L6234
THREE PHASE MOTOR DRIVER
SUPPLY VOLTAGE FROM 7 TO 52V
5A PEAK CURRENT
R
DS ON
0.3
TYP. VALUE AT 25
C
CROSS CONDUCTION PROTECTION
TTL COMPATIBLE DRIVER
OPERATING FREQUENCY TO 50KHz
THERMAL SHUTDOWN
INTRINSIC FAST FREE WHEELING DIODES
INPUT
AND
ENABLE
FUNCTION
FOR
EVERY HALF BRIDGE
10V EXTERNAL REFERENCE AVAILABLE
DESCRIPTION
The L6234 is a triple half bridge to drive a
brushless motor.
It is realized in Multipower BCD technology which
combines isolated DMOS power transistors with
CMOS and Bipolar circuits on the same chip.
By using mixed technology it has been possible to
optimize the logic circuitry and the power stage to
achieve the best possible performance.
The output DMOS transistors can sustain a very
high current due to the fact that the DMOS struc-
ture is not affected by the second breakdown ef-
fect, the RMS maximum current is practically lim-
ited by the dissipation capability of the package.
All the logic inputs are TTL, CMOS and
P com-
patible. Each channel is controlled by two sepa-
rate logic input.
L6234 is available in 20 pin POWER DIP package
(16+2+2) and in PowerSO20.
March 1998
PIN CONNECTION (Top view)
ORDERING NUMBERS: L6234 (POWER DIP 16+2+2)
L6234PD (PowerSO20)
PowerSO20
POWER DIP (16+2+2)
OUT1
IN1
EN1
V
S
GND
V
S
GND
EN3
IN3
1
3
2
4
5
6
7
8
9
VCP
VBOOT
SENSE2
GND
GND
SENSE1
EN2
IN2
OUT2
20
19
18
17
16
14
15
13
12
D98IN848
OUT3
10
VREF
11
POWER DIP (16+2+2)
GND
SENSE1
EN2
IN2
OUT2
IN1
OUT1
EN1
V
S
V
S
EN3
IN3
V
REF
OUT3
V
cp
V
BOOT
SENSE2
GND
1
3
2
4
5
6
7
8
9
18
17
16
15
14
12
13
11
19
10
20
GND
GND
D94IN129A
PowerSO20
1/10
CHARGE
PUMP
V
REF
=
10V
10nF
1
F
VREF
VCP
0.22
F
Vs 7
to 52V
0.1
F
100
F
THERMAL
PROTECTION
TH1
TL1
TH2
TL2
TH3
TL3
VBOOT
1N4148
OUT1
OUT2
SENSE1
OUT3
SENSE2
IN1
EN1
IN2
EN2
IN3
EN3
D95IN309A
R
SENSE
GND
BLOCK DIAGRAM
L6234
2/10
THERMAL DATA
Symbol
Parameter
DIP16+2+2
PowerSO20
Unit
R
th j-pin
Thermal Resistance, Junction to Pin
12
C/W
R
th j-amb1
Thermal Resistance, Junction to Ambient
(see Thermal Characteristics)
40
C/W
R
th j-amb2
Thermal Resistance, Junction to Ambient (see Thermal
Characteristics)
50
C/W
R
th j-case
Thermal Resistance Junction-case
1.5
C/W
Figure 1: Printed Heatsink
THERMAL CHARACTERISTICS
R
th j-pins
DIP16+2+2. The thermal resistance is referred to
the thermal path from the dissipating region on
the top surface of the silicon chip, to the points
along the four central pins of the package, at a
distance of 1.5 mm away from the stand-offs.
R
th j-amb1
If a dissipating surface, thick at least 35
m, and
with a surface similar or bigger than the one
shown, is created making use of the printed cir-
cuit.
Such heatsinking surface is considered on the
bottom side of an horizontal PCB (worst case).
R
th j-amb2
If the power dissipating pins (the four central
ones), as well as the others, have a minimum
thermal connection with the external world (very
thin strips only) so that the dissipation takes place
through still air and through the PCB itself.
It is the same situation of point above, without any
heatsinking surface created on purpose on the
board.
Additional data on the PowerDip and the
PowerSO20 package can be found in:
Application Note AN467:
Thermal Characteristics of the PowerDip
20,24 Packages Soldered on 1,2,3 oz.
Copper PCB
Application Note AN668:
A New High Power IC Surface Mount Package:
PowerSO20 Power IC Packaging from Insertion
to Surface Mounting.
