ON NCP2809ADMR2 Nocap 135 mw stereo headphone power amplifier Datasheet

NCP2809 Series
NOCAPt 135 mW Stereo
Headphone Power Amplifier
The NCP2809 is a cost−effective stereo audio power amplifier
capable of delivering 135 mW of continuous average power per
channel into 16 loads.
The NCP2809 audio power amplifier is specifically designed to
provide high quality output power from low supply voltage,
requiring very few external components. Since NCP2809 does not
require bootstrap capacitors or snubber networks, it is optimally
suited for low−power portable systems. NCP2809A has an internal
gain of 0 dB while specific external gain can externally be set with
NCP2809B.
If the application allows it, the virtual ground provided by the
device can be connected to the middle point of the headset (Figure 1).
In such case, the two external heavy coupling capacitors typically
used can be removed. Otherwise, you can also use both outputs in
single ended mode with external coupling capacitors (Figure 43).
Due to its excellent Power Supply Rejection Ratio (PSRR), it can
be directly connected to the battery, saving the use of an LDO.
Features
•
•
•
•
•
•
•
•
•
135 mW to a 16 Load from a 5.0 V Power Supply
Excellent PSRR (85 dB Typical): Direct Connection to the Battery
“Pop and Click” Noise Protection Circuit
Ultra Low Current Shutdown Mode
2.2 V–5.5 V Operation
Outstanding Total Harmonics Distortion + Noise (THD+N): Less
than 0.01%
External Turn−on and Turn−off Configuration Capability
Thermal Overload Protection Circuitry
Pb−Free Packages are Available
January, 2006 − Rev. 8
Micro10
DM SUFFIX
CASE 846B
10
1
MAx
AYWG
G
x
= E for NCP2809A
C for NCP2809B
A = Assembly Location
Y = Year
W = Work Week
G = Pb−Free Package
(Note: Microdot may be in either location)
PIN CONNECTIONS
IN_R
1
10
SD
BYP
2
3
9
8
REF_I
4
7
VP
IN_L
5
6
OUT_L
OUT_R
VM
OUT_I
See detailed ordering and shipping information in the package
dimensions section on page 20 of this data sheet.
Cellular Phone
Portable Stereo
MP3 Player
Personal and Notebook Computers
© Semiconductor Components Industries, LLC, 2006
MARKING
DIAGRAM
ORDERING INFORMATION
Typical Applications
•
•
•
•
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1
Publication Order Number:
NCP2809/D
NCP2809 Series
VP
1 F
CS
VP
CI
AUDIO
INPUT
20 k
20 k
IN_L
390 nF
VP
BYPASS
−
+
OUT_L
+
−
OUT_I
HEADPHONE JACK
LEFT
BYPASS
VMC
BRIDGE
SLEEVE
1 F
Cbypass
REF_I
CI
AUDIO
INPUT
RIGHT
+
−
IN_R
OUT_R
20 k
390 nF
20 k
SHUTDOWN
VIH
VM
VIL
SHUTDOWN
CONTROL
Figure 1. NCP2809A Typical Application Schematic without Output Coupling Capacitor
(NOCAP Configuration)
VP
1 F
CS
VP
AUDIO
INPUT
CI
20 k
IN_L
390 nF
VP
BYPASS
VMC
BRIDGE
1 F
AUDIO
INPUT
CI
BYPASS
20 k
−
+
OUT_L
+
−
OUT_I
Cout
REF_I
+
−
IN_R
OUT_R
HEADPHONE JACK
LEFT
NC
NC
220 F
+
SLEEVE
RIGHT
Cout
20 k
390 nF
220 F
+
20 k
SHUTDOWN
VIH
VIL
SHUTDOWN
CONTROL
VM
Figure 2. NCP2809A Typical Application Schematic with Output Coupling Capacitor
TIP
(LEFT)
RING
SLEEVE
(RIGHT)
Figure 3. Typical 3−Wire Headphone Plug
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2
NCP2809 Series
20 k
VP
1 F
AUDIO
INPUT
CI
20 k
CS
VP
IN_L
390 nF
VP
BYPASS
−
+
OUT_L
+
−
OUT_I
HEADPHONE JACK
LEFT
BYPASS
VMC
BRIDGE
SLEEVE
1 F
Cbypass
REF_I
RIGHT
AUDIO
INPUT
CI
20 k
+
−
IN_R
OUT_R
390 nF
SHUTDOWN
SHUTDOWN
CONTROL
VM
VIH
VIL
20 k
Figure 4. NCP2809B Typical Application Schematic without Output Coupling Capacitor
(NOCAP Configuration)
20 k
VP
1 F
CS
VP
AUDIO
INPUT
CI
20 k
IN_L
VP
390 nF
BYPASS
BYPASS
1 F
Cbypass
AUDIO
INPUT
CI
20 k
VMC
BRIDGE
−
+
OUT_L
+
−
OUT_I
IN_R
390 nF
SHUTDOWN
OUT_R
HEADPHONE JACK
LEFT
NC
SLEEVE
NC
220 F
+
RIGHT
Cout
SHUTDOWN
CONTROL
VIH
VIL
Cout
REF_I
+
−
220 F
+
VM
20 k
Figure 5. NCP2809B Typical Application Schematic with Output Coupling Capacitor
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NCP2809 Series
PIN FUNCTION DESCRIPTION
Pin
Type
Symbol
1
I
IN_R
2
I
SHUTDOWN
3
I
BYPASS
4
O
REF_I
5
I
IN_L
6
O
OUT_L
7
I
VP
8
O
OUT_I
9
I
VM
10
O
OUT_R
Description
Negative input of the second amplifier. It receives the audio input signal. Connected to the input
capicator Cin (NCP2809A) or the external Rin (NCP2809B).
