Datasheet L9925 Datasheet (SGS Thomson Microelectronics)



DMOS DUAL FULL BRIDGEDRIVER

2 INDEPENDENTLYCONTROLLED
H-BRIDGES

DS,ON

R

<0.9Ω @T

0.8ADC CURRENTWITHOUT HEATSINK
LOW QUIESCENTMODEI
THEMALPROTECTION
CROSSCONDUCTIONPROTECTION
SUPPLYVOLTAGEUP TO 40V
CMOSCOMPATIBLEINPUTS
OUTPUTSHORT-CIRCUIT PROTECTION

amb

=25°C,VS= 14V

q <200µA

L9925

SO28

DESCRIPTION

The L9925 is a dual full bridge driver for stepper
motor applications. Realized in BCD (Bipolar,
CMOS & DOS) techology, logic circuits, precise
linear blocks and power transistors are combined
to optimize circuit performance and minimize off
chip components.Schmitttriggers are used for all
input stages and are fully compatible with 5V
CMOS logic levels. When both enable signalsare
low, the IC is commanded to a low quiescentcur­rent state and will draw less than 200µA from the
battery.

BLOCK DIAGRAM

OUT1 VS1 OUT2

CHARGE

PUMP

IN1

EN1

7V T1

1st FULLBRIDGE

EN1

T1T2T2

ORDERING NUMBER: L9925

The charge pump is integrated on chip; no exter­nal componentsare required. Full performanceis
maintaned for 9V <V
6V <<V

S <9V and 16V <VS <40V yields full func-

S <16V. Extended ranges of

tionally but with relaxed performance. Over tem­perature protectionand ESD protectionto all pins
ensures relability and reduces system integration
failures.

CHARGE

PUMP

IN2

TEMP

EN1

EN1

7V7V

PGND1

GND

EN2

IN3

IN4

2nd FULLBRIDGE

T1 T2

5V

REGULATOR

40V

EN2

D99AT423

VS2

OUT3

OUT4

March 1999

...............................................................................................................................................................................................................

1/9

L9925

ABSOLUTEMAXIMUMRATINGS

Absolute Maximum Ratings are those values beyond whih damage to the device may occur. Functional
operation underthese conditionisn’t implied.

For voltages andcurrents applied externallyto the device:

Symbol Parameter Value Unit

V

VSDC Dc Supply Voltage -0.3 to 26 V

V

VSP Supply Voltage Pulse (T ≤400ms)

I

OUT

I

OUT MAX

DC Output Load Current
DC Output Current:for VOUT > VVS +0.3V or VOUT < -0.3V

the internal DMOS reverse and/or substrate diode become
conductive and the applied current should not exceedthe
specified limit.

V

IN1,2

V

T

stg,Tj

P

EN

tot

DC Input Voltage -0.3 to 7 V
Enable Input Voltage -0.3 to 7 V
Storage and Junction Temperature -40 to 150 °C
Total Power Dissipation (T

(T

(T

(1) Device may be overstressed if pulsed simultaneous with short circuit at one or more of the outputs willbe present.

(1)

=80°C)

pins

=70°C no copper area on PCB)

amb
amb =70°C 8cm

2

copperareaon PCB)

40 V

1.2 A

±

1.8 A

±

5

1.23
2

W
W
W

PIN CONNECTION

PGND

IN1
EN1
N.C.
N.C.

OUT1

GND
GND

OUT3 VS2

N.C. N.C.
N.C.
EN2

IN3 IN4

2
3
4
5
6
7
8
9
10

12
13

D88AT424

28
27
26
25
24
23
22
21
20
19
18
17
16
1514PGND N.C.

