STPA003
4 x 52 W quad bridge power amplifier with high side driver and
low voltage operation
Datasheet - production data
– No external compensation
– No bootstrap capacitors
On board 0.4 A high side driver
Flexiwatt25
Protections:
– Output short circuit to GND, to Vs, across
the load
– Very inductive loads
– Overrating chip temperature with soft
thermal limiter
– Output DC offset detection
– Load dump voltage
– Fortuitous open GND
– Reversed battery
– ESD
GAPGPS00070
GAPGPS00670
Flexiwatt27
Features
High output power capability:
– 4 x 52 W/4 Ω max.
– 4 x 30 W/4 Ω @ 14.4 V, 1 kHz, 10 %
– 4 x 85 W/2 Ω max.
– 4 x 55 W/2 Ω @ 14.4V, 1 kHz, 10 %
Description
MOSFET output power stage
Capable to operate in low voltage conditions
(e.g.: “Start - Stop”)
Excellent GSM noise immunity
Excellent 2 Ω driving capability
Hi-Fi class distortion
Low output noise
Standby function and mute function
Automute at min. supply voltage detection
Low external component count:
– Internally fixed gain (26 dB)
The STPA003 is a MOSFET class AB audio
power amplifier, designed for high-power car
radio. In addition to the outstanding output current
capability and distortion performance, the
STPA003 is extremely robust against several
kinds of fortuitous misconnection.
It is compliant to the most recent OEM
specifications for low voltage operation (the so
called 'start-stop' battery profile during engine
stop).
It includes a DC offset detector and, in
Flexiwatt27 package, a high side driver or a
clipping detector.
Table 1. Device summary
Order code
Package
Packing
STPA003OD-4WX
Flexiwatt25 (with OD)
Tube
STPA003CD-48X
Flexiwatt27 (with CD)
Tube
STPA003HSD-48X
Flexiwatt27 (with HSD)
Tube
January 2020
This is information on a product in full production.
DS10473 Rev 2
1/25
www.st.com
Contents
STPA003
Contents
1
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1
Block diagram and application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3
Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2
Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
4
Electrical characteristics typical curves . . . . . . . . . . . . . . . . . . . . . . . . 13
5
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2
Battery variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.3
5.4
5.5
5.2.1
Low voltage operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2.2
Cranks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2.3
Advanced battery management (hybrid vehicles) . . . . . . . . . . . . . . . . . 18
Protections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.3.1
Short circuits and open circuit operation . . . . . . . . . . . . . . . . . . . . . . . . 19
5.3.2
Over-voltage and load dump protection . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.3.3
Thermal protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4.1
DC offset detection (OD pin) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4.2
Clipping detection and diagnostics (CD-DIAG pin) . . . . . . . . . . . . . . . . 20
Heat sink definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
7
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2/25
DS10473 Rev 2
STPA003
List of tables
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Pin functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
DS10473 Rev 2
3/25
3
List of figures
STPA003
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
Figure 14.
Figure 15.
Figure 16.
Figure 17.
Figure 18.
Figure 19.
Figure 20.
Figure 21.
Figure 22.
Figure 23.
Figure 24.
Figure 25.
Figure 26.
Figure 27.
Figure 28.
Figure 29.
