Sanyo LB1975 Dc fan motor driver Datasheet

Ordering number : ENN6087A
Monolithic Digital IC
LB1975
DC Fan Motor Driver
Overview
Package Dimensions
The LB1975 is a three-phase brushless motor driver IC
suited for use in direct PWM driving of DC fan motors for
air conditioners, water heaters, and other similar
equipment. Since a shunt regulator circuit is built in,
single power supply operation sharing the same power
supply for the motor is supported.
unit: mm
[LB1975]
28
15
12.7
11.2
R1.7
0.4
8.4
Features
Withstand voltage 45 V, output current 2.5 A
Direct PWM drive output
3 built-in output top-side diodes
Built-in current limiter
Built-in FG output circuit
1
14
20.0
4.0
26.75
4.0
•
•
•
•
•
3147C-DIP28H
(1.81)
1.78
0.6
1.0
SANYO: DIP28H
Any and all SANYO products described or contained herein do not have specifications that can handle
applications that require extremely high levels of reliability, such as life-support systems, aircraft’s
control systems, or other applications whose failure can be reasonably expected to result in serious
physical and/or material damage. Consult with your SANYO representative nearest you before using
any SANYO products described or contained herein in such applications.
SANYO assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other
parameters) listed in products specifications of any and all SANYO products described or contained
herein.
SANYO Electric Co.,Ltd. Semiconductor Company
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
21003AS (OT) / 52199RM (KI) No. 6087-1/12
LB1975
Specifications
Absolute Maximum Ratings at Ta = 25°C
Parameter
Symbol
Supply voltage
Unit
V
VM max
45
V
IO max
2.5
A
10
mA
IREG max
Allowable power dissipation
Ratings
7
Output current
Maximum input current
Conditions
VCC max
VREG pin
Pd max1
IC only
Pd max2
With infinite heat sink
3
W
20
W
Operating temperature
Topr
–20 to +100
°C
Storage temperature
Tstg
–55 to +150
°C
Ratings
Unit
Allowable Operating Ranges at Ta = 25°C
Parameter
Symbol
Supply voltage range
Conditions
VCC
4.5 to 6.7
V
VM
20 to 42
V
Input current range
IREG
FG pin applied voltage
VFG
0 to VCC
FG pin output current
IFG
0 to 10
VREG pin
1 to 5
mA
V
mA
Allowable power dissipation, Pd max – W
Pd max – Ta
24
20
With infinite heat sink
16
12
8
4
3
0
–20
Independent IC
0
20
40
60
80
100
120
Ambient temperature, Ta – ˚C
No. 6087-2/12
LB1975
Electrical Characteristics at Ta = 25°C, VCC = 5 V, VM = 30 V
Parameter
Supply current
Symbol
Conditions
ICC
Ratings
min
typ
10
max
Unit
14
18
mA
VOsat1 (L) IO = 1.0 A, VO (sink)
1.1
1.4
V
VOsat1 (H) IO = 1.0 A, VO (source)
0.9
1.3
V
2.0
2.6
V
VOsat2 (L) IO = 2.0 A, VO (sink)
