STEREO CASSETTE PLAYER AND
WIDE OPERATINGSUPPLY VOLTAGE (1.8V
to 6V)
HIGHOUTPUTPOWER(30mW/32Ω/3V)
LOW DISTORTIONDC VOLUMECONTROL
NO BOUCHEROTCELL
LOW QUIESCENTCURRENT(15mA)
NO INPUT CAPACITORS FOR PREAMPLIFI-
ERS
LOW MOTOR REFERENCE VOLTAGE
(200mV)
DESCRIPTION
The TDA7285 is a monolithic integrated circuit
designed for the portable players market and assembled in a plastic DIP20 and SO20. The internal functions are: preamplifier, DC volume con-
BLOCK DIAGRAM
TDA7285
MOTOR SPEED CONTROLLER
DIP20 SO20
ORDERING NUMBERS:
TDA7285 TDA7285D
trol, headphone driver and motor speed controller.
May 1997
1/11
TDA7285
PIN CONNECTION
(Top view)
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
Supply Voltage 8 V
S
Maximum Output Current 70 mA
Maximum Motor Current 700 mA
Total Power Dissipation T
tot
Operating Temperature -20 to +70
op
=90°C 0.9 W
amb
Storage and Junction Temperature -40 to 150 °C
C
°
I
Omax
I
m max
P
T
T
stg,Tj
V
THERMAL DATA
Symbol Description SO20 DIP20 Unit
R
th j-amb
DC CHARACTERISTICS
V
= 0; VOL. Control = V
i
Terminal No 1234567891011121314151617181920
Term. Volt.(V) 0 1.5 1.5 1.5 1.5 2.7 1.4 0 2.8 0 1.6 3 3 1.4 1.5 1.5 1.5 1.5 1.5 1.5
Thermal Resistance Junction-ambient 150 100 °C/W
=25°C; VS= 3V; RL=32Ω(Headphone)and RL= 10KΩ (Preamplifier);
(T
amb
).
ref
2/11
TDA7285
ELECTRICAL CHARACTERISTICS
= 3V; RL=32Ω, Vol. Control = 2/3 V
(V
S
ref (pin20);Tamb
=25°C;f =
1KHz; unless otherwise specified
Symbol Parameter Test Condition Min. Typ. Max. Unit
V
S
I
d
Supply Range 1.8 6 V
Total Quiescent Drain Current 15 22 mA
PLAYBACKAMPLIFIER
G
vo
G
v
V
O
THD Total Harmonic Distortion V
I
b
C
t
e
n
SVR1 Ripple Rejection R
Open Loop Gain 70 dB
Close Loop Gain 33 dB
Output Voltage THD = 1% 600 750 mV
= 330mVrms 0.05 0.25 %
O
Bias Current 3
Cross Talk RS= 2.2KΩ;VO= 330mVrms 74 dB
Total Input Noise RS= 2.2KΩ; B =22Hz to 22KHz 1.2 µV
= 2.2KΩ; Vr = 100mVrms
S
f = 100Hz; C
SVR
= 100µF
50 dB
HEADPHONEDRIVER
V
DC
P
O
P
O1
G
V
THD Total Harmonic Distortion P
C
t
SVR2 Ripple Rejection R
Output DC Voltage 1.4 V
Output Power THD = 10% 20 30 mW
Transient Output Power THD = 10% RL=16
Ω
50 mW
Close Loop Gain PO= 5mW 31 dB
Volume Control range 66 75 dB
= 5mW 0.3 1 %
O
Cross Talk PO=5mW;RS= 10K
= 600Ω; Vr = 100mV
S
f = 100Hz; C
SVR
= 100µF
Ω
50 dB
47 dB
MOTOR SPEEDCONTROL
A
µ
V
ref
Motor Reference Voltage (pin 12) 0.18 0.20 0.22 V
K Shunt Ratio I
Residual Voltage Im= 100mA 0.13 0.30 V
Line Regulation Im= 100mA;
S
Voltage Characteristics of Shunt
V
S
Ratio
Load Regulation Im= 30 to 200mA 0.015 0.08 %/mA
m
Current Characteristics of Shunt
I
m
Ratio
Temperature Characteristics of
amb
Reference Voltage
Temperature Characteristics of
T
amb
Shunt Ratio
∆ V
∆ V
∆ V
V
∆ K
V
∆ K
K
V
∆ K
K
ref
K
ref
ref
ref
V
ref
ref
⁄ ∆
sat
⁄ ∆ V
⁄ ∆
⁄ ∆I
⁄ ∆
⁄ ∆ T
= 100mA 45 50 55 -
m
0.20 0.8 %/V
V
= 1.8 to 6V
S
Im= 100mA;
V
= 1.8 to 6V
S
0.80 3 %/V
Im= 30 to 200mA 0.03 0.1 %/mA
Im= 100mA
T
= -20 to +60°C
amb
Im= 100mA
T
= -20 to +60°C
amb
0.04 %/°C
0.02 %/°C
3/11
TDA7285
Figure 1: Test and ApplicationCircuit
Figure 2: P.C. Board and ComponentLayout of the Circuit of Figure 2 (1:1 scale)
4/11