N.C.1
IN2
OUT2
N.C.
N.C.
VS1
GND
GND

N.C.11
OUT4

THERMAL DATA

Symbol Parameter Value Unit

T

jTS

T

jTSH

R

th j-amb

R

th j-pins

(2)

With 6cm2on board heat sink area

Thermal Shut-downjunction temperature min. 150 °C
Thermal Shut-downthereshold hysteresis typ. 25 °C
Thermal Resistance Junction-ambient

(2)

50 °C/W

Thermal Resistance Junction-pins 15 °C/W

2/9

PIN FUNCTIONS

N. Name Function

1 PGND1 Ground for DMOS sources in bridge 1
2 IN1 Digital Input from motor controller for bridge 1
3 EN1 Logic enable/disable for bridge 1 (active high)

4, 5 NC No connect

6 OUT1 Output of one half of bridge1

7, 8 GND Ground

9 OUT3 Output of one half of bridge2

10, 11 NC No connect

12 EN2 Logic enable/disable for bridge 2 (active high)
13 IN3 Digital Input from motor controller for bridge 2
14 PGND2 Ground for DMOS sources in bridge 2
15 NC No connect
16 IN4 Digital Input from motor controller for bridge 2
17 OUT4 Output of one half of bridge 2

18, 19 NC No connect

20 VS2 Supply Voltage for bridge 2

21, 22 GND Ground

23 VS1 Supply Voltage for bridge 1

24, 25 NC No connect

26 OUT2 Output of one half of bridge 1
27 IN2 Digital Input from motor controller for bridge 1
28 NC No connect

L9925

ELECTRICALCHARACTERISTICS (VS = 9 to 16V; Tj =-40 to 150°C

(3)

, unlessotherwise specified.)

Symbol Parameter Test Condition Min. Typ. Max. Unit

T
T
T

I

R

d-on
d-SB
d-off

t

rise

t

fall

IL

S

ds

Quiescent Current EN1 = EN2 =0V; Tj=85°C 200

EN1 = EN2 =5V; I

= 0A 5 12 mA

load

Switch on Resistance Tj=25°C; VS= 14V; Io=300mA 0.75 0.8

= 125°C; VS= 6V; Io=300mA 1.5 1.9

T

j

Turn-on delay See Fig 1 10 50
Standby setting time See Fig 1 50 200
Turn-off delay See Fig 1 10 50
Output rise time (10 to 90%) See Fig 1 0.5 5 20
Output fall time (90to 10%) See Fig 1 0.5 5 20

o Output leakage current EN = 0V;Vo =VS or GND -10 10 mA

INx, ENx Logic Input Lowvoltage -0.3 1.5 V

Logic Input High voltage 3.5 6 V
Hysteresis 0.5 1.0 2.0 V

Ibias Input bias current -50 300 µA

The voltage referedto GND and currents are assumed positive, when the current flows into thepin.
(3) Tested up to 125°C, parameter guaranted by correlation up to150°C

A

µ

Ω
Ω

s

µ

s

µ

s

µ

s

µ

s

µ

3/9

L9925

Logic Levels

All inputs are positive,non invertinglogic

Logic State Voltage Range

0 -0.3 to 1.5V
1 3.5 to 6.0V

Truth Table

Enable/Disable

EN1 EN0 Bridge 1 Bridge 2 Iq

0 0 Disabled Disabled <200µA
0 1 Disabled Enabled <12mA
1 0 Enabled Disabled <12mA
1 1 Enabled Enabled <12mA

Figure 1. TimingDiagram

STANDBY MODE OPERATING MODE OVERTEMPERATURE STANDBY MODE

EN2

EN1

IN1

GeneralOperation

With the bridge enabled, each input INx, maps di­rectly to thecorrespondingoutput OUTx.

The output voltage will be equal to the difference
between the supply rail and the product of the
load current ad the on resistance of the output
switch.V

out =Vsupply -(RDS,ON ⋅ ILOAD).

Sourcedload currentsare positive.

IN1 OUT1 IN2 OUT2 IN3 OUT3 IN4 OUT4

00000000
1V

1VS1VS1VS

S

IN2

OUT1

OUT2

Tristate

Tristate

t

t

dSB

dON

50%

10%

t

dSB

t

r

t

r

t

dOFF

90%

t

f

t

dOFF

Figure 2. Typical RON - Characteristicsof Source

and Sink Stage

RON

(Ω)

2

1

-20 0 20 40 60 80 100 120 140 160 T(°C)

