PANASONIC AN6657S

ICs for Motor
AN6657, AN6657S
Micromotor Forward/ Reverse Electronic Governors
■ Overview
AN6657
16
2
15
3
14
4
13
5
12
6
11
supply voltage range ; V CC =4.5V to
7
10
14V
• Stable reference voltage (1.3V) and easy speed control
• Large starting torque and maximum control torque
• Good secular drift because of external power transistor
• Provided with the motor stop function ; ICC =20µA or
less at stop time
• Capable of controlling forward/reverse rotation, fast forward/constant speed, and start/stop via 3 input pins
8
9
3 ~ 15˚
7.62±0.25
16-Lead DIP Package (DIP016-P-0300E)
AN6657S
15
3
14
4
13
5
12
6
11
7
10
8
9
0.3
0.65
1.5±0.2
16
2
0.1±0.1
1
10.1±0.3
Unit : mm
0.15
settes
Speed control of the micromotors for the microcassettes of the automatic answering telephone sets
• Control of the tape loading motors for the DATs, etc.
•
+ 0.1 5
0.0
0.3 –
0.4
of the micromotors for the radio cas-
(3.45)
3.8±0.25
0.4±0.25
■ Applications
• Speed control
0.51min.
6.3±0.25
1.27
■ Features
• Wide operating
21.7±0.3
1
0.5±0.1
1.2±0.25
Unit : mm
2.54
The AN6657 and the AN6657S are the electronic governors capable of controlling the forward/reverse speed,
fast forward, rewind, and start/stop of the micromotors
used for the radio/cassette tape recorders, automatic answering telephone sets, and so on.
4.2±0.3
6.5±0.3
■ Block Diagrom
16-Lead SOP Package (SOP016-P-0300)
GND
16
15
14
13
Drive Mode
Swiching Logic
12
VCC
11
10
9
Ref.Voltage
1kΩ
For./Rev.
Drive Circuit
10kΩ
Amp.
1
2
3
4
5
6
7
8
ICs for Motor
AN6657, AN6657S
■ Absolute Maximum Ratings (Ta= 25˚C)
Symbol
Rating
Supply Voltage
Parameter
VCC
14.4
Supply Current
ICC
50
mA
IO
700
mA
Output Current
Power Dissipation
AN6657
Storage Temperature
AN6657
–20 ~ + 70
˚C
–55 ~ +150
Tstg
AN6657S
mW
380
Topr
Operating Ambient Temperature
V
500
PD
AN6657S
Unit
˚C
–55 ~ +125
■ Recommended Operating Range (Ta = 25˚C)
Parameter
Symbol
Range
Operating Supply Voltage Range
VCC
4.5V ~ 14V
■ Electrical Characteristics (Ta = 25˚C)
Parameter
Symbol
Condition
Bias Current
Ibias
VCC = 5V
Prestart Current
Istop
VCC = 5V
Reference Voltage
Vref
VCC = 5V
Start Voltage
VCC (S)
min.
typ.
max.
4
1.1
1.3
mA
20
µA
1.5
V
3
Supply voltage at which a 50mA current flows to Ra
Unit
10
V
Start Current
IST
VCC = 4.5V, Ra = 13Ω
130
Rated Load r.p.m
NL
VCC = 5V, IL = 55mA, N = 2000rpm
–10
0
10
∆NLogi
VCC = 5V, IL = 55mA, N = 2000rpm
–5
0
5
%
FF/Rated r.p.m. Ratio
∆N
VCC = 5V, IL = 55mA, N = 4000rpm
1.85
2
2.15
Times
r.p.m. Characteristics on Voltage Change
∆NV
VCC = 4.5V ~ 9V, IL = 55mA
r.p.m. Characteristics on Load Change
∆NL
Switching Mode Input H
VH
VCC = 5V ~ 14V
Switching Mode Input L
VL
VCC = 5V ~ 14V
Forward/Reverse r.p.m Difference
Current Limiting Starting Voltage
VLim
Ref. Voltage Temperature Characteristics
∆Vr/Ta
mA
50
rpm/V
120
rpm
3
6
V
0
0.7
V
VCC = 4.5V, IL = 55mA ~ 90mA
0.55
VCC = 9V, RT = 1.3Ω
0.62
0.015
VCC = 5V, Ta = 0˚C ~ 60˚C
■ Application Circuit
To Mechanism Controller, etc
VCC
+
3900
rpm/˚C
1.2Ω
–
4.7µF
NC
16
15
1
2
14
13
12
11
10
9
7
8
AN6657, AN6657S
2000
rpm/˚C 15kΩ
3
4
5
6
2SD2249
or
2SD2177
4.3kΩ
0.022µF
1kB
–
+
M
680Ω
0.01µF
%
HKN–3A6LDI (Ra=13Ω)
(National Micromotors Co., Ltd)
0.7
V
%/˚C
ICs for Motor
AN6657, AN6657S
■ Pin Descriptions
1
Description
I/O
Voltage
Constant speed setting pin
O
VCC – 1.3V
Pin Name
Pin No.