1.4
1.8
V
VOsat2 (H) IO = 2.0 A, VO (source)
1.2
1.7
V
2.6
3.4
V
100
µA
[Output Block]
Output saturation voltage
VOsat1
VOsat2
Output leak current
Upper side diode forward voltage
IO = 1.0 A, VO (sink) + VO (source)
IO = 2.0 A, VO (sink) + VO (source)
IOLeak (L)
IOLeak (H)
–100
µA
VFH1
IO = 1.0 A
1.2
1.6
V
VFH2
IO = 2.0 A
2.1
2.6
V
[Hall Amplifier]
Input bias current
IHB
–4
Common-mode input voltage range
VICM
1.5
Hall input sensitivity
VHIN
60
–1
µA
VCC – 1.5
V
mVp-p
∆VIN (HA)
23
32
39
mV
Input voltage (low to high)
VSLH
6
16
25
mV
Input voltage (high to low)
VSHL
–25
–16
–6
mV
Hysteresis width
[FG Pin (speed pulse output)]
Output low-level voltage
VFGL
0.5
V
Pull-up resistor value
RFG
7.5
10
12.5
kΩ
VRF
0.45
0.50
0.55
V
150
180
°C
40
°C
IFG = 5 mA
[Current Limiter]
Limiter
[Thermal Shutdown]
Thermal shutdown operating temperature
Hysteresis width
TSD
Desigh target Value (junction temperature)
∆TSD
Desigh target Value (junction temperature)
[Low-Voltage Protection]
Operating voltage
Non-operating voltage
VLVSD
3.5
VLVSD (OFF)
3.8
4.1
V
4.3
4.5
V
∆VLSD
0.4
0.5
0.6
V
Output high-level voltage
VOH (OSC)
2.95
3.10
3.25
V
Output low-level voltage
VOL (OSC)
1.38
1.45
1.59
V
VOSC
1.50
1.65
1.71
Vp-p
kHz
Hysteresis width
[PWM Oscillator]
Amplitude
Ocillator frequency
fOSC
Charge current
ICHG
Discharge resistance
C = 2200 pF
RDCHG
19.6
23.0
27.6
–110
–94
–83
µA
1.6
2.1
2.6
kΩ
[VREG Pin]
Pin voltage
VREG
IREG = 1.5 mA
6.6
7.0
7.2
V
VCTL1
Output duty 0%
1.1
1.4
1.7
V
VCTL2
Output duty 100%
3.2
3.5
3.8
[VCTL Pin]
Input voltage
Input bias current
IB1 (CTL) VCTL = 0 V
–82
V
µA
IB2 (CTL) VCTL = 5 V
92
µA
[VCTL Amplifier]
Reference voltage
Output voltage
VCREF
2.23
2.35
2.46
V
VCOUT1
VCTL = 0 V
3.90
4.20
4.40
V
VCOUT2
VCTL = 5 V
0.60
0.80
1.10
V
[Start/Stop Pin]
High-level input voltage range
VIH (S/S)
VCC – 1.5
VCC
V
Low-level input voltage range
VIL (S/S)
0
1.5
V
Input open voltage
VIO (S/S)
VCC – 0.5
VCC
V
Continued on next page.
No. 6087-3/12
LB1975
Continued from preceding page.
Parameter
Symbol
Ratings
Conditions
min
∆VIN (S/S)
Hysteresis width
typ
max
Unit
0.35
0.50
0.65
V
High-level input current
IIH (S/S)
V (S/S) = VCC
–10
0
10
µA
Low-level input current
IIL (S/S)
V (S/S) = 0 V
–280
–210
µA
[Forward/Reverse Pin]
High-level input voltage range
VIH (F/R)
VCC – 1.5
VCC
V
Low-level input voltage range
VIL (F/R)
0
1.5
V
Input open voltage
VIO (F/R)
VCC – 0.5
VCC
V
Hysteresis width
∆VIN (F/R)
0.35
0.50
0.65
V
10
µA
High-level input current
IIH (F/R)
V (F/R) = VCC
–10
0
Low-level input current
IIL (F/R)
V (F/R) = 0 V
–280
–210
µA
Pin Assignment
–
VCOUT VCTL OSC (NC) VCREF IN1
28