4/25
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Standard test and application circuit (Flexiwatt25 with OD) . . . . . . . . . . . . . . . . . . . . . . . . . 6
Standard test and application circuit (Flexiwatt27 with CD) . . . . . . . . . . . . . . . . . . . . . . . . . 6
Standard test and application circuit (Flexiwatt27 with HSD) . . . . . . . . . . . . . . . . . . . . . . . . 7
Pin connections (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Quiescent current vs. supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Output power vs. supply voltage (4 Ω) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Output power vs. supply voltage (2 Ω) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Distortion vs. output power (4 Ω) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Distortion vs. output power (2 Ω) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Distortion vs. frequency (4 Ω) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Distortion vs. frequency (2 Ω) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Distortion vs. output power (4 Ω, Vs = 6 V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Distortion vs. output power (2 Ω, Vs = 6 V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Supply voltage rejection vs. frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Crosstalk vs. frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Total power dissipation & efficiency vs. Po (4 Ω, Sine) . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Power dissipation vs. average output power (4 Ω, audio program simulation) . . . . . . . . . . 15
Power dissipation vs. average output power (2 Ω, audio program simulation) . . . . . . . . . . 15
ITU R-ARM frequency response, weighting filter for transient pop. . . . . . . . . . . . . . . . . . . 15
SVR charge diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Battery cranking curve example 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Battery cranking curve example 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Upwards fast battery transitions diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Load dump protection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Thermal protection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Audio section waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Flexiwatt25 (vertical) mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . . 22
Flexiwatt27 (Vertical) mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . 23
DS10473 Rev 2
STPA003
1
Overview
Overview
The STPA003 is a complementary quad audio power amplifier. It is available in two different
packages, Flexiwatt25 and Flexiwatt27. It embeds four independent amplifiers working in
class AB, a standby, a mute pin and an offset detector output. In the Flexiwatt27 package
also a high side driver or a clipping detection pin with diagnostics information is present. In
Flexiwatt25, the user can choose to have the offset detector or the high side driver on
pin 25. The amplifier is fully operational down to a battery voltage of 6 V, without producing
pop noise and continuing to play during battery transitions.
The STPA003 can drive 2 ohm loads and has a very high immunity to disturbs without need
of external components or compensation. It is protected against any kind of short or open
circuit, over-voltage and over-temperature.
1.1
Block diagram and application circuit
Figure 1. Block diagram
Vcc1
Vcc2
2200 μF
ST-BY
0.1μF
OD (*)
MUTE
HSD
IN1
HSD / CD-DIAG (*)
HSD / OD (**)
OUT1+
OUT1PW-GND
0.22μF
OUT2+
OUT2-
IN2
0.22μF
PW-GND
OUT3+
IN3
OUT3PW-GND
0.22μF
OUT4+
OUT4-
IN4
PW-GND
0.22μF
AC-GND
4x0.22 μF
SVR
TAB
47μF
S-GND
(*) only in Flexiwatt27
(**) only in Flexiwatt25
DS10473 Rev 2
GAPGPS02229
5/25
24
Overview
STPA003
Figure 2. Standard test and application circuit (Flexiwatt25 with OD)
OFFSET
DETECTOR OUT
C8
