TOSHIBA TB6575FNG

TB6575FNG
TOSHIBA CMOS Integrated Circuit
Silicon Monolithic
TB6575FNG
PWM Sensorless Controller for 3-Phase Full-Wave BLDC Motors
The TB6575FNG provides sensorless commutation and PWM
current control for 3-phase full-wave BLDC motors. It controls
rotation speed by changing a PWM duty cycle by analog voltage.
Features
•
3-phase full-wave sensorless drive
•
PWM chopper drive
•
PWM duty cycle control by analog input
•
20-mA current sink capability on PWM output pins
•
Overcurrent protection
•
Forward/reverse rotation
•
Lead angle control (7.5° and 15°)
•
Overlap commutation
•
Rotation speed sensing signal
•
DC excitation mode to improve startup characteristic
•
DC excitation time and forced commutation time for startup operation can be changed.
•
Forced commutation frequency can be selected. (fXT/(6 × 216), fXT/(6 × 217), fXT/(6 × 218) )
•
Output polarity switching (P-channel + N-channel, N-channel + N-channel)
Weight: 0.14 g (typ.)
The following conditions apply to solderability:
*Solderability
1. Use of Sn-37Pb solder bath
*solder bath temperature = 230ºC
*dipping time = 5 seconds
*number of times = once
*use of R-type flux
2. Use of Sn-3.0Ag-0.5Cu solder bath
*solder bath temperature = 245ºC
*dipping time = 5 seconds
*number of times = once
*use of R-type flux
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TB6575FNG
Block Diagram
Startup time
setting
VSP 5
6-bit AD
converter
Duty
VDD
19
21
OS FG_OUT
3
7
PWM
control
13 OUT_UP
15 OUT_VP
SC 2
START 8
PWM
generator
DC excitation
control circuit
IP 9
FST 24
Forced
commutation
frequency setting
FMAX 4
Maximum
commutation
frequency setting
14 OUT_UN
16 OUT_VN
Timing
control
18 OUT_WN
Overcurrent
protection
Lead angle
setting
LA 12
17 OUT_WP
22 OC
CW_CCW 6
SEL_LAP 20
Clock
generation
Position
recognition
10
11
1
XTout
XTin
GND
23 WAVE
Pin Assignment
GND
1
24
FST
SC
2
23
WAVE
OS
3
22
OC
FMAX
4
21
VDD
VSP
5
20
SEL_LAP
CW_CCW
6
19
Duty
FG_OUT
7
18
OUT_WN
START
8
17
OUT_WP
IP
9
16
OUT_VN
XTout
10
15
OUT_VP
XTin
11
14
OUT_UN
LA
12
13
OUT_UP
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TB6575FNG
Pin Description
Pin No.
Symbol
I/O
1
GND
⎯
2
SC
I
Connection pin for a capacitor to set a startup commutation time and duty cycle ramp-up
time
I
Select the polarity of transistors.
High or open : High-side transistor = P-channel (active low)
Low-side transistor = N-channel (active low)
Low
: High-side transistor = N-channel (active low)
Low-side transistor = N-channel (active low)
The pin has a pull-up resistor.
3
OS
Description
Ground pin
Set an upper limit of the maximum commutation frequency.
<Fst=Low>
FMAX =High or Open , Maximum commutation frequency fMX = fXT/ (6×2 )
12
FMAX =Low , Maximum commutation frequency fMX = fXT/(6 × 2 )
11
4
FMAX
I
<Fst=High or Middle>
FMAX =High or Open , Maximum commutation frequency fMX = fXT/ (6×2 )
9
FMAX =Low , Maximum commutation frequency fMX = fXT/(6 × 2 )
The pin has a pull-up resistor.
8
5
VSP
I
Duty cycle control input
0 ≤ VSP ≤ VAD (L): Output off
VAD (L) ≤ VSP ≤ VAD (H): Set the PWM duty cycle according to the analog input.
VAD (H) ≤ VSP ≤ VDD: Duty cycle = 100% (31/32)
The pin has a pull-down resistor.
6
CW_CCW
I
Rotation direction input
High
: Reverse rotation (U → W → V)
Low or open : Forward rotation (U → V → W)
The pin has a pull-down resistor.