27
26
25
24
IN1+
IN2–
IN2+
IN3–
IN3+
FG1
22
21
20
19
18
17
23
FG2 GND1
16
15
LB1975
Top view
1
2
3
4
VCC VREG S/S
F/R
13
14
(NC) OUT1 OUT2 OUT3 (NC) (NC) GND3 GND2 RF
5
6
7
8
9
10
11
12
VM
A11950
Truth Table
Input
IN1
IN2
Forward/reverse control
Output
F/R
Source → Sink
L
OUT2 → OUT1
H
OUT1 → OUT2
IN3
1
H
L
H
2
H
L
L
3
H
H
L
4
L
H
L
5
L
H
H
6
L
L
H
F/R
Forward rotation Low
Reverse rotation High
L
OUT3 → OUT1
H
OUT1 → OUT3
L
OUT3 → OUT2
H
OUT2 → OUT3
L
OUT1 → OUT2
H
OUT2 → OUT1
L
OUT1 → OUT3
H
OUT3 → OUT1
L
OUT2 → OUT3
H
OUT3 → OUT2
FG output
FG1
FG2
L
L
L
H
L
L
H
H
H
L
H
H
FG output
0 V to 1.5 V
VCC – 1.5 V to VCC
FG1
FG2
No. 6087-4/12
LB1975
Duty – VCTL characteristics
100
80
Duty — %
60
40
20
0
VCTL1
Control voltage, VCTL — V
VCTL2
Block Diagram and Peripheral Circuit
VREG
VCC
VCC
S/S
F/R
FG1 FG2
Reg
LVSD
+
+
TSD
VM
Hys.Amp
+
IN1
VM
–
OUT1
OUT2
+
IN2
Logic
–
OUT3
+
IN3
–
31 kΩ
VCTL
Current
limiter
VCTL Amp
–
40 kΩ
PWM
OSC
+
VCTL
RF
Rf
0.5 V
2.35 V
+
VCREF
VCOUT
OSC
GND1
GND2 GND3
A11952
No. 6087-5/12
LB1975
Pin Functions
Pin No.
Pin name
Pin voltage
1
VCC
4.5 V to 6.7 V
Pin function
Equivalent circuit
Power supply for blocks other than
the output block
2
2
VREG
0.0 V to 7.3 V
Shunt regulator output pin (7 V)
A11953
VCC
Start/stop control pin
Low: start
High or Open: stop
3
S/S
20 kΩ
0.0 V to VCC
Typical threshold voltage for
VCC = 5 V:
3.8 kΩ
approx. 2.8 V (low to high)
3
approx. 2.3 V (high to low)
A11954
VCC
Forward/reverse pin
Low: forward
High or Open: reverse
4
F/R
20 kΩ
0.0 V to VCC
Typical threshold voltage for
VCC = 5 V:
3.8 kΩ
approx. 2.8 V (low to high)
4
approx. 2.3 V (high to low)
A11955
6
OUT1
Output pin 1
7
OUT2
Output pin 2
8
OUT3
Output pin 3
VCC
VM
14
6
7
13
RF
0.0 V to VCC
Output current detect pin. Connect
resistor RF between this pin and
ground. Output current is limited to
value set with VRF/Rf. (Current limiter
operation)
8
0.5 V
200 Ω
13
14
VM
11
GND3
Output block power supply
A11956
Output block ground
Continued on next page.
No. 6087-6/12
LB1975
Continued from preceding page.
Pin No.
Pin name
15
GND1
12
GND2
Pin voltage
Pin function
Equivalent circuit
Ground for blocks other than the
output block
VCC
10 kΩ
17
FG1
0.0 V to VCC
16
FG2
Speed pulse output pin 1 with built-in
pull-up resistor
16 17
Speed pulse output pin 2 with built-in
pull-up resistor
A11957
VCC
22
23
20
21
18
19
IN1+
IN1–
IN2+
IN2–
1.5 V to
VCC – 1.5 V
IN3+
IN3–
18
Hall input pin
IN+ > IN– : High input
20
IN+ < IN– : Low input
300 Ω
300 Ω
22
19
21
23
A11958
VCC
2V
26
OSC
1.0 V to VCC
94 µA
200 Ω
This pin sets the PWM oscillation
frequency. Connect a capacitor
between this pin and ground.