L6234
3/10
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
S
Power Supply Voltage
52
V
V
IN
,V
EN
Input Enable Voltage
0.3 to 7
V
I
peak
Pulsed Output Current (note 1)
5
A
V
SENSE
Sensing Voltage (DC Voltage)
-1 to 4
V
V
b
Bootstrap Peak Voltage
62
V
V
OD
Differential Output Voltage (between any of the 3 OUT pins)
60
V
f
C
Commutation Frequency
50
KHz
V
REF
Reference Voltage
12
V
P
tot
Total Power Dissipation
L6234PD T
amb
= 70
C
2.3
W
P
tot
Total Power Dissipation
L6234 T
amb
= 70
C
1.6 (*)
W
T
stg
, T
j
Storage and Junction Temperature Range
-40 to 150
C
Note 1: Pulse width limited only by junction temperature and the transient thermal impedance
(*) Mounted on board with minimized copper area
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Value
Unit
V
S
Supply Voltage
7 to 42
V
V
OD
Peak to Peak Differential Voltage (between any of the 3 OUT
pins)
52
V
I
out
DC Output Current Power SO20 (T
amb
= 25
C)
4
A
DC Output Current Power DIP (T
amb
= 25
C) with infinite heatsink
2.8
A
V
SENSE
Sensing Voltage (pulsed t
w
< 300nsec)
-4 to 4
V
Sensing Voltage (DC)
-1 to 1
V
T
j
Junction Temperature Range
-40 to 125
C
PIN FUNCTIONS
Powerdip
PowerSO20
Name
Function
1
20
10
6
5
15
OUT 1
OUT 2
OUT 3
Output of the channels 1/2/3.
2
19
9
7
4
14
IN 1
IN 2
IN 3
Logic input of channels 1/2/3. A logic HIGH level (when the corresponding
EN pin is HIGH) switches ON the upper DMOS Power Transistor, while a
logic LOW switches ON the corresponding low side DMOS Power.
3
18
8
8
3
13
EN 1
EN 2
EN 3
Enable of the channels 1/2/3. A logic LOW level on this pin switches off both
power DMOS of the related channel.
4,7
9, 12
V
s
Power Supply Voltage.
14
19
SENSE2
A resistance Rsense connected to this pin provides feedback for motor
current control for the bridge 3.
17
2
SENSE1
A resistance Rsense connected to this pin provides feedback for motor
current control for the bridges 1 and 2.
11
16
V
ref
Internal Voltage Reference. A capacitor connected from this pin to GND
increases the stability of the Power DMOS drive circuit.
12
17
V
cp
Bootstrap Oscillator. Oscillator output for the external charge pump.
13
18
V
BOOT
Overvoltage input to drive the upper DMOS
5,6
15,16
1,10
11,20
GND
Common Ground Terminal. In Powerdip and SO packages these pins are
used to dissipate the heat forward the PCB.
L6234
4/10
ELECTRICAL CHARACTERISTICS (V
s
= 42V ; T
j
= 25
C unless otherwise specified)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
V
S
Supply Voltage
7
52
V
V
ref
Reference Voltage
10
V
I
S
Quiescent Supply Current
6.5
mA
T
S
Thermal Shutdown
150
C
T
D
Dead Time Protection
300
ns
OUTPUT DMOS TRANSISTOR
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
I
DSS
Leakage Current
1
mA
R
DS (ON)
ON Resistance
0.3
SOURCE DRAIN DIODE
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
V
SD
Forward ON Voltage
I
SD
= 4A; EN = LOW
1.2
V
T
RR
Reverse Recovery Time
I
F
= 4A
900
ns
T
pr
Forward Recovery Time
200
ns
LOGIC LEVELS
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
V
INL
, V
ENL
Input LOW Voltage
-0.3
0.8
V
V
INH
, V
ENH
Input HIGH Voltage
2
7
V
I
INL,
I
ENL
Input LOW Current
V
IN
,V
EN
= L
-10
A
I
INH,
I
ENH
Input HIGH Current
VIN,V
EN
= H
30
A
CIRCUIT DESCRIPTION
L6234 is a triple half bridge designed to drive
brushless DC motors.
Each half bridge has 2 power DMOS transistors
with R
ds
ON = 0.3
.
The 3 half bridges can be
controlled independentlyby means of the 3 inputs
IN1, IN2, IN3 and the 3 inputs EN1, EN2, and
EN3. An external connection to the 3 common
low side DMOS sources is provided to connect a
sensing resistor for constant current chopping ap-
plication.
The driving stage and the logic stage are de-
signed to work from 7V to 52V.
L6234
5/10
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