ST L6235 User Manual

THREE-PHASE BRUSHLESS DC MOTOR

■

OPERATING SUPPLY VOLTAGE FROM 8 TO 52V

■ 5.6A OUTPUT PEAK CURRENT (2.8A DC)

■ R

■ OPERATING FREQUENCY UP TO 100KHz

■ NON DISSIPATIVE OVERCURRENT

DETECTION AND PROTECTION

■ DIAGNOSTIC OUTPUT

■

CONSTAN T t

■ SLOW DECAY SYNCHR. RECTIFICATION

■ 60° & 120° HALL EFFECT DECODING LOGIC

■ BRAKE FUNCTION

■ TACHO OUTPUT FOR SPEED LOOP

■ CROSS CONDUCTION PROTECTION

■ THERMAL SHUTDOWN

■ UNDERVOLTAGE LOCKOUT

■ INTEGRATED FAS T FREEWEELING DIO DES

DESCRIPTION

The L6235 is a DMOS Fully Integrated Three-Phase
Motor Driver with Overcurrent Protection.

Realized in MultiPower-BCD technology, the device

0.3Ω TYP. VA LUE @ Tj = 25 °C

DS(ON)

PWM CURRENT CONTROLLER

OFF

L6235

DMOS DRIVER FOR

PowerDIP24

(20+2+2)

L6235N L6235PD L6235D

combines isolated DMOS Power Transistors with
CMOS and bipolar circuits on the same chip.

The device includes all the circuitry needed to drive a
three-phase BLDC motor including: a three-phase
DMOS Bridge, a constant off time PWM Current Con­troller and the decoding logic for single ended hall
sensors that generates the required s equence for the
power stage.

Available in PowerDIP24 (20+2+2), PowerSO36 and
SO24 (20+2+2) packages, the L6235 features a non­dissipative overcurrent protection on the high side
Power MOSFETs and thermal shutdown.

PowerSO36

ORDERING NUMBERS:

SO24

(20+2+2)

BLOCK DIAGRAM

September 2003

VBOOT V

VCP

DIAG

EN

BRAKE

FWD/REV

H

3

H

2

H

1

RCPULSE

TACHO

BOOT

CHARGE

PUMP

TACHO

MONOSTABLE

10V 5V

VOLTAGE

REGULATOR

PROTECTION

OCD

HALL-EFFECT

SENSORS

DECODING

LOGIC

THERMAL

OCD1
OCD2

OCD

OCD3

ONE SHOT

MONOSTABLE

GATE

LOGIC

PWM

MASKING

TIME

V

BOOT

OCD1

10V

V

BOOT

OCD2

10V

V

BOOT

OCD3

10V

COMPARATOR

SENSE

VS

A

OUT

1

OUT

2

SENSE

A

VS

B

OUT

3

SENSE

B

+

-

VREF

RCOFF

D99IN1095B

1/25

L6235

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Test conditions Value Unit

V

V

OD

V

BOOT

VIN, V

V

REF

V

RCOFF

V

RCPULSE

V

SENSE

I

S(peak)

I

S

, T

T

stg

Supply Voltage VSA = VSB = V

S

Differential Voltage between:

, OUT1, OUT2, SENSEA

VS

A

and VSB, OUT3, SENSE

B

VSA = VSB = VS = 60V;
V

SENSEA

Bootstrap Peak Voltage VSA = VSB = V
Logic Inputs Voltage Range -0.3 to 7 V

EN

= V

S

SENSEB

S

= GND

60 V
60 V

VS + 10 V

Voltage Range at pin VREF -0.3 to 7 V
Voltage Range at pin RCOFF -0.3 to 7 V
Voltage Range at pin RCPULSE -0.3 to 7 V
Voltage Range at pins SENSEA

and SENSE

B

Pulsed Supply Current (for each

and VSB pin)

VS

A

DC Supply Current (for each

and VSB pin)

