Diodes ZXBM2003 User Manual

ZXBM2001
ZXBM2002 ZXBM2003

VARIABLE SPEED 2-PHASE FAN MOTOR CONTROLLER

DESCRIPTION

The ZXBM200x is a series of 2-phase, DC brushless motor pre-drivers with PWM
variable speed control suitable for fan and blower motors.

FEATURES

· Built in lock detect protection, rotational speed sensing and automatic recovery

· Built in Hall amplifier allows direct connection to Hall element

· PWM Speed control via

- External voltage

- Thermistor input

- External PWM source

· Speed (FG) pulse output – ZXBM2003

· Rotor lock output – ZXBM2002

· Combined Rotor Lock (RD) and Speed (FG) signal – ZXBM2001

· Up to 18V input voltage (60V with external regulator)

· MSOP10 package

APPLICATIONS

· Mainframe and Personal Computer Fans and Blowers

· Instrumentation Fans

· Central Heating Blowers

· Automotive climate control

ORDERING INFORMATION

DEVICE REEL SIZE TAPE WIDTH QUANTITY PER REEL

ZXBM200xX10TA 7” (180mm) 12mm 1,000
ZXBM200xX10TC 13” (330mm) 12mm 4,000

Example: ZXBM2001X10TA

DEVICE MARKING

ZXBM2001 or BM21
ZXBM2002 or BM22
ZXBM2003 or BM23

ISSUE 4 - OCTOBER 2004

1

SEMICONDUCTORS

ZXBM2001
ZXBM2002 ZXBM2003

Absolute maximum ratings

Parameter Symbol Limits Unit

Supply Voltage V
Input Current I
Power Dissipation 25°C P
Operating Temp. T
Storage Temp. T

Power Dissipation

1) Maximum allowable Power Dissipation, PD,
is shown plotted against Ambient Temperature,
T

, in the accompanying Power Derating Curve,

A

indicating the Safe Operating Area for the device.

CCmax

CCmax

Dmax

OPR

STG

-0.6 to 20 V
200 mA
500 mW

-40 to 85 ⬚C

-55 to 150 ⬚C

2)Power consumed by the device, P

, can be

T

calculated from the equation:

P

= PQ+ P

T

Ph

where PQis power dissipated under quiescent

current conditions, given by:
P

= VCCx I

Q

CC

where VCCis the application

device Supply Voltage

and I

is the maximum Supply

CC

Current given in the Electrical
Characteristics

and P

is power generated due to either one of

Ph

the phase outputs Ph1 or Ph2 being
active, given by:

P

= IOLx V

Ph

OL

where IOLis the application Ph1 and Ph2

output currents

and V

is the maximum Low Level

OL

Output Voltage for the Ph1 and
Ph2 outputs given in the Electrical
Characteristics

SEMICONDUCTORS

ISSUE 4 - OCTOBER 2004

2

ZXBM2001
ZXBM2002 ZXBM2003

Electrical Characteristics (at T

= 25°C & VCC= 12V)

amb

Parameter Symbol Min Typ Max Unit Conditions

Supply Voltage V
Supply Current I

CC

CC

4.5 18 V

2.2 3.25 mA No Load
Hall Amp Input Voltage 40 mV diff p-p
Hall Amp Common Mode Voltage V
Hall Amp Input Offset V
Hall Amp Bias Current V
PH1, PH2 Output High V
PH1, PH2 Output Off Leakage

Current
PH1, PH2 Output Current High I
Lock/FG Maximum Collector

Voltage
Lock/FG Sink Current I
Lock/FG Low Level O/P Voltage V
C

Charge Current I

LCK

C

Discharge Current I

LCK

CM

OFS

BS

OH

I

OFF

OH

V

OH

OL

OL

LCKC

LCKD

0.5 0.5V

CC

VCC-1.5 V

±7 mV

-350 nA

VCC-2.2 VCC-1.8 V IOH= 80mA

⫾10 ␮A

-80 mA

V

CC

V

5mA

0.3 0.5 V IOL= 5mA

-1.8 -2.8 ␮AVin= 1.5V

0.28 0.35 ␮AVin= 1.5V
Lock condition On:Off ratio 1:7 1:10
C

High Threshold Voltage V

LCK

C

Low Threshold Voltage V

LCK

C

Charge Current I

PWM

C

Discharge Current I

PWM

PWM Frequency F

C

High Threshold Voltage V

PWM

C

Low Threshold Voltage V

PWM

SPD Voltage Control Range V

THH

THL

PWMC

PWMD

PWM

THH

THL

SPD

3.6 4.3 5.0 ␮AVin= 1.5V
50 62 75 ␮AVin= 1.5V

12V2

2.0 V

1.0 V

24
34

kHz
kHz

2.0 V

1.0 V

C
C

PWM
PWM

SPD Open Circuit Voltage 1.5 V 3

1

= 150pF
= 100pF

Notes:
1

Measured with pins H+, H-, C

2

The 1V minimum represents 100% PWM drive and 2V represents 0% PWM drive.