26
2.1 kΩ
A11959
31 kΩ
VCC
Output duty cycle control pin
• VCTL ≤ VCTL1
Duty cycle 0%
27
VCTL
0.0 V to 6.7 V
• VCTL1 < VCTL < VCTL2
Duty cycle is controlled by VCTL
• VCTL ≥ VCTL2
2.35 V
40 kΩ
27
Duty cycle 100%
A11960
Continued on next page.
No. 6087-7/12
LB1975
Continued from preceding page.
Pin No.
Pin name
Pin voltage
Pin function
Equivalent circuit
VCC
100 µA
24
VCREF
0.0 V to
VCC – 2.0 V
V CTL amplifier internal reference
voltage pin (2.35 V)
200 Ω
24
23.5 kΩ
A11961
28
31 kΩ
VCC
28
VCOUT
0.7 V to
VCC – 0.7 V
VCTL amplifier output pin
200 Ω
A11962
No. 6087-8/12
LB1975
IC Description
Direct PWM Drive
This IC (LB1975) employs the direct PWM drive principle. Motor rotation speed is controlled by varying the output
duty cycle according to an analog voltage input (VCTL). This eliminates the need to alter the motor power supply
voltage. Compared to previous ICs using the PAM principle (such as the Sanyo LB1690), this allows simplification of
the power supply circuitry. The VCTL input can be directly supplied by a microcontroller, motor speed can, therefore, be
controlled directly from the microcontroller.
For PWM, the source-side output transistors are switched on and off so that the ON duty tracks the VCTL input. The
output duty cycle can be controlled over the range of 0% to 100% by the VCTL input.
PWM Frequency
The PWM oscillator frequency fPWM [Hz] is set by the capacitance C [pF] connected between the OSC pin and GND.
The following equation applies:
fPWM ≈ 1 / (1.97 × C) × 108
Because output transistor on/off switching is subject to a delay, setting the PWM frequency to a very high value will
cause the delay to become noticeable. The PWM frequency therefore should normally be kept below 40 kHz (typ.),
which is achieved with a capacitance C of 1300 pF or higher. For reference, the source-side output transistor switching
delay time is about 2 µs for ON and about 4 µs for OFF.
Output Diodes
Because the PWM switching operation is carried out by the source-side output transistors, Schottky barrier diodes must
be connected between the OUT pins and GND (OUT1 to OUT3). Use diodes with an average forward current rating in
the range of 1.0 to 2.0 A, in accordance with the motor type and current limiting requirements.
If no Schottky barrier diodes are connected externally, or if Schottky barrier diodes with high forward voltage (VF) are
used, the internal parasitic diode between OUT and GND becomes active. When this happens, the output logic circuit
may malfunction, resulting in feedthrough current in the output which can destroy the output transistors. To prevent this
possibility, Schottky barrier diodes must be used and dimensioned properly.
The larger the VF of the externally connected Schottky barrier diodes, or the hotter the IC is, the more likely are the
parasitic diodes between OUT and GND to become active and the more likely is malfunction to occur. The VF of the
Schottky barrier diodes must be determined so that output malfunction does not occur also when the IC becomes hot. If
malfunction occurs, choose a Schottky barrier diode with lower VF.
Protection circuits
• Low voltage protection circuit
When the VCC voltage falls below a stipulated level (VLVSD), the low voltage protection circuit cuts off the source-side
output transistors to prevent VCC related malfunction.
• Thermal shutdown circuit (overheat protection circuit)
When the junction temperature rises above a stipulated value (TSD), the thermal shutdown circuit cuts off the sourceside output transistors to prevent IC damage due to overheating. Design the application heat characteristics so that the
protection circuit will not be triggered under normal circumstances.
• Current limiter
The current limiter cuts off the source-side output transistors when the output current reaches a preset value (limiter
value). This interrupts the source current and thereby limits the output current peak value. By connecting the
resistance Rf between the RF pin and ground, the output current can be detected as a voltage. When the RF pin voltage
reaches 0.5 V (typ.), the current limiter is activated. It performs on/off control of the source-side output transistors,
thereby limiting the output current to the value determined by 0.5 /Rf.
