ZXBM2004
VARIABLE SPEED 2-PHASE BLDC MOTOR CONTROLLER
DESCRIPTION
The ZXBM2004 is a 2-phase, DC brushless motor pre-driver with PWM
variable speed control suitable for fan and blower motors. The controller is
intended for applications where the fan or blower speed is controlled by an
external PWM signal, thermistor or DC voltage.
FEATURES
•
Compliant with external PWM speed control
•
Compliant with thermistor control
•
Minimum speed setting
•
Low noise
•
Auto restart
•
Built in hall amplifier
•
Speed pulse (FG) and lock rotor (RD) outputs
•
Up to 18V input voltage (60V with external regulator)
•
QSOP16 package
•
Lead free product
QSOP16
Associated application notes:-
AN41 - Thermistor control
AN42 - External PWM control
AN43 - Interfacing to the motor windings
APPLICATIONS
•
Mainframe and personal computer fans and blowers
•
Instrumentation fans
•
Central heating blowers
•
Automotive climate control
ORDERING INFORMATION - QSOP16
DEVICE
ZXBM2004Q16TC
REEL SIZE
13" (330mm)
TAPE WIDTH
12mm
QUANTITY PER REEL
2,500
DEVICE MARKING
•
ZETEX
ZXBM
2004
ISSUE 3 - MAY 2005
1
SEMICONDUCTORS
ZXBM2004
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Supply voltage
Input current
Input voltage
Output voltage
Power dissipation
Operating temp.
Storage temp.
SYMBOL
V
CCmax
I
CCmax
V
IN
max
V
OUT
max
P
Dmax
T
OPR
T
STG
LIMITS
-0.6 to 20
100
-0.5 to V
CC
+0.5
-0.5 to V
CC
+0.5
500
-40 to 110
-55 to 125
UNIT
V
mA
V
V
mW
C
C
Power Dissipation
1) Maximum allowable Power Dissipation, P
D
,
is shown plotted against Ambient Temperature,
T
A
, in the accompanying Power Derating Curve,
indicating the Safe Operating Area for the device.
2) Power consumed by the device, P
T
, can be
calculated from the equation:
P
T
= P
Q
+ P
Ph
where
P
Q
is power dissipated under quiescent
current conditions, given by:
P
Q
= V
CC
x I
CC
where V
CC
is the application
device Supply Voltage
and
I
CC
is the maximum Supply
Current given in the Electrical
Characteristics
and
P
Ph
is power generated due to either one of
the phase outputs Ph1 or Ph2 being
active, given by:
P
Ph
= I
OL
x V
OL
where I
OL
is the application Ph1 and Ph2
output currents
and
V
OL
is the maximum Low Level
Output Voltage for the Ph1 and
Ph2 outputs given in the Electrical
Characteristics
j-a = 112°C/W
ISSUE 3 - MAY 2005
SEMICONDUCTORS
2
ZXBM2004
ELECTRICAL CHARACTERISTICS (at Tamb = 25°C & Vcc = 12V)
PARAMETER
Supply Voltage
Supply Current
Hall Amp Input Voltage
Hall Amp Common Mode Voltage
Hall Amp Input Offset
Hall Amp Bias Current
PH1, PH2 Output High
PH1, PH2 Output Low
PH1, PH2 Output Low
PH1, PH2 Output Source Current
PH1, PH2 Output Sink Current
C
PWM
Charge Current
C
PWM
Discharge Current
C
PWM
High Threshold Voltage
C
PWM
Low Threshold Voltage
PWM Frequency
ThRef Voltage
ThRef Output Current
S
MIN
Input Current
SPD Voltage Minimum
SPD Voltage Maximum
SPD Input Current
C
LCK
Charge Current
C
LCK
Discharge Current
C
LCK
High Threshold Voltage
C
LCK
Low Threshold Voltage
Lock condition On:Off ratio
FG & RD Low Level Output Current
FG & RD Low Level Output Voltage
Commutation dead time
I
OL
V
OL
t
CD
7.5
SYMBOL
V
CC
I
CC
V
IN
V
CM
V
OFS
I
BS
V
OH
V
OLA
V
OLB
I
OH
I
OL
I
PWMC
I
PWMD
V
THH
V
THL
F
PWM
V
ThReF
I
OThRef
I
ISMIN
V
SPDL
V
SPDH
I
ISPD
I
LCKC
I
LCKD
V
THH
V
THL
-2.8
-0.25
1
3
-0.8
-3.8
0.46
3
1
1:12
5
0.5
mA
V
s
I
OL
= 5mA
0.54
-2
2.88
-4.5
38
3
1
24
2.96
3.10
-1
-0.3
V
CC
-2.2
40
0.5
±7
-400
V
CC
-1.8
0.4
0.4
0.6
0.6
-80
16
-7.85
65
-710
Vcc-1.5
MIN
4.7
5.5
TYP
MAX
18
7.5
UNIT CONDITIONS
V
mA
mV
V
mV
nA
V
V
V
mA
mA
A
A
V
V
kHz
V
mA
A
V
V
A
A
A
V
V
V
IN
= 2V,SPD=open
100% PWM Drive
0% PWM Drive
V
IN
= 2V
C
PWM
= 0.1nF
I
OThRef
=-100 A
I
OH
=-80mA
I
OL
=16mA
2
I
OL
=50 A
3
No Load
1
diff p-p
Notes:
1. Measured with pins H+, H-, C
LCK
and C
PWM
= 0V and all other signal pins open circuit.