3

This voltage is determined by an internal resistor network of 52.5k⍀ from the pin to Gnd and 19.5k⍀ from the pin to a 2V reference. Whilst both

resistors track each other the absolute values are subject to a ±20% manufacturing tolerance

LCK

and C

= 0V and all other signal pins open circuit.

PWM

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SEMICONDUCTORS

ZXBM2001
ZXBM2002 ZXBM2003

Block Diagram (ZXBM2001):

Pin Assignments

Top View

Pin Functional Descriptions

1. VCC - Applied voltage

Thisisthedevice supplyvoltage. For5V to12V fansthis
canbe supplieddirectly fromthe Fan Motorsupply. For
fans likely to run in excess of the 18V maximum rating
for the device this will be supplied from an external
regulator such as a zener diode.

SEMICONDUCTORS

2. H+ - Hall input

3. H- - Hall input

Therotor positionof the FanMotor isdetected by aHall
sensor whose output is applied to these pins. This
sensor can be either a 4 pin ‘naked’ Hall device or a 3
pin buffered switching type. For a 4 pin device the
differential Hall output signal is connected to the H+
and H- pins. For a 3 pin buffered Hall sensor the Hall
deviceoutput is attached to the H+ pin whilstthe H- pin
has an external potential divider attached to hold the
pin at half V
the active drive.

4

. When H+ is high in relation to H- Ph2 is

CC

ISSUE 4 - OCTOBER 2004

ZXBM2001
ZXBM2002 ZXBM2003

4. SPD - Speed control voltage input

This pin provides control over the Fan Motor speed by
varying the Pulse Width Modulated (PWM) drive ratio
atthe Ph1 and Ph2 outputs.Thiscontrol signal can take
the form of either a voltage input of nominal range 2V
to 1V, representing 0% to 100% drive respectively, or
alternatively a thermistor can be attached to this pin to
control the voltage. A third method of speed control is
available by the application of an externally derived
PWM signal and this will be discussed under the C

PWM

pin.
This pin has an internal potential divider between an

internal 2.0V reference and Gnd (see Block Diagram)
designed to hold the pin at approximately 1.5V. This
will represent a drive of nominally 50% PWM. For
thermal speed control a 100k NTC thermistor is
connected between the SPD and ground will provide a
drive nominally 70% at 25°C and 100% at 50°C. As the
thermistor is connected in parallel with the internal
resistor the non-linearity of an NTC thermistor is
largely taken out. A linearity of typically ±2.5% is
achievable.

Lower values of thermistor can be used if needed and
in this situation an external potential divider will be
neededto setthe speedrange. Thiswill takethe formof
a resistor from the SPD pint to Vcc and a resistor from
the SPD pin to Gnd. Full details are given in the
ZXBM200x series Application Note.

If speed control is not required this pin is can be left
open circuit for 50% drive or tied to ground by a 10k⍀
resistor to provide 100% drive.

If required this pin can also be used as an enable pin.
The application of a voltage of 2.0V to V

will to force

CC

the PWM drive fully off, in effect disabling the drive.

5. GND - Ground

This is the device supply ground return pin and will
generally be the most negative supply pin to the fan.

6. LOCK/FG - Locked Rotor error output /
Frequency Generator (speed) output

This pin is an open collector output and so will require
an external pull up resistor for correct operation.

On the ZXBM2001 the Lock/FG pin is designed to be a
dual function pin to provide an indication of the Fans
rotational speed together with an indication of when
the Fan has failed rotating for whatever reason (Rotor
Lockedcondition). Under correct operatingconditions,
and with the external pull-up in place, this pin will
providean output signalwhose frequencywillbe twice
that of the rotational frequency of the fan. Should the
fan itself stop rotating for any reason, i.e. an
obstruction in the fan blade or a seized bearing, then
the device will enter a Rotor Locked condition. In this
condition the Lock/FG pin will go high (regardless of
the state of the Hall sensor) when the C
the V

threshold and will remain high until the fan

THH

pin reaches

LCK

blades start rotating again.
On the ZXBM2002 variant this pin is Lock. During

normal operation the signal will be low and during a
Locked Rotor condition the pin will go high when the
C

pin reaches the V

LCK

threshold.

THH

Forthe ZXBM2003 variantthispin is FG.This signal is a
buffered and inverted output of the Hall signal and
therefore provides an output signal whose frequency
willbetwicethatof therotational frequencyof thefan.