-40

V
V

D99AT426

VS
VS

=6V
=12V

t

dSB

t

f

Tristate

t

dON

Tristate

D99AT425

Tristate

Tristate

t

dSB

Figure3. ON - Resistance vs SupplyVoltage

RON

(Ω)

1.9

1.5

0.9

0.75

6

I

OUT1/2

=±0.3A

12 16.5 V

max for TJ≤125°C

typ. for T

=25°C

J

(V)

VS

D99AT427

4/9

Figure 4. ApplicationDiagram

L9925

CEN

100nF

D

0

+5V

D

0

I/O

µP

10KΩ

I/O
I/O

EN1

O

GND

O

EN2O

OOIN3

D

R

IN1

IN4

0

1 D

1st FULL BRIDGE

2nd FULL BRIDGE

CB

100nF

CB40V

100µF

EN1

T1T2T2

T1 T2

2

40V

7V T1

CHARGE

PUMP

REGULATOR

CEN

100nF

OUT1 VS1 OUT2

TEMP

5V

R

0

10KΩ

EN1

EN2

A

CHARGE

PUMP

STEPPER MOTOR

B

IN2

7V7V

EN1

PGND1

VS2

40V

OUT3

CEX

100nF

OUT4

CEX

PGND2

100nF

D99AT423

Figure 4 shows a typical application diagram for
DC motordriving. To assure the safety of the cir­cuit in the reverse battery conditiona reverse pro­tetion diode D
tection diode D
supply voltage V
V

BAT line will be limited to a value lower than the

absolute maximu ratings for V

B are used to lower VS-EMR and its values de-

C

1 is necessary. The transient pro-

2 must assure that themaximum

S during the transients at the

VSP. The capacities

pend on the driving load.
The resistance feedback loop realized by R

o lim-

ited to theµP power supply line by the diode D
allows open load detection. To protect the device
at the outputsagainst EMI or ESD> 2KV external
capacitorsC

ex maybe used.

CIRCUIT DESCRIPTION

L9925 is a dual full bridge IC designed to drive
DC motors, stepper motors and other inductive
loads. Eah bridge has 4 power DMOS transistor
with R

DSon = 0.75Ω and the relative protection

and control circuitry (see fig. 5). Tthe 4 half
bridges can be controlled independently by
means of the 4 inputs IN1, IN3, IN4 and 2 enable
inputs ENABLE1and ENABLE2.

LOGIC DRIVE(true table for the two full bridges)

INPUTS

IN1

IN2

IN3

IN4

EN1 =EN2 = H L

L

H

L

L

H

H

H

@Tj > 150°C X X All transistors turned OFF

o

EN1 =EN2 = L X X All transistorsturned OFF

OUTPUT

MOSFETS

Sink 1, Sink2
Sink1, Source2
Source1, Sink2
Source1, Source2

L = Low; H = High; X = Don’t care

CROSSCONDUCTION

The device guaranteesthe absenceof cross-con­duction by watching internal gate-source voltage
of the driving power DMOS.

TRANSISTOR OPERATION

ON STATE
When one of POWER DMOS transistors is ON it

can be consideredas a resistor R

DS(ON) = 0.75

at a junctiontemperatureof 25°C

Ω

5/9

L9925

In this conditionthe dissipated power is ginen by:

P

ON =RDS(ON) ⋅ IDS

2

The low RDS(ON) of the Multipower BCD process
can provide high currents with low power dissipa­tion.

OFF STATE
When one of the POWER DMOS transistor is

OFF the V
age and only the leakage currentI

DS voltage is equal to the supply volt-

DSSflows.

The power dissipation during this period is given
by:

P

OFF =VS ⋅IDSS

Figure 5a. Two phasechopping

EN

IN1

IN1 =
IN2 =
EN1 = H

H
L

D99AT429

IN2

TRANSITIONS
Like all MOS power transistors the DMOS

POWER transistors have an intrinsic diode be­tween their source and drain that can operate as
a fast freewheeling diode in switched mode appli­cations. During recirculation with the ENABLE in­put is low, the POWER MOS is OFF and the di­ode voltage it is clamped to its characteristics.
When the ENABLE input is low, the POWER
MOS is OFF and the diode carries all of the recir­culationcurrent. The power dissipatedin the tran­sitional times in the cycle depends upon the volt­age and current waveformsin theapplication.