The device enters in shutdown mode when a a low level is applied on this pin.
Bypass capacitor pin which provides the common mode voltage (VP/2).
Virtual ground amplifier feed back. This pin sets the stereo headset ground. In order to improve
crosstalk, this pin must be connected as close as possible to the ground connection of the headset
(ideally at the ground pin of the headset connector). When one uses bypassing capacitors, this pin
must be left unconnected.
Negative input of the first amplifier. It receives the audio input signal. Connected to the input
capacitor Cin (NCP2809A) or the external Rin (NCP2809B).
Stereo headset amplifier analog output left. This pin will output the amplified analog signal and,
depending on the application, must be coupled with a capacitor or directly connected to the left
loudspeaker of the headset. This output is able to drive a 16 load in a single−ended configuration.
Positive analog supply of the cell. Range: 2.2 V – 5.5 V
Virtual ground for stereo Headset common connection. This pin is directly connected to the
common connection of the headset when use of bypassing capacitor is not required. When one
uses bypassing capacitors, this pin must be left unconnected.
Analog Ground
Stereo headset amplifier analog output right. This pin will output the amplified analog signal and,
depending on the application, must be coupled with a capacitor or directly connected to the right
loudspeaker of the headset. This output is able to drive a 16 load in a single−ended configuration.
MAXIMUM RATINGS (TA = +25°C)
Rating
Symbol
Value
Unit
Vp
6.0
V
Op Vp
2.2 to 5.5
V
Input Voltage
Vin
−0.3 to VCC + 0.3
V
Max Output Current
Iout
250
mA
Power Dissipation
Pd
Internally Limited
−
Operating Ambient Temperature
TA
−40 to +85
°C
Max Junction Temperature
TJ
150
°C
Storage Temperature Range
Tstg
−65 to +150
°C
Thermal Resistance, Junction−to−Air
RJA
200
°C/W
−
8000
200
V
±100
mA
Supply Voltage
Operating Supply Voltage
ESD Protection
Human Body Model (HBM) (Note 1)
Machine Model (MM) (Note 2)
Latch up current at Ta = 85_C (Note 3)
Maximum ratings applied to the device are individual stress limit values (not normal operating conditions) and are not valid simultaneously. If stress
limits are exceeded device functional operation is not implied, damage may occur and reliability may be affected. Functional operation should be
restricted to the Recommended Operating Conditions.
1. Human Body Model, 100 pF discharged through a 1.5 k resistor following specification JESD22/A114 8.0 kV can be applied on OUT_L,
OUT_R, REF_I and OUT_I outputs. For other pins, 2.0 kV is the specified voltage.
2. Machine Model, 200 pF discharged through all pins following specification JESD22/A115.
3. Maximum ratings per JEDEC standard JESD78.
*This device contains 752 active transistors and 1740 MOS gates.
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NCP2809 Series
ELECTRICAL CHARACTERISTICS All the parameters are given in the capless configuration (typical application).
The following parameters are given for the NCP2809A and NCP2809B mounted externally with 0 dB gain, unless otherwise noted.
(For typical values TA = 25°C, for min and max values TA = −40°C to 85°C, TJmax = 125°C, unless otherwise noted.)
