcc
Vcc
Vcc
16V
VR2 =
56.6% Vcc
VR3 =
6.6% Vcc
7V
Td_on
Td_pwm
Td_off
10V
open
over
temp.
VOLT.
SENSE
over volt.
over volt.
DELAY 1
Td_ov_1
(130
s)
Vcc
open
START
LATCH
Latch
IN
STOP
STOP
START
DIRECTION
PWM
DRIVE R
CONTROL
OFF
OFF
over volt.
D ELAY2
Td_ov_2
(1ms)
Q
curr.
limit
curr.
limit
BLOCK DIAGRAM
MInidip
ORDERING NUMBER: L9909
L9909
DC MOTOR DRIVER WITH POSITION CONTROL
1/9
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
CC
DC battery supply voltage
-0.3 to 55
V
V
CC_t
Transient battery supply voltage (Figs. 4 and 5)
-0.3 to VCC_CL (*)
V
V
in
Voltage at VCOM and VFB pins
-0.3 to V
CC
+0.3
V
V
ROSC
Voltage AT ROSC pin
-0.3 to 7
V
V
COSC
Voltage at COSC pin for VCC >16V
-0.3 to16
V
Voltage at COSC pin for V
CC
>16V
-0.3 to V
CC
+0.3
V
I
CC
Current at V
CC
GND, M+ and M-
1.9
A
I
CC_t
Transient Current at V
CC
GND (figs. 4 and 5)
4
A
I
sig
Current at VFB, VCOM, COSC and ROSC
10
mA
Pd
Device Power Dissipation
internally limited
W
T
j
Junction Temperature
-40 to 150
C
T
stg
Storage and Junction Temperature
-55 to 150
C
VESD
ESD Voltage Level (Human body Model - MIL STD883C)
2000
V
(*) NOTE: SELF PROTECTING
Stressed above those listed under"Absolute Maximum Ratings" may cause permanent damage to the device . This is a stress rating anly and
functional operation of the device at any condition above those indicated in the operational section of this specification is not implied. Exposure
to absolute maximum rating conditions for extended periods may affect device reliability.
THERMAL DATA
Symbol
Parameter
Value
Unit
R
th j-case
Thermal resistance Junction to case (pin 1)
70
C/W
GND
COSC
VFB
VCOM
1
3
2
4
M-
VCC
ROSC
M+
8
7
6
5
D99AT436
PIN CONNECTION
L9909
2/9
ELECTRICAL CHARACTERISTICS (V
CC
= 7 to 18V; T
j
= -40 to 85
C, unless otherwise specified.)
Pin
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
POWER SUPPLY
VCC
I
CC
Quiescent Supply Current
I
M+
= I
M-
= 0, I
ROSC
= 100
A;
V
COSC
= 0
10
mA
V
CC_OV
Over Voltage Shut Down
18
20
V
V
CC_OVdel
Over Voltage Shut Down Delay
130
s
V
CC_min
Minimum V
CC
Operating
Voltage - Other Parameter
may not be in spec
5.5
V
V
CC_CL
Battery Supply Clamp Voltage
Transients of Fig.5
70
80
V
T
d_ov_1
Battery Supply Clamp Time
Transients of Fig.5
130
1000
s
T
d_ov_2
Battery Supply Clamp Time
Transients of Fig.4
1
ms
OSCILLATOR
COSC
ROSC
R
OSC
Oscillator Resistor
10
100
K
C
OSC
Oscillator Capacitor
2
100
nF
T
OUT
Timer Run Time
16384
T
OSC
F
OSC
Oscillator Frequency
ROSC 27K
; C
OSC
= 10nF
430
530
630
Hz
ROSC
V
rosc
Voltage at R
OSC
pin
R
OSC
27K
14.2
%V
CC
COSC
I
COSC
Current at C
OSC
pin
R
OSC
27K
-20
I
ROSC
20
%
V
THCOSC
High Threshold Voltage
56.6
1000 %V
CC
V
TLCOSC
Low Threshold Voltage
6.6
1000 %V
CC
V
LI NERR
Voltage Ramp Linearity Error
-20
20
%
PIN FUNCTIONS
N.
Name
Function
1
GND
Ground
2
COSC
Oscillator Capacitor
3
VFB
Position Feedback Voltage
4
VCOM
Position Command Voltage
5
M-
Negative Motor Terminal
6
VCC
Power Supply
7
ROSC
Oscillator Resistor
8
M+
Positive Motor Terminal
L9909
3/9
ELECTRICAL CHARACTERISTICS (continued.)
