FOSLINK FSP33035ND

BRUSHLESS DC MOTOR CONTROLLER
FSP33035
„
FEATURES
„
z
z
z
z
z
z
10V to 30 V Operation
Undervoltage Lockout
6.25V Reference Capable of Supplying Sensor
Power
Fully Accessible Error Amplifier for Closed Loop
Servo Applications
High Current Drivers Can Control External
3–Phase MOSFET Bridge
Cycle–By–Cycle Current Limiting
Pinned–Out Current Sense Reference
Internal Thermal Shutdown
Selectable 60°/300° or 120°/240° Sensor
Phasings
Can Efficiently Control Brush DC Motors with
External MOSFET H–Bridge
Top driver output current not more than 50mA
Bottom driver output current not more than 100mA
SOP24L and PDIP24L Packages
The FSP33035 is a high performance second
generation monolithic brushless DC motor controller
containing all of the active functions required to
implement a full featured open loop, three or four
phase motor control system. This device consists of a
rotor position decoder for proper commutation
sequencing, temperature compensated reference
capable of supplying sensor power, frequency
programmable sawtooth oscillator, three open collector
top drivers, and three high current totem pole bottom
drivers ideally suited for driving power MOSFETs.
Also included are protective features consisting of
undervoltage lockout, cycle–by–cycle current limiting
with a selectable time delayed latched shutdown mode,
internal thermal shutdown, and a unique fault output
that can be interfaced into microprocessor controlled
systems.
Typical motor control functions include open loop
speed, forward or reverse direction, run enable, and
dynamic braking. The FSP33035 is designed to
operate with electrical sensor phasings of 60°/300° or
120°/240°, and can also efficiently control brush DC
motors.
„
PIN CONFIGURATION
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GENERAL DESCRIPTION
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
„
FSP33035
PIN DESCRIPTION
Pin Number
1, 2, 24
3
4, 5, 6
7
8
9
10
11
12
13
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Pin Name
Pin Function
These
three
open
collector
Top
Drive outputs are designed to drive
BT , AT , CT
the external upper power switch transistors.
Fwd/Rev
The Forward/Reverse Input is used to change the direction of motor
rotation.
These three Sensor Inputs control the commutation sequence.
SA, SB, SC
A logic high at this input causes the motor to run, while a low causes it to
Output Enable
coast.
Reference Output This output provides charging current for the oscillator timing capacitor CT
and a reference for the error amplifier. It may also serve to furnish sensor
power.
Current Sense
A 100 mV signal, with respect to Pin 15, at this input terminates output
Noninverting Input switch conduction during a given oscillator cycle. This pin normally
connects to the top side of the current sense resistor.
Oscillator
The Oscillator frequency is programmed by the values selected for the
timing components, RT and CT.
This input is normally connected to the speed set potentiometer.
Error Amp
Noninverting Input
Error Amp
This input is normally connected to the Error Amp Output in open loop
Inverting Input
applications.
This pin is available for compensation in closed loop applications.
Error Amp
Out/PWM Input
14
Fault Output
This open collector output is active low during one or more of the following
conditions: Invalid Sensor Input code, Enable Input at logic 0, Current
Sense Input greater than 100 mV (Pin 9 with respect to Pin 15),
Undervoltage Lockout activation, and Thermal Shutdown.
15
16
Current Sense
Inverting Input
Gnd
17
VCC
18
VC
19, 20, 21
CB, BB, AB
Reference pin for internal 100 mV threshold. This pin is normally
connected to the bottom side of the current sense resistor.
This pin supplies a ground for the control circuit and should be referenced
back to the power source ground.
This pin is the positive supply of the control IC. The controller is functional
over a minimum VCC range of 10 to 30 V.
The high state (VOH) of the Bottom Drive Outputs is set by the voltage
applied to this pin. The controller is operational over a minimum VC range
of 10 to 30 V.
These three totem pole Bottom Drive Outputs are designed for direct drive
of the external bottom power switch transistors.
22
60°/120 ° Select
23
Brake
The electrical state of this pin configures the control circuit operation for
either 60° (high state) or 120°(low state) sensor electrical phasing inputs.
A logic low state at this input allows the motor to run, while a high state
does not allow motor operation and if operating causes rapid deceleration.
