ENN7498 D

Ordering number : ENN7498A
LB11923V
Monolithic Digital IC
Three-Phase Brushless
Motor Driver
http://onsemi.com
Overview
The LB11923V is a pre-driver IC designed for variable-speed control of 3-phase brushless motors. It can be used to
implement a motor drive circuit with the desired output capacity (voltage, current) by using discrete transistors for the
output stage. It implements direct PWM drive for minimal power loss. Since the LB11923V includes a built-in VCO
circuit, applications can control the motor speed arbitrarily by varying the external clock frequency.
Function
 Direct PWM drive output
 Speed discriminator + PLL speed control circuit
 Speed lock detection output
 Built-in crystal oscillator circuit
 Forward/reverse switching circuit
 Braking circuit (short braking)
 Full complement of on-chip protection circuits, including lock protection, current limiter, and thermal shutdown
protection circuits.
Specifications
Absolute Maximum Ratings at Ta = 25C
Parameter
Symbol
Conditions
Ratings
Maximum supply voltage
VCC max
Maximum input current
IREG max
VREG pin
Output current
IO max
UH, VH, WH, UL, VL, and WL outputs
Allowable power dissipation 1
Pd max1
Allowable power dissipation 2
Pd max2
Operating temperature
Storage temperature
Unit
8
V
2
mA
30
mA
Independent IC
0.62
W
* When mounted on the specified PCB
1.79
W
Topr
20 to +80
C
Tstg
55 to +150
C
* Specified PCB : 114.3  76.1  1.6 mm glass epoxy PCB
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating
Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.
Semiconductor Components Industries, LLC, 2013
September, 2013
D0606 MS IM 20060327-S0004/21604TN (OT) No.7498-1/20
LB11923V
Allowable Operating Ranges at Ta = 25°C
Parameter
Symbol
Conditions
Ratings
Unit
4.4 to 7.0
V
0.2 to 1.5
mA
Supply voltage
VCC
Input current range
IREG
FG Schmitt output applied voltage
VFGS
0 to 7
V
FG Schmitt output current
IFGS
0 to 5
mA
Lock detection applied voltage
VLD
0 to 7
V
Lock detection output current
ILD
0 to 20
mA
VREG pin (7 V)
Electrical Characteristics at Ta = 25°C, VCC = 6.3 V
Parameter
Symbol
Conditions
Ratings
min
typ
ICC1
ICC2
In stop mode
ICC3
VCC = 5 V
ICC4
VCC = 5 V, In stop mode
Output saturation voltage 1-1
VO sat1-1 At low level: IO = 400 µA
Output saturation voltage 1-2
VO sat1-2 At low level: IO = 10 mA
Supply current
Output saturation voltage 2
VO sat2
At high level: IO = –20 mA
max
Unit
21
29.5
mA
2.3
3.3
mA
20
28
mA
2.1
2.9
mA
0.1
0.3
V
0.8
1.2
VCC – 1.2
VCC – 0.9
–2
–0.1
V
V
[Hall Amplifier]
Input bias current
IHB(HA)
Common-mode input voltage range 1
VICM1
When Hall-effect sensors are used
VICM2
When one-side biased inputs are used
(Hall-effect IC applications)
Common-mode input voltage range 2
Hall input sensitivity
Sine wave
µA
0.5
VCC – 2.0
V
0
VCC
V
100
mVp-p
∆VIN(HA)
25
35
52
Input voltage low → high
VSLH
9
17
29
mV
Input voltage high → low
VSHL
–29
–18
–9
mV
Hysteresis
mV
[PWM Oscillator]
Output high-level voltage 1
VOH(PWM)1
Output high-level voltage 2
VOH(PWM)2 VCC = 5 V
Output low-level voltage 1
VOL(PWM)1
Output low-level voltage 2
VOL(PWM)2 VCC = 5 V
3.5
3.8
4.1
V
2.75
3.0
3.25
V
1.8
2.1
2.4
V
1.45
1.65
1.9
V
1.4
1.7
2.0
Vp-p
VCC = 5 V
1.1
1.35
1.6
Vp-p
Output high-level voltage 1
VOH(CSD)1
3.95
4.4
4.85
V
Output high-level voltage 2
VOH(CSD)2 VCC = 5 V
3.15
3.5
3.85
V
Oscillator frequency
f(PWM)
Amplitude 1
V(PWM)1
Amplitude 2
V(PWM)2
C = 560 pF
22
kHz
[CSD Oscillator]
Output low-level voltage 1
VOL(CSD)1
1.1
1.4
1.7
V
Output low-level voltage 2
VOL(CSD)2 VCC = 5 V
0.9
1.1
1.3
V
External capacitor charge current
ICHG1
–13
–9
–6
µA
External capacitor discharge current
ICHG2
8
12
16
µA
2.65
3.0
3.35
Vp-p
VCC = 5 V
2.1
2.4
2.65
Vp-p
2.10
2.40
2.65
V
VCC = 5 V
2.00
2.30
2.55
V
1.60
1.90
2.10
V
VCC = 5 V
1.55
1.80
2.05
V
1.0
MHz
0.3
0.5
0.7
Vp-p
0.3
0.5
0.7
Vp-p
Oscillator frequency
f(RK)
Amplitude 1
V(RK)1
Amplitude 2
V(RK)2
C = 0.068 µF
22
Hz
[VCO Oscillator C pin]
Output high-level voltage 1
VOH(C)1
Output high-level voltage 2
VOH(C)2
Output low-level voltage 1
VOL(C)1
Output low-level voltage 2
VOL(C)2
Oscillator frequency
f(C)
Amplitude 1
V(C)1
Amplitude 2
V(C)2
*Note: Not tested
VCC = 5 V
Continued on next page.
