Datasheet LB1975 Datasheet (SANYO)

Ordering number : ENN6087A

21003AS (OT) / 52199RM (KI) No. 6087-1/12

Overview

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.

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

Package Dimensions

unit: mm

3147C-DIP28H

1

14

28

15

0.4

0.6

4.04.0

26.75

20.0

R1.7

8.4

(1.81)

1.78

1.0

12.7

11.2

SANYO: DIP28H

[LB1975]

LB1975

SANYO Electric Co.,Ltd. Semiconductor Company

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN

DC Fan Motor Driver

Monolithic Digital IC

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.

No. 6087-2/12

LB1975

Parameter Symbol Conditions Ratings Unit

Supply voltage

V

CC

max 7 V

V

M

max 45 V

Output current I

O

max 2.5 A

Maximum input current I

REG

max V

REG

pin 10 mA

Allowable power dissipation

Pd max1 IC only 3 W

Pd max2 With infinite heat sink 20 W
Operating temperature Topr –20 to +100 °C
Storage temperature Tstg –55 to +150 °C

Specifications

Absolute Maximum Ratings at Ta = 25°C

Parameter Symbol Conditions Ratings Unit

Supply voltage range

V

CC

4.5 to 6.7 V

V

M

20 to 42 V

Input current range I

REG

V

REG

pin 1 to 5 mA

FG pin applied voltage V

FG

0 to V

CC

V

FG pin output current I

FG

0 to 10 mA

Allowable Operating Ranges at Ta = 25°C

3

0

4

8

12

16

20

24

–20 0 20 40 60 80 100 120

Allowable power dissipation, Pd max – W

Pd max – Ta

Ambient temperature, Ta – ˚C

With infinite heat sink

Independent IC

No. 6087-3/12

LB1975

Parameter Symbol Conditions

Ratings

Unit

min typ max

Supply current I

CC

10 14 18 mA

[Output Block]

V

O

sat1 (L) IO= 1.0 A, VO(sink) 1.1 1.4 V

V

O

sat1 (H) IO= 1.0 A, VO(source) 0.9 1.3 V

Output saturation voltage

V

O

sat1 IO= 1.0 A, VO(sink) + VO(source) 2.0 2.6 V

V

O

sat2 (L) IO= 2.0 A, VO(sink) 1.4 1.8 V

V

O

sat2 (H) IO= 2.0 A, VO(source) 1.2 1.7 V

V

O

sat2 IO= 2.0 A, VO(sink) + VO(source) 2.6 3.4 V

Output leak current

I

O

Leak (L) 100 µA

I

O

Leak (H) –100 µA

Upper side diode forward voltage

V

FH

1 IO= 1.0 A 1.2 1.6 V

V

FH

2 IO= 2.0 A 2.1 2.6 V

[Hall Amplifier]

Input bias current I

HB

–4 –1 µA

Common-mode input voltage range V

ICM

1.5

VCC– 1.5

V

Hall input sensitivity VH

IN

60 mVp-p

Hysteresis width ∆V

IN

(HA) 23 32 39 mV

Input voltage (low to high) V

SLH

6 16 25 mV

Input voltage (high to low) V

SHL

–25 –16 –6 mV

[FG Pin (speed pulse output)]

Output low-level voltage V

FGLIFG

= 5 mA 0.5 V

Pull-up resistor value R

FG

7.5 10 12.5 kΩ

[Current Limiter]

Limiter V

RF

0.45 0.50 0.55 V

[Thermal Shutdown]

Thermal shutdown operating temperature TSD Desigh target Value (junction temperature) 150 180 °C
Hysteresis width ∆TSD Desigh target Value (junction temperature) 40 °C

[Low-Voltage Protection]

Operating voltage V

LVSD

3.5 3.8 4.1 V

Non-operating voltage

V

LVSD

(OFF)

4.3 4.5 V

Hysteresis width ∆V

LSD

0.4 0.5 0.6 V

[PWM Oscillator]

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

Amplitude V

OSC

1.50 1.65 1.71 Vp-p

Ocillator frequency f

OSC

C = 2200 pF 19.6 23.0 27.6 kHz

Charge current I

CHG

–110 –94 –83 µA

Discharge resistance R

DCHG

1.6 2.1 2.6 kΩ

[V

REG

Pin]

Pin voltage V

REGIREG

= 1.5 mA 6.6 7.0 7.2 V

[V

CTL

Pin]

Input voltage

V

CTL

1 Output duty 0% 1.1 1.4 1.7 V

V

CTL

2 Output duty 100% 3.2 3.5 3.8 V

Input bias current

I

B

1 (CTL) V

CTL

= 0 V –82 µA

I

B

2 (CTL) V

CTL

= 5 V 92 µA

[V

CTL

Amplifier]

