STK4412
SANYO Electric Co., Ltd. Semiconductor Business Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
110297HA (ID) / 9098TA No. 2860--1/7
Ordering number: EN2860A
Thick Film Hybrid IC
2-Channel AF Power Amplifier
(20W+20W min, THD = 1.0%)
Features
Small and slim package with 31mm height
Pin compatible with STK430 series heretofore in use
Greatly reduced heat sink due to case temperature
125
C guaranteed
Excellent cost performance
Package Dimensions
unit: mm
4033
[STK4412]
Specifications
Maximum Ratings
at Ta = 25
C
Recommended Operating Conditions
at Ta = 25
C
Operating Characteristics
at Ta = 25
C, V
CC
= 44V, R
L
= 8
, Rg = 600
, VG = 40dB
Parameter
Symbol
Conditions
Ratings
Unit
Maximum supply voltage
V
CC
max
63
V
Operating substrate temperature
Tc
125
C
Storage temperature
Tstg
-
30 to +125
C
Available Time for load short-circuit
t
s
V
CC
= 44V, R
L
= 8
, f = 50Hz, Po = 20W
2
s
Parameter
Symbol
Conditions
Ratings
Unit
Recommended operating voltage
V
CC
44
V
Load resistance
R
L
8
Parameter
Symbol
Conditions
min
typ
max
Unit
Quiescent current
Icco
V
CC
= 53V
20
60
120
mA
Output power
Po (1)
THD = 1.0%, f = 1kHz
20
W
Po (2)
THD = 1.0%,
f = 30Hz to 20kHz
10
W
Total harmonic distortion
THD
Po = 0.1W, f = 1kHz
0.3
%
Frequency response
f
L
, f
H
Po = 0.1W,
dB
20 to 100k
Hz
Input impedance
r
i
Po = 0.1W, f = 1kHz
110
k
Output noise voltage
V
NO
V
CC
= 53V, Rg = 10k
0.8
mVrms
+0
-
3
STK4412
No. 2860--2/7
Specified Transformer Power Supply
(Equivalent to RP-25)
Notes.
For power supply at the time of test, use a constant-voltage power
supply unless otherwise specified.
For measurement of the available time for load short-circuit and out-
put noise voltage, use the specified transformer power supply shown
right.
The output noise voltage is represented by the peak value on rms
scale (VTVM) of average value indicating type. For AC power supply,
use an AC stabilized power supply (50Hz) to eliminate the effect of
flicker noise in AC primary line.
Equivalent Circuit
Sample Application Circuit:
20W min 2-Channel AF Power Amplifier
STK4412
No. 2860--3/7
Sample Printed Circuit Pattern for Application Circuit
(Cu-foiled side)
Input voltage, Vi - mV
Frequency, f - Hz
Output po
wer
, Po -
W
Output po
wer
, Po -
W
Output power, Po - W
Frequency, f - Hz
T
otal harmonic distortion,
THD - %
V
oltage g
ain,
V
G
- dB
STK4412
No. 2860--4/7
Operating substrate temperature, Tc -
C
Supply voltage, V
CC
- V
Frequency, f - Hz
Quiescent current, Icco - mA
Current drain, I
CC
-
A
Output po
w
o
r
,
Po -
W
V
oltage g
ain,
V
G
- dB
Supply voltage, V
CC
- V
Output powor, Po - W
Quiescent current, Icco - mA
IC Po
wer dissipation, Pd -
W
STK4412
No. 2860--5/7
Description of External Parts
C1, C2
Input filter capacitors
A filter formed with R1 or R2 can be used to reduce noise at high frequencies.
C3, C4
Input coupling capacitors
Used to block DC current. When the reactance of the capacitor increases at low frequencies, the dependence of 1/f noise on signal source
resistance causes the output noise to worsen. It is better to decrease the reactance.
C5, C6
NF capacitors
These capacitors fix the low cutoff frequency shown below.
To provide the desired voltage gain at low frequencies, it is better to increase C5. However, do not increase C5 more than needed because
the pop noise level becomes higher at the time of application of power.