Pin
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
INPUT OUTPUT TRANSER FUNCTION
VCOM
VFB
COSC
M+
M -
A
V
Input Output Gain
7
10
14
V
STP
Stop Motor Voltage
V
STP
= 2 V
R4
2.5
3
3.5
V
V
STR
Start Error Voltage
V
STR
= V
R7/5
1
1.5
2
%V
CC
V
of f_c1
Comp 1 Input Offset Voltage
Error Voltage when the motor
starts braking
-20
20
mV
T
on
Switch on Delay
1
2
T
OSC
T
off
Switch off Delay
1
2
T
OSC
VCOM
VFB
R
diff
Differential Input Impedance
(see fig 3)
2V
COM
-
V
FB
I
com
-
I
FB
100
300
K
R
com
Common Mode Input (see fig 3)
V
COM
+
V
FB
I
com
+
I
FB
50
K
OUTPUT DRIVERS
M+
M -
R
ON_H
High Side R
DS
I
M+
= I
M-
= 0.3A; V
CC
=13.5V
0.6
1.5
I
M+
= I
M-
= 0.3A; V
CC
=7V
1
2.6
R
ON_L
Low Side RDS
I
M+
= I
M-
= 0.3A; V
CC
=13.5V
0.6
1.5
I
M+
= I
M-
= 0.3A; V
CC
=7V
1
2.6
I
LIM
Output Current Limit for each
of 4 Output Transistors
Separately
1
1.9
A
T
R
Output Rise Time
20% to 80%
20
s
T
F
Output Fall Time
80% to20%
20
s
V
MTRAN
|V(M+) - V(M-)| Output Voltage
During V
CC
Transients
Transients of figs.4 and 5
20
V
T
HSHDN
Thermal Shutdown
170
C
V
OUT
Vcc
Vcc
V
OUT
Verr
=10
-Vcc
-Vcc
V
STR
=
1.5% Vcc
V
STP
Vcc-V
STP
10
Verr
-V
STP
V
STR
=
-1.5% Vcc
Vcc-V
STP
10
Figure 1. Static Transfer Characteristic. Error
Voltage vs. Output Voltage
V
OUT
Vcc
100
V
OUT
Verr
=10
-100
-Vcc
1.5
Perr [%]
-V
STP
-1.5
V
STP
10 (1+ -------)
V
STP
Vcc
-10 (1+ -------)
V
STP
Vcc
Figure 2. Static Transfer Characteristic. Position
Error Voltage vs. Output Voltage
Perr = Verr/V
CC
L9909
4/9
Position Feedback.
As shown in Figs. 3 and 6, a positive error voltage
VERR = VCOM - VFBK drives the motor with a
positive M+ voltage with respect to M-. A correct
negative electro-mechanical feedback is estab-
lished when the motor, supplied with a positive
M+ voltage with respect to M-, drives the feed-
back potentiometerwiper to Vcc.
Rest Zone.
When the differential input voltage VERR crosses
the zero Volts threshold, as detected by the preci-
sion comparator COMP1, the motor is braked by
driving it with a zero Volts voltage.
As long as VERR is kept inside the Rest Zone,
ranging from -VSTR to +VSTR (see Figs. 1 and
2), no electrical stimulus is applied to the motor
terminals. When in the Rest Zone M+ and M- are
both driven to Vcc.
Running Zone.
When the input error voltage VERR goes out of
the Rest Zone (see Figs. 1 and
2) the motor
starts and the wiper voltage VFB of the feedback
potentiometer moves in the direction of the input
voltage VCOM, bringing the VERR voltage back
to zero.
When VERR becomes lower than (Vcc-VSTP)/10,
a proportional control activates. The motor volt-
age at M+ and M- lowers with a rate factor of 10
times VERR. This motor voltage is generated, ac-
cording to the motor direction, by connecting to
Vcc one motor terminal and by switching the op-
posite one with a PWM control.
When
approaching
the
target
position,
at
VERR=0, the motor jumps into the Rest Zone
from a residual VSTP supply voltage. This control
is suitable for motors that still run with the min.
VSTP=2.5V residual supply voltage in all condi-
tions, ensuring that the rest position is finally
reached. But at the same time the
max.
VSTP=3.5V should not make any motor run too
fast and stop far away from the set point for me-
chanical inertia, or even get out of the rest zone
possibly starting oscillations.
Time Out Counter.
The Time Out is performed by a 14 Bit Counter
that counts 16384 Tosc periods. When the input
error voltage VERR goes out of the Rest Zone the
motor and the counter start. The motor stops at
the VERR zero crossing or when the Counter
times out, whichever comes first.