Reference voltage V

CREF

2.23 2.35 2.46 V

Output voltage

V

COUT

1 V

CTL

= 0 V 3.90 4.20 4.40 V

V

COUT

2 V

CTL

= 5 V 0.60 0.80 1.10 V

[Start/Stop Pin]

High-level input voltage range V

IH

(S/S)

VCC– 1.5

V

CC

V

Low-level input voltage range V

IL

(S/S) 0 1.5 V

Input open voltage V

IO

(S/S)

VCC– 0.5

V

CC

V

Electrical Characteristics at Ta = 25°C, VCC= 5 V, VM= 30 V

Continued on next page.

No. 6087-4/12

LB1975

Parameter Symbol Conditions

Ratings

Unit

min typ max

Hysteresis width ∆V

IN

(S/S) 0.35 0.50 0.65 V

High-level input current I

IH

(S/S) V (S/S) = V

CC

–10 0 10 µA

Low-level input current I

IL

(S/S) V (S/S) = 0 V –280 –210 µA

[Forward/Reverse Pin]

High-level input voltage range V

IH

(F/R)

VCC– 1.5

V

CC

V

Low-level input voltage range V

IL

(F/R) 0 1.5 V

Input open voltage V

IO

(F/R)

VCC– 0.5

V

CC

V

Hysteresis width ∆V

IN

(F/R) 0.35 0.50 0.65 V

High-level input current I

IH

(F/R) V (F/R) = V

CC

–10 0 10 µA

Low-level input current I

IL

(F/R) V (F/R) = 0 V –280 –210 µA

Continued from preceding page.

LB1975

V

COUT

VCCV

REG

S/S F/R (NC) OUT1 OUT2 OUT3 (NC) (NC) GND3 GND2 RF V

M

V

CTL

OSC (NC) V

CREF

IN1–IN1+IN2–IN2+IN3–IN3+FG1 FG2 GND1

1 2 3 4 5 6 7 8 9 10 11 12 13 14

28 27 26 25 24 23 22 21 20 19 18 17 16 15

Top view

A11950

Pin Assignment

Truth Table

F/R

Forward rotation Low 0 V to 1.5 V
Reverse rotation High V

CC

– 1.5 V to V

CC

FG output

Input Forward/reverse control Output FG output

IN1 IN2 IN3 F/R Source

→ Sink FG1 FG2

1 H L H

L OUT2 → OUT1

L L

H OUT1 →OUT2

2 H L L

L OUT3 → OUT1

L H

H OUT1 →OUT3

3 H H L

L OUT3 → OUT2

L L

H OUT2 →OUT3

4 L H L

L OUT1 → OUT2

H H

H OUT2 →OUT1

5 L H H

L OUT1 → OUT3

H L

H OUT3 →OUT1

6 L L H

L OUT2 → OUT3

H H

H OUT3 →OUT2

FG1
FG2

Block Diagram and Peripheral Circuit

No. 6087-5/12

LB1975

0

20

40

60

80

100

Duty — %

Duty – V

CTL

characteristics

Control voltage, V

CTL

— V

V

CTL

1 V

CTL

2

+
–

31 kΩ

2.35 V

40 kΩV

CTL

V

CC

Hys.Amp

V

CC

V

REG

Reg

LVSD TSD

S/S F/R FG1 FG2

V

M

OUT1
OUT2

OUT3

RF

V

M

IN3

IN2

IN1

V

CREF

V

CTL

V

COUT

OSC GND1 GND2 GND3

0.5 V

+
–

+

+

–

V

CTL

Amp

Rf

Current
limiter

Logic

PWM

OSC

+

+

–

A11952

+

No. 6087-6/12

LB1975

Pin Functions

Pin No. Pin name Pin voltage Pin function Equivalent circuit

Power supply for blocks other than
the output block

1

A11953

2

V

CC

4.5 V to 6.7 V

Shunt regulator output pin (7 V)2

V

REG

0.0 V to 7.3 V

A11954

3

V

CC

20 kΩ

3.8 kΩ

Start/stop control pin
Low: start
High or Open: stop

Typical threshold voltage for
V

CC

= 5 V:
approx. 2.8 V (low to high)
approx. 2.3 V (high to low)

3 S/S

0.0 V to V

CC

A11955

4

V

CC

20 kΩ

3.8 kΩ

Forward/reverse pin
Low: forward
High or Open: reverse

Typical threshold voltage for
V

CC

= 5 V:
approx. 2.8 V (low to high)
approx. 2.3 V (high to low)

4 F/R

0.0 V to V

CC

A11956

8

7

6

14

13

V

CC

200 Ω

0.5 V

V

M

Output pin 1
Output pin 2
Output pin 3

Output current detect pin. Connect
resistor RF between this pin and
ground. Output current is limited to
value set with V

RF

/Rf. (Current limiter

operation)

6
7
8

13

OUT1
OUT2
OUT3

RF

0.0 V to V

CC

Output block power supply14

V

M

Output block ground11 GND3

Continued on next page.