C15
Capacitor for ripple filter
Used to eliminate the ripple components that mix into the input side from the power line (+V
CC
).
R7, R8
Front stage bias resistors
R11
Front stage bias resistor
C9, C10
Oscillation blocking capacitors
A polyester film capacitor, being excellent in temperature characteristic, frequency characteristic, is recommended for C9, C10.
R1, R2
Resistors for input filter
R12
Front stage bias resistor
R3, R5
(R4, R6)
These resistors fix voltage gain VG.
It is recommended to use R3 (R4) = 12
for VG = 40dB.
To adjust VG, it is desirable to change R3 (or R4).
C7, C8
Bootstrap capacitors
When the capacitor value is decreased, the distortion is liable to be higher at low frequencies.
R13
Resistor for ripple filter
(Limiting resistor for predriver TR at the time of load short)
C11, C12
Output capacitors
These capacitors fix the low cutoff frequency.
C13
Oscillation blocking capacitor
Must be inserted as close to the IC power supply pins as possible so that the power supply impedance is decreased to operate the IC stably.
C14
Decoupling capacitor
When the capacitor value is increased, the starting time is made longer.
R9, R10
Oscillation blocking resistors
f
L
1
2
C5 R3
----------------------------------- Hz
=
STK4412
No. 2860--6/7
Sample Application Circuit
(protection circuit and muting circuit)
Thermal Design
The IC power dissipation of the STK4412 at the IC-oper-
ated mode is 26.8W max. at load resistance 8
(simulta-
neous drive of 2 channels) for continuous sine wave as
shown in Figure 1.
In an actual application where a music signal is used, it is
impractical to estimate the power dissipation based on the
continuous signal as shown right, because too large a heat
sink must be used. It is reasonable to estimate the power
dissipation as 1/10 Po max. (EIAJ).
That is, Pd = 17.2W at 8
Thermal resistance
c-a of a heat sink for this IC power
dissipation (Pd) is fixed under conditions 1 and 2 shown
below.
Figure 1. STK4412 Pd Po (R
L
= 8
)
Output power, Po - W
IC Po
wer dissipation, Pd -
W
Condition 1: T
C
= Pd
c-a + Ta
125
C .............................................. (1)
where
Ta : Specified ambient temperature
T
C
: Operating substrate temperature
Condition 2: Tj
= Pd
(
c-a) + Pd/4
(
j-c) + Ta
150
C .................... (2)
where
Tj : Junction temperature of power transistor
Assuming that the power dissipation is shared equally among the four power transistors (2 channels
2), thermal resis-
tance
j-c is 3.6
C/W and
Pd
(
c-a + 3.6/4) + Ta
150
C ........................................ (3)
STK4412
No. 2860--7/7
s
No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace equipment, nuclear
power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of which may directly or indirectly cause injury,
death or property loss.
s
Anyone purchasing any products described or contained herein for an above-mentioned use shall:
Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors and all their
officers and employees, jointly and severally, against any and all claims and litigation and all damages, cost and expenses associated
with such use:
Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on SANYO ELECTRIC CO.,
LTD., its affiliates, subsidiaries and distributors or any of their officers and employees, jointly or severally.
s
Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. SANYO
believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of
intellectual property rights or other rights of third parties.
This catalog provides information as of November, 1997. Specifications and information herein are subject to change without notice.
Thermal resistance
c-a of a heat sink must satisfy ine-
qualities (1) and (3).
Figure 2 shows the relation between Pd and
c-a given
from (1) and (3) with Ta as a parameter.
[Example] The thermal resistance of a heat sink is
obtained when the ambient temperature speci-
fied for a stereo amplifier is 50
C.
Assuming V
CC
= 44V, R
L
= 8
,
R
L
= 8
: Pd = 17.2W at 1/10 Po max.
The thermal resistance of a heat sink is
obtained from Figure 2.
R
L
= 8
:
c-a = 4.36
C/W
Tj when a heat sink is used is obtained from
(3).
R
L
= 8
: Tj = 140.5
C
Figure 2. STK4412
c-a Pd
IC Power dissipation, Pd - W
Thermal resistance of heat sink,
c-a -
C/W
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