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
„
3/28
ELECTRICAL CIRCUIT
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
„
ABSOLUTE MAXIMUM RATINGS
Parameter
Power Supply Voltage, VCC
Digital Inputs (Pins 3, 4, 5, 6, 22, 23),
Rating
40
Vref
Unit
V
V
Oscillator Input Current (Source or Sink), IOSC
30
mA
Error Amp Input Voltage Range (Pins 11, 12), VIR
-0.3 to Vref
V
Error Amp Output Current (Source or Sink), Iout
10
mA
Current Sense Input Voltage Range (Pins 9, 15), Vsense
-0.3 to 5
V
Fault Fault Output Voltage, VCE(fault)
20
V
Fault Output Sink Current, ISINK(fault)
20
mA
Top Drive Voltage (Pins 1, 2, 24), VCE(top)
40
V
Top Drive Sink Current (Pins 1, 2, 24), ISINK(top)
50
mA
Bottom Drive Supply Voltage (Pin 18),Vc
30
V
Bottom Drive Out put Current(Source or Sink, Pins19, 20, 21), IDRV
100
mA
Maximum Power Dissipation @ TA = 85°C, PD
867(PDIP24L)
mW
650(SOP24L)
Thermal Resistance, Junction–to–Air, RQJA
75(PDIP24L)
°C/W
100(SOP24L)
„
Operating Junction Temperature, TJ
150
°C
Operating Ambient Temperature Range, TA
-40 to 85
°C
Storage Temperature Range, TSTG
-65 to 150
°C
ELECTRICAL CHARACTERISTICS
(VC C = VC = 20 V, RT = 4.7 k, CT = 10 nF, TA = 25°C, unless otherwise noted.)
PARAMETER
SYMBOL
TEST CONDITIONS
REFERENCE SECTION
Reference Output Voltage
Line Regulation
Load Regulation
Output Short Circuit Current ,
Reference
Under
Voltage
Lockout Threshold,
ERROR AMPLIFIER
Input Offset Voltage
Input Offset Current
Input Bias Current
Input Common Mode Voltage
Range
Open Loop Voltage Gain
Input Common Mode Rejection
Ratio
Power Supply Rejection Ratio
4/28
Vref
(Ire f = 1.0 mA), TA = 25°C
(Ire f = 1.0 mA), TA = -40 to 85°C
(VC C = 10 to 30 V, Ir e f = 1.0 mA),
(Ir e f = 1.0 to 20 mA),
MIN
5.9
5.82
Isc
40
Vth
4.0
Vio
Iio
Iib
MAX
6.5
6.57
30
30
TA = -40 to 85°C
TA = -40 to 85°C
TA = -40 to 85°C
Vicr
AVOL
TYP
CMRR
V
mV
mV
mA
5.0
V
10
500
-1000
mV
nA
nA
0~Vref
(VO = 3.0 V, RL = 15 k)
UNIT
V
70
dB
55
dB
PSRR
(VCC=VC =10 to 30V)
65
dB
Output Voltage Swing High level
VOH
RL= 15 k to GND
4.6
V
Output Voltage Swing Low level
VOL
RL = 15 k to Vref
1.0
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
„
FSP33035
ELECTRICAL CHARACTERISTICS(CONTINUED)
(VC C = VC = 20 V, RT = 4.7 k, CT = 10 nF, TA = 25°C, unless otherwise noted.)