No. 7498-2/20
LB11923V
Continued from preceding page.
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
max
0.235
0.260
0.285
150
180
°C
30
°C
[Current Limiter Operation]
Limiter
VRF
V
[Thermal Shutdown Operation]
Thermal shutdown operating temperature
TTSD
Design target value *
Hysteresis
∆TSD
Design target value *
VREG
I = 500 µA
[VREG Pin]
VREG pin voltage
6.6
7.0
7.4
V
[Low-voltage Protection Circuit]
Operating voltage
VSDL
3.55
3.75
4.00
V
Release voltage
VSDH
3.85
4.03
4.25
V
Hysteresis
∆VSD
0.18
0.28
0.38
V
VIO(FG)
–10
+10
mV
IB(FG)
–1
+1
µA
[FG Amplifier]
Input offset voltage
Input bias current
Output high-level voltage 1
VOH(FG)1
IFGI = –0.1 mA, No load
4.2
4.6
5.0
V
Output high-level voltage 2
VOH(FG)2
IFGI = –0.1 mA, No load, VCC = 5 V
3.6
3.95
4.3
V
Output low-level voltage 1
VOL(FG)1
IFGI = 0.1 mA, No load
1.3
1.7
2.1
V
Output low-level voltage 2
VOL(FG)2
IFGI = 0.1 mA, No load, VCC = 5 V
0.7
1.05
1.4
V
180
250
mV
4
kHz
FG input sensitivity
Gain: 100×
Schmitt amplitude for the next stage
3
100
mV
Operating frequency range
Open-loop gain
Reference voltage
f (FG) = 2 kHz
VB(FG)
45
51
–5%
VCC/2
5%
dB
0.2
0.4
V
10
µA
1.1
V
V
[FGS Output]
Output saturation voltage
VO(FGS)
IO(FGS) = 2 mA
Output leakage current
IL(FGS)
VO = VCC
[Speed Discriminator Output]
Output high-level voltage
VOH(D)
Output low-level voltage
VOL(D)
VCC – 1.0
V
VCC – 0.7
0.8
[Speed Control PLL Output]
Output high-level voltage
Output low-level voltage
VOH(P)1
4.05
4.30
4.65
V
VCC = 5 V
3.25
3.50
3.85
V
1.85
2.15
2.45
V
VOL(P)2
VCC = 5 V
1.25
1.60
1.85
V
VOL(LD)
ILD = 10 mA
0.25
0.4
V
10
µA
+6.25
%
VOH(P)2
VOL(P)1
[Lock Detection]
Output saturation voltage
Output leakage current
IL(LD)
VO = VCC
Lock range
–6.25
[Integrator]
Input offset voltage
Input bias current
VIO(INT)
–10
+10
mV
IB(INT)
–0.4
+0.4
µA
Output high-level voltage 1
VOH(INT)1 IINTI = –0.1 mA, No load
Output high-level voltage 2
VOH(INT)2 IINTI = –0.1 mA, No load, VCC = 5 V
4.1
4.4
4.7
V
3.45
3.7
3.95
V
Output low-level voltage 1
VOL(INT)1 IINTI = 0.1 mA, No load
1.2
1.4
1.65
V
Output low-level voltage 2
VOL(INT)2 IINTI = 0.1 mA, No load, VCC = 5 V
1.1
1.3
1.5
V
Open-loop gain
45
Gain-bandwidth product
Design target value *
51
dB
1.0
MHz
VB(INT)
–5%
VCC/2
Output source current
IOH(FIL)
–17
–13
–7
µA
Output sink current
IOL(FIL)
7
12
17
µA
Reference voltage
5%
V
[FIL Output]
*Note: Not tested
Continued on next page.
No. 7498-3/20
LB11923V
Continued from preceding page.