Characteristic
Supply Quiescent Current
Symbol
Conditions
IDD
Vin = 0 V, RL = 16 Vp = 2.4 V
Vp = 5.0 V
Min
(Note 4)
Typ
Max
(Note 4)
1.54
1.84
2.8
3.6
1.0
+25
mV
10
600
nA
Unit
mA
Output Offset Voltage
Voff
Vp = 2.4 V
Vp = 5.0 V
Shutdown Current
ISD
Vp = 5.0 V
Shutdown Voltage High (Note 5)
VSDIH
−
Shutdown Voltage Low
VSDIL
−
Turning On Time (Note 6)
TWU
Cby = 1.0 F
285
ms
Turning Off Time (Note 6)
TSD
Cby = 1.0 F and Vp = 5.0 V
385
ms
Vloadpeak
Vp = 2.4 V, RL = 16 Vp = 5.0 V, RL = 16 0.9
2.05
V
Max Output Swing
Max Rms Output Power
Voltage Gain
Crosstalk
Signal to Noise Ratio
POrms
−25
1.2
V
0.4
0.82
1.94
Vp = 2.4 V, RL = 32 Vp = 5.0 V, RL = 32 1.04
2.26
Vp = 2.4 V, RL = 16 , THD+N<0.1%
Vp = 5.0 V, RL = 16 , THD+N<0.1%
24
131
Vp = 2.4 V, RL = 32 , THD+N<0.1%
Vp = 5.0 V, RL = 32 , THD+N<0.1%
17
80
G
NCP2809A only
CS
f = 1.0 kHz
Vp = 2.4 V, RL = 16 , Pout = 20 mW
Vp = 2.4 V, RL = 32 , Pout = 10 mW
−63.5
−72.5
Vp = 3.0 V, RL = 16 , Pout = 30 mW
Vp = 3.0 V, RL = 32 , Pout = 20 mW
−64
−73
Vp = 5.0 V, RL = 16 , Pout = 75 mW
Vp = 5.0 V, RL = 32 , Pout = 50 mW
−64
−73
f = 1.0 kHz
Vp = 2.4 V, RL = 16 , Pout = 20 mW
Vp = 2.4 V, RL = 32 , Pout = 10 mW
88.3
89
Vp = 3.0 V, RL = 16 , Pout = 30 mW
Vp = 3.0 V, RL = 32 , Pout = 20 mW
90.5
92
Vp = 5.0 V, RL = 16 , Pout = 75 mW
Vp = 5.0 V, RL = 32 , Pout = 50 mW
95.1
96.1
SNR
4. Min/Max limits are guaranteed by production test.
5. At TA = −40°C, the minimum value is set to 1.5 V.
6. See page 10 for a theoretical approach to these parameters.
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5
−0.5
0
V
mW
+0.5
dB
dB
dB
NCP2809 Series
ELECTRICAL CHARACTERISTICS All the parameters are given in the capless configuration (typical application).
The following parameters are given for the NCP2809A and NCP2809B mounted externally with 0 dB gain, unless otherwise noted.
(For typical values TA = 25°C, for min and max values TA = −40°C to 85°C, TJmax = 125°C, unless otherwise noted.)
Characteristic
Positive Supply Rejection Ratio
Min
(Note 7)
Symbol
Conditions
Typ
PSRR V+
RL = 16 Vpripple_pp = 200 mV
Cby = 1.0 F
Input Terminated with 10 NCP2809A
F = 217 Hz
Vp = 5.0 V
Vp = 2.4 V
−73
−82
F = 1.0 kHz
Vp = 5.0 V
Vp = 2.4 V
−73
−85
Max
(Note 7)
Unit
dB
RL = 16 Vpripple_pp = 200 mV
Cby = 1.0 F
Input Terminated with 10 NCP2809B
with 0 dB External Gain
F = 217 Hz
Vp = 5.0 V
Vp = 2.4 V
−80
−82
F = 1.0 kHz
Vp = 5.0 V
Vp = 2.4 V
−81
−81
VP = 5.0 V, RL = 16 = 135 mW
63
%
Thermal Shutdown Temperature
(Note 8)
Tsd
−
160
°C
Total Harmonic Distortion + Noise
(Note 9)
THD+N
VP = 2.4 V, f = 1.0 kHz
RL = 16 , Pout = 20 mW
RL = 32 , Pout = 15 mW
0.006
0.004
VP = 5.0 V, f = 1.0 kHz
RL = 16 , Pout = 120 mW
RL = 32 , Pout = 70 mW
0.005
0.003
Positive Supply Rejection Ratio
Efficiency
PSRR V+
dB
%
7. Min/Max limits are guaranteed by production test.
8. This thermal shutdown is made with an hysteresis function. Typically, the device turns off at 160°C and turns on again when the junction
temperature is less than 140°C.