Rotation speed sensing output
The pin is low at startup or upon a detection of a fault. This pin drives three pulses per
rotation (3 ppr) based on the back-EMF (electromotive force) sensing. (In the case of 4
pole motor, 6 pulse output per rotation.)
7
FG_OUT
O
8
START
O
9
IP
I
10
XT
⎯
11
XTin
⎯
12
LA
I
Lead angle control input
LA = Low or open : Lead angle of 7.5°
LA = high
: Lead angle of 15°
The pin has a pull-down resistor.
13
OUT_UP
O
PWM output signal for the high-side (positive-side) transistor driving motor phase U
The PWM polarity can be specified by pin 3.
14
OUT_UN
O
PWM output signal for the low-side (negative-side) transistor driving motor phase U
This signal is active high.
15
OUT_VP
O
PWM output signal for the high-side (positive-side) transistor driving motor phase V
The PWM polarity can be specified by pin 3.
16
OUT_VN
O
PWM output signal for the low-side (negative-side) transistor driving motor phase V
This signal is active high.
17
OUT_WP
O
PWM output signal for the high-side (positive-side) transistor driving motor phase W
The PWM polarity can be specified by pin 3.
18
OUT_WN
O
PWM output signal for the low-side (negative-side) transistor driving motor phase W
This signal is active high.
19
Duty
O
PWM output monitor pin
This pin drives PWM output whose duty cycle corresponds to the VSP input. It also
reflects the information at the OC pin.
20
SEL_LAP
I
Overlap commutation select pin
Low: Overlap commutation
The pin has a pull-up resistor.
DC excitation time setting pins
When VSP ≥ 1 V (typ.), the START pin goes low to start DC excitation.
After the IP pin reaches VDD/2, the TB6575FNG moves from DC excitation to forced
commutation mode.
Connection pins for a crystal oscillator
These pins have a feedback resistor.
3
High: 120° commutation
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TB6575FNG
Pin No.
Symbol
I/O
21
VDD
⎯
22
OC
I
Overcurrent detection input
The all PWM output signals are stopped when OC ≥ 0.5 (V).
The pin has a pull-up resistor.
23
WAVE
I
Position sensing input
3-phase voltage is applied to this pin.
The pin has a pull-up resistor.
I
Forced commutation frequency select pin
16
High or open : Forced commutation frequency fST = fXT/(6 × 2 )
17
Middle
: Forced commutation frequency fST = fXT/(6 × 2 )
18
Low
: Forced commutation frequency fST = fXT/(6 × 2 )
The pin has a pull-up resistor.
24
FST
Description
5-V power supply pin
Functional Description
1. Sensorless drive
On receiving an analog voltage command input, the rotor is aligned to a known position in DC excitation
mode, and then the rotation is started in forced commutation mode by applying a PWM signal to the motor.
As the rotor moves, back-EMF is acquired.
When a signal indicating the polarity of each of the phase voltages including back-EMF is applied to the
position signal input pin, automatic switching occurs from the forced commutation PWM signal to the
natural commutation PWM signal (which is generated based on the back-EMF sensing) to drive a BLDC
motor in sensorless mode.
2. Startup operation
When the motor is stationary, there is no back-EMF and the motor position is unknown. For this reason,
the rotor is aligned to a known position in DC excitation mode and then the rotation is started in forced
commutation mode. An external capacitor sets the times that the TB6575FNG stays in DC excitation and
forced commutation modes. Those times vary depending on the motor type and motor loading. Thus, they
must be adjusted experimentally.
VSP ≥ 1.0 (V)
VSP (5 pin)
VSP
VAD (L)
SC (2 pin)
TUP (typ.) = C1 × VSP/3.8 µA (s)
TUP
START_SP (8 pin)
VDD
IP (9 pin)
(a) (b)
VDD
2
GND
VSP
5
TB6575FNG
(a): DC excitation period : TFIX (typ.) = 0.69 × C1 × R1 (s)
(b): Forced commutation period
2
C1
9
8
R1
C2
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TB6575FNG
The rotor is aligned to a known position in DC excitation mode for period (a), during which the IP pin voltage
decreases to half VDD level. The time constant for the period is determined by C2 and R1. After that, switching
occurs to forced commutation mode represented by (b). The duty cycles for DC excitation and forced commutation
modes are determined according to the SC pin voltage. When the number of turn of a motor is time more than
forced commutation frequency, the motor switches to sensorless mode. The duty cycle for sensorless mode is
determined by the VSP value.