Parameter
Symbol
Conditions
Ratings
min
typ
max
Unit
[S/S Pin]
Input high-level voltage
VIH(S/S)
VCC = 6.3 V, 5 V
2.0
VCC
Input low-level voltage
VIL(S/S)
VCC = 6.3 V, 5 V
0
1.0
V
Input open voltage
VIO(S/S)
VCC – 0.5
VCC
V
Hysteresis
∆VIN(S/S)
V
VCC = 6.3 V, 5 V
0.13
0.22
0.31
V
IIH(S/S)
VS/S = VCC
–10
0
+10
µA
Input low-level current
IIL(S/S)
VS/S = 0 V
–170
–118
Pull-up resistance
RU(S/S)
37
53.5
70
kΩ
Input high-level current
µA
[F/R Pin]
Input high-level voltage
VIH(F/R)
VCC = 6.3 V, 5 V
2.0
VCC
Input low-level voltage
VIL(F/R)
VCC = 6.3 V, 5 V
0
1.0
V
Input open voltage
VIO(F/R)
VCC – 0.5
VCC
V
Hysteresis
∆VIN(F/R)
V
VCC = 6.3 V, 5 V
0.13
0.22
0.31
V
IIH(F/R)
VF/R = VCC
–10
0
+10
µA
Input low-level current
IIL(F/R)
VF/R = 0 V
–170
–118
Pull-up resistance
RU(F/R)
37
53.5
70
kΩ
Input high-level current
µA
[BR Pin]
Input high-level voltage
VIH(BR)
VCC = 6.3 V, 5 V
2.0
VCC
Input low-level voltage
VIL(BR)
VCC = 6.3 V, 5 V
0
1.0
V
Input open voltage
VIO(BR)
VCC – 0.5
VCC
V
Hysteresis
∆VIN(BR)
V
VCC = 6.3 V, 5 V
0.13
0.22
0.31
V
IIH(BR)
VBR = VCC
–10
0
+10
µA
Input low-level current
IIL(BR)
VBR = 0 V
–170
–118
Pull-up resistance
RU(BR)
37
53.5
70
kΩ
Input high-level current
µA
[CLK Pin]
Input high-level voltage
VIH(CLK)
VCC = 6.3 V, 5 V
2.0
VCC
Input low-level voltage
VIL(CLK)
VCC = 6.3 V, 5 V
0
1.0
V
V
Input open voltage
VIO(CLK)
VCC – 0.5
VCC
V
Hysteresis
∆VIN(CLK) VCC = 6.3 V, 5 V, design target value *
0.13
0.22
0.31
V
Input high-level current
IIH(CLK)
VCLK = VCC
–10
0
+10
µA
Input low-level current
IIL(CLK)
VCLK = 0 V
–170
–118
3.9
kHz
70
kΩ
Input frequency
Pull-up resistance
f(CLK)
37
RU(CLK)
53.5
µA
[N1 Pin]
Input high-level voltage
VIH(N1)
VCC = 6.3 V, 5 V
2.0
VCC
Input low-level voltage
VIL(N1)
VCC = 6.3 V, 5 V
0
1.0
V
V
Input open voltage
VIO(N1)
VCC – 0.5
VCC
V
Hysteresis
∆VIN(N1)
VCC = 6.3 V, 5 V, design target value *
0.13
0.22
0.31
V
IIH(N1)
VN1 = VCC
–10
0
+10
µA
Input low-level current
IIL(N1)
VN1 = 0 V
–170
–118
Pull-up resistance
RU(N1)
37
53.5
70
kΩ
Input high-level current
µA
[N2 Pin]
Input high-level voltage
VIH(N2)
VCC = 6.3 V, 5 V
2.0
VCC
Input low-level voltage
VIL(N2)
VCC = 6.3 V, 5 V
0
1.0
V
V
Input open voltage
VIO(N2)
VCC – 0.5
VCC
V
Hysteresis
∆VIN(N2)
VCC = 6.3 V, 5 V, design target value *
0.13
0.22
0.31
V
IIH(N2)
VN2 = VCC
–10
0
+10
µA
Input low-level current
IIL(N2)
VN2 = 0 V
–170
–118
Pull-up resistance
RU(N2)
37
53.5
70
kΩ
Input high-level current
µA
*Note: Not tested
No. 7498-4/20
LB11923V
Package Dimensions
unit : mm (typ)
3277
15.0
0.5
5.6
7.6
23
44
1
0.65
22
0.22
0.2
0.1
(1.5)
1.7max
(0.68)
SSOP44(275mil)
Allowable power dissipation, Pdmax – W
2.0
Pd max – Ta
Mounted on the specified PCB
(114.3 × 76.1 × 1.6 mm glass epoxy PCB)
1.79 W
1.5
1.0
1.002 W
Independent IC
0.62 W
0.5
0.347 W
0
–20
0
20
40
60
80
Ambient temperature, Ta – °C
100
ILB01550
IN1+
IN1–
IN2+
IN2–
IN3+
IN3–
VCC1
VCC2
WH
WL
VH
VL
UH
UL
GND2
GND1
RF
RFGND
NC
FGOUT
FGIN–
FGIN+
Pin Assignment
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
LB11923V
22
CSD
21
C
20
R
19
FIL
18
NC
17
PWM
16
TOC
15
INT.OUT
14
INT.IN
13
INT.REF
12
NC
11
POUT
10
DOUT
9
LD
8
FGS
7
N2
6
N1
5
BR
4
F/R
3
CLK
2
S/S
VREG
1
Top view
No. 7498-5/20
LB11923V
Speed Discriminator Count and VCO Divisor
N1
N2
Count
Divisor
High or open
High or open
1024
1024
High or open
Low
1024
512
Low
High or open
256
256
Low
Low
512
512
fFG = (divisor ÷ count) × fCLK
Three-Phase Logic Truth Table (A high (H) input is the state where IN+ > IN–.)