9. The outputs of the device are sensitive to a coupling capacitor to Ground. To ensure THD+N at very low level for any sort of headset
(16 or 32 , outputs (OUT_R, OUT_L, OUT_I and REF_I) must not be grounded with more than 500 pF.
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NCP2809 Series
10
10
1
1
THD+N (%)
THD+N (%)
TYPICAL CHARACTERISTICS
0.1
0.01
0.001
10
0.1
0.01
100
1000
10000
FREQUENCY (Hz)
0.001
10
100000
10
10
1
1
0.1
0.01
0.001
10
0.01
100
1000
10000
FREQUENCY (Hz)
0.001
10
100000
100
1000
10000
FREQUENCY (Hz)
100000
Figure 9. THD+N vs. Frequency
Vp = 3.0 V, RL = 32 , Pout = 20 mW
10
10
1
1
THD+N (%)
THD+N (%)
100000
0.1
Figure 8. THD+N vs. Frequency
Vp = 3.0 V, RL = 16 , Pout = 30 mW
0.1
0.01
0.001
10
1000
10000
FREQUENCY (Hz)
Figure 7. THD+N vs. Frequency
Vp = 5.0 V, RL = 32 , Pout = 50 mW
THD+N (%)
THD+N (%)
Figure 6. THD+N vs. Frequency
Vp = 5.0 V, RL = 16 , Pout = 75 mW
100
0.1
0.01
100
1000
10000
FREQUENCY (Hz)
100000
0.001
10
Figure 10. THD+N vs. Frequency
Vp = 2.4 V, RL = 16 , Pout = 20 mW
100
1000
10000
FREQUENCY (Hz)
Figure 11. THD+N vs. Frequency
Vp = 2.4 V, RL = 32 , Pout = 10 mW
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100000
NCP2809 Series
10
10
1
1
THD+N (%)
THD+N (%)
TYPICAL CHARACTERISTICS
0.1
0.01
0.001
0
0.1
0.01
20
40
60
80
100
120
140
0.001
0
160
10
20
30
OUTPUT POWER (mW)
1
1
THD+N (%)
THD+N (%)
10
0.1
0.01
70
80
90
0.1
0.01
10
20
30
40
50
0.001
0
60
10
OUTPUT POWER (mW)
20
30
40
OUTPUT POWER (mW)
Figure 14. THD+N vs. Power Out
Vp = 3.3 V, RL = 16 , 1.0 kHz
Figure 15. THD+N vs. Power Out
Vp = 3.3 V, RL = 32 , 1.0 kHz
10
10
1
1
THD+N (%)
THD+N (%)
60
Figure 13. THD+N vs. Power Out
Vp = 5.0 V, RL = 32 , 1.0 kHz
10
0.1
0.01
0.001
0
50
OUTPUT POWER (mW)
Figure 12. THD+N vs. Power Out
Vp = 5.0 V, RL = 16 , 1.0 kHz
0.001
0
40
0.1
0.01
10
20
30
40
0.001
0
50
OUTPUT POWER (mW)
5
10
15
20
25
30
OUTPUT POWER (mW)
Figure 17. THD+N vs. Power Out
Vp = 3.0 V, RL = 32 , 1.0 kHz
Figure 16. THD+N vs. Power Out
Vp = 3.0 V, RL = 16 , 1.0 kHz
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35
NCP2809 Series
10
10
1
1
THD+N (%)
THD+N (%)
TYPICAL CHARACTERISTICS
0.1
0.01
0.001
0.1
0.01
0
5
10
15
20
25
0.001
30
0
5
OUTPUT POWER (mW)
−50
−50
CROSSTALK (dB)
CROSSTALK (dB)
−40
−60
−70
−60
−70
100
1000
10000
100000
−80
10
100
FREQUENCY (Hz)
1000
10000
100000
FREQUENCY (Hz)
Figure 21. Crosstalk
Vp = 5.0 V, RL = 32 , Pout = 50 mW
Figure 20. Crosstalk
Vp = 5.0 V, RL = 16 , Pout = 75 mW
−40
−40
−50
−50
CROSSTALK (dB)
CROSSTALK (dB)
20
Figure 19. THD+N vs. Power Out
Vp = 2.4 V, RL = 3.2 , 1.0 kHz