3. Forced commutation frequency
The forced commutation frequency for startup operation is set as follows.
The optimal frequency varies depending on the motor type and motor loading. Thus, It must be adjusted
experimentally.
FST = High or Open : Forced commutation frequency fST = fXT/(6 × 216)
FST = Middle
: Forced commutation frequency fST = fXT/(6 × 217)
18
FST = Low
: Forced
TFIX commutation frequency fST = fXT/(6 × 2 )
* fXT: Crystal oscillator frequency
4. PWM frequency
The PWM frequency is determined by an external oscillator.
PWM frequency (fPWM) = fXT/256
* fXT: Crystal oscillator frequency
The PWM frequency must be sufficiently high, compared with the electrical frequency of the motor and
within the switching performance of the transistors.
OS = High or Open
PWM signal driving
high-side transistors
PWM signal driving
low-side transistors
Motor pin voltage
5. Speed control VSP pin
An analog voltage applied to the VSP pin is converted by the 6-bit AD converter to control the duty cycle
Duty cycle
of the PWM.
0 ≤ VDUTY ≤ VAD (L)
→ Duty cycle = 0%
VAD (L) ≤ VDUTY ≤ VAD (H)
→ Figure at the right (1/64 to 63/64)
VAD (H) ≤ VDUTY ≤ VDD
→ Duty cycle = 100% (63/64)
100%
0%
5
VAD (L)
VAD (H)
1 V (typ.)
4 V (typ.)
VSP
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TB6575FNG
6. Fault protection
When a signal indicating the following faults is applied to the WAVE pin, the output transistors are
disabled. After about one second, the motor is restarted. This operation is repeated as long as a fault is
detected.
• The maximum commutation frequency is exceeded.
• The rotation speed falls below the forced commutation frequency.
VSP = 1 V or higher
VSP (Pin5)
Output pin
ON
OFF
When the SC pin capacitor = 0.47 µF
and VSP = 4 V
ON
(a): TOFF =
START (Pin8)
=
CSC × (VSP − 1)
i
0.47 µF × ( 4 − 1)
1.5 µA
= 940 ms (typ.)
IP (Pin9)
(a)
VSP
SC (Pin9)
1V
Fault detected
7. Motor position detection error
A position detection is synchronized with the PWM signal generated in the IC. Thus, a position detection
error relative to the PWM signal frequency may occur. Keep this in mind especially when the TB6575FNG
is used for a high-speed motor.
A detection is performed on the falling edge of the PWM signal. An error is recognized when the pin
voltage exceeds the reference voltage.
Detection error time < 1/fp
fp: PWM frequency = fXT/256
fXT: Crystal oscillator frequency
Output ON
Internal PWM signal
Pin voltage
Pin voltage
Reference voltage
Position sensing input
Ideal detection timing
Actual detection timing
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TB6575FNG
8. Lead angle control
The motor runs with a lead angle of 0° in forced commutation mode at startup. After switching to natural
commutation, the lead angle automatically changes to the value set by the LA pin.
U
Back-EMF
PWM signal
(1) Lead angle of 0°
V
W
30°
OUT_UP
OUT_UN
OUT_VP
OUT_VN
OUT_WP
OUT_WN
(2) Lead angle of 7.5°
22.5°
OUT_UP
OUT_UN
OUT_VP
OUT_VN
OUT_WP
OUT_WN
(3) Lead angle of 15°
15°
OUT_UP
OUT_UN
OUT_VP
OUT_VN
OUT_WP
OUT_WN
*OS = High
9. Overlap commutation
When SEL_LAP = high, the TB6575FNG is configured to allow for 120° commutation. When SEL_LAP =
low, it is configured to allow for overlap commutation. In overlap commutation, there is an overlap period
during which both the outgoing transistor and incoming transistor are conducting (as shown in the shaded
areas). This period varies according to the lead angle.