0.1μF
C7
2200μF
R4
V
Vcc1-2
47K
Vcc3-4
6
R1
25
20
4
ST-BY
10K
R2
9
C9
1μF
7
22
MUTE
10K
C10
4.7μF
5
C1
OUT2
2
11
IN1
3
0.22μF
STPA003OD
12
IN2
IN3
17
4WX
C2 0.22μF
OUT3
18
19
15
C3 0.22μF
21
14
IN4
C4 0.22μF
OUT1
8
S-GND
OUT4
24
23
13
16
10
AC-GND
1
SVR
TAB
C6
47μF
C5 4x 0.22μF
GAPGPS02230
Figure 3. Standard test and application circuit (Flexiwatt27 with CD)
OFFSET
DETECTOR OUT
C8
0.1μF
C7
2200μF
R4
V
Vcc1-2
Vcc3-4
7
R1
47K
2
21
5
ST-BY
10K
R2
10
C9
1μF
10K
8
C10
4.7μF
6
C1
OUT2
3
12
IN1
4
0.22μF
STPA003CD
13
IN2
IN3
18
48X
C2 0.22μF
OUT3
19
20
16
C3 0.22μF
22
15
IN4
C4 0.22μF
OUT1
9
23
MUTE
S-GND
24
17
11
AC-GND
C5 4x 0.22μF
OUT4
25
14
26
SVR
C6
47μF
27
TAB
R3
V
47K
CD OUT
6/25
DS10473 Rev 2
GAPGPS02495
STPA003
Overview
Figure 4. Standard test and application circuit (Flexiwatt27 with HSD)
OFFSET
DETECTOR OUT
C8
0.1μF
C7
2200μF
R4
V
Vcc1-2
7
R1
47K
Vcc3-4
2
21
10
5
ST-BY
10K
R2
C9
1μF
9
23
MUTE
10K
C10
4.7μF
6
C1
IN1
3
12
OUT2
4
0.22μF
STPA003HSD
13
IN2
IN3
18
48X
C2 0.22μF
19
OUT3
20
16
C3 0.22μF
22
IN4
25
15
C4 0.22μF
OUT1
8
S-GND
17
11
AC-GND
C5 4x 0.22μF
OUT4
24
14
26
SVR
27
TAB
C6
47μF
HSD
DS10473 Rev 2
GAPGPS02496
7/25
24
Pin description
2
STPA003
Pin description
Figure 5. Pin connections (top view)
TAB
1
PW-GND2
OUT2ST-BY
OUT2+
VCC
OUT1PW-GND1
OUT1+
SVR
IN1
IN2
Flexiwatt25
STPA003OD-4WX
S-GND
IN4
IN3
AC-GND
OUT3+
PW-GND3
OUT3VCC
OUT4+
MUTE
OUT4PW-GND4
OD
25
GAPGPS02057
TAB
TAB
1
OD
OD
PW-GND
PW-GND
OUT2-
OUT2-
ST-BY
ST-BY
OUT2+
OUT2+
VCC
VCC
OUT1-
OUT1-
PW-GND
PW-GND
OUT1+
OUT1+
SVR
SVR
IN1
IN1
IN2
Flexiwatt27
STPA003HSD-48X
S-GND
IN4
IN2
Flexiwatt27
STPA003CD-48X
S-GND
IN4
IN3
IN3
AC-GND
AC-GND
OUT3+
OUT3+
PW-GND
PW-GND
OUT3-
OUT3-
VCC
VCC
OUT4+
OUT4+
MUTE
MUTE
OUT4-
OUT4-
PW-GND
PW-GND
HSD
CD-DIAG
TAB
1
TAB
27
27
GAPGPS02058
8/25
DS10473 Rev 2
STPA003
Pin description
Table 2. Pin functions
Pin #
FW27
Pin #
FW25
Pin name
1
1
TAB
2
25
OD/HSD
3
2
PW-GND2
4
3
5
Description
Device slug connection
Offset detector output or high side driver output
Type
Output (open
collector)
Channel 2 power ground
Ground
OUT2-
Channel 2 negative output
Output
4
ST-BY
Standby
6
5
OUT2+
Channel 2 positive output
Output
7
6
VCC
Supply voltage
Supply
8
7
OUT1-
Channel 1 negative output
Output
9
8
PW-GND1
Channel 1 power ground
Ground
10
9
OUT1+
Channel 1 positive output
Output
11
10
SVR
Supply voltage rejection pin
Supply
12
11
IN1
Channel 1 input
Input
13
12
IN2
Channel 2 input
Input
14
13
S-GND
15
14
IN4
Channel 4 input
Input
16
15
IN3
Channel 3 input
Input
17
16
AC-GND
18
17
19
Signal ground
-
Ground
AC ground
Ground
OUT3+
Channel 3 positive output
Output
18
PW-GND3
Channel 3 power ground
Ground
20
19
OUT3-
Channel 3 negative output
Output
21
20
VCC
Supply voltage
Supply
22
21
OUT4+
Channel 4 positive output
Output
23
22
MUTE
Mute pin
24
23
OUT4-
Channel 4 negative output
Output
25
24
PW-GND4
Channel 4 power ground
Ground
26
n.a
HSD / CD-DIAG
27
n.a
TAB
High side driver or clipping detector and
diagnostics output
Device slug connection
DS10473 Rev 2
Input
Output (open
collector)
-
9/25
24
Electrical specifications
STPA003
3
Electrical specifications
3.1
Absolute maximum ratings
Table 3. Absolute maximum ratings
Symbol
Value
Unit
Operating supply voltage
18
V
VS (DC)
DC supply voltage
28
V
VS (pk)
Peak supply voltage (for t = 50 ms)
50
V
Output peak current
Non repetitive (t = 100 µs)
Repetitive (duty cycle 10 % at f = 10 Hz)
10
9
A
A
Power dissipation Tcase = 70 °C
85
W
Tj
Junction temperature
150
°C
Tstg
Storage temperature
-55 to 150
°C
Ground pin voltage
-0.3 to 0.3
V
-0.3 to 8
V
-0.3 to Vs(pk)
V
-0.3 to 6
V
-40 to 105
°C
Value
Unit
1
°C/W
VS
IO
Ptot
GNDmax
Parameter
Vin max
Input pin max voltage
VSB max
ST-BY pin max voltage
Vmute max Mute pin max voltage
Top
3.2
Operating ambient temperature
Thermal data
Table 4. Thermal data
Symbol
Rth j-case
10/25
Parameter
Thermal resistance junction-to-case
DS10473 Rev 2
Max.