trans =IDS(t)⋅ VDS(t)

P

EN

IN1

IN1 =
IN2 =
EN1 = H

L
H

D99AT430

IN2

Figure 5b. Onephase chopping

EN

IN1

IN1 =

H

IN2 =

L

EN1 = H

Figure 5c. Enable chopping

EN

IN1

IN1 =

H

IN2 =

L

EN1 = H

D99AT431

D99AT433

EN

IN2

IN1

IN1 =

H

IN2 =

H

EN1 = H

EN

IN2

IN1

IN1 =

X

IN2 =

X

EN1 = L

D99AT432

D99AT434

IN2

IN2

6/9

L9925

THERMAL PROTECTION

A thermalprotectioncircuit has been included that
will disable the device if the junction temperature
reaches 150°C. When the temperature has fallen
to a safe level the device restarts under the con­trol of the input and enable signals.

APPLICATIONINFORMATION

RECIRCULATION
During recirculationwith the ENALBE input high,

the voltage drop across the transistor is R

DS(ON).

for voltages less than 0.6V and is clamped at a
voltages depending on the characteristics of the
source-drain diode for greater voltages. Although
the deviceis protectedagainstcross conduction.

POWERDISSIPATION each bridge
In order to achieve the high performanceprovided

by the L9925 some attention must be paid t en­sure that it has an adequate PCB area to dissi­pate the heat. The forst stage of any thermal de­sign is to calculate the dissipated power in the
application, for this example the half step opera­tion shown in Fig. 6 is considered.

RISE TIMET

R

When an arm of the half bridge is turned on cur­rent begins to flow in the inductive load until the
maximum current I
The dissipatedenergy E

OFF/ON =[RDS(ON)

E

L is reached after a time TR,

OFF/ON.

2

I

L

⋅

2

T

R]

⋅

⋅

3

Figure 6.

commutationE
transistorsare ON E

COM. As two of the POWER DMOS

ON isgiven by:

2

ON =IL

E

⋅RDS(ON) ⋅ 2 ⋅ TON

In the commutationthe energy dissipatedis:

CON =VS ⋅IL ⋅TCOM ⋅ fSWITCH ⋅ TON

E

Where:
T

COM =CommunicationTimeandit isassumedthat:;

T

COM =trise =tfall

T

SWITCH=Chopperfrequency

FALL TIME T

F

≤20µ

s

For this example it is assumed that the energy
dissipated in this part of the cycle takes the same
form as that shown for therise time:

OFF/ON =[RDS(ON) ⋅ IL

E

2

⋅ TF] ⋅

2
3

QUIESCENTENERGY
The last contribution of the energy dissipation is

due to the quiescrent supply current and is given
by:

E

QUIESCENT =IQUIESCENT ⋅ VS ⋅ T

TOTALENERGY PER CYCLE

TOT =(2 ⋅EOFF/ON +EON +ECOM) bridge1+

E

+(2 ⋅E

OFF/ON +EON +ECOM) bridg2 +EQUIESCENT

T

switch

I

L

ON TIME T

TRT

ON

ON

T

T

OFF

F

D99AT435

During this time the energy dissipated is due to
the ON resistance of the transistors E

ON and the

The total power dissipationPDIS issimply:

E

tot

=

P

DIS

=Rise time

T

R

T

=ON time

ON

T

= Fall time

F

T

= OFF time

OFF

T

T =Period

T=T

R+TON +TF +TOFF

7/9

L9925

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 2.65 0.104

a1 0.1 0.3 0.004 0.012

b 0.35 0.49 0.014 0.019

b1 0.23 0.32 0.009 0.013

C 0.5 0.020

c1 45° (typ.)

D 17.7 18.1 0.697 0.713

E 10 10.65 0.394 0.419
e 1.27 0.050

e3 16.51 0.65

F 7.4 7.6 0.291 0.299
L 0.4 1.27 0.016 0.050
S8°(max.)

mm inch

OUTLINE AND

MECHANICAL DATA

SO28

8/9

L9925

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