−40
−60
−70
−80
10
15
OUTPUT POWER (mW)
Figure 18. THD+N vs. Power Out
Vp = 2.4 V, RL = 16 , 1.0 kHz
−80
10
10
−60
−70
100
1000
10000
100000
−80
10
FREQUENCY (Hz)
100
1000
10000
FREQUENCY (Hz)
Figure 23. Crosstalk
Vp = 3.0 V, RL = 32 , Pout = 20 mW
Figure 22. Crosstalk
Vp = 3.0 V, RL = 16 , Pout = 30 mW
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100000
NCP2809 Series
−40
−40
−50
−50
CROSSTALK (dB)
CROSSTALK (dB)
TYPICAL CHARACTERISTICS
−60
−70
−80
10
−60
−70
100
1000
10000
−80
10
100000
100
FREQUENCY (Hz)
−10
−10
−20
NCP2809A
−30
−30
−40
−40
PSRR (dB)
PSRR (dB)
−20
−50
−60
−70
−60
−70
−80
−90
−90
−100
−100
100
1000
10000
NCP2809A
−50
−80
−110
10
100000
100
FREQUENCY (Hz)
10000
100000
Figure 27. PSRR − Input Grounded with 10 Vp = 2.4 V, Vripple = 200 mV pk−pk, RL = 32 −10
−10
−20
−20
NCP2809A
−30
−30
−40
−40
PSRR (dB)
PSRR (dB)
1000
FREQUENCY (Hz)
Figure 26. PSRR − Input Grounded with 10 Vp = 2.4 V, Vripple = 200 mV pk−pk, RL =16 −50
−60
−70
−60
−70
−80
−90
−90
−100
−100
100
1000
10000
100000
NCP2809A
−50
−80
−110
10
100000
Figure 25. Crosstalk
Vp = 2.4 V, RL = 32 , Pout = 10 mW
Figure 24. Crosstalk
Vp = 2.4 V, RL = 16 , Pout = 20 mW
−110
10
1000
10000
FREQUENCY (Hz)
−110
10
100
FREQUENCY (Hz)
1000
10000
100000
FREQUENCY (Hz)
Figure 29. PSRR − Input Grounded with 10 Vp =3.0 V, Vripple = 200 mV pk−pk, RL = 32 Figure 28. PSRR − Input Grounded with 10 Vp = 3.0 V, Vripple = 200 mV pk−pk, RL =16 http://onsemi.com
10
NCP2809 Series
TYPICAL CHARACTERISTICS
−10
−10
−20
NCP2809A
−30
−30
−40
−40
PSRR (dB)
PSRR (dB)
−20
−50
−60
−70
−80
−50
−60
−70
−80
−90
−90
−100
−100
−110
10
NCP2809A
100
1000
10000
−110
10
100000
100
FREQUENCY (Hz)
−10
100000
−10
−20
−20
NCP2809A
−30
−30
−40
−40
PSRR (dB)
PSRR (dB)
10000
Figure 31. PSRR − Input Grounded with 10 Vp = 3.3 V, Vripple = 200 mV pk−pk, RL = 32 Figure 30. PSRR − Input Grounded with 10 Vp = 3.3 V, Vripple = 200 mV pk−pk, RL =16 −50
−60
−70
−60
−70
−80
−90
−90
−100
−100
100
1000
10000
100000
NCP2809A
−50
−80
−110
10
1000
FREQUENCY (Hz)
−110
10
100
FREQUENCY (Hz)
1000
10000
100000
FREQUENCY (Hz)
Figure 32. PSRR − Input Grounded with 10 Vp = 5.0 V, Vripple = 200 mV pk−pk, RL =16 Figure 33. PSRR − Input Grounded with 10 Vp = 5.0 V, Vripple = 200 mV pk−pk, RL = 32 http://onsemi.com
11
NCP2809 Series
TYPICAL CHARACTERISTICS
−10
−10
−20
NCP2809B
−30
−30
−40
−40
PSRR (dB)
PSRR (dB)
−20
−50
−60
−70
−80
NCP2809B
−50
−60
−70
−80
−90
−90
−100
−100
−110
−110
10
100
1000
10000
100000
10
100
FREQUENCY (Hz)
10000
100000
FREQUENCY (Hz)
Figure 34. PSRR − Input Grounded with 10 Vp = 