F/R=L
Item
F/R=H
Output
IN1
IN2
IN3
IN1
IN2
IN3
PWM
—
1
H
L
H
L
H
L
VH
UL
2
H
L
L
L
H
H
WH
UL
3
H
H
L
L
L
H
WH
VL
4
L
H
L
H
L
H
UH
VL
5
L
H
H
H
L
L
UH
WL
6
L
L
H
H
H
L
VH
WL
S/S Pin
BR Pin
High or open
Stop
High or open
Brake
Low
Start
Low
Released
No. 7498-6/20
LB11923V
IN3–
IN3+
IN2–
IN2+
IN1–
CSD
IN1+
Block Diagram
WH
HALL
FR
F/R
CSD
HYS
OSC
AMP
VH
LOGIC
PRI
UH
DRIVER
WL
VL
VCC
UL
LOGIC
BR
BR
TSD
TOC
S/S
RF
S/S
INT
OUT
CURR
COMP
LIM
+
–
RFGND
INT
IN
RES
1.3VREF
PWM
VCC
LVSD
INT
REF
PWM
OSC
GND
POUT
LD
LD
DOUT
SPEED
SPEED
DISCRI
PLL
N2
N2
N1
N1
1/N
FG
FGS
FILTER
R
VCO
VCO
C
PLL
+
–
FIL
CLK
VREG
CLK
VREG
FGO
FIL
–
+
FGIN–
FGIN+
VCC
No. 7498-7/20
LB11923V
Pin Functions
Pin No.
Pin
Functions
Equivalent circuit
1
VCC1
1
VREG
7-V shunt regulator output
2
S/S
50 kΩ
VCC1
Start/stop control
Low: 0 V to 1.0 V
High: 2.0 V to VCC
Goes high when left open.
Low for start.
High or open for stop.
The hysteresis is about 0.22 V.
3.5 kΩ
2
3
CLK
50 kΩ
VCC1
External clock signal input
Low: 0 V to 1.0 V
High: 2.0 V to VCC
Goes high when left open.
The hysteresis is about 0.22 V.
f = 3.9 kHz, maximum
3.5 kΩ
3
4
F/R
Forward/reverse control
Low: 0 V to 1.0 V
High: 2.0 V to VCC
Goes high when left open.
Low for forward.
High or open for reverse.
The hysteresis is about 0.22 V.
50 kΩ
VCC1
3.5 kΩ
4
Continued on next page.
No. 7498-8/20
LB11923V
Continued from preceding page.
Pin No.
Pin
Functions
Equivalent circuit
5
BR
50 kΩ
VCC1
Brake control (short braking operation)
Low: 0 V to 1.0 V
High: 2.0 V to VCC
Goes high when left open.
High or open for brake mode operation.
The hysteresis is about 0.22 V.
3.5 kΩ
5
6
N1
50 kΩ
VCC1
Switches the speed discriminator VCO divisor count.
Low: 0 V to 1.0 V
High: 2.0 V to VCC
Goes high when left open.
The hysteresis is about 0.22 V.
3.5 kΩ
6
7
N2
50 kΩ
VCC1
The speed discriminator count switching.
Low: 0 V to 1.0 V
High: 2.0 V to VCC
Goes high when left open.
The hysteresis is about 0.22 V.
3.5 kΩ
7
VCC1
8
8
FGS
FG amplifier output (after the Schmitt circuit)
This is an open collector output.
VCC1
9
9
LD
Speed lock detection output
This is an open collector output.
Goes low when the motor speed is within the speed lock
range (±6.25%).
Continued on next page.
No. 7498-9/20
LB11923V
Continued from preceding page.
Pin No.
Pin
Functions
Equivalent circuit
VCC1
10
DOUT
Speed discriminator output
Acceleration → high, deceleration → low
10
VCC1
POUT
13
INT REF
14
INT IN
Speed control system PLL output
Outputs the phase comparison result for
CLK and FG.
Integrating amplifier non-inverting input (1/2 VCC potential)
11
VCC1
30 kΩ
11
500 Ω
500 Ω
13
14
30 kΩ
Integrating amplifier inverting input
VCC1
INT OUT
Integrating amplifier output (speed control)
15
40 kΩ
15
Continued on next page.