Constant Speed
Setting
Equivalent Circuit
11
VREF
2
2
FF Setting
FF speed setting pin
O
3
Speed Control
Controls the speed
I
4
Phase Compensation
Oscillation preventive
phase compensation pin
I
5
Motor Drive +
Motor + pin connection pin
O
VCC – 1.3V
1
3
11
6
Collector
Connection
Collector connection pin of
the external NPN transistor
O
7
Base Connection
Base connection pin of the
external NPN transistor
O
Motor Drive –
Moror – pin connection pin
O
9
Load
Characteristics
Setting
Motor torque load
characteristics setting pin
O
10
VCC
VCC pin
I
11
To the pin 9.
Connect to the pin o.
O
12
GND
GND pin
I
13
NC
No connection
14
Start/Stop
Start/stop control pin
I
15
Forward/Reverse
Forward/reverse control pin
I
9
6
50Ω
150Ω
7
70kΩ
40kΩ
14
15
Constant Speed/FF
8
4
8
16
5
Constant speed/FF control
pin
I
16
30kΩ
ICs for Motor
AN6657, AN6657S
■ Supplementary Explanation
• Principle of Functioning
The AN6657 and the AN6657S are the electronic
governors which control the motor speed constantly by
making use of the fact that the counter electromotive force
generated in the motor winding is proportional to the motor
speed when the DC motor rotates. They have two motor drive
systems which correspond to the forward and reverse
rotations, respectively. The inter-pin voltage of the motor Em
is given by the following expression.
Em = Ea + Ra Ia
(1)
Ea : Motor reverse electromotive voltage
Ra : Motor internal resistor
Ia : Motor current
There are the following relationships between the motor
reverse electromotive voltage Ea and Motor speed, and motor
torque T and motor current Ia, respectively.
Ea = Ka · N
(2)
T = KT · Ia
(3)
speed signal. In Fig. 1, the motor speed N (∝ motor generated
voltage Ea) in the motor control state can be expressed by the
following formula.
r5
r2 + r3
r1r2
Ea = VREF r
·
+
r3 – Ra Ia
3
r4 + r5
+ VCE SAT1
(4)
The expression (4) applies in case of motor forward rotation,
in which a current flows from the motor + pin (5) to the
motor – pin (8). The following expression applies in case of
motor reverse rotation, in which a current flows form the
motor – pin (8) to the motor + pin (5).
Ea = VREF
r5
r2 + r3
·
+
r3
r4 + r5
r1r2
r3 – Ra Ia
+VCE SAT2
(5)
VREF : Reference voltage, Ra : Motor internal resistor
Ia : Motor current
r2, r3 : Diffusion resistance in the IC, r4, r5 : Resistance for
speed control
r1 : Torque control Resistance
VCE SAT1 : Forward/reverse drive circuit saturation voltage
when motor forward rotation is set
VCE SAT2 : Forward/reverse drive circuit saturation voltage
when motor reverce rotation is set
Ka : Motor generation constant
KT : Motor torque constant
In the expression (1), the inter-pin voltage of the motor Em
includes the voltage Ra · Ia which changes depending on
motor current Ia. The counter electromotive voltage Ea is
taken out by configuring the bridge circuit and used as a motor
VCC
+
Constant Speed/
Fast Forward
Forward/
Reverse
1
r1 < 10 Ra
S/S
4.7µF
–
NC
16
15
14
13
Drive Mode
Switching Logic
12
11
10
9
Reference
Voltage
Forward/
Reverse
Drive Circuit
r3
1kΩ
10kΩ
r2
Amp.
2SD2249
or
2SD2177
1
r4
15kΩ
1kB
2
r6
3
4.3kΩ
4
1
0.022µF
5
6
2SD2249
or
2SD2177
7
+
8
=
M
r5
680Ω
2
Ea
–
0.01µF
Ra
Ra : Motor-coiled resistor
Ea : Motor counter electromotive voltage
1 : Oscillation preventive capacitor
2 : Prevention of motor noise
Fig.1 AN6657/AN6657S Motor Control Basic Circuit
ICs for Motor
AN6657, AN6657S
As it is clear from the expression (4), r1r2/r3 – Ra = 0, that is,
when r1 = r3/r2÷Ra is established, Ea (∝ motor speed N)
becomes a constant value without depending on the motor
current Ia (load torque T). This is also true for the expression
(5).