No. 6087-9/12
LB1975
Hall Input Circuit
The Hall input circuit is a differential amplifier with a hysteresis of 32 mV (typ.). The operation DC level must be within
the common-mode input voltage range (1.5V to VCC – 1.5 V). To prevent noise and other adverse influences, the input
level should be at least 3 times the hysteresis (120 to 160 mVp-p). If noise at the Hall input is a problem, a noisecanceling capacitor (about 0.01 µF) should be connected across the Hall input IN+ and IN– pins.
FG Output Circuit
The Hall input signal at IN1, IN2, and IN3 is combined and subject to waveform shaping before being output. The signal
at FG1 has the same frequency as the FG1 Hall input, and the signal at FG2 has a frequency that is three times higher.
Start/Stop Control Circuit
The start/stop control circuit turns the source-side output transistors OFF (motor stop) when a High signal is input at the
S/S pin or when the pin is Open. When a Low signal is input at the S/S pin, the source-side output transistors are turned
ON, and the normal operation state is established (motor start).
Forward/Reverse Switching
This IC is designed under the assumption that forward/reverse switching is not carried out while the motor is running. If
switching is carried out while the motor is running, reverse torque braking occurs, leading to a high current flow. If the
current limiter is triggered, the source-side output transistors are switched off, and the sink-side output transistors go into
the short brake condition. However, because the current limiter of this IC cannot control the current flowing in the sinkside output transistors, these may be destroyed by the short brake current. Therefore F/R switching while the motor is
running is permissible only if the output current (IO) is limited to a maximum of 2.5 A using the motor coil resistance or
other suitable means.
F/R switching should be carried out only while a High signal is input to the S/S pin or the pin is Open (stop condition), or
while the VCTL pin conforms to the following condition: VCTL ≤ VCTL1 (duty cycle 0%). In any other condition, F/R
switching will result in feedthrough current. The F/R pin should therefore be fixed to Low (forward) or High or Open
(reverse) during use.
VCC, VM Power Supplies
When the power supply voltage (VCC, VM) rises very quickly when a power is first applied, a feedthrough current may
occur at the output. If the current remains below about 0.2 A to 0.3 A, it does not pose a problem, but such a possibility
should still be prevented by slowing down the voltage rise at power-on. Especially if the F/R pin is set to High or Open
(reverse), a quick rise in VCC is likely to cause feedthrough current. This should be prevented by ensuring that ∆VCC / ∆t
= 0.2 V/µs or less. Feedthrough current can also be prevented by first switching on VCC and then VM during power-on.
The sequence at power-down should be as follows. Provide a stop input to the S/S pin or a duty ratio 0% input to the
VCTL pin. When the motor has come to a full stop, switch off VM and then VCC. If power is switched off while the
motor is still rotating or a current is flowing in the motor coil (including motor restraint or inertia rotation), a
counterelectromotive current or kickback current may flow on the VM side, depending on the motor type and power-off
procedure. If this current cannot be absorbed by the VM power supply or a capacitor, VM voltage may rise and exceed
the absolute maximum VM rating for the IC. Ensure that this does not happen through proper design of the VM power
supply or through use of a capacitor.
Because the IC (LB1975) incorporates a shunt regulator, it can be used on a single power supply. In this case, supply
VCC (6.3 typ.) to the VREG pin via an external NPN transistor and resistor. When not using the regulator, leave the VREG
pin open.