PARAMETER
SYMBOL
TEST CONDITIONS
OSCILLATOR SECTION
Oscillator Frequency
Frequency Change with Voltage
Sawtooth Peak Voltage
Sawtooth Valley Voltage
LOGIC INPUTS
Input Threshold Voltage (Pins 3,
4, 5, 6, 7, 22, 23)High State
Input Threshold Voltage (Pins 3,
4, 5, 6, 7, 22, 23) Low State
Sensor Inputs (Pins 4, 5, 6)
High State Input Current
Sensor Inputs (Pins 4, 5, 6)
Low State Input Current
Forward/Reverse, 60°/ 120 °
Select (Pins 3, 22, 23)
High State Input Current
Forward/Reverse, 60°/ 120 °
Select (Pins 3, 22, 23)
Low State Input Current
Output Enable
High State Input Current
fosc
fosc/V
Vosc(p)
Vosc(v)
MIN
TYP
22
(VCC = 10 to 30 V)
MAX
UNIT
28
5.0
4.5
kHz
%
V
V
1.2
VIH
3.0
V
VIL
0.8
IIHS
(VIH = 5.0 V)
-150
-20
IILS
(VIL = 0 V)
-600
-150
IIHF
(VIH = 5.0 V)
-75
-10
uA
uA
IILF
(VIL = 0 V)
-300
-75
IIHE
(VIH = 5.0 V)
-60
-10
uA
Output Enable
Low State Input Current
CURRENT LIMIT COMPARATOR
Threshold Voltage
Input Bias Current
IILE
Vthc
Iibc
OUTPUTS AND POWER SECTIONS
Top
Drive
Output
Sink
VCE(sat)
Saturation
Top Drive Output Off–State
IDRVleak
Leakage
Top Drive Output Switching
Time , Rise Time
trT
(VIL = 0 V)
-60
-10
85
115
-5.0
mV
uA
(Isink = 25 mA)
1.5
V
(VCE = 30 V)
100
uA
(CL = 47 pF, RL = 1.0 k)
300
ns
Top Drive Output Switching
Time ,Fall Time
Bottom Drive Output Voltage,
High State
Bottom Drive Output Voltage,
Low state
Bottom Drive Output Switching
Time Rise Time
Bottom Drive Output Switching
Time Fall Time
Fault Output Sink Saturation
Fault Output Off–State Leakage
5/28
tfT
(CL = 47 pF, RL = 1.0 k)
VOHB
VCC = 20 V, VC = 30 V
( Isource = 50 mA)
VOHL
VCC = 20 V, VC = 30 V
( Isink = 50 mA)
300
VCC-2
V
2.0
trB
(CL = 1000 pF)
200
tfB
(CL = 1000 pF)
200
VCE(sat)
IFLTleak
(Isink = 16 mA)
(VCE = 20 V)
500
100
ns
2007-3-16
mV
uA
BRUSHLESS DC MOTOR CONTROLLER
„
FSP33035
ELECTRICAL CHARACTERISTICS(CONTINUED)
(VC C = VC = 20 V, RT = 4.7 k, CT = 10 nF, TA = 25°C, unless otherwise noted.)
PARAMETER
SYMBOL
TEST CONDITIONS
OUTPUTS AND POWER SECTIONS
Under Voltage Lockout
VTH(on)
Drive Output Enabled
Hysteresis,
VH
Power Supply Current,
Pin 17
Power Supply Current,
Pin 18
„
6/28
(VCC or VC Increasing)
MIN
TYP
MAX
UNIT
8.2
10
V
0.1
0.3
V
VCC = VC = 20 V
ICC
16
mA
VCC = 20 V, VC = 30 V
20
VCC = VC = 20 V
6.0
VCC = 20 V, VC = 30 V
10
IC
BLOCK DIAGRAM
2007-3-16
mA
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
„
FUNCTION DESCRIPTION
Rotor Position Decoder
An internal rotor position decoder monitors the three sensor inputs (Pins 4, 5, 6) to provide the proper sequencing of
the top and bottom drive outputs. The sensor inputs are designed to interface directly with open collector type Hall
Effect switches or opto slotted couplers. Internal pull–up resistors are included to minimize the required number of
external components. The inputs are TTL compatible, with their thresholds typically at 2.2 V. The FSP33035 series is
designed to control three phase motors and operate with four of the most common conventions of sensor phasing. A
60°/120° Select (Pin 22) is conveniently provided and affords the FSP33035 to configure itself to control motors
having either 60°, 120°, 240° or 300° electrical sensor phasing. With three sensor inputs there are eight possible
input code combinations, six of which are valid rotor positions. The remaining two codes are invalid and are usually
caused by an open or shorted sensor line. With six valid input codes, the decoder can resolve the motor rotor
position to within a window of 60 electrical degrees.
The Forward/Reverse input (Pin 3) is used to change the direction of motor rotation by reversing the voltage across
the stator winding. When the input changes state, from high to low with a given sensor input code (for example 100),
the enabled top and bottom drive outputs with the same alpha designation are exchanged (AT to AB , BT to BB , CT to
CB ). In effect, the commutation sequence is reversed and the motor changes directional rotation.