7. C

- Locked Rotor timing capacitor

LCK

When in a Locked Rotor condition as described above
thePh1 andPh2 driveoutputs gointo asafe drivemode
to protect the external drive devices and the motor
windings. This condition consists of driving the motor
for a short period then waiting for a longer period
before trying again. The frequency at which this takes
place is determined by the size of the capacitor applied
to this CLCK pin. For a 12V supply a value of 1.0uF will
typically provide an ‘On’ (drive) period of 0.33s and an
‘Off’(wait)periodof4.0s, givingan On:Offratio of1:12.

The C

timing periods are determined by the

LCK

following equations:

THH LCK

VC

lock

T

Where V

×

=

LCKC

I

THH

voltages and I

THH THL LCK

VVC

on

T

=

and V

THL

and I

LCKC

−×()

LCKC

I

are the C

LCKD

THH THL LCK

VVC

off

T

−×()

=

pin threshold

LCK

I

LCKD

are the charge and

discharge currents.

ISSUE 4 - OCTOBER 2004

5

SEMICONDUCTORS

ZXBM2001
ZXBM2002 ZXBM2003

Locked Rotor timing capacitor (CONT).

As these threshold voltages are nominally set to
V

THH

=2V and V

=1V the equations can be simplified

THL

as follows:

8. C

T

PWM

LCK

C

×2

lock

=

LCKC

I

- Sets PWM frequency

- external PWM input

T=

on

C
I

LCK

LCKC

LCK

C

off

T

=

LCKD

I

This pin has an external capacitor attached to set the
PWM frequency for the Phase drive outputs. A
capacitor value of 0.15nF will provide a PWM
frequency of typically 24kHz.

The C

timing period (T

LCK

) is determined by the

pwm

following equation:

Where T

THH THL

(V - V ) CI(V V ) C

T=

lock

is in ␮s

PWM

×

PWMC

+

THH THL

−×

PWMD

I

C

C

I

The C

T

PWM

=+

PWMC PWMD

I

pin can also be used as in input for an

PWM

externally derived PWM signal to control the motor
speed. The signal should have a VOL <1V and a VOH
>2V. A standard TTL or CMOS digital signal is ideal.
When driving from an external PWM source no
capacitor should be attached to the C

PWM

pin and the

SPD pin should be left open circuit.

9. PH2 - External transistor driver

10. PH1 - External transistor driver

These are the Phase drive outputs and are open
darlington emitter followers designed to provide up to
80mA of drive to external transistors as shown in the
Application circuits following. The external transistors
in turn drive the fan motor windings.

C = C
I

PWM&IPWMD

Where V

THH

voltages and I

PWM

and V

PWMC

+15 in pF

are in ␮A

are the C

THL

and I

PWM

are the charge and

PWMD

pin threshold

discharge currents.
As these threshold voltages are nominally set to

V

=2V and V

THH

=1V the equations can be simplified

THL

as follows:

SEMICONDUCTORS

ISSUE 4 - OCTOBER 2004

6

Lock & FG Timing Waveform:

Lock Timing Example:
Using the equation previously described and to be

found under the C

C

×2

lock

T

=

LCKC

I

LCK

LCK

pin description:

LCK

C

on

T

= T

LCKC

I

LCK

C

off

=

LCKD

I

ZXBM2001
ZXBM2002 ZXBM2003

Using a value of C
of I

LCKC

and I

= 1.0uF together with the values

LCK

to be found in the Electrical

LCKD

Characteristics we can derive the following timings for
operation at 12V and 25°C.

21.0F

T=

lock

×=␮

␮

2.8 A
T=

on

s

0714.

×=␮

21.0F

␮

2.8 A

T=

off

036.

␮

1.0 F

␮

0.28 A

s

= 36.

s

Figure 2
TYPICAL APPLICATION (ZXBM2001) using MOSFET power transistors

Figure 1
TYPICAL APPLICATION (ZXBM2001) using Bipolar power transistors

ISSUE 4 - OCTOBER 2004

Graph 1

7

SEMICONDUCTORS

ZXBM2001
ZXBM2002 ZXBM2003

APPLICATION INFORMATION

Thissection givesa briefinsight intoapplications using
the ZXBM200x series. More complete data is available
in the ZXBM200x Series Applications Note, visit
www.zetex.com/zxbm or contact your nearest Zetex
office for full details.

The ZXBM200x series of 2-phase DC brushless motor
pre-drivers are capable of driving both Bipolar or
MOSFET power transistors.

For smaller fans and blowers it is likely that bipolar
power transistors would be used as shown in the
following Applications circuit.

InFigure 1,R1 & R2have theirvalue selected toprovide
suitable base current in keeping with the winding
currentand gainof the powertransistors Q1& Q2. R3&
R4 have their value selected to provide efficient
switch-off of Q1 & Q2. The Zener diodes ZD1 & ZD2
provideactiveclampinginconjunction withQ1 &Q2.

