LOW-VOLTAGE DC MOTOR SPEED CONTROLLER
WIDEOPERATINGVOLTAGERANGE
(1.8 to 6 V)
BUILT-IN LOW-VOLTAGE REFERENCE (0.2
V)
LINEARITYIN SPEED ADJUSTMENT
HIGHSTABILITY VS. TEMPERATURE
LOW NUMBER OF EXTERNALPARTS
DESCRIPTION
TDA7274
MINIDIP
The TDA7274 is a monolithic integrated circuit
DC motor speed controller intended for use in microcassettes, radio cassette players and other
consumer equipment. It is particulary suitable for
low-voltage applications.
PIN CONNECTION (top view)
ORDERING NUMBER : TDA7274
November 1988
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TDA7274
APPLICATION CIRCUIT
VS= 3.0V
= 4.9Ω
R
M
= 220Ω
R
T
= 1.65V
E
g
= 100mA
I
M
V
M=RMIM+Eg
= 2.14V
SCHEMATIC DIAGRAM
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TDA7274
ABSOLUTE MAXIMUMRATINGS
Symbol Parameter Value Unit
V
Supply Voltage
S
Motor Current 700 mA
I
M
P
Power Dissipation at T
tot
=25°C 1.25 W
amb
THERMAL DATA
Symbol Parameter Value Unit
R
th j-amb
Thermal Resistance Junction-ambient Max. 100 °C/W
6V
ELECTRICAL CHARACTERISTICS (Refer to test circuit, VS= 3V, T
=25°C unless otherwisespeci-
amb
fied)
Symbol Parameter Test Condition Min. Typ. Max. Unit
V
V
I
(Pin 6) Quiescent Current 120 µA
I
d
K
V
sat
∆V
ref
V
ref
∆K
⁄∆VSVoltage Characteristic of Shut
K
∆V
ref
V
ref
∆K
⁄∆IMCurrent Characteristic of Shut
K
∆V
ref
⁄∆T
V
ref
∆K
⁄∆T
K
Supply Voltage Range
S
Reference Voltage IM= 100mA 0.18 0.20 0.22 V
ref
Quiescent Current 2.4 6.0 mA
q
Shunt Ratio I
= 100mA
M
Residual Voltage IM= 100mA 0.13 0.3 V
⁄∆V
Line Regulation IM= 100mA
S
= 1.8 to 6V
V
S
IM= 100mA
Ratio
= 1.8 to 6V
V
S
⁄∆IMLoad Regulation IM= 20 to 200mA 0.004 %/mA
IM= 20 to 200mA –0.03 %/mA
Ratio
Temperature Characteristic of
amb
Reference Voltage
Temperature Characteristic of
amb
Shut Ratio
IM= 100mA
Tamb = –20 to +60°C
IM= 100mA
Tamb = 20 to +60°C
1.8 6 V
45 50 55 –
0.20 %/V
0.80 %/V
0.04 %/°C
0.02 %/°C
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TDA7274
Figure1 : Test Circuit.
Figure2 : QuiescentCurrent vs.
SupplyVoltage.
Figure3 : Reference Voltagevs.
Supply Voltage.
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TDA7274
Figure5 : Reference Voltagevs. Load Current.Figure4 : ShuntRatio vs. Supply Voltage.
Figure6 : Shunt Ratio vs. Load Current. Figure 7 : Minimum SupplyVoltage (typical) vs.
Load Current.
Figure8 : SaturationVoltage vs. Load Current.
Figure9 : QuiescentCurrent vs.
AmbientTemperature.
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TDA7274
Figure10 : ReferenceVoltage vs.
Figure11 : ApplicationCircuit.
AmbientTemperature.
VS= 3.0V
= 4.9Ω
R
M
= 220Ω
R
T
E
g
I
M
V
M=RMIM+Eg
Figure12 : P. C. Boardand Componentslayout of the Circuit offig. 11 (1 : 1 scale).
= 1.65V
= 100mA
= 2.14V
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Figure14 : SpeedVariationsvs. MotorCurrent.Figure13 : Speed Variationsvs. Supply Voltage.
Figure15 : SpeedVariationsvs.
AmbientTemperature.
APPLICATION INFORMATION
Figure16.
TDA7274
R
R
+I
B
S
M
+
R
K
R
T
R
S
E
g=RTId
1 +
R
has to be adjusted so that the applied voltage
S
V
is suitable for a given motor, the speed is then
M
linearlyadjustable varing R
T
(1 +
.
B
−
R
M
+V
ref
1
)
K
IM= Motorcurrent at rated speed
= Motor resistance
R
M
E
= Back electromotive force
g
V
M=IM.RM+Eg
Thevalue of R
IfR
T (max.)
The values of C
iscalculated so that
T
R
T (max.)
<K
(min.)
•.R
M (min.)
>K •RM, instabilitymay occur.
(4.7 µF typ.) and C2(1 µF typ.)
1
depend on the type of motor used. C
WOW and flutter of the system. C
suppresses
2
motorspikes.
adjusts
1
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TDA7274
Figure17 : 3V Stereo CassetteMiniplayer with Motor SpeedControl.
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MINIDIP PACKAGE MECHANICAL DATA
TDA7274
DIM.
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
mm inch
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TDA7274
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties whichmay result from its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics.
1994 SGS-THOMSON Microelectronics - All RightsReserved
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