VS

A

Storage and Operating

OP

V

= VSB = VS; T

SA

V

= VSB = V

SA

S

< 1ms 7.1 A

PULSE

-1 to 4 V

2.8 A

-40 to 150 °C

Temperature Range

RECOMMENDED OPERATING CONDITION

Symbol Parameter Test Conditions MIN MAX Unit

V

V

V

V

SENSE

I

OUT

T

f

SW

OD

REF

Supply Voltage VSA = VSB = V

S

Differential Voltage between:

, OUT1, OUT2, SENSEA and

VS

A

VS

, OUT3, SENSE

B

B

VSA = VSB = VS;
V

SENSEA

= V

SENSEB

S

12 52 V

Voltage Range at pin VREF -0.1 5 V
Voltage Range at pins SENSEA

and SENSE

B

DC Output Current VSA = VSB = V
Operating Junction Temperature -25 125 °C

J

(pulsed tW < trr)
(DC)

-6

-1

S

Switching Frequency 100 KHz

52 V

6
1

2.8 A

V
V

2/25

THERMA L D ATA

Symbol Description PDIP24 SO24

PowerSO36

L6235

Unit

R

th(j-pins)

R

th(j-case)

R

th(j-amb)1

R

th(j-amb)1

R

th(j-amb)1

R

th(j-amb)2

Maximum Thermal Resistance Junction-Pins 18 14 °C/W
Maximum Thermal Resistance Junction-Case 1 °C/W

MaximumThermal Resistance Junction-Ambient
Maximum Thermal Resistance Junction-Ambient
MaximumThermal Resistance Junction-Ambient
Maximum Thermal Resistance Junction-Ambient

(1)

(2)

(3)

(4)

43 51 - °C/W

--35°C/W

--15°C/W

58 77 62 °C/W

(1) Mount ed on a multi-l ayer FR4 PCB wi t h a di ssipating copper sur face on the bottom side of 6 c m2 (with a thickness of 35 µm) .
(2) Mount ed on a multi-l ayer FR4 PCB wi t h a di ssipating copper sur face on the top side of 6 cm2 (with a thi ck ness of 35 µm) .
(3) Mounted on a multi-layer F R4 PCB with a di ssipating copper sur face on the top s id e of 6 cm2 (with a thi ck ness of 35 µm),

16 via holes and a ground layer.

(4) Mounted on a mult i- l ayer FR4 PCB wi t h out any heat-sinking surface on the board.

PIN CONNECTIONS (Top view)

H

DIAG

SENSE

RCOFF

OUT

GND
GND

TACHO

RCPULSE

SENSE

FWD/REV

EN

1

1

2
3

A

4
5

1

6
7
8
9
10

B

11
12

D01IN1194A

PowerDIP24/SO24

GND

N.C.

H

24

3

H

23

2

VCP

22

OUT

21
20

VS

2

A

N.C.

VS

OUT

N.C.
VCP

GND19
GND

18
17

VS
16
15
14
13

B

OUT

3

VBOOT

BRAKE

VREF

DIAG

SENSE

RCOFF

N.C.

OUT

N.C.
N.C.

GND

2
3
4

A

5

2

7

H

8

2

H

3

H

10

1

11
12

A

13
14
15

1

16
17
18

D01IN1195A

PowerSO36

36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19

(5)

GND1
N.C.
N.C.
VS

B

OUT

3

N.C.6
VBOOT
BRAKE
VREF9
EN
FWD/REV
SENSE

B

RCPULSE
N.C.
TACHO
N.C.
N.C.
GND

(5) The slug is internal l y connected to pins 1, 18, 19 and 36 (GND pi ns).