Motor on/off control is accomplished by the Output Enable (Pin 7). When left disconnected, an internal 25 µA current
source enables sequencing of the top and bottom drive outputs. When grounded, the top drive outputs turn off and
the bottom drives are forced low, causing the motor to coast and the Fault output to activate.
Dynamic motor braking allows an additional margin of safety to be designed into the final product. Braking is
accomplished by placing the Brake Input (Pin 23) in a high state. This causes the top drive outputs to turn off and the
bottom drives to turn on, shorting the motor–generated back EMF. The brake input has unconditional priority over all
other inputs. The internal 40 k: pull–up resistor simplifies interfacing with the system safety–switch by insuring brake
activation if opened or disconnected. The commutation logic truth table is shown in Table below. A four input NOR
gate is used to monitor the brake input and the inputs to the three top drive output transistors. Its purpose is to
disable braking until the top drive outputs attain a high state. This helps to prevent simultaneous conduction of the
top and bottom power switches. In half wave motor drive applications, the top drive outputs are not required and are
normally left disconnected.
Three Phase, Six Step Commutation Truth Table (Note 1)
NOTES: 1. V = Any one of six valid sensor or drive combinations X = Don’t care.
2. The digital inputs (Pins 3, 4, 5, 6, 7, 22, 23) are all TTL compatible. The current sense input (Pin 9) has a
100 mV threshold with respect to Pin 15. A logic 0 for this input is defined as < 85 mV, and a logic 1 is >
115 mV.
3. The fault and top drive outputs are open collector design and active in the low (0) state.
4.With 60°/120 ° select (Pin 22) in the high (1) state, configuration is for 60° sensor electrical phasing
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BRUSHLESS DC MOTOR CONTROLLER
FSP33035
inputs. With Pin 22 in low (0) state, configuration is for 120° sensor electrical phasing inputs.
5. Valid 60° or 120° sensor combinations for corresponding valid top and bottom drive outputs.
6. Invalid sensor inputs with brake = 0; All top and bottom drives off, Fault low.
7. Invalid sensor inputs with brake = 1; All top drives off, all bottom drives on, Fault low.
8. Valid 60° or 120° sensor inputs with brake = 1; All top drives off, all bottom drives on, Fault high.
9. Valid sensor inputs with brake = 1 and enable = 0; All top drives off, all bottom drives on, Fault low.
10. Valid sensor inputs with brake = 0 and enable = 0; All top and bottom drives off, Fault low.
11. All bottom drives off, Fault low.
Error Amplifier
A high performance, fully compensated error amplifier with access to both inputs and output (Pins 11, 12, 13) is
provided to facilitate the implementation of closed loop motor speed control. The amplifier features a typical DC
voltage gain of 80 dB, 0.6 MHz gain bandwidth, and a wide input common mode voltage range that extends from
ground to Vref. In most open loop speed control applications, the amplifier is configured as a unity gain voltage
follower with the noninverting input connected to the speed set voltage source.
Oscillator
The frequency of the internal ramp oscillator is programmed by the values selected for timing components RT and
CT. Capacitor CT is charged from the Reference Output (Pin 8) through resistor RT and discharged by an internal
discharge transistor. The ramp peak and valley voltages are typically 4.1 V and 1.5 V respectively. To provide a good
compromise between audible noise and output switching efficiency, an oscillator frequency in the range of 20 to 30
kHz is recommended.
Pulse Width Modulator
The use of pulse width modulation provides an energy efficient method of controlling the motor speed by varying the
average voltage applied to each stator winding during the commutation sequence. As CT discharges, the oscillator
sets both latches, allowing conduction of the top and bottom drive outputs. The PWM comparator resets the upper
latch, terminating the bottom drive output conduction when the positive–going ramp of CT becomes greater than the
error amplifier output. The pulse width modulator timing diagram is shown in the Figure below. Pulse width
modulation for speed control appears only at the bottom drive outputs.