STPA003
3.3
Electrical specifications
Electrical characteristics
Refer to the test and application diagram, VS = 14.4 V; RL = 4 Ω; Rg = 600 Ω; f = 1 kHz;
Tamb = 25 °C; unless otherwise specified.
Table 5. Electrical characteristics
Symbol
Parameter
Test condition
Min.
Typ.
Max.
Unit
6
-
18
V
General characteristics
VS
Supply voltage range
-
Iq1
Quiescent current
RL =
100
200
400
mA
Output offset voltage
Mute mode
-80
-
+80
mV
-10
-
+10
mV
-10
-
+10
mV
50
55
60
kΩ
VSt-by = 0.8 V
-
0.2
2
µA
VSt-by = 0
-
0.1
1
µA
VS = 13.2 V; THD = 10 %, 2 Ω
VS = 13.2 V; THD = 1 %, 2 Ω
VS = 13.2 V; THD = 10 %, 4 Ω
VS = 13.2 V; THD = 1 %, 4 Ω
42
32
23
16
45
34
25
19
-
W
W
W
W
VS = 14.4 V; THD = 10 %, 2 Ω
VS = 14.4 V; THD = 1 %, 2 Ω
VS = 14.4 V; THD = 10 %, 4 Ω
VS = 14.4 V; THD = 1 %, 4 Ω
50
40
27
21
55
43
30
24
-
W
W
W
W
VOS
dVOS
Output offset voltage when mute
moves from ON to OFF
Output offset voltage when standby moves from ON to OFF
Ri
Input impedance
ISB
Standby current consumption
ITU R-ARM weighted
(see Figure 20)
-
Audio performances
Po
Output power
50
85
52
W
W
W
Max. output power(1)
VS = 14.4 V; RL = 4 Ω
VS = 14.4 V; RL = 2 Ω
VS = 15.2 V; RL = 4 Ω(square
wave input (2 Vrms))
-
Distortion
Po = 4 W
-
0.01
0.02
%
Gv
Voltage gain
-
25.5
26
26.5
dB
dGv
Channel gain unbalance
-
-1
-
+1
dB
eNo
Output Noise
"A" Weighted
Bw = 20 Hz to 20 kHz
-
40
50
70
µV
µV
SVR
Supply voltage rejection
f = 100 Hz; Vr = 1 Vrms
50
70
-
dB
fch
High cut-off frequency
PO = 0.5 W
100
300
-
kHz
CT
Cross talk
f = 1 kHz PO = 4 W
f = 10 kHz PO = 4 W
60
50
80
60
-
dB
dB
AM
Mute attenuation
POref = 4 W
80
100
-
dB
Po max.
THD
DS10473 Rev 2
-
11/25
24
Electrical specifications
STPA003
Table 5. Electrical characteristics (continued)
Symbol
Parameter
Test condition
Min.
Typ.
Max.