No. 7498-10/20
LB11923V
Continued from preceding page.
Pin No.
Pin
Functions
Equivalent circuit
VCC1
16
TOC
Torque command input
Normally, this pin is connected to the INT.OUT pin. The
PWM duty is increased when the TOC pin voltage falls.
Do not apply a voltage that exceeds VCC – 0.5 V to this pin.
(An input from a normal operational amplifier is desirable.)
300 Ω
16
VCC1
PWM
PWM oscillator frequency setting.
Connect a capacitor between this pin and ground.
300 Ω
17
7.5 kΩ
17
VCC1
19
FIL
VCO PLL filter connection
19
300 Ω
VCC1
20
R
Sets the value of the charge current from the VCO circuit C
pin.
Insert a resistor between this pin and ground.
300 Ω
20
Continued on next page.
No. 7498-11/20
LB11923V
Continued from preceding page.
Pin No.
Pin
Functions
Equivalent circuit
VCC1
21
C
VCO oscillator connection
This pin sets the VCO frequency.
Insert a capacitor between this pin and ground.
Set the value of the capacitor so that the oscillator
frequency does not exceed 1 MHz.
300 Ω
VCC1
22
CSD
21
Reset circuit
Sets the operating time of the constrained-rotor protection
circuit.
Reference signal oscillator used when the clock signal is cut
off and to prevent malfunctions.
The protection function operating time can be set by
connecting a capacitor between this pin and ground.
This pin also functions as the logic circuit block power-on
reset pin.
300 Ω
22
500 Ω
FGOUT
30 kΩ
VCC1
23
24
FGIN+
FGIN–
FG amplifier input
500 Ω
500 Ω
24
30 kΩ
23
VCC1
FGOUT
FG amplifier output
This pin is connected to the FG Schmitt comparator circuit
internally in the IC.
25
40 kΩ
25
FG Schmitt comparator
VCC1
27
RF GND
Output current detection
Connect a resistor between this pin and ground.
27
Continued on next page.
No. 7498-12/20
LB11923V
Continued from preceding page.
Pin No.
Pin
Functions
Equivalent circuit
VCC1
Output current detection
Connect a resistor between this pin and ground.
The output limitation maximum current, IOUT, is set to be
0.26/Rf by this resistor.
28
RF
29
GND1
Control block ground
30
GND2
Output block ground
31
32
33
34
35
36
UL
UH
VL
VH
WL
WH
Outputs (that are used to drive external transistors).
The PWM duty is controlled on the UH, VH, and WH side of
these outputs.
37
38
VCC2
VCC1
Output block power supply
Control block power supply
Short VCC1 to VCC2 and, for stability, insert a capacitor
between these pins and ground.
28
VCC2
50 kΩ
31 33 35
32 34 36
VCC1
39
40
41
42
43
44
IN3–
IN3+
IN2–
IN2+
IN1–
IN1+
Hall-effect device inputs.
The input is seen as a high-level input when IN+ > IN–, and
as a low-level input for the opposite state.
If noise on the Hall-effect device signals is a problem, insert
capacitors between the corresponding IN+ and IN– inputs.
The logic high state indicates that VIN+ > VIN–
12
18
26
NC
These are unconnected pins, and can be used for wiring.
40 42 44
500 Ω
500 Ω
39 41 43
No. 7498-13/20
LB11923V
Sample Application Circuit 1 (P-channel + n-channel, Hall-effect sensor application)
1
VREG
IN1+ 44
S/S
2
S/S
IN1– 43
CLK
3
CLK
IN2+ 42
F/R
4
F/R
IN2– 41
BR
5
BR
IN3+ 40
N1
6
N1
IN3– 39
+
N2
7
N2
VCC1 38
FGS
8
FGS
VCC2 37
LD
9
LD
WH 36
10 DOUT
WL 35
11 POUT
LB11923V
VH 34
12 NC
VL 33
13 INT.REF
UH 32
14 INT.IN
UL 31
15 INT.OUT
GND2 30
16 TOC
GND1 29
17 PWM
RF 28
18 NC
RFGND 27
19 FIL
NC 26
20 R
FGOUT 25
21 C
FGIN– 24
22 CSD
FGIN+ 23
+
24 V
Top view
No. 7498-14/20
LB11923V
Sample Application Circuit 2 (PNP + NPN, Hall-effect sensor application)
1 VREG
IN1+ 44
S/S
2
S/S
IN1– 43
CLK
3
CLK
IN2+ 42
F/R
4
F/R
IN2– 41
BR
5
BR
IN3+ 40
N1
6
N1
IN3– 39
N2
7
N2
VCC1 38
FGS
8
FGS
VCC2 37
LD
9
LD
WH 36
10 DOUT
WL 35
+
11 POUT
LB11923V
VH 34
12 NC
VL 33
13 INT.REF
UH 32
14 INT.IN
UL 31
15 INT.OUT
GND2 30
16 TOC
GND1 29
17 PWM
RF 28
18 NC
RFGND 27
19 FIL
NC 26
20 R
FGOUT 25
21 C
FGIN– 24
22 CSD
FGIIN+ 23
+
24 V
Top view
No. 7498-15/20
LB11923V
IC Operation Description
1. Speed Control Circuit
This IC implements speed control using the combination of a speed discriminator circuit and a PLL circuit. The speed
discriminator circuit outputs (This counts a single FG period.) an error signal once every two FG periods. The PLL
circuit outputs an error signal once every one FG Period. As compared to the earlier technique in which only a speed
discriminator circuit was used, the combination of a speed discriminator and a PLL circuit allows variations in motor
speed to be better suppressed when a motor that has large load variations is used. The FG servo frequency (fFG) is
determined by the frequency relationship shown below and by the clock signal (fCLK) input to the CCLK pin.
