SANYO LB8500M

Ordering number : EN8336
Monolithic Digital IC
DC Fan Motor Speed
Control IC
LB8500M
Overview
The LB8500M easily and simply implements feedback-based motor speed control in combination with a general-purpose
motor driver IC.
Compared to open-loop control, the use of speed feedback allows the motor speed precision to be improved and the speed
fluctuations due to load variations to be minimized.
• LB8500M : For use as a driver IC that increases the motor speed as the command voltage falls (single phase systems)
Features
• Achieves linear speed control
Applications can set the slope of the change in motor speed with change in the input duty.
• Minimized speed fluctuations in the presence of line or load variations
• Allows a minimum speed to be set
• Soft start function
• Settings using external capacitors and resistors (to support easier mass production of end products)
• Supports both PWM duty and analog voltage control inputs
Specifications
Absolute Maximum Ratings at Ta = 25°C
Parameter
Symbol
Conditions
Supply voltage
VCC max
VCC pin
Output current
IO max
E0 pin
Allowable power dissipation
Pd max
When mounted on a circuit board *1
Ratings
Unit
18
V
3
mA
0.87
W
Operating temperature
Topr
-30 to +95
°C
Storage temperature
Tstg
-55 to +150
°C
*1 Specified circuit board : 114.3 × 76.1 × 1.6mm3, glass epoxy.
Any and all SANYO Semiconductor Co.,Ltd. products described or contained herein are, with regard to
"standard application", intended for the use as general electronics equipment (home appliances, AV equipment,
communication device, office equipment, industrial equipment etc.). The products mentioned herein shall not be
intended for use for any "special application" (medical equipment whose purpose is to sustain life, aerospace
instrument, nuclear control device, burning appliances, transportation machine, traffic signal system, safety
equipment etc.) that shall require extremely high level of reliability and can directly threaten human lives in case
of failure or malfunction of the product or may cause harm to human bodies, nor shall they grant any guarantee
thereof. If you should intend to use our products for applications outside the standard applications of our
customer who is considering such use and/or outside the scope of our intended standard applications, please
consult with us prior to the intended use. If there is no consultation or inquiry before the intended use, our
customer shall be solely responsible for the use.
Specifications of any and all SANYO Semiconductor Co.,Ltd. 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.
32207 TI PC B8-8969 No.8336-1/15
LB8500M
Allowable Operating Ranges at Ta = 25°C
Parameter
Symbol
Conditions
Ratings
Unit
Supply voltage range 1
VCC1
VCC pin
7.5 to 17
Supply voltage range 2
VCC2
VCC pin, with VCC shorted to
6VREG
5.5 to 6.5
Output current
IO
V
2.5
mA
IREG
-5
mA
CTL pin voltage
VCTL
0 to VREG
V
LIM pin voltage
VLIM
0 to VREG
V
6V constant voltage output
E0 pin
V
current
Electrical Characteristics at Ta = 25°C, VCC = 12V
Parameter
Symbol
Ratings
Conditions
min
Supply current
Unit
typ
ICC
max
4.5
6.5
mA
6V constant voltage output (VREG pin)
Output voltage
VREG
6.0
6.2
V
Line regulation
ΔVREG1
VCC = 8 to 17V
5.8
40
100
mV
Load regulation
ΔVREG2
IO = 0 to 5mA
50
100
Temperature coefficient
ΔVREG3
Design target*
0
mV
mV/°C
Integrating Amplifier Block
Common-mode input voltage
VICM
2.0
VREG
V
1.0
V
range
High-level output voltage
VOH
IEO = -0.2mA
Low-level output voltage
VOL
IEO = 0.2mA
VREG - 1.2
V
VREG - 0.8
0.8
FGIN pin
High-level input voltage
VFGH
3.0
VREG
V
Low-level input voltage
VFGL
0
1.5
V
Input open voltage
VFGO
VREG - 0.5
VREG
V
Hysteresis
VFGS
High-level input current
IFGH
VFGIN = 6VREG
Low-level input current
IFGL
VFGIN = 0V
0.2
0.25
0.4
V
-10
0
10
μA
-140
-110
μA
RC pin
High-level output voltage
VOH(RC)
3.2
3.45
3.7
V
Low-level output voltage
VOL(RC)
0.8
0.95
1.05
V
Clamp voltage
VCLP(RC)
1.6
V
CTL pin
High-level input voltage
VCTH
2.0
VREG
V
Low-level input voltage
VCTL
0
1.0
V
Input open voltage
VCTO
VREG - 0.5
VREG
V
High-level input current
ICTH
VFGIN = 6VREG
10
μA
Low-level input current
ICTL
VFGIN = 0V
-10
0
-140
-110
VREG - 0.3
VREG - 0.1
μA
C pin
High-level input voltage
VOH(C)
VREG 0.01
Low-level input voltage
VOL(C)
1.8
IB(LIM)
VILIM
2.0
V
2.2
V
-1
1
μA
2.0
VREG
V
LIM pin
Input bias current
Common-mode input voltage
range
* The design specification items are design guarantees and are not measured.