Pulse Width Modulator Timing Diagram Reference
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BRUSHLESS DC MOTOR CONTROLLER
FSP33035
Current Limit
Continuous operation of a motor that is severely over–loaded results in overheating and eventual failure. This
destructive condition can best be prevented with the use of cycle–by–cycle current limiting. That is, each on–cycle
is treated as a separate event. Cycle–by–cycle current limiting is accomplished by monitoring the stator current
build–up each time an output switch conducts, and upon sensing an over current condition, immediately turning off
the switch and holding it off for the remaining duration of oscillator ramp–up period. The stator current is converted
to a voltage by inserting a ground–referenced sense resistor RS in series with the three bottom switch transistors
(Q4, Q5, Q6). The voltage developed across the sense resistor is monitored by the Current Sense Input (Pins 9 and
15), and compared to the internal 100 mV reference. The current sense comparator inputs have an input common
mode range of approximately 3.0 V. If the 100 mV current sense threshold is exceeded, the comparator resets the
lower sense latch and terminates output switch conduction. The value for the current sense resistor is:
The Fault output activates during an over current condition. The dual–latch PWM configuration ensures that only
one single output conduction pulse occurs during any given oscillator cycle, whether terminated by the output of the
error amp or the current limit comparator.
Reference voltage source
The on–chip 6.25 V regulator (Pin 8) provides charging current for the oscillator timing capacitor, a reference for the
error amplifier, and can supply 20 mA of current suitable for directly powering sensors in low voltage applications. In
higher voltage applications, it may become necessary to transfer the power dissipated by the regulator off the IC.
This is easily accomplished with the addition of an external pass transistor as shown in Figure below. A 6.25 V
reference level was chosen to allow implementation of the simpler NPN circuit, where Vref – VBE exceeds the
minimum voltage required by Hall Effect sensors over temperature. With proper transistor selection and adequate
heatsinking, up to one amp of load current can be obtained.
Reference Output Buffers
The NPN circuit is recommended for powering Hall or opto sensors, where the output voltage temperature
coefficient is not critical. The PNP circuit is slightly more complex, but is also more accurate over temperature.
Neither circuit has current limiting.
Undervoltage Lockout
A triple Undervoltage Lockout has been incorporated to prevent damage to the IC and the external power switch
transistors. Under low power supply conditions, it guarantees that the IC and sensors are fully functional, and that
there is sufficient bottom drive output voltage. The positive power supplies to the IC (VCC) and the bottom drives
(VC) are each monitored by separate comparators that have their thresholds at 9.1 V. This level ensures sufficient
gate drive necessary to attain low RDS(on) when driving standard power MOSFET devices. When directly powering
the Hall sensors from the reference, improper sensor operation can result if the reference output voltage falls below
4.5 V. A third comparator is used to detect this condition. If one or more of the comparators detects an undervoltage
condition, the Fault Output is activated, the top drives are turned off and the bottom drive outputs are held in a low
state. Each of the comparators contains hysteresis to prevent oscillations when crossing their respective
thresholds.
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FSP33035
Fault Output
The open collector Fault Output (Pin 14) was designed to provide diagnostic information in the event of a system
malfunction. It has a sink current capability of 16 mA and can directly drive a light emitting diode for visual indication.
Additionally, it is easily interfaced with TTL/CMOS logic for use in a microprocessor controlled system. The Fault
Output is active low when one or more of the following conditions occur:
1) Invalid Sensor Input code
2) Output Enable at logic [0]
3) Current Sense Input greater than 100 mV
4) Undervoltage Lockout, activation of one or more of the comparators
5) Thermal Shutdown, maximum junction temperature
being exceeded
This unique output can also be used to distinguish between motor start–up or sustained operation in an overloaded
condition. With the addition of an RC network between the Fault Output and the enable input, it is possible to create
a time–delayed latched shutdown for overcurrent. The added circuitry shown in the Figure makes easy starting of
motor systems which have high inertial loads by providing additional starting torque, while still preserving
overcurrent protection. This task is accomplished by setting the current limit to a higher than nominal value for a
predetermined time. During an excessively long overcurrent condition, capacitor CDLY will charge, causing the
enable input to cross its threshold to a low state. A latch is then formed by the positive feedback loop from the Fault
Output to the Output Enable. Once set, by the Current Sense Input, it can only be reset by shorting CDLY or cycling
the power supplies.