No. 6087-10/12
LB1975
Power Supply Stabilizing Capacitors
If the V CC line fluctuates drastically, the low-voltage protection circuit may be activated by mistake, or other
malfunctions may occur. The VCC line must therefore be stabilized by connecting a capacitor of at least several µF
between VCC and GND. Because a large switching current flows in the VM line, wiring inductance and other factors can
lead to VM voltage fluctuations. As the GND line also fluctuates, the VM line must be stabilized by connecting a
capacitor of at least several µF between VM and GND, to prevent exceeding VMmax or other problems. Especially when
long wiring runs (VM, VCC, GND) are used, sufficient capacitance should be provided to ensure power supply stability.
VCREF Pin, VCOUT Pin
These pins are always used in the Open condition. If chattering occurs in the PWM switching output, connect a capacitor
(about 0.1 µF) between VCREF and ground or between VCOUT and GND.
IC Heat Dissipation Fins
A heat sink may be mounted to the heat dissipation fins of this IC, but it may not be connected to GND. The sink should
be electrically open.
Sample calculation for internal power dissipation (approximate)
The calculation assumes the following parameters:
VCC = 5 V
VM = 30 V
Source-side output transistor ON duty cycle 80% (PWM control)
Output current IO = 1 A (RF pin average current)
• ICC power dissipation P1
P1 = VCC × ICC = 5 V × 14 mA = 0.07 W
• Output drive current power dissipation P2
P2 = VM × 11 mA = 30 V × 11 mA = 0.33 W
• Source-side output transistor power dissipation P3
P3 = VO (source) × IO × Duty (on) = 0.9 V × 1 A × 0.8 = 0.72 W
• Sink-side output transistor power dissipation P4
P4 = VO (sink) × IO = 1.1 V × 1 A = 1.10 W
• Total internal power dissipation P
P = P1 + P2 + P3 + P4 = 2.22 W
IC temperature Rise Measurement
Because the chip temperature of the IC cannot be measured directly, measurement according to one of the following
procedures should always be carried out.
• Thermocouple measurement
A thermocouple element is mounted to the IC heat dissipation fin. This measurement method is easy to implement, but
it will be subject to measurement errors if the temperature is not stable.
• Measurement using internal diode characteristics of IC
This is the recommended measurement method. It makes use of the parasitic diode incorporated in the IC between FG1
and GND. Set FG1 to High and measure the voltage VF of the parasitic diode to calculate the temperature.
(Sanyo data: for IF = –1 mA, VF temperature characteristics are about –2 mV/°C)
NC Pins
Because NC pins are electrically open, they may be used for wiring purpose etc.
No. 6087-11/12
LB1975
Specifications of any and all SANYO products described or contained herein stipulate the performance,
characteristics, and functions of the described products in the independent state, and are not guarantees
of the performance, characteristics, and functions of the described products as mounted in the customer’s
products or equipment. To verify symptoms and states that cannot be evaluated in an independent device,
the customer should always evaluate and test devices mounted in the customer’s products or equipment.
SANYO Electric Co., Ltd. strives to supply high-quality high-reliability products. However, any and all
semiconductor products fail with some probability. It is possible that these probabilistic failures could
give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire,
or that could cause damage to other property. When designing equipment, adopt safety measures so
that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective
circuits and error prevention circuits for safe design, redundant design, and structural design.
In the event that any or all SANYO products (including technical data, services) described or contained
herein are controlled under any of applicable local export control laws and regulations, such products must
not be exported without obtaining the export license from the authorities concerned in accordance with the
above law.
No part of this publication may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying and recording, or any information storage or retrieval system,
or otherwise, without the prior written permission of SANYO Electric Co., Ltd.
Any and all information described or contained herein are subject to change without notice due to
product/technology improvement, etc. When designing equipment, refer to the “Delivery Specification”
for the SANYO product that you intend to use.
Information (including circuit diagrams and circuit parameters) herein is for example only; it is not
guaranteed for volume production. SANYO believes information herein is accurate and reliable, but
no guarantees are made or implied regarding its use or any infringements of intellectual property rights
or other rights of third parties.
This catalog provides information as of February, 2003. Specifications and information herein are subject
to change without notice.
PS No. 6087-12/12