It is also recommended that the supply de-coupling
capacitor C3 is positioned as close as is practical to the
ZXBM device pins.

In the case of higher power fans and blowers it may be
more applicable to use MOSFET devices to switch the
windings as illustrated in the second applications
circuit shown in Figure 2.

In Figure 2, the Resistor ratio of R1 to R3 and R2 to R4
provide the required Gate turn-on voltage whilst the
absolute values will be chosen to provide sufficient
gate switching currents.

Also illustrated in the two Applications circuits above
are the methods of connection for both a ‘naked’ Hall
device, as seen in the bipolar circuit in Figure 1, and a
bufferedHall device, as in the MOSFET circuitin Figure

2.In thislatter circuitR5 &R6 biasthe H-pin atavoltage
equivalent to half the swing of the Hall device. R7 will
be needed if the buffered Hall device does not have its
own internal pull-up.

Graph 1 below, illustrates the PWM drive waveform
takenfrom and applicationusing theMOSFETcircuit in
Figure 2. This shows the waveforms to be found at the
Ph1 output and at the drain/Winding node.

SEMICONDUCTORS

ISSUE 4 - OCTOBER 2004

8

ZXBM2001
ZXBM2002 ZXBM2003

When driving fans with bipolar transistors, at higher
voltages it may be necessary to provide extra noise
protection by the addition of a diode from the driver
collectorto Gnd on each phase. This prevents negative
voltage excursions from the windings affecting
operation. See Figure 3 right, showing the placement
of these diodes. It should be noted that these are not
required for the MOSFET solution in Figure 2 as the
diodes are inherent in the MOSFET structure.

Zetexprovide avariety ofsuitable powertransistors for
using with the ZXBM200x series of 2-phase DC
brushless motor pre-drivers and suitable devices
sufficient for a range of applications are given in the
following table.

Figure 3
TYPICAL APPLICATION (ZXBM2001) illustrating addition of Clamp
diodes.

SUMMARY TABLE OF SUITABLE DEVICES

Bipolar Types V

FZT1053A 75 4.5 300 @ 0.5A 200 @ 1A, 10mA SOT223

FZT851 60 6 100 @ 2A 100 @ 1A, 10mA SOT223
FZT853 100 6 100 @ 2A 175 @ 1A, 100mA SOT223
FZT855 150 4 100 @ 1A 65 @ 0.5A, 50mA SOT223

ZXT13N50DE6 50 4 300 @ 1A 100 @ 1A, 10mA SOT23-6

(V) IC(A) min HFE@ICV

CEO

CE(sat)

@I

max(mV)

C&IB

Package

MOSFET Types BV

ZXMN3A04DN8
ZXMN6A09DN8

ZXMN6A11Z

ZXMN6A11G 60 3.8 10 140 @ 10V SOT223

ZXMN10A11G

Notes:
1

Contact your nearest Zetex office for further details and technical enquiries.

2

Dual device

3

Provisional information

4

Advanced information

23
23

1

24

(V) ID(A) I

DSS

(A)

PEAK

(Pulsed)

R

DS(on)

max(m )

@V

GS

30 7.6 25 20 @ 10V SO8
60 5 17.6 45 @ 10V SO8
60 3.8 10 140 @ 10V SOT89

100 1.9 5.9 600 @ 10V SOT223

ISSUE 4 - OCTOBER 2004

9

SEMICONDUCTORS

Package

ZXBM2001
ZXBM2002 ZXBM2003

Conforms to JEDEC MO-187 VARIATION BA

CONTROLING DIMENSIONS IN METRIC

APPROX. DIMENSION IN INCHES

PACKAGE DIMENSIONSPACKAGE OUTLINE

MILLIMETERS INCHES

DIM

MIN. MAX. MIN. MAX.

A ᎏ 1.10 ᎏ 0.43
A1 ᎏ 0.15 ᎏ 0.006
A2 0.75 0.95 0.0295 0.037

D 3.00 BSC 0.118 BSC

E 4.90 BSC 0.1929 BSC

E1 3.00 BSC 0.118 BSC

b 0.17 0.27 0.0066 0.0106
c 0.08 0.23 0.003 0.009
e 0.50 BSC 0.0196 BSC

⍜ 0⬚ 15⬚ 0⬚ 15⬚

L 0.40 0.80 0.015 0.031

L1 0.95 BSC 0.037 BSC

© Zetex Semiconductors plc 2004

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reserves the right to alter without notice the specification, design, price or conditions of supply of any product or service.

For the latest product information, log on to www.zetex.com

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USA

Telephone: [phone]
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ISSUE 4 - OCTOBER 2004

SEMICONDUCTORS

10