No.8336-2/15
LB8500M
Package Dimensions
unit : mm (typ)
3086B
5
6.4
1
0.15
0.1 (1.5)
1.7max
4.4
6
0.63
5.0
10
0.35
(0.5)
1.0
SANYO : MFP10S(225mil)
Pin Assignment
EO
EI
GND
LIM
FGIN
10
9
8
7
6
LB8500M
1
2
3
4
5
RC
VREG
VCC
C
CTL
Top view
Pin Functions
Pin
Pin No.
Description
1
RC
One-shot multivibrator pulse width setting. Connect a resistor between this pin and VREG, and a capacitor between this
2
VREG
3
VCC
4
C
pin and ground.
6V regulator output. Connect a capacitor between this pin and ground for stabilization.
Power supply. Connect a capacitor between this pin and ground for stabilization.
Duty pulse signal smoothing and soft start time setting. Connect a capacitor between this pin and VREG.
5
CTL
Duty pulse signal input. The speed is controlled by the duty of this pulse signal.
6
FGIN
FG pulse input
7
LIM
8
GND
9
EI
10
EO
Minimum speed setting. Normally, the 6V regulator level is resistor divided to set this pin's input level.
Ground pin
One-shot multivibrator output and integrating amplifier input. A capacitor must be connected between this pin and EO for
this integration.
Integrating amplifier output.
No.8336-3/15
LB8500M
Block Diagrams and Application Examples
When the FG signal is
output to another circuit
board
Driver IC
VCC
12V
LB8500M
VREG
6VREG
C4
6VREG
FG
FGIN
C5
EDGE
R3
FGIN
One-shot
multivibrator
RC
EI
C3
R1
C2
LIM
EO
C1
VTH
R2
VREF
C
180kΩ
CTL
signal
CTL
CTL
GND
No.8336-4/15
LB8500M
Speed Control Diagrams
The slope is determined by the external
constant connected to the RC pin.
(RPM)
For a larger RC
time constant
For a smaller RC
time constant
Speed
Minimum
speed
Determined by the LIM pin voltage
Low← CTL pin (PWM DUTY)
High←
EO pin voltage (V)
0%
Set minimum
speed
→High
→Low
Variable speed
Low on duty
100%
(V)
Full speed
High on duty
CTL pin
6VREG
LIM voltage
EO pin
EO voltage
0V
Startup Timing (soft start)
VCC pin
CTL pin
EO pin
Stop
Stop
Full speed
Soft start
The slope can be changed with the capacitor
connected to the C pin (A larger capacitor increases
the slope.)
Full speed
No.8336-5/15
LB8500M
Supplementary Operational Descriptions
The LB8500M accepts a duty pulse input and an FG signal from the driver IC, and generates the driver IC control
voltage so that the FG period (motor speed) becomes proportional to the control voltage.
Driver IC
LB8500M
FGIN
CTL
signal
FG
CTL
Closed
feedback
loop
EO
VTH
As shown in the figure below, the LB8500M generates a pulse signal from edges on the FG signal and then generates a
pulse width waveform determined by the RC time constant in a one-shot multivibrator.
The LB8500M then integrates that pulse waveform to create the output driver IC control voltage (a DC voltage).
FG
EDGE pulse
Slope due to the
RC time constant
RC pin
One-shot
multivibrator
TRC(s) = 0.85RC
It is also possible to change the slope of the VCTL/speed relationship as shown in the speed control diagram in the
previous section by changing the pulse width with the RC time constant.