fFG = (VCO divisor ÷ speed discriminator count) × fCLK
N1
N2
Count
Divisor
High or open
High or open
1024
1024
High or open
Low
1024
512
Low
High or open
256
256
Low
Low
512
512
Therefore it is possible to implement half-speed control without switching the clock frequency by using combinations
of the N1 = high, N2 = low state and other setting states.
2. VCO Circuit
The LB11923V includes a built-in VCO circuit to generate the speed discriminator circuit reference signal. The
reference signal frequency is given by the following formula.
fVCO = fCLK × divisor
fVCO: Reference signal frequency
fCLK: Externally input clock frequency
The range over which the reference signal frequency can be varied is determined by the resistor and capacitor
components connected to the R and C pins (pins 20 and 21) and by the VCO loop filter constant (the values of the
external components connected to pin 19).
Supply voltage
R (kΩ)
When VCC is 5 V
7.5
C (pF)
200
When VCC is 6.3 V
11
200
To acquire the widest possible range, it is better to use 6.3 V than 5 V as the supply voltage. It is also possible to
handle an even wider range than is possible with fixed counts by making the speed discriminator count and the VCO
divisor switchable.
The components connected to the R, C, and FIL pins must be connected with lines to their ground pins (pins 29 and
30) that are as short as possible.
3. Output Drive Circuit
To reduce power loss in the output, this IC adopts the direct PWM drive technique. The output transistors (which are
external to the IC) are always saturated when on, and the motor drive output is adjusted by changing the duty with
which the output is on. The PWM switching is performed on the high side for each phase (UH, VH, and WH). The
PWM switching side in the output can be selected to be either the high or low side depending on how the external
transistors are connected.
4. Current Limiter Circuit
The current limiter circuit limits the (peak) current at the value I = VRF/Rf (VRF = 0.26 V (typical), Rf: current
detection resistor). The current limitation operation consists of reducing the output duty to suppress the current.
High accuracy detection can be achieved by connecting the RF and RFGND pin lines near the ends of the current
detection resistor (Rf).
5. Speed Lock Range
The speed lock range is ±6.25% of the fixed speed. When the motor speed is in the lock range, the LD pin (an open
collector output) goes low. If the motor speed goes out of the lock range, the motor on duty is adjusted according to
the speed error to control the motor speed to be within the lock range.
No. 7498-16/20
LB11923V
6. Notes on the PWM Frequency
The PWM frequency is determined by the capacitor (F) connected to the PWM pin.
When VCC = 6.3 V: fPWM ≈ 1/(82000 × C)
When VCC = 5.0 V: fPWM ≈ 1/(66000 × C)
A PWM frequency of between 15 and 25 kHz is desirable. If the PWM frequency is too low, the motor may resonate
at the PWM frequency during motor control, and if that frequency is in the audible range, that resonation may result
in audible noise. If the PWM frequency is too high, the output transistor switching loss will increase. To make the
circuit less susceptible to noise, the connected capacitors must be connected to the GND pin (pin 29 and pin 30) with
lines that are as short as possible.
7. Hall effect sensor input signals
An input amplitude of over 100 mV p-p is desirable in the Hall effect sensor inputs. The closer the input waveform is
to a square wave, the lower the required input amplitude. Inversely, a higher input amplitude is required the closer the
input waveform is to a triangular wave. Also note that the input DC voltage must be set to be within the commonmode input voltage range.
If noise on the Hall inputs is a problem, that noise must be excluded by inserting capacitors across the inputs. Those
capacitors must be located as close as possible to the input pins.
When the Hall inputs for all three phases are in the same state, all the outputs will be in the off state.
If a Hall sensor IC is used to provide the Hall inputs, those signals can be input to one side (either the + or - side) of
the Hall effect sensor signal inputs as 0 to VCC level signals if the other side is held fixed at a voltage within the
common-mode input voltage range that applies when a Hall effect sensors are used.
8. Forward/Reverse Switching
The motor rotation direction can be switched using the F/R pin. However, the following notes must be observed if the
motor direction is switched while the motor is turning.