Unit
-
-
0.5
µA
Control pin characteristics
Ipin5
Standby pin current
VSt-by = 0.8 V to 2.2 V
VSB out
Standby out threshold voltage
(Amp: ON)
2.2
-
-
V
VSB in
Standby in threshold voltage
(Amp: OFF)
-
-
0.8
V
VM out
Mute out threshold voltage
(Amp: Play)
2.3
-
-
V
VM in
Mute in threshold voltage
(Amp: Mute)
-
-
0.8
V
(Amp: Mute)
Att 80 dB; POref = 4 W
4.5
5
5.5
V
(Amp: Play)
Att < 0.1 dB; PO = 0.5 W
-
-
6
V
VMUTE = 0.8 V
(Sourced current)
-
9
14
µA
Dropout voltage
IO = 0.35 A
-
0.25
0.3
V
Current limits
-
400
-
800
mA
-
±2.3
±3
±3.7
V
Vo > ±3 V, Ioff Det = 1 mA
0 V < Voff Det < 18 V
-
0.05
0.1
V
Vo < ±1 V
-
0
15
µA
VAM in
Ipin23
VS automute threshold
Muting pin current
HSD section
Vdropout
Iprot
Offset detector
VOFF
Detected differential output offset
VOFF_SAT Off detector saturation voltage
VOFF_LK
Off detector leakage current
Clipping detector
CDLK
Clip detector high leakage current
Cd off
-
0
1
µA
CDSAT
Clip detector saturation voltage
DC On; ICD = 1 mA
-
0.2
0.4
V
CDTHD
Clip detector THD level
-
-
1
-
%
1. Saturated square wave output
12/25
DS10473 Rev 2
STPA003
Electrical characteristics typical curves
4
Electrical characteristics typical curves
Figure 6. Quiescent current vs. supply voltage Figure 7. Output power vs. supply voltage (4 Ω)
Po (W)
Iq (mA)
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
250
240
Vin = 0
RL = ȍ
230
220
210
200
190
180
170
160
150
6
8
10
12
Vs (V)
14
16
18
Po-max
THD=10%
THD=1%
6
7
8
9
10
11
13
14
15
16
17
18
GAPGPS02485
Figure 9. Distortion vs. output power (4 Ω)
Po (W)
10
RL= 2 Ω
f = 1 kHz
12
Vs (V)
GAPGPS02484
Figure 8. Output power vs. supply voltage (2 Ω)
120
110
100
90
80
70
60
50
40
30
20
10
0
RL= 4 Ω
f = 1 kHz
THD (%)
Vs = 14.4 V
RL = 4 Ω
Po-max
1
f =10 k Hz
THD=10%
0.1
THD=1%
0.01
f =1 kHz
0.001
6
7
8
9
10
11 12
Vs (V)
13
14
15
GAPGPS02486
Figure 10. Distortion vs. output power (2 Ω)
10
0.1
16
1
Po (W)
10
GAPGPS02487
Figure 11. Distortion vs. frequency (4 Ω)
THD (%)
10
THD (%)
Vs = 14.4 V
RL = 2 Ω
1
Vs= 14.4 V
RL= 4
Po= 4 W
1
f =10 k Hz
0.1
0.1
f =1 kHz
0.01
0.01
0.001
0.001
0.1
1
Po (W)
10
10
100
1000
10000
f (Hz)
GAPGPS02488
DS10473 Rev 2
GAPGPS02489
13/25
24
Electrical characteristics typical curves
STPA003
Figure 12. Distortion vs. frequency (2 Ω)
10
Figure 13. Distortion vs. output
power (4 Ω, Vs = 6 V)
THD (%)
THD (%)
10
Vs = 14.4 V
RL = 2
Po = 8 W
Vs = 6 V
RL = 4
1
1
f = 10 kHz
0.1
0.1
0.01
f = 1 kHz
0.001
0.01
10
100
f (Hz)
1000
0.1
10000
1
Po (W)
GAPGPS02490
Figure 14. Distortion vs. output
power (2 Ω, Vs = 6 V)
10
GAPGPS02491
Figure 15. Supply voltage rejection vs.
frequency
THD (%)
SVR (dB)
-20
-30
Vs = 6 V
RL = 2
1
Rg = 600
Vripple = 1 Vrms
-40
f = 10 kHz
-50
-60
0.1
-70
-80
f = 1 kHz
0.01
-90
-100
-110
0.001
0.1
10
1
Po (W)
100
GAPGPS02492
Figure 16. Crosstalk vs. frequency
-30
100000
GAPGPS02493
RL = 4
Po = 4 W
Rg = 600
η ( %)
Pdiss (W)
90
-50
10000
Figure 17. Total power dissipation & efficiency
vs. Po (4 Ω, Sine)
CROSSTALK (dB)
-40
1000
f (Hz)
90
80
70
80
η
Vs = 14.4 V
RL = 4 x 4 Ω
f = 1 kHz
70
60
-60
50
-70
40
60
50
Pdiss
40
30
30
20
20
-90
10
10
-100
0
-80
10
100
1000
f (Hz)
14/25
10000
0
GAPGPS02494
DS10473 Rev 2
2
4
6
8
10 12 14 16 18 20 22 24 26 28
Po (W)
GAPGPS02076
STPA003
Electrical characteristics typical curves
Figure 18. Power dissipation vs. average output Figure 19. Power dissipation vs. average output
power (4 Ω, audio program simulation)
power (2 Ω, audio program simulation)
Pdiss (W)
60
80
Vs = 14 V
5/ [
PINK NOISE
50
Pdiss (W)
90
Vs = 14 V
5/ [
PINK NOISE
70
60
40
CLIP START
50
CLIP START
30
40
30
20
20
10
10
0
0
0
1
2
3
Po-avg (W)
4
5
6
GAPGPS02077
0
1
2
3
4
5
Po-avg (W)
6
7
8
9
GAPGPS02078
Figure 20. ITU R-ARM frequency response,
weighting filter for transient pop
40
Output attenuation (dB)
30
20
10
0
-10
-20
-30
-40
-50
10
100
1000
Hz
10000
100000
GAPGPS00153
DS10473 Rev 2
15/25
24
General information
STPA003
5
General information
5.1
Operation
The STPA003's inputs are ground-compatible. If the standard value for the input capacitors
(0.22 µF) is adopted, the low frequency cut-off will amount to 16 Hz. For optimum pop
performances, the capacitor connected to AC-GND should be four times bigger than input
capacitors (see Figure 2).