Drive Outputs
The three top drive outputs (Pins 1, 2, 24) are open collector NPN transistors capable of sinking 50mA with a
minimum breakdown of 30 V. Interfacing into higher voltage applications is easily accomplished with the circuits
shown in two Figures below.
The three totem pole bottom drive outputs (Pins 19, 20, 21) are particularly suited for direct drive of N–Channel
MOSFETs or NPN bipolar transistors. Each output is capable of sourcing and sinking up to 100mA. Power for the
bottom drives is supplied from VC (Pin 18). This separate supply input allows the designer added flexibility in
tailoring the drive voltage, independent of VCC. A zener clamp should be connected to this input when driving
power MOSFETs in systems where VCC is greater than 20 V so as to prevent rupture of the MOSFET gates.
The control circuitry ground (Pin 16) and current sense inverting input (Pin 15) must return on separate paths to the
central input source ground.
Thermal Shutdown
Internal thermal shutdown circuitry is provided to protect the IC in the event the maximum junction temperature is
exceeded. When activated, typically at 170°C, the IC acts as though the Output Enable was grounded.
Timed Delayed Latched Over Current Shutdown
10/28
High Voltage Interface with NPN Power Transistors
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
High Voltage Interface with N-Channel Power MOSFETS
MOSFET Drive Precautions
11/28
Current Waveform Spike Suppression
Bipolar Transistor Drive
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
High Voltage Boost Supply
Current Sensing Power MOSFETs
Differential Input Speed Controller
12/28
Controlled Acceleration/Deceleration
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BRUSHLESS DC MOTOR CONTROLLER
FSP33035
Digital Speed Controller
Closed Loop Speed Control
Closed Loop Temperature Control
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BRUSHLESS DC MOTOR CONTROLLER
„
FSP33035
APPLICATION
Three Phase Motor Commutation
The three phase application shown in Figure below is a full–featured open loop motor controller with full wave, six
step drive. The upper power switch transistors are Darlingtons while the lower devices are power MOSFETs. Each
of these devices contains an internal parasitic catch diode that is used to return the stator inductive energy back to
the power supply. The outputs are capable of driving a delta or wye connected stator, and a grounded neutral wye if
split supplies are used. At any given rotor position, only one top and one bottom power switch (of different totem
poles) is enabled. This configuration switches both ends of the stator winding from supply to ground which causes
the current flow to be bidirectional or full wave. A leading edge spike is usually present on the current waveform and
can cause a current–limit instability. The spike can be eliminated by adding an RC filter in series with the Current
Sense Input. Using a low inductance type resistor for RS will also aid in spike reduction. Care must be taken in the
selection of the bottom power switch transistors so that the current during braking does not exceed the device rating.
During braking, the peak current generated is limited only by the series resistance of the conducting bottom switch
and winding.
If the motor is running at maximum speed with no load, the generated back EMF can be as high as the supply
voltage, and at the onset of braking, the peak current may approach twice the motor stall current. The next figure
shows the commutation waveforms over two electrical cycles. The first cycle (0° to 360°) depicts motor operation at
full speed while the second cycle (360° to 720°) shows a reduced speed with about 50% pulse width modulation.
The current waveforms reflect a constant torque load and are shown synchronous to the commutation frequency for
clarity.
Three Phase, Six Step, Full Wave Motor Controller
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FSP33035
Three Phase, Six Step, Full Wave Commutation Waveforms
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BRUSHLESS DC MOTOR CONTROLLER
FSP33035
The figure below shows a three phase, three step, half wave motor controller. This configuration is ideally suited for
automotive and other low voltage applications since there is only one power switch voltage drop in series with a
given stator winding. Current flow is unidirectional or half wave because only one end of each winding is switched.
Continuous braking with the typical half wave arrangement presents a motor overheating problem since stator
current is limited only by the winding resistance. This is due to the lack of upper power switch transistors, as in the
full wave circuit, used to disconnect the windings from the supply voltage VM. A unique solution is to provide
braking until the motor stops and then turn off the bottom drives. This can be accomplished by using the Fault
Output in conjunction with the Output Enable as an over current timer. Components RDLY and CDLY are selected to
give the motor sufficient time to stop before latching the Output Enable and the top drive AND gates low. When
enabling the motor, the brake switch is closed and the PNP transistor (along with resistors R1 and RDLY ) are used
to reset the latch by discharging CDLY. The stator flyback voltage is clamped by a single zener and three diodes.