• This IC is designed to avoid through currents when switching directions. However, increases in the motor supply
voltage (due to instantaneous return of motor current to the power supply) during direction switching may cause
problems. The values of the capacitors inserted between power and ground must be increased if this increase is
excessive.
• If the motor current after direction switching exceeds the current limit value, the PWM drive side outputs will be
turned off, but the opposite side output will be in the short-circuit braking state, and a current determined by the
motor back EMF voltage and the coil resistance will flow. Applications must be designed so that this current does
not exceed the ratings of the output transistors used. (The higher the motor speed at which the direction is
switched, the more severe this problem becomes.)
9. Brake Switching
The LB11923V provides short-circuit braking implemented by turning the output transistors for the high side for all
phases (UH, VH, and WH) on. (The opposite side transistors are turned off for all phases.) Note that the current
limiter does not operate during braking. During braking, the duty is set to 100%, regardless of the motor speed. The
current that flows in the output transistors during braking is determined by the motor back EMF voltage and the coil
resistance. Applications must be designed so that this current does not exceed the ratings of the output transistors
used. (The higher the motor speed at which braking is applied, the more severe this problem becomes.)
The braking function can be applied and released with the IC in the start state. This means that motor startup and stop
control can be performed using the brake pin with the S/S pin held at the low level (the start state). If the startup time
becomes excessive, it can be reduced by controlling motor startup and stop with the brake pin rather than with the S/S
pin. (Since the IC goes to the power saving state when stopped, enough time for the VCO circuit to stabilize will be
required at the beginning of the motor start operation.)
10. Constraint Protection Circuit
The LB11923V includes an on-chip constraint protection circuit to protect the IC and the motor in motor constraint
mode. If the LD output remains high (indicating the locked state) for a fixed period in the start state, the upper side
(external) transistors are turned off. This time is set by the capacitance of the capacitor attached to the CROCK pin. A
time of a few seconds can be set with a capacitance of under 0.1 µF.
No. 7498-17/20
LB11923V
When VCC = 6.3 V: The set time (in seconds) is 37 × C (µF)
When VCC = 5.0 V: The set time (in seconds) is 30 × C (µF)
To clear the rotor constrained protection state, the application must either switch to the stop state for a fixed period
(about 1 ms or longer) or turn off and reapply power.
If the rotor constrained protection circuit is not used, a 220 kΩ resistor and a 1500 pF capacitor must be connected in
parallel between the CSD pin and ground. However, in that case, the clock disconnect protection circuit described
below will no longer function. Since the CSD pin also functions as the power-on reset pin, if the CSD pin were
connected directly to ground, the IC would go to the power-on reset state and motor drive operation would remain
off. The power-on reset state is cleared when the CSD pin voltage rises above a level of about 0.64 V.
11. Clock Disconnect Protection Circuit
If the clock input goes to the no input state when the IC is in the start state, this protection circuit will operate and
turn off the PWM output. If the clock is resupplied before the motor constraint protection circuit operates, the IC will
return to the drive state, but if the motor constraint protection circuit does operate, the IC must either be set
temporarily (approximately 1 ms or over) to the stop or brake state, or the power must be turned off and reapplied.
12. Low-Voltage Protection Circuit
The LB11923V includes a low-voltage protection circuit to protect against incorrect operation when power is first
applied or if the power-supply voltage (VCC) falls. The (external) all output transistors are turned off if VCC falls
under about 3.75 volts, and this function is cleared at about 4.0 volts.
13. Power Supply Stabilization
Since this IC is used in applications that draw large output currents, the power-supply line is subject to fluctuations.
Therefore, capacitors with capacitances adequate to stabilize the power-supply voltage must be connected between
the VCC pin and ground. If diodes are inserted in the power-supply line to prevent IC destruction due to reverse
power supply connection, since this makes the power-supply voltage even more subject to fluctuations, even larger
capacitors will be required.
14. Ground Lines
The signal system ground and the output system ground must be separated and a single ground point must be taken at
the connector. Since the output system ground carries large currents, this ground line must be made as short as
possible.
Output system ground ... Ground for Rf and the output diodes
Signal system ground ... Ground for the IC and the IC external components
15. VREG Pin
If a motor drive system is formed from a single power supply, the VREG pin (pin 1) can be used to create the powersupply voltage (about 6.3 V) for this IC. The VREG pin is a shunt regulator and generates a voltage of about 7 volts by
passing a current through an external resistor. A stable voltage can be generated by setting the current to value in the
range 0.2 to 1.5 mA. The external transistors must have current capacities of at least 80 mA (to cover the ICC + Hall
bias current + output current <source> requirements) and they must have voltage handling capacities in excess of the
motor power-supply voltage. Since the heat generated by these transistor may be a problem, heat sinks may be
required depending on the packages used. If the IC power-supply voltage (4.4 to 7.0 V) is provided from an external
circuit, apply that voltage directly to the VCC pin(pin 37 and pin 38). In that case, the VREG pin must either be left
open or connected to ground.