Standby and mute pins are 3.3 V and 5 V compatible.
RC cells at both mute and stand-by pins have always to be used in order to smooth the
transitions for preventing any audible transient noise. A time constant slower than 2.5 V/ms
is suggested for the stand-by pin and 0.5 V/ms for the mute pin.
In case the standby function is not used, it could steadily be connected to Vs through a
470 kΩ resistor.
The capacitance on SVR sets the start-up and shut-down times and helps to have pop-noise
free transitions. Its minimum recommended value is 10 µF. However, to have a fast start-up
time, the internal resistor on SVR pin, used to set the time constant, is reduced from 100 kΩ
to 3 kΩ till voltage on SVR reaches VCC/4 - 2 VBE and then released. In this way the
capacitor on SVR is charged very quickly to VCC/4, as shown in the following figure.
Figure 21. SVR charge diagram
VCC/4
VCC/4 – 2VBE
Time
GAPGPS00673
SVR pin accomplishes multiple functions:
it is used as a reference voltage for input pins (VCC/4)
the capacitor connected to SVR helps the supply voltage ripple rejection
it is used as a reference to generate the half supply voltage for the output
When the amplifier goes in stand-by mode or goes out from this condition, it is suggested to
put the amplifier in mute to ensure the absence of audible noise. Then the standby pin can
be set to the appropriate value (ground or > 2.2 V) and the capacitance on SVR pin is
discharged or charged consequently.
16/25
DS10473 Rev 2
STPA003
General information
5.2
Battery variations
5.2.1
Low voltage operation
Most recent OEM specifications require automatic stop for car engine at traffic lights, in
order to reduce emissions of polluting substances. The STPA003, thanks to its innovating
design, allows a continuous operation when battery falls down. At 6 V it is still fully
operational, only the maximum output power is reduced according to the available voltage
supply.
If the battery voltage drops below the minimum operating voltage of 6 V the amplifier is fast
muted, the capacitor on SVR is discharged and the amplifier restarts when the battery
voltage returns to the correct voltage.
5.2.2
Cranks
STPA003 can sustain worst case cranks from 16 V to 6 V, continuing to play and without
producing any pop noise.
Examples of battery cranking curves are shown below, indicating the shape and duration of
allowed battery transitions.
Figure 22. Battery cranking curve example 1
Vbatt(V)
V1
V4
V3
V2
t1
t2
t3
t4 t5
t6
t7
t (s)
GAPGPS00674
V1 = 16 V; V2 = 6 V; V3 = 7 V; V4 = 8 V
t1 = 2 ms; t2 = 50 ms; t3 = 5 ms; t4 = 300 ms; t5 =10 ms; t6 = 1 s; t7 = 2 ms
DS10473 Rev 2
17/25
24
General information
STPA003
Figure 23. Battery cranking curve example 2
Vbatt (V)
V1
V3
V2
t1
t2
t3
t5
t6
t (s)
GAPGPS00675
V1 = 16 V; V2 = 6 V; V3 = 7 V
t1 = 2 ms; t2 = 5 ms; t3 = 15 ms; t5 = 1 s; t6 = 50 ms
5.2.3
Advanced battery management (hybrid vehicles)
In addition to compatibility with low Vbatt, the STPA003 is able to sustain upwards fast
battery transitions without causing unwanted audible effects, like pop noise, and without any
sound interruption thanks to the innovative circuit topology. In fact, in hybrid vehicles, the
engine ignition causes a fast increase of battery voltage which can reach 16 V in less than
10 ms.