Back-EMF
PWM signal
U
V
W
(1) Lead angle of 7.5°
OUT_UP
OUT_UN
OUT_VP
OUT_VN
OUT_WP
OUT_WN
(2) Lead angle of 15°
OUT_UP
OUT_UN
OUT_VP
OUT_VN
OUT_WP
OUT_WN
*OS = High
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TB6575FNG
Absolute Maximum Ratings (Ta = 25°C)
Characteristics
Symbol
Rating
Unit
Power supply voltage
VDD
5.5
V
Input voltage
Vin
−0.3~VDD + 0.3
V
IOUT
20
mA
Turn-on signal output current
Power dissipation
PD
Operating temperature
Topr
−30~105
780 (Note)
mW
°C
Storage temperature
Tstg
−55~150
°C
Note: Without a PCB, stand-alone operation
Recommended Operating Conditions (Ta = −30 to 105°C)
Characteristics
Power supply voltage
Symbol
Test Condition
Min
Typ.
Max
Unit
VDD
⎯
4.5
5.0
5.5
V
V
MHz
Input voltage
Vin
⎯
−0.3
⎯
VDD
+ 0.3
Oscillation frequency
fXT
⎯
2.0
4.0
8.0
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TB6575FNG
Electrical Characteristics (Ta = 25°C, VDD = 5 V)
Characteristics
Static power supply current
Dynamic power supply current
Input current
Symbol
Test
Circuit
IDD
⎯
IDD (opr)
Min
Typ.
Max
Unit
VSP = 0 V, XTin = H
⎯
0.7
1
mA
⎯
VSP = 2.5 V, XTin = 4 MHz,
Output open
⎯
2
6
mA
IIN-1 (H)
⎯
VIN = 5 V, OC, WAVE, SEL_LAP
FMAX, FST, OS
⎯
0
1
IIN-1 (L)
⎯
VIN = 0 V, OC, WAVE, SEL_LAP,
FMAX, FST, OS
−75
−50
⎯
IIN-2 (H)
⎯
VIN = 5 V, CW_CCW, LA, VSP
⎯
50
75
IIN-2 (L)
⎯
VIN = 0 V, CW_CCW, LA, VSP
−1
0
⎯
VIN-1 (H)
⎯
OC, SEL_LAP, CW_CCW
WAVE, LA, FMAX, OS
3.5
⎯
5
VIN-1 (L)
⎯
OC, SEL_LAP, CW_CCW
WAVE, LA, FMAX, OS
GND
⎯
1.5
VIN-2 (H)
⎯
FST
4
⎯
5
VIN-2 (M)
⎯
FST
2
⎯
3
VIN-2 (L)
⎯
FST
GND
⎯
1
VH
⎯
⎯
0.45
⎯
VO-1 (H)
⎯
IOH = −2 mA
OUT_UP, OUT_VP, OUT_WP
4.5
⎯
VDD
VO-1 (L)
⎯
IOL = 20 mA
OUT_UP, OUT_VP, OUT_WP
GND
⎯
0.5
VO-2 (H)
⎯
IOH = −20 mA
OUT_UN, OUT_VN, OUT_WN
4.5
⎯
VDD
VO-2 (L)
⎯
IOL = 2 mA
OUT_UN, OUT_VN, OUT_WN
GND
⎯
0.5
VO-3 (H)
⎯
IOH = −0.5 mA
FG_OUT
4.5
⎯
VDD
VO-3 (L)
⎯
IOL = 0.5 mA
FG_ OUT
GND
⎯
0.5
IL (H)
⎯
VDD = 5.5 V, VOUT = 0 V
OUT_UP, OUT_VP, OUT_WP,
OUT_UN, OUT_VN, OUT_WN,
FG_OUT
⎯
0
10
⎯
VDD = 5.5 V, VOUT = 5.5 V
OUT_UP, OUT_VP, OUT_WP
OUT_UN, OUT_VN, OUT_WN,
FG_OUT
⎯
0
10
⎯
0.8
1.0
1.2
VSP
3.8
4.0
4.2
Input voltage
Input hysteresis voltage
Output voltage
Output leak current
IL (L)
PWM input voltage
VAD (L)
VAD (H)
Test Condition
WAVE, IP
µA
V
V
V
µA
V
ISC
⎯
SC
2.6
3.8
5.0
µA
Fault retry time
TOFF
⎯
VSP = 4 V, SC pin = 0.47 µF
⎯
940
⎯
ms
Overcurrent detection voltage
VOC
⎯
OC
0.46
0.5
0.54
V
CSC charge current
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TB6575FNG
Input Equivalent Circuit
1. VSP pin
2. SEL_LAP, FMAX, FST, WAVE and OS pins
VDD VDD
1 kΩ
100 kΩ
Input pin
100 kΩ
VDD
Startup time
setting block
Input pin
Internal logic
1 kΩ
Hysteresis width
WAVE : 450 mV (typ.)