3/25

L6235

PIN DESCRIPTION

P ACKAGE

SO24/

PowerDIP24

PowerSO36

PIN # PIN #

110H
2 11 DIAG Open Drain

3 12 SENSE

4 13 RCOFF RC Pin RC Network Pin. A parallel RC network connected

5 15 OUT

6, 7,

18, 19

1, 18,

19, 36

8 22 TACHO Open Drain

9 24 RCPULSE RC Pin RC Network Pin. A parallel RC network connected

10 25 SENSE

11 26 FWD/REV Logic Input Selects the direction of the rotation . HIGH logic level

12 27 EN Lo gic Input Chip Enable. LOW log ic level switches OFF a ll Power

13 28 VREF Logic Input Current Controller Reference Voltage.

14 29 BRAKE Logic Input Brake Input pin. LOW logic level switches ON all High

15 30 VBOOT Supply Voltage Bootstrap Voltage needed for driving the u pper Power

16 32 OUT
17 33 VS

Name Type Function

1

Sensor Input Single Ended Hall Effect Sensor Input 1.

Overcurrent Detect ion an d The r mal P rotec tion p in. An

Output

internal open drain transistor pulls to GND when an
overcurrent on one of the High Side MOSFETs is
detected or during Thermal Protection.

Power Supply Half Bridge 1 and Half Bridge 2 Source Pin. This pin

A

must be connected together with pin SENSE
Power Ground through a sensing power resistor.

between this pin and ground sets the Current
Controller OFF-Time.

Power Output Output 1

1

GND GND Ground terminals. On PowerDIP24 and SO24

packages, these pins are also used for heat
dissipation toward the PCB. On PowerSO36 package
the slug is connected on these pins.

Frequency-to-Voltage open drain output. E very pulse

Output

from pin H

is shaped as a fixed and adjustable length

1

pulse.

between this p in and ground sets th e duration of the
Monostable Pulse used for the Frequency-to-Voltage
converter.

Power Supply Half Bridge 3 S ource Pin. This pin mu st be conn ected

B

together with p in SEN SE

to Power Ground through a

A

sensing power resistor. At this pin also the Inverting
Input of the Sense Comparator is connected.

sets Forward Operation, whereas LOW logic level sets
Reverse Operation.
If not used, it has to be connected to GND or +5V..

MOSFETs.
If not used, it has to be connected to +5V.

Do not leave this pin open or connect to GND.

Side Power MOSFETs, implementing the Brake
Function.
If not used, it has to be connected to +5V.

MOSFETs.

Power Output Output 3.

3

Power Supply Half Bridge 3 Power Supply Voltage. It must be

B

connected to the supply voltage together with pin VS

B

to

.

A

4/25

L6235

PIN DESCRIPTION

(continued)

PACKAGE

SO24/

PowerDIP24

PowerSO36

Name Type Function

PIN # PIN #

20 4 VS

Power Supply Half Bridge 1 and Half Bridge 2 Power Supply Voltage.

A

It must be connected to the supply voltage together

.

B

21 5 OUT

Power Output Output 2.

2

with pin VS

22 7 VCP Output Charge Pump Oscillator Output.
23 8 H
24 9 H

2
3

Sensor Input Single Ended Hall Effect Sensor Input 2.
Sensor Input Single Ended Hall Effect Sensor Input 3.

ELECTRICAL CHARACTERISTICS

(VS = 48V , T

Symbol Parameter Test Conditions Min Typ Max Unit

V

Sth(ON)

V

Sth(OFF)

I

S

T

J(OFF)

Output DMOS Transistors

R

DS(ON)

I

DSS

Source Drain Diodes

V

SD

t

rr

t

fr

Logic Input (H1, H2, H3, EN, FWD/REV, BRAKE)

V

IL

V

IH

I

IL

I

IH

V

th(ON)

V

th(OFF)

V

thHYS

= 25 °C , unless otherwise specified)

amb

Turn ON threshold 6.6 7 7.4 V
Turn OFF threshold 5.6 6 6.4 V
Quiescent Supply Current All Bridges OFF;

Tj = -25 to 125°C

(6)

510mA

Thermal Shutdown Temperature 165 °C

High-Side Switch ON Resistance Tj = 25 °C 0.34 0.4 Ω

(6)