Three Phase, Three Step, Half Wave Motor Controller
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FSP33035
Three Phase Closed Loop Controller
The FSP33035, by itself, is only capable of open loop motor speed control. For closed loop motor speed control, the
FSP33035 requires an input voltage proportional to the motor speed. Traditionally, this has been accomplished by
means of a tachometer to generate the motor speed feedback voltage. Figure below shows an application whereby
an MC33039, powered from the 6.25 V reference (Pin 8) of the FSP33035, is used to generate the required
feedback voltage without the need of a costly tachometer. The same Hall sensor signals used by the FSP33035 for
rotor position decoding are utilized by the MC33039. Every positive or negative going transition of the Hall sensor
signals on any of the sensor lines causes the MC33039 to produce an output pulse of defined amplitude and time
duration, as determined by the external resistor R1 and capacitor C1. The output train of pulses at Pin 5 of the
MC33039 are integrated by the error amplifier of the FSP33035 configured as an integrator to produce a DC
voltage level which is proportional to the motor speed. This speed proportional voltage establishes the PWM
reference level at Pin 13 of the FSP33035 motor controller and closes the feedback loop. The FSP33035 outputs
drive a TMOS power MOSFET 3–phase bridge. High currents can be expected during conditions of start–up,
breaking, and change of direction of the motor. The system shown in the below Figure is designed for a motor
having 120/240 degrees Hall sensor electrical phasing. The system can easily be modified to accommodate 60/300
degree Hall sensor electrical phasing by removing the jumper (J2) at Pin 22 of the FSP33035.
Closed Loop Brushless DC Motor Control Using the FSP33035 and MC33039
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FSP33035
Sensor Phasing Comparison
There are four conventions used to establish the relative phasing of the sensor signals in three phase motors. With
six step drive, an input signal change must occur every 60 electrical degrees; however, the relative signal phasing is
dependent upon the mechanical sensor placement. A comparison of the conventions in electrical degrees is shown
in the figure in page 17. From the sensor phasing table, note that the order of input codes for 60° phasing is the
reverse of 300°. This means the FSP33035, when configured for 60° sensor electrical phasing, will operate a motor
with either 60° or 300° sensor electrical phasing, but resulting in opposite directions of rotation. The same is true for
the part when it is configured for 120° sensor electrical phasing; the motor will operate equally, but will result in
opposite directions of rotation for 120° for 240° conventions.
Sensor Phasing Comparison
Sensor Phasing Table
In this data sheet, the rotor position is always given in electrical degrees since the mechanical position is a
function of the number of rotating magnetic poles. The relationship between the electrical and mechanical position
is:
An increase in the number of magnetic poles causes more electrical revolutions for a given mechanical revolution.
General purpose three phase motors typically contain a four pole rotor which yields two electrical revolutions for
one mechanical.
Two and Four Phase Motor Commutation
The FSP33035 is also capable of providing a four step output that can be used to drive two or four phase motors.
The truth table in page 19 shows that by connecting sensor inputs SB and SC together, it is possible to truncate the
number of drive output states from six to four. The output power switches are connected to BT, CT, BB, and CB. The
figure in page 20 shows a four phase, four step, full wave motor control application. Power switch transistors Q1
through Q8 are Darlington type, each with an internal parasitic catch diode. With four step drive, only two rotor
position sensors spaced at 90 electrical degrees are required. The commutation waveforms are shown in the figure
in page 21. Figure in page 22 shows a four phase, four step, half wave motor controller. It has the same features as
the circuit in the figure in page 16, except for the deletion of speed control and braking.
Two and Four Phase, Four Step, Commutation Truth Table
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2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
Four Phase, Four Step, Full Wave Motor Controller
19/28
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
Four Phase, Four Step, Full Wave Motor Controller
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2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
Four Phase, Four Step, Half Wave Motor Controller
21/28
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
H–Bridge Brush–Type Controller
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BRUSHLESS DC MOTOR CONTROLLER
FSP33035
Brush Motor Control
Though the FSP33035 was designed to control brushless DC motors, it may also be used to control DC brush type
motors. Figure in page 22 shows an application of the FSP33035 driving a MOSFET H–bridge affording minimal
parts count to operate a brush–type motor. Key to the operation is the input sensor code [100] which produces a
top–left (Q1) and a bottom–right (Q3) drive when the controller’s forward/reverse pin is at logic [1]; top–right (Q4),
bottom–left (Q2) drive is realized when the Forward/Reverse pin is at logic [0]. This code supports the requirements
necessary for H–bridge drive accomplishing both direction and speed control.
