TDA1154
SPEED REGULATOR FOR DC MOTORS
MATCHING FLEXIBILITY TO MOTORS WITH
VARIOUS CHARACTERISTICS
BUILT-IN CURRENT LIMIT
ON-CHIP 1.2V REFERENCE VOLTAGE
STARTING CURRENT: 0.5 A @ 2.5V
REFLECTION COEFFICIENT K = 20
DESCRIPTION
The TDA1154 is a monolithic integrated circuit in-
tended for speed regulation of permanent magnet
dc motors used in record players, tape recorders,
cassette recorders and toys.
The circuit offers an excellent speed regulation with
much higher power supply, temperature and load
variations than conventional circuits built around
discrete components.
March 1993
Figure 1. Application circuit
Minidip
ORDERING NUMBER : TDA1154
V
CC
= 12 V
R
m
= 14.7
R
t
= 290
R
S
= 1 k
(total)
E
g
= 2.65 V
I
m
= 110 mA
3 : Ground
5 : Reference
8 : Output
Other pins are not connected
1/6
Symbol
Parameter
Value
Unit
R
th-j-amb
Thermal resistance junction-ambient
max
100
C/W
Rt
hj-amb
Thermal resistance junction-pin 4
max
70
C/W
THERMAL DATA
2/6
PIN CONNECTION (Top view)
Figure 2. Test circuit
Symbol
Parameter
Value
Unit
V
CC
Supply voltage
20
V
I
O
Output current
1.2
A
P
tot
Power dissipation
(see curve)
W
T
j
Junction temperature
+150
C
T
stg
Storage temperature range
-55 to +150
C
ABSOLUTE MAXIMUM RATINGS
TDA1154
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
(ref)
Reference voltage
V
CC
= +6V
I(8) = 0.1A
1.15
1.25
1.35
V
V
(
ref
)
V
(
ref
)
/
T
Reference voltage
temperature coefficient
V
CC
= +6V I(8) = 0.1A
T
amb
= -20
C to +70
C
-
0.02
-
%/
C
V
(
ref
)
V
(
ref
)
/
V
CC
Line regulator
V
CC
= +4V to +18V
I(8) = 0.1A
-
0.02
-
%/V
V
(
ref
)
V
(
ref
)
/ | (
8
)
Load regulator
V
CC
= +6V
l(8) = 25 to 400 mA
-
0.009
-
%/mA
V (5 - 3)
Minimum supply voltage
|
(
8
) =
0.1A
V
(
ref
)
V
(
ref
)
= -
5%
2.5
-
-
V
I(8)
Starting current(*)
V
(
ref
)
V
(
ref
)
= -
50%
V
CC
= +5V
1.2
-
-
A
V
CC
= +2.5V
0.5
0.8
-
I
O
(5)
Quiescent current on pin 5
V
CC
= +6V
I(8) = 100
A
-
1.7
-
mA
K
K
=
|
(
8
)
| (
5
)
reflection
coefficient
V
CC
= +6V
I(8) = 0.1A
18
20
22
K
K
/
V
CC
K spread versus V
CC
V
CC
= +6V to +18V
I(8) = 0.1A
-
0.45
-
%/V
K
K
/
| (
8
)
K spread versus I(8)
V
CC
= +6V
I(8) = 25 to 400 mA
-
0.005
-
%/mA
K
K
/
T
K spread versus temperature
V
CC
= +6V I(8) = 0.1A
T
amb
= +20
C to +70
C
-
0.02
-
%/
C
ELECTRICAL CHARACTERISTICS T
amb
= +25
C (Unless otherwise specified)
(*) An internal protection circuit reduces the current if the temperature of the junction increase: I(8) = 0.75A at T
j
= +140
C
OPERATING MODE
The circuit maintains a 1.2V costant reference volt-
age between pins 5 and 8:
V(5 - 8) = V
(ref)
= 1.2V
The current (I(5)) drawn by the circuit at pin 5 is
sum of two currents.
One is constant: I
O
(5) = 1.7mA and the other is
proportional to pin 8 current (I(8)):
I(5) = I
O
(5) +I(8)K(a)
(I
O
(5) = 1.7mA, K = 20)
Figure 3
3/6
TDA1154
4/6
Figure 4. Application circuit
If E
g
and R
m
are motor back electromotive force and
motor internal resistance respectively, then:
E
g
+
R
m
I
m
=
R
t
[ I
(
5
) +
V
(
ref
)
R
S
]
+
V
(
ref
)
(
b
)
From figure 2 it is seen that:
I
(
8
)
=
I
m
+
V
(
ref
)
R
S
(
c
)
Subsituting equations (a) and (c) into (b) yields:
E
g
=
I
m
[
R
t
K
-
R
m
]
+
+
V
(
ref
)
[
R
t
R
s
(
1
+
1
K
) +
1
]
+
R
t
I
O
(
5
) (
d
)
The motor speed will be independent of the resist-
ing torque if E
g
is also independentof I
m
. Therefore,
in order to determine the value of R
t
term(1) in (d)
must be zero:
R
t
=
K R
m
(
K
=
20
)
If R
t
>
KR
m
, an instability may occur as a result of
overcompensation.
The value of R
S
is determinated by term (2) in (d)
so as to obtain he back electromotive force (E
g
)
corresponding to required motor speed:
R
S
=
R
t
V
(
ref
)
(
1
+
1
/
K
)
E
g
-
V
(
ref
)
-
R
t
I
O
(
5
)
R
t
V
(
ref
)
E
g
-
V
(
ref
)
-
R
t
I
O
(
5
)
Where V
(ref)
= 1.2V and I
O
(5) = 1.7 mA
(1)
(2)
TDA1154
DIM.
mm
inch
MIN.
TYP.
MAX.
MIN.
TYP.
MAX.
A
3.32
0.131
a1
0.51
0.020
B
1.15
1.65
0.045
0.065
b
0.356
0.55
0.014
0.022
b1
0.204
0.304
0.008
0.012
D
10.92
0.430
E
7.95
9.75
0.313
0.384
e
2.54
0.100
e3
7.62
0.300
e4
7.62
0.300
F
6.6
0.260
I
5.08
0.200
L
3.18
3.81
0.125
0.150
Z
1.52
0.060
MINIDIP PACKAGE MECHANICAL DATA
5/6
TDA1154
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