(6)

Low-Side Switch ON Resistance T

=125 °C

T

j

= 25 °C 0.28 0.34 Ω

j

=125 °C

T

j

Leakage Current EN = Low; OUT = V

CC

0.53 0.59 Ω

0.47 0.53 Ω
2mA

EN = Low; OUT = GND -0.15 mA

Forward ON Voltage ISD = 2.8A, EN = LOW 1.15 1.3 V
Reverse Recovery Time If = 2.8A 300 ns
Forward Recovery Time 200 ns

Low level logic input voltage -0.3 0.8 V
High level logic input voltage 2 7 V
Low level logic input current GND Logic Input Voltage -10 µA
High level logic input current 7V Logic Input Voltage 10 µA
Turn-ON Input Threshold 1.8 2.0 V
Turn-OFF Input Threshold 0.8 1.3 V
Input Thresholds Hysteresy s 0.25 0.5 V

5/25

L6235

ELECTRICAL CHARACTERISTICS

(V

= 48V , T

S

= 25 °C , unless otherwise specified)

amb

(continued)

Symbol Parameter Test Conditions Min Typ Max Unit

Switching Characteristics

(7)

I

t

D(on)EN

t

D(off)EN

t

D(on)IN

Enable to out turn-ON delay time
Enable to out turn-OFF delay time

Other Logic Inputs to Output Turn-

(7

)

= 2.8 A, Resistive Load 110 250 400 ns

LOAD

I

= 2.8 A, Resistive Load 300 550 800 ns

LOAD

I

= 2.8 A, Resistive Load 2 µs

LOAD

ON delay Time

t

D(off)IN

Other Logic Inputs to out Turn-OFF

I

= 2.8 A, Resistive Load 2 µs

LOAD

delay Time

(7)

(7)

I

= 2.8 A, Resistive Load 40 250 ns

LOAD

I

= 2.8 A, Resistive Load 40 250 ns

LOAD

Tj = -25 to 125°C

(6)

0.6 1 MHz

t

RISE

t

FALL

t

DT

f

CP

Output Rise Time
Output Fall Time

Dead Time 0.5 1 µs
Charge Pump Frequency

PWM Comparator and Monostable

I

RCOFF

V

OFFSET

Source current at pin RC
Offset Voltage on Sense

V

OFF

V

= 2.5 V 3.5 5.5 mA

RCOFF

= 0.5 V ±5 mV

ref

Comparator

t

prop

t

blank

Turn OFF Propagation delay
Internal Blanking Time on Sense

(8)

V

= 0.5 V 500 ns

ref

1µs

Comparator

t

ON(min)

t

I

BIAS

Minimum on Time
PWM Recirculatio nTim e R

OFF

OFF

R

OFF

= 20kΩ ; C
= 100kΩ ; C

OFF

OFF

=1nF

=1nF

1.5 2 µs
13
61

Input Bias Current at pin VREF 10 µA

Tacho Monostable

I

RCPULSE

t

PULSE

R

TACHO

Source Current at pin RCPULSE V
Monostable of Time R

RCPULSE

PUL

R

PUL

Open Drain ON Resistance 40 60 Ω

= 2.5V 3.5 5.5 mA
= 20kΩ ; C
= 100kΩ ; C

PUL

PUL

=1nF

=1nF

12
60

Over Current Detection & Protection

I

SOVER

R

OPDR

t

OCD(ON)

t

OCD(OFF)

(6) Teste d at 2 5°C in a restricted range and guaranteed by ch aracterization.
(7) See Fig. 1.

(8) Measured applying a voltage of 1V to pin SEN S E and a voltage drop from 2V t o 0V to pin VREF.

(9) See Fig. 2.