Figure 24. Upwards fast battery transitions diagram
GAPGPS00676
18/25
DS10473 Rev 2
STPA003
General information
5.3
Protections
5.3.1
Short circuits and open circuit operation
When the IC detects a short circuit to ground, to Vsupply or across the load, the output of the
amplifier is put in three-state (high impedance condition). The power stage remains in this
condition until the short is removed.
In case of short circuit to ground or Vcc, the amplifier exits from the three-state condition
only when the output returns inside the limits imposed by an internal voltage comparator.
When a short across the load is present, the power stage sees an over-current and is
brought in protection mode for 100 µs. After this time, if the short circuit condition is removed
the amplifier returns to play, otherwise the high impedance state is maintained and the
check is repeated every 100 µs.
Disconnection of load (open load condition) doesn't damage the amplifier, which continues to play.
5.3.2
Over-voltage and load dump protection
When the battery voltage is higher than 19 V, the amplifier is switched to a high impedance
state. It stops playing till the supply voltage returns in the permitted range.
The amplifier is protected against load dump surges having amplitude as high as 50 V and a
rising time lower than 5 ms (see Figure 25).
Figure 25. Load dump protection diagram
50V Vdump
14.4V Vcc
< 5ms
50ms
GAPGPS00710
Thermal protection
If the junction temperature of the IC reaches Tj = 150 °C, a smooth mute is applied to reduce
output power and limit power dissipation. If this is not enough and the junction temperature
continues to increase, the amplifier is switched off when reaches the maximum temperature
of 170 °C.
Figure 26. Thermal protection diagram
Output power
5.3.3
150 C
Junction temperature ( C)
DS10473 Rev 2
170 C
GAPGPS00711
19/25
24
General information
STPA003
5.4
Warnings
5.4.1
DC offset detection (OD pin)
The STPA003 integrates a DC offset detector to avoid that an anomalous input DC offset is
multiplied by the amplifier gain producing a dangerous large offset at the output. In fact an
output offset may lead to speakers damage for overheating. To correctly detect a DC offset,
the power amplifier has to be un-muted with no input signal.
When the differential output voltage is out of a window comparator with thresholds ± 3 V
(typ), the OD pin is pulled down.
5.4.2
Clipping detection and diagnostics (CD-DIAG pin)
When clipping occurs, the output signal is distorted. If the signal distortion on one of the
output channels exceeds 1 %, the CD-DIAG pin is pulled down. This information can be
sent to an audio processor in order to reduce the input signal of the amplifier and reduce the
clipping.
A short to ground and short to Vcc is signaled by CD-DIAG. This pin is pulled down to 0 V till
these shorts are present to inform the user a protection occurred.
CD-DIAG acts also as thermal warning. In fact every time Tj exceeds 140 °C, it is pulled
down to notify this occurrence.
Figure 27. Audio section waveforms
ST-BY PIN
VOLTAGE
t
MUTE PIN
VOLTAGE
t
Vs
OUTPUT
WAVEFORM
t
DIAG pin
WAVEFORM
t
CLIPPING
SHORT TO GND
OR TO Vs
THERMAL
PROXIMITY
GAPGPS00712
20/25
DS10473 Rev 2
STPA003
5.5
General information
Heat sink definition
Assuming we have a maximum dissipated power of 26 W (e.g. in the worst case situation of
frequent clipping occurrence), considering Tj max is 150 °C and assuming ambient
temperature is 70 °C, the available temperature gap for a correct dissipation is 80 °C.
This means the thermal resistance of the system Rth has to be 80 °C/26 W = 3 °C/W.
The junction to case thermal resistance is 1 °C/W. So the heat sink thermal resistance
should be approximately 2 °C/W. This would avoid any thermal shutdown occurrence even
after long-term and full-volume operation.
DS10473 Rev 2
21/25
24
Package information
6
STPA003
Package information
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK packages, depending on their level of environmental compliance. ECOPACK
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK is an ST trademark.
Figure 28. Flexiwatt25 (vertical) mechanical data and package dimensions
DIM.