Direction Control.
The motor can be driven in both direction and
stopped by the timer as shown in Fig. 7.
The bias voltage at VFB input sets the threshold
voltage for the direction control input pin (DIR).
VFB and VCOM inputs may be swapped causing
the motor to reverse directions.
M
-
-
+
+
M+
M-
VFB
VCOM
U709
Vcc
GND
Vcc
V
ERR
V
OUT
I
COM
I
FB
Figure 3. L9909 Simplified Application Diagram
Vs = 60V
Source resistance = 0.5
1ms < tr < 10ms
T = 400ms
t1 = 10s
Time
Vcc
Vs
10%
90%
tr
T
Figure 4. Load Dump Transient
Vs = 100V
Source resistance = 10
tr = 1
s
T = 200
s to 500
s
t1 = 200ms to 500ms
Time
Vcc
Vs
10%
90%
tr
T
t1
Figure 5. Inductive Switching Transient - Positive
L9909
5/9
Over Current Protection.
The driver output pins (M+ and M-) are over cur-
rent protected by 4 separate linear current limit-
ers, one for each of the 4 power output transis-
tors. The output drivers resume normal operation
as soon as the over current is removed.
Motor Over Voltage Protection.
The motor is over voltage protected by switching
off (to Hi-Z) the M+ and M- output drivers, when
Vcc rises above the 19V typ. over voltage shut
down threshold.
Over Temperature Protection.
The chip is over temperature protected by switch-
ing off (to Hi-Z) the M+ and M- output drivers.
Power Supply Transient Protections.
The device provides over voltage suppression for
fast Vcc voltage transients (Fig. 5). The Vcc is
clamped at typ. 70V by turning on all four, bridge
connected, power output transistors. They are
roughly subjected to equal currents and voltages
for even transient energy distribution.
The over voltage suppression is deactivated for
slow Vcc voltage transients (Fig. 4) by raising the
Vcc voltage clamp at typ. 80V.
M
M+
M-
-
-
+
+
OSCILLATOR
U709
R osc
27K
Cosc
10nF
1nF
1nF
GND
COSC
ROSC
VCOM
VFB
1K
1K
EMI
Protection
Networ k
100nF
DC
MOTOR
COMMAND
POTENTIOMETER
VCC
Reverse Battery
Protection Diode
GROUND
POWER
FEEDBACK
POTENTIOMETER
100nF
1nF
V
ERR
Figure 6. Recommended Application Diagram for Positive Control
M
M+
M-
-
-
+
+
OSCILLATOR
U709
Rosc
27K
Cosc
10nF
1nF
1nF
GND
COSC
ROSC
VCOM
VFB
10K
20K
EMI
Protection
Capacitors
100nF
DC
MOTOR
VCC
Reverse Battery
Protection Diode
GROUND
POWER
100nF
1nF
DIR
20K
Protection
Resistor
DIR
Threshold
Voltage
Figure 7. Recommended Application Diagram for Direction Control
L9909
6/9
The following is the discriminating algorithm be-
tween fast and slow Vcc transients. The transient
voltage clamp is normally set at 70V. If Vcc rises
above the Vcc_ov=19V typ. over voltage shut-
down threshold, both Td_ov_1 and Td_ov_2 tim-
ers start. When the first timer stops (after 130
s
typ. delay) the clamp status is evaluated and
locked. If the transient has been fast enough and
the voltage clamp activated, then it remains 70V
active until the second timer stops (after 1ms de-
lay), then it deactivates by rising to 80V. If the
transient has been slow and the voltage clamp
unreached when the first timer stops, then
it de-
activates by rising to 80V. A new 70V clamp cycle
may restart only by lowering Vcc below the 19V
over voltage shutdown threshold.
The VFB and VCOM input pins may connect to
the Vcc or lower voltage during the power supply
transients of Figs. 4 and 5.
L9909
7/9
OUTLINE AND
MECHANICAL DATA
DIM.
mm
inch
MIN.
TYP.
MAX.
MIN.
TYP.
MAX.
A
3.32
0.131
a1
0.51
0.020
B
1.15
1.65
0.045
0.065
b
0.356
0.55
0.014
0.022
b1
0.204
0.304
0.008
0.012
D
10.92
0.430
E
7.95
9.75
0.313
0.384
e
2.54
0.100
e3
7.62
0.300
e4
7.62
0.300
F
6.6
0.260
I
5.08
0.200
L
3.18
3.81
0.125
0.150
Z
1.52
0.060
Minidip
L9909
8/9
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are
subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics
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L9909
9/9
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