Supply Overcurrent Protection
Threshold

Open Drain ON Resistance I
OCD high level leakage current V

I

OH

OCD Turn-ON Delay Time
OCD Turn-OFF Delay Time

(9)

(9)

= -25 to 125°C

T

J

= 4mA 40 60 Ω

DIAG

= 5V 1 µA

DIAG

I

= 4mA; C

DIAG

I

= 4mA; C

DIAG

(6)

< 100pF 200 ns

DIAG

< 100pF 100 ns

DIAG

4.0 5.6 7.1 A

µs
µs

µs
µs

6/25

Figure 1. Switching Characteristic Definition

EN

V

th(ON)

V

th(OFF)

I

OUT

90%

10%

D01IN1316

t

D(OFF)EN

t

FALL

Figure 2. Ove rcurrent Detect i on Timi ng Definition

I

OUT

I

SOVER

t

D(ON)EN

t

RISE

L6235

t

t

ON

BRIDGE

OFF

V

DIAG

90%

10%

t

OCD(ON)

t

OCD(OFF)

D02IN1387

7/25

L6235

8

CIRCUIT DESCRIPTION

POWER STAGES and CHARGE PUMP

The L6235 integrates a Three-Phase Bridge, which
consists of 6 Power MOSFETs connected as shown
on the Block Diagram. Each Power MOS has an
R

= 0.3Ω (typical value @25°C) with intrinsic

DS(ON)

fast freewheeling diode. Switching patterns are gen­erated by the PWM Current Controller and the Hall
Effect Sensor Decoding Logic (see relative para­graphs). Cross conduc tion protec tion is impl emented
by using a dead time (t

= 1µs typical value) set by

DT

internal timing circuit between the turn off and turn on
of two Power MOSFETs in one leg of a bridge.

Pins VS
the supply voltage (V

and VSB MUST be connected together to

A

).

S

Using N-Channel Power MOS for the upper transis­tors in the bridge requires a gate drive voltage above
the power supply voltage. The Bootstrapped Supply
(V

) is obtained through an internal osci llator and

BOOT

few external components to realize a charge pump
circuit as shown in Figure 3. The oscillator output (pin
VCP) is a squar e wave at 600K Hz (typi cally) wi th 10V
amplitude. Recommended values/part numbers for
the charge pump circuit are shown in Table1.

LOGIC INPUTS

Pins FWD/REV, BRAKE, EN, H1, H2 and H3 are TTL/
CMOS and µC compatible logic inputs. The internal
structure is shown in Figure 4. Typical value for turn­ON and turn-OFF thresholds are respectively V
= 1.8V and V

th(OFF)

= 1.3V.

th(ON )

Pin EN (enable) may be used to implement Overc urrent
and Thermal protection by connect ing it to t he open col­lector DIAG output If the protecti on and an exter nal dis­able function are both desired, the appropriate
connection must be implemented. When the external
signal is from an open col lect or output, the circui t in Fig­ure 5 can be used . For external circuits that are push
pull outp uts t he circui t in Figur e 6 coul d be us ed. The re­sistor R
180K
spectively 100K

should be chosen in the rang e from 2.2KΩ to

EN

Ω

. Recommended values for REN and CEN are re-

Ω

and 5.6nF. More information for se­lecting the values can be found in the Overcurrent
Protection section.

Figure 4. Logi c Inp ut Int ernal Structu re

5V

Table 1. Charge Pump External Component
Values.

C
C
R
D
D

BOOT
P
P
1
2

220nF
10nF
100Ω
1N4148
1N4148

Figure 3. Char ge Pump Circu it

V

S

D1

D2

R

P

C

P

VCP VBOOT VS

C

BOOT

VS

B

D01IN1328

A

ESD

PROTECTION

D01IN1329

Figure 5. Pin EN Open Collector Driving

DIAG

5V

EN

EN

ESD

PROTECTION

OPEN

COLLECTOR

OUTPUT

5V

R

EN

C

Figure 6. Pin EN Push-Pull Driving

DIAG

5V

R

PUSH-PULL

OUTPUT

EN

C

EN

EN

ESD

PROTECTION

D02IN137

D02IN1379

8/25