2. Measured when opposing Phase Output is Low
3. Measured when opposing Phase Output is High
4. In this datasheet a negative sign for a current indicates current flowing out of the pin whilst no sign indicates current flowing into the pin.
ISSUE 3 - MAY 2005
3
SEMICONDUCTORS
ZXBM2004
PIN FUNCTIONAL DESCRIPTION
H+ - Hall input
H- - Hall input
The rotor position is detected by a Hall sensor, with the
output applied to the H+ and H- pins. This sensor can be
either a 4 pin 'naked' Hall device or of the 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
buffered Hall sensor the Hall device output is attached
to the H+ pin, with a pull-up attached if needed, whilst
the H- pin has an external potential divider attached to
hold the pin at half V
cc
. When H+ is high in relation to
H-, Ph2 is the active drive.
If required this pin can also be used as an enable pin.
The application of a voltage >3.0V will force the PWM
drive fully off, in effect disabling the drive.
S
MIN
- Sets Minimum Speed
A voltage can be set on this pin via a potential divider
between the ThRef and Gnd. This voltage is monitored
by the SPD pin such that it cannot rise above it. As a
higher voltage on the SPD pin represents a lower speed
it therefore restricts the lower speed range of the fan. If
this feature is not required the pin is left tied to ThRef so
no minimum speed will be set.
If the fan is being controlled from an external voltage
source onto the SPD pin then either this feature should
not be used or if it is required then a >1k resistor
should be placed in series with the SPD pin.
ThRef - Network Reference
This is a reference voltage of nominal 3V. It is designed
for the ability to 'source' and therefore it will not 'sink'
any current from a higher voltage.
The current drawn from the pin by the minimum speed
potential divider to pin S
MIN
and any voltage setting
network should not exceed 1mA in total at maximum
temperature.
C
PWM
- Sets PWM Frequency
This pin has an external capacitor attached to set the
PWM frequency for the Phase drive outputs. A
capacitor value of 0.1nF will provide a PWM frequency
of typically 24kHz.
The C
PWM
timing period (T
PWM
) is determined by the
following equation:
SPD - Speed Control Input
The voltage applied to the SPD pin provides control
over the Fan Motor speed by varying the Pulse Width
Modulated (PWM) drive ratio at the Ph1Lo and Ph2Lo
outputs. The control signal takes the form of a voltage
input of range 3V to 1V, representing 0% to 100% drive
respectively.
If variable speed control is not required this pin can be
left with an external potential divider to set a fixed
speed or tied to ground to provide full speed i.e. 100%
PWM drive.
T
PWM
=
(
V
THH
−
V
THL
)
x C
(
V
THH
−
V
THL
)
x C
+
I
PWMC
I
PWMD
C = C
PWM
+15, in pF
V
T H H
a n d V
T H L
a re t h e C
P W M
p i n
threshold voltages
I
PWMC
and I
PWMD
are the charge and
discharge currents in A.
T
PWM
is in ms
Where:
ISSUE 3 - MAY 2005
5
SEMICONDUCTORS
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