• Switching the Various Modes
The AN6657 and the AN6657S have five motor drive
modes as shown in Table 1. Those modes can be selected
depending on the voltage H (3V to 6V) and voltage L (0V to
0.7V) signals applied to the input pins14, 15 and 16.
1) Forward/reverse switching : Forward/reverse rotation is
switched over whether a current flows from the pin5 to
the pin8 (forward rotation) or vice versa (reverse
rotation).
2) Power-off (pause) mode : turning off the constant current
source inside the IC stops a current to the motor and stops
motor. In this mode, all the transistors of the IC are turned
off and only a leak current (20µA) is available.
3) Setting the motor speed
The motor speed at constant speed time can be expressed
by the expression (4).
The torque control resistance r1 is important in setting the
motor rotating state. Select the resistance which satisfies the
condition of the expression (7) within a working temperature
range. If this condition is not satisfied, the motor may have
abnormal rotation such as hunting, etc.
r3
r1 < r2 Ra
≈
(r3/r2 = 1/10 for the AN6657, AN6657S)
(7)
Ra is the copper coiled resistor of the motor and has the
temperature characteristics of + 3,900r.p.m/˚C, Therefore, it
is necessary to set the value of r1 so that the relationship in
the expression (7) will be satisfied at the minimum working
temperature. The diffusion resistance r3/r2 in the IC has the
flat temperature characteristics, and if the temperature
characteristics of r1 is adjusted to that of Ra, + 3900 r.p.m/˚C,
the value of the second term (r1r2r – Ra) of the expressions
(4) and (5) shows the flat temperature characteristics and the
torque characteristics of the motor speed becomes constant
without depending on a temperature. Fig. 2 and Fig. 3 show
this relationship.
r5
r4 · r6
r
r4+r6 + 5
Low Temperature
Normal Temperature
In the FF (REW) mode, the pin2 is turned on and the first
term of the expression (4) is ;
Ea =VREF
r2+r3
r3
r5
+
· r4 · r6
r5
r4+r6 +
High Temperature
N (R.P.M.)
r2+r3
r3 ·
VREF
• Setting the External Resistor r1
r1r2
r3 – Ra Ia
TM (Torque)
+ VCE SAT
(6)
and the motor speed N (motor generated voltage Ea) is
expressed as follows.
From the expression (4), the motor speed at constant speed
can be controlled with r4 and r5 (external VRs).
From the expression (6), the motor speed at the FF (REW)
mode can be controlled with r6.
Fig. 2
r1 Temperature Characteristics < Ra Temperature Characteristics
Table 1 AN6657/AN6657S Mode Switching Table
Input
Output
Motor Drive Mode
Pin14
Pin15
Pin16
Pin5 Motor +
Pin8 Motor –
Pin2
L
—
—
—
—
OFF
H
H
L
H
L
OFF
Forward (constant speed)
H
L
L
L
H
OFF
Reverse (constant speed)
H
H
H
H
L
ON
FF
H
L
H
L
H
ON
REW
Power OFF (pause)
ICs for Motor
AN6657, AN6657S
• Current Limiting Function
N (R.P.M.)
All Temperatures
TM (Torque)
Fig. 3.
r1 Temperature Characteristics = Ra Temperature Characteristics
The current limitting function detects the voltage drop of
the torque control resistance r1, operates the PNP transistor,
and controls the input voltage of the amplifier in the IC to
limit the current.
Limiting the current can reduce the useless current at start
and motor lock time and prevent the supply voltage from
dropping.
The limited current ILim is calculated by the following
expression.
ILim =
• Temperature Compensation of Motor Speed
For the normally used motor with core, the temperature
compensation of the motor speed can be done by using 3,900
r.p.m/˚C metal coated or coiled resistor as the torque control
resistance r1, and metal coated resistor with a positive
temperature coefficient of about 2,000r.p.m/˚C as the speed
control resistance r4.
VLim
r1
(8)
VLim : VBEON Voltage < 0.6V
When r1 = 1.2Ω, from the expression (8) ILim is ;
0.6V
ILim =
= 500mA
1.2Ω
■ Characteristics Curve
PD – Ta
r.p.m. Load Torque
800
FF/REW
600
R.p.m. N (rpm)
Power Dissipation PD (mW)
4000
AN6657
400
Constant
Speed
2000
AN6657S
VCC = 9V
200
VCC = 6V
0
0
40
80
120
Ambient Temperature Ta (˚C)
160
0
0
40
80
Load Torque T (g – cm)
120
160