No. 6087-7/12

LB1975

Continued from preceding page.

Pin No. Pin name Pin voltage Pin function Equivalent circuit

Ground for blocks other than the
output block

15
12

A11957

16 17

V

CC

10 kΩ

GND1
GND2

Speed pulse output pin 1 with built-in
pull-up resistor

Speed pulse output pin 2 with built-in
pull-up resistor

17

16

FG1

FG2

0.0 V to V

CC

A11958

V

CC

21
23

19
20
22

18

300 Ω300 Ω

Hall input pin
IN+> IN–: High input
IN+< IN–: Low input

22
23
20
21
18
19

IN1

+

IN1

–

IN2

+

IN2

–

IN3

+

IN3

–

1.5 V to

V

CC

– 1.5 V

26

A11959

V

CC

2 V

200 Ω

94 µA

2.1 kΩ

This pin sets the PWM oscillation
frequency. Connect a capacitor
between this pin and ground.

26 OSC

1.0 V to V

CC

27

A11960

V

CC

2.35 V

31 kΩ

40 kΩ

Output duty cycle control pin

• V

CTL

≤ V

CTL

1

Duty cycle 0%

• V

CTL

1 < V

CTL

< V

CTL

2

Duty cycle is controlled by V

CTL

• V

CTL

≥ V

CTL

2

Duty cycle 100%

27

V

CTL

0.0 V to 6.7 V

Continued on next page.

No. 6087-8/12

LB1975

Continued from preceding page.

Pin No. Pin name Pin voltage Pin function Equivalent circuit

V

CTL

amplifier internal reference

voltage pin (2.35 V)

24

V

CREF

0.0 V to

V

CC

– 2.0 V

A11962

28

V

CC

200 Ω

31 kΩ

V

CTL

amplifier output pin

28

V

COUT

0.7 V to

V

CC

– 0.7 V

V

CC

100 µA

24

200 Ω

23.5 kΩ

A11961

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 (V

CTL

). 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 V

CTL

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 V

CTL

input. The

output duty cycle can be controlled over the range of 0% to 100% by the V

CTL

input.

PWM Frequency
The PWM oscillator frequency f

PWM

[Hz] is set by the capacitance C [pF] connected between the OSC pin and GND.
The following equation applies:
f

PWM

≈ 1 / (1.97 × C) × 10

8

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 VFof 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 VFof 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 VCCvoltage falls below a stipulated level (V

LVSD

), the low voltage protection circuit cuts off the source-side

output transistors to prevent VCCrelated 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 V

CTL

pin conforms to the following condition: V

CTL

≤ V

CTL

1 (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, VMPower 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 VCCis 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 VCCand then VMduring 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
V

CTL

pin. When the motor has come to a full stop, switch off VMand 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 VMside, depending on the motor type and power-off
procedure. If this current cannot be absorbed by the VMpower supply or a capacitor, VMvoltage may rise and exceed
the absolute maximum VMrating for the IC. Ensure that this does not happen through proper design of the VMpower
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 V

REG

pin via an external NPN transistor and resistor. When not using the regulator, leave the V

REG

pin open.

No. 6087-10/12

LB1975

Power Supply Stabilizing Capacitors
If the VCCline fluctuates drastically, the low-voltage protection circuit may be activated by mistake, or other

malfunctions may occur. The VCCline must therefore be stabilized by connecting a capacitor of at least several µF
between VCCand GND. Because a large switching current flows in the VMline, wiring inductance and other factors can
lead to VMvoltage fluctuations. As the GND line also fluctuates, the VMline must be stabilized by connecting a
capacitor of at least several µF between VMand 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.

V

CREF

Pin, V

COUT

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 V

CREF

and ground or between V

COUT

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)

• ICCpower 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 VFof the parasitic diode to calculate the temperature.
(Sanyo data: for IF= –1 mA, VFtemperature 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

PS No. 6087-12/12

LB1975

This catalog provides information as of February, 2003. Specifications and information herein are subject
to change without notice.

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.