Note, however, that since pulses determined by this RC time constant are used, variation in the RC components will
appear as speed control errors.
No.8336-6/15
LB8500M
Pin Setting Procedures (Provided for reference purposes)
1. RC pin
The one-shot multivibrator pulse width can be calculated with the following equation.
TRC(s) ≈ 0.85 × R × C..................................................... Equation 1
If the FG signal frequency at full motor speed is fFG (Hz) and the control duty desired for full speed is DUTY (for
example: 50% → 0.5), the values of the resistor and capacitor connected to the RC pin can be determined from the
following equation.
R × C = DUTY/(3 × 0.85 × fFG) ..................................... Equation 2
Note that if "rpm" is the full motor speed, since one revolution will be two FG periods, the following equation gives the
FG frequency, fFG (Hz).
fFG(Hz) = 2rpm/60 ......................................................... Equation 3
For reference purposes, the following table lists the RC pin external component values determined from equations 2
and 3 when the control duty at full speed will be 80% for a variety of full motor speed values.
Note that the capacitor value must be in the range 0.01µF to 0.015µF due to the RC pin discharge capacity of the IC.
Full motor speed
R×C
R
C
10000rpm
0.94 × 10-3
63kΩ
0.015μF
8000rpm
1.18 × 10-3
78kΩ
0.015μF
6000rpm
1.57 × 10-3
105kΩ
0.015μF
4000rpm
2.39 × 10-3
157kΩ
0.015μF
2000rpm
4.68 × 10-3
312kΩ
0.015μF
The table below lists the RC pin external component values when the control duty for full motor speed is changed for a
full motor speed of 10,000rpm.
Duty at full speed
R×C
R
C
80% (= 0.8)
0.94 × 10-3
94kΩ
0.01μF
60% (= 0.6)
0.71 × 10-3
71kΩ
0.01μF
40% (= 0.4)
0.47 × 10-3
47kΩ
0.01μF
Also, note that the FG frequency can be determined from the following equation for various control duty input states.
fFG = DUTY/(3 × 0.85 × RC).......................................... Equation 4
2. C Pin
Since a capacitor that can smooth the pin voltage is connected to the C pin, if the CTL pin input signal frequency is f
(Hz), then the capacitor must meet the following condition. (Here, R is the IC internal resistance of 180kΩ (typical).)
1/f = t < RC
Note that the larger the capacitor, the longer the soft start time will be and its response to changes in the input signal will
be slower.
6VREG
A capacitor that can smooth the pin voltage is
connected here.
1/f = t < CR
CTL pin input inverted
waveform (the frequency is the
same)
C pin
180kΩ
CTL pin
CTL circuit
VREF circuit
No.8336-7/15
LB8500M
3. LIM pin
The LIM pin external component values can be derived as follows for the case where a motor whose maximum speed
of 10,000rpm is to be achieved with an 80% duty, and a minimum speed of 3000rpm is to be set.
Ra = minimum speed/full speed = 3000/10,000 = 0.3
Full-speed duty × Ra = 0.8 × 0.3 = 0.24
LIM pin voltage = 6 - (4 × 0.24) ≈ 5V
From the above, the required LIM pin voltage is about 5V.
To generate this 5V level by resistor dividing the 6 V regulator level, the resistor ratio will be 1:5, and the resistors
connected to the LIM pin will have the following values.
Between 6VREG and LIM pin : 10kΩ
Between LIM pin and GND : 50kΩ
(RPM)
12000
10000
8000
6000
4000
Minimum
speed
2000
0
0%
6V
20% 24%
5V
40%
60%
CTL Duty (PWM duty)
LIM pin voltage
80%
100%
2V
No.8336-8/15
LB8500M
Application Example 2
[Used in Combination with the LB11660FV]
Driver IC
12V
VCC
LB8500M
VREG
6VREG
EDGE
One-shot
multivibrator
RC
FG
EI
LIM
EO
VREF
C
CTL
signal
FGIN
FGIN
VTH
180kΩ
CTL
CTL
GND
In this circuit, the dynamic range of the LB8500M EO pin (the range from the amplifier block output high to output low
levels) must be wider than the dynamic range (from the high to low levels of the PWM signal) of VTH pin of driver IC
with which this IC is combined.