The controller functions in a normal manner with a pulse width modulated frequency of approximately 25 kHz. Motor
speed is controlled by adjusting the voltage presented to the noninverting input of the error amplifier establishing the
PWM’s slice or reference level. Cycle–by–cycle current limiting of the motor current is accomplished by sensing the
voltage (100 mV) across the RS resistor to ground of the H–bridge motor current. The over current sense circuit
makes it possible to reverse the direction of the motor, using the normal forward/reverse switch, on the fly and not
have to completely stop before reversing.
„
LAYOUT CONSIDERSIONS
Do not attempt to construct any of the brushless motor control circuits on wire–wrap or plug–in prototype
boards. High frequency printed circuit layout techniques are imperative to prevent pulse jitter. This is usually caused
by excessive noise pick–up imposed on the current sense or error amp inputs. The printed circuit layout should
contain a ground plane with low current signal and high drive and output buffer grounds returning on separate paths
back to the power supply input filter capacitor VM. Ceramic bypass capacitors (0.1 µF) connected close to the
integrated circuit at VCC , VC , Vref and the error amp noninverting input may be required depending upon circuit
layout. This provides a low impedance path for filtering any high frequency noise. All high current loops should be
kept as short as possible using heavy copper runs to minimize radiated EMI.
„
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TYPICAL PERFORMANCE CHARACTERISTICS
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
„
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FSP33035
TYPICAL PERFORMANCE CHARACTERISTICS(CONTINUED)
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
„
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FSP33035
TYPICAL PERFORMANCE CHARACTERISTICS(CONTINUED)
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
„
TYPICAL PERFORMANCE CHARACTERISTICS(CONTINUED)
„
ORDERING INFORMATION
FSP33035XXX
Package:
S: SOP24L
N: PDIP24L
„
Packing:
Blank: Tube or Bulk
Temperature Grade:
D: -40~85℃
MARKING INFORMATION
FSP33035
Logo
Part number
YYWWXX
Internal code
Date code:
YY: Year (01=2001)
WW: Nth week (01~52)
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2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
„
PACKAGE INFORMATION
(1) SOP24L
Symbol
A
A1
b
C
D
E
e
H
h
L
Y
θ
27/28
Dimensions In Millimeters
Nom.
Max.
2.54
2.64
0.20
0.30
0.406
0.48
0.254
0.31
15.29
15.60
7.50
7.60
1.27BSC
10.00
10.31
10.65
0.25
0.66
0.75
0.51
0.76
1.02
0.075
0º
8º
Min.
2.36
0.10
0.35
0.23
15.20
7.40
Dimensions In Inches
Nom.
0.102
0.008
0.016
0.010
0.612
0.300
0.051BSC
0.400
0.412
0.010
0.026
0.020
0.030
Min.
0.094
0.004
0.014
0.009
0.600
0.296
Max.
0.106
0.012
0.019
0.012
0.624
0.304
0º
0.426
0.030
0.041
0.003
8º
2007-3-16
BRUSHLESS DC MOTOR CONTROLLER
FSP33035
(2) PDIP24L
Symbol
A
A1
A2
B
B1
C
D
E
E1
e
L
E2
28/28
Dimensions In Millimeters
Min.
Max.
3.710
4.310
0.510
3.200
3.600
0.360
0.560
1.524(Typ.)
0.204
0.360
29.250
29.850
6.200
6.600
7.620(Typ.)
2.540(Typ.)
3.000
3.600
8.200
9.400
Dimensions In Inches
Min.
Max.
0.148
0.172
0.020
0.128
0.144
0.014
0.022
0.061(Typ.)
0.008
0.014
1.170
1.194
0.248
0.264
0.305(Typ.)
0.102(Typ.)
0.120
0.144
0.328
0.376
2007-3-16