3. LA and CW_CCW pins
4. OUT_UP, OUT_UN, OUT_VP, OUT_VN, OUT_WP,
OUT_WN and FG_OUT pins
VDD
VDD
1 kΩ
Internal logic
100 kΩ
Internal logic
5. XTin and XTout pins
VDD
VDD VDD
150 Ω
XTout pin
OC pin
10
200 kΩ
Internal logic
0.5 V
150 Ω
XTin pin
1MΩ
6. OC pin
100 kΩ
VDD
Output pin
5 pF
Input pin
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TB6575FNG
Application Circuit Example
MCU
Startup time
setting
SC
2
START
8
IP
9
PWM
control
PWM
generator
1-phase excitation
control circuit
Startup commutation
frequency setting
Timing
setting
OUT_UP
13
OUT_VP
15
OUT_WP
17
OUT_UN
14
OUT_VN
16
OUT_WN
18
M
1Ω
FST
24
FMAX
4
Maximum commutation
frequency setting
Overcurrent
protection
Lead angle setting
OC
22
(*1)
SEL_LAP
20
1 kΩ
22 pF
LA
12
CW_CCW
6
100 kΩ
VDD
6-bit AD
converter
7
FG_OUT
100 kΩ
VDD
2
VSP
5
24
OS
10 kΩ
Speed command
(analog voltage)
VM
21
VDD
100 kΩ × 3
Duty
19
5V
TA75393P
Clock
generation
XTout
10
XTin
11
Position
recognition
WAVE
23
GND
1
4-MHz crystal oscillator
Note 1: Utmost care is necessary in the design of the output, VCC, VM, and GND lines since the IC may be destroyed by short-circuiting between outputs, air contamination faults,
or faults due to improper grounding, or by short-circuiting between contiguous pins.
Note 2: The above application circuit including component values is reference only. Because the values may vary depending on the motor type, the optimal values must be
determined experimentally.
*1: Connect a resistor, if necessary, to prevent malfunction due to noise.
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TB6575FNG
Package Dimensions
Weight: 0.14 g (typ.)
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TB6575FNG
Notes on Contents
1. Block Diagrams
Some of the functional blocks, circuits, or constants in the block diagram may be omitted or simplified
for explanatory purposes.
2. Equivalent Circuits
The equivalent circuit diagrams may be simplified or some parts of them may be omitted for
explanatory purposes.
3. Timing Charts
Timing charts may be simplified for explanatory purposes.
4. Application Circuits
The application circuits shown in this document are provided for reference purposes only. Thorough
evaluation is required, especially at the mass production design stage.
Toshiba does not grant any license to any industrial property rights by providing these examples of
application circuits.
5. Test Circuits
Components in the test circuits are used only to obtain and confirm the device characteristics. These
components and circuits are not guaranteed to prevent malfunction or failure from occurring in the
application equipment.
IC Usage Considerations
Notes on handling of ICs
[1] The absolute maximum ratings of a semiconductor device are a set of ratings that must not be
exceeded, even for a moment. Do not exceed any of these ratings.
Exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result
injury by explosion or combustion.
[2] Do not insert devices in the wrong orientation or incorrectly.
Make sure that the positive and negative terminals of power supplies are connected properly.
Otherwise, the current or power consumption may exceed the absolute maximum rating, and
exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result
injury by explosion or combustion.
In addition, do not use any device that is applied the current with inserting in the wrong orientation
or incorrectly even just one time.
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TB6575FNG
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