16. FG Amplifier
The FG amplifier is normally implemented as a filter amplifier such as that shown in the application circuits to reject
noise. Since a clamp circuit has been added at the FG amplifier output, the output amplitude is clamped at about
3 V p-p, even if the gain is increased.
Since a Schmitt comparator is inserted after the FG amplifier, applications must set the gain so that the amplifier
output amplitude is at least 250 mV p-p. (It is desirable that the gain be set so that the amplitude is over 0.5 V p-p at
the lowest controlled speed to be used.)
The capacitor inserted between the FGIN+ pin (pin 23) and ground is required for bias voltage stabilization. To make
the connected capacitor as immune from noise as possible, connect this capacitor to the GND pin (pin 29 and pin 30)
with a line that is as short as possible.
No. 7498-18/20
LB11923V
17. Integrating Amplifier
The integrating amplifier integrates the speed error pulses and the phase error pulses and converts them to a speed
command voltage. At the same time it also sets the control loop gain and frequency characteristics using external
components.
The integrating amplifier output (pin 15) is normally connected to the TOC pin (pin 16) using external wiring. In
cases where it is necessary to switch the integration constant in an application that uses a wide speed range by
isolating the integrating amplifier output and the PWM control circuit, this type of constant switching application can
be implemented by adding external operational amplifier, analog switch, and other components.
In either case, the basic idea is that the operational amplifier output is connected to the TOC pin. (Note that voltages
in excess of VCC – 0.5 V must not be applied to the TOC pin.)
18. FIL Pin External Components
The capacitor inserted between the FIL pin and ground is used to suppress ripple on the FIL pin voltage. Therefore,
application designers must select a capacitance value that provides fully adequate smoothing of the FIL pin voltage
even at the lowest external clock input frequency used. Also, the FIL pin voltage convergence time (the time until the
reference signal stabilizes) when the input clock frequency is switched is shortened by connecting a resistor and a
capacitor in series between the FIL pin and ground. Therefore, designers must select values for the resistor and
capacitor that give the required convergence time.
19. R and C Pin External Components
The maximum range over which the reference signal frequency fVCO can be varied when 5 V is used as the VCC
supply voltage is about a factor of three.
When it is desirable to make this range as wide as possible, since the values of the R pin external resistor (R) and the
C pin external capacitor (C) are determined by the maximum value of the reference signal frequency (fVCO1) and the
minimum value (VCCL) of the VCC power supply due to unit-to-unit variations, R and C can be determined using the
following procedure as a reference.
(1) Calculate R1 and C1 using the following formulas and determine values for R and C such that the conditions R ≤
R1 and C ≤ C1 will hold taking the sample-to-sample variations (including other issues such as temperature
characteristics) into account.
R1 = (VCCL – 2.2 V) / 280 µA
C1 = (280 µA / 0.9 V) × (1/fVCO1) × 0.7
(2) The minimum value (fVCO2) for the reference signal frequency that can be set for the R and C values determined
in step (1) can be calculated from the following formula if we let R2 and C2 be the smallest values for R and C
due to the sample-to-sample variations (including other issues such as temperature characteristics). Therefore, the
range over which the reference signal frequency can be set is fVCO1 to fVCO2.
fVCO2 = 0.38 / (R2 × C2)
(3) The following are the conditions that must be met and the points that require care when determining the values of
the external components connected to the R and C pins.
1. The maximum value of the set reference signal frequency must not exceed 1 MHz.
2. The R pin voltage and the FIL pin voltage must be in the range 0.3 V to (VCCL – 2.2 V). (VCCL is the lowest
value of the VCC supply voltage given the unit-to-unit variations. VCCL is always greater than or equal to 4.4
V.) However, the lower the R pin voltage, the more susceptible the system will be to ground line noise, and the
reference signal frequency may become unstable as a result. Therefore the lower end of the R pin voltage range
must not be used if there is much ground line noise in the system.
3. Set the value of the R pin external resistor to a value in the range 6.8 kΩ to 15 kΩ. Also, assure that the R pin
current remains under 280 µA.
4. Set the value of the C pin external capacitor to a value in the range 150 pF to 1000 pF.
5. When it is desirable to make the range of the reference signal frequency as wide as possible, set the values of R
and C to the largest possible values. (However, those values must be lower than the calculated values R1 and
C1.) Use components with the smallest sample-to-sample variations possible. The VCC voltage must be made
as much higher than 5 V as possible by, for example, using this IC’s VREG pin (7 V shunt regulator), to
acquire the widest possible range for the reference signal frequency.
No. 7498-19/20
LB11923V
20. NC pin
Since the NC pins are electrically open with respect to the IC itself, they can be used as intermediate connection
points for lines in the PCB pattern.
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PS No.7498-20/20