A
B
C
D
E
F (1)
G
G1
H (2)
H1
H2
H3
L (2)
L1
L2 (2)
L3
L4
L5
M
M1
N
O
R
R1
R2
R3
R4
V
V1
V2
V3
MIN.
4.45
1.80
0.75
0.37
0.80
23.75
28.90
22.07
18.57
15.50
7.70
3.70
3.60
mm
TYP.
4.50
1.90
1.40
0.90
0.39
1.00
24.00
29.23
17.00
12.80
0.80
22.47
18.97
15.70
7.85
5
3.5
4.00
4.00
2.20
2
1.70
0.5
0.3
1.25
0.50
MAX.
4.65
2.00
MIN.
0.175
0.070
1.05
0.42
0.57
1.20
24.25
29.30
0.029
0.014
22.87
19.37
15.90
7.95
0.869
0.731
0.610
0.303
4.30
4.40
0.145
0.142
0.031
0.935
1.139
inch
TYP.
0.177
0.074
0.055
0.035
0.015
0.040
0.945
1.150
0.669
0.503
0.031
0.884
0.747
0.618
0.309
0.197
0.138
0.157
0.157
0.086
0.079
0.067
0.02
0.12
0.049
0.019
MAX.
0.183
0.079
OUTLINE AND
MECHANICAL DATA
0.041
0.016
0.022
0.047
0.955
1.153
0.904
0.762
0.626
0.313
0.169
0.173
Flexiwatt25 (vertical)
5° (Typ.)
3° (Typ.)
20° (Typ.)
45° (Typ.)
(1): dam-bar protusion not included
(2): molding protusion included
V
C
B
V
H
H1
V3
A
H2
O
H3
R3
L4
R4
V1
R2
L2
N
L3
R
L
L1
V1
V2
R2
D
R1
L5
Pin 1
R1
R1
E
G
G1
F
FLEX25ME
M
M1
7034862
GAPGPS00669
22/25
DS10473 Rev 2
STPA003
Package information
Figure 29. Flexiwatt27 (Vertical) mechanical data and package dimensions
DIM.
MIN.
4.45
1.80
A
B
C
D
E
F (1)
G
G1
H (2)
H1
H2
H3
L (2)
L1
L2 (2)
L3
L4
L5
M
M1
N
O
R
R1
R2
R3
R4
V
V1
V2
V3
0.75
0.37
0.80
25.75
28.90
22.07
18.57
15.50
7.70
3.70
3.60
mm
TYP.
4.50
1.90
1.40
0.90
0.39
1.00
26.00
29.23
17.00
12.80
0.80
22.47
18.97
15.70
7.85
5
3.5
4.00
4.00
2.20
2
1.70
0.5
0.3
1.25
0.50
MAX.
4.65
2.00
MIN.
0.175
0.070
1.05
0.42
0.57
1.20
26.25
29.30
0.029
0.014
0.031
1.014
1.139
22.87
19.37
15.90
7.95
0.869
0.731
0.610
0.303
4.30
4.40
0.145
0.142
inch
TYP.
0.177
0.074
0.055
0.035
0.015
0.040
1.023
1.150
0.669
0.503
0.031
0.884
0.747
0.618
0.309
0.197
0.138
0.157
0.157
0.086
0.079
0.067
0.02
0.12
0.049
0.019
MAX.
0.183
0.079
OUTLINE AND
MECHANICAL DATA
0.041
0.016
0.022
0.047
1.033
1.153
0.904
0.762
0.626
0.313
0.169
0.173
Flexiwatt27 (vertical)
5° (Typ.)
3° (Typ.)
20° (Typ.)
45° (Typ.)
(1): dam-bar protusion not included; (2): molding protusion included.
V
C
B
V
H
H1
V3
A
H2
O
H3
R3
L4
R4
V1
R2
L2
N
L3
R
L
L1
V1
V2
R2
L5
Pin 1
D
R1
R1
R1
E
G
G1
F
M
M1
7139011 E
GAPGPS00096
DS10473 Rev 2
23/25
24
Revision history
7
STPA003
Revision history
Table 6. Document revision history
24/25
Date
Revision
Changes
11-Jul-2014
1
Initial release.
21-Jan-2020
2
Updated Table 5: Electrical characteristics (Po Test condition).
DS10473 Rev 2
STPA003
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DS10473 Rev 2
25/25
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