However, since the LB11660FV PWM low-level voltage is lower than the LB8500M amplifier output low-level
voltage, it must be resistor divided.
No.8336-9/15
LB8500M
Application Example 3
[Fixed Speed + Soft Start]
With this circuit, the motor speed remains constant even if there are fluctuations in the supply voltage or static voltage.
(RPM)
Motor
full speed
0%
20%
40%
60%
80%
100%
CTL signal (PWM duty)
C pin voltage
6V
Driver IC
12V
VCC
VREG
LB8500M
6VREG
FGIN
EDGE
FG
FGIN
One-shot
multivibrator
RC
EI
LIM
EO
VTH
VREF
C
180kΩ
CTL signal
CTL
CTL
GND
Input a fixed-duty signal to the CTL pin signal input as an input signal for which soft start is enabled at startup.
Alternatively, apply a constant voltage to the C pin. (In this case, the CTL pin must be left open.)
No.8336-10/15
LB8500M
Application Example 4
[Analog Input]
DC voltage speed control
(RPM)
Motor
full speed
Set minimum
speed
0
6.0V
5.2V
4.4V
3.6V
2.8V
2.0V
C pin voltage
Driver IC
12V
VCC
LB8500M
VREG
6VREG
FGIN
EDGE
One-shot
multivibrator
RC
EI
LIM
VCTL
voltage
FG
FGIN
EO
VTH
VREF
C
180kΩ
CTL
CTL
GND
No.8336-11/15
LB8500M
Application Example 5
[Thermistor + Soft Start]
Ambient temperature based speed control using a thermistor
(RPM)
Motor
full speed
C pin voltage change with the thermistor
Set minimum
speed
Ambient temperature, Ta – °C
Driver IC
12V
VCC
LB8500M
VREG
6VREG
FGIN
EDGE
FG
FGIN
One-shot
multivibrator
RC
EI
LIM
EO
VTH
VREF
C
180kΩ
CTL
CTL
GND
No.8336-12/15
LB8500M
Application Example 6
[Thermistor + External PWM]
Ambient temperature plus external PWM duty based speed control using a thermistor
(RPM)
ty
du
PW
M
PW
M
du
:l
ty
ow
:h
ig
h
Motor
full speed
Set minimum
speed
Ambient temperature, Ta – °C
Driver IC
12V
VCC
LB8500M
VREG
6VREG
FGIN
EDGE
FG
FGIN
One-shot
multivibrator
RC
EI
LIM
EO
VTH
VREF
C
180kΩ
CTL
CTL
GND
No.8336-13/15
LB8500M
Application Example 7
[Origin Shift]
Changing the origin from 0rpm at 0% to a state where there is rotation at 0%
(RPM)
0%
20%
40%
60%
80%
100%
CTL signal (PWM duty)
Driver IC
VCC
12V
LB8500M
VREG
6VREG
FGIN
EDGE
One-shot
multivibrator
RC
EI
LIM
EO
-
VTH
VREF
C
+
FG
FGIN
180kΩ
CTL
signal
CTL
CTL
GND
No.8336-14/15
LB8500M
SANYO Semiconductor Co.,Ltd. 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 Semiconductor Co.,Ltd.
products described or contained herein.
SANYO Semiconductor Co.,Ltd. strives to supply high-quality high-reliability products, however, any and all
semiconductor products fail or malfunction with some probability. It is possible that these probabilistic failures or
malfunction could give rise to accidents or events that could endanger human lives, trouble that could give rise
to smoke or fire, or accidents 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 Semiconductor Co.,Ltd. products described or contained herein are
controlled under any of applicable local export control laws and regulations, such products may require 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 consent of SANYO Semiconductor 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 Semiconductor Co.,Ltd. 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.
Upon using the technical information or products described herein, neither warranty nor license shall be granted
with regard to intellectual property rights or any other rights of SANYO Semiconductor Co.,Ltd. or any third
party. SANYO Semiconductor Co.,Ltd. shall not be liable for any claim or suits with regard to a third party's
intellctual property rights which has resulted from the use of the technical information and products mentioned
above.
This catalog provides information as of March, 2007. Specifications and information herein are subject
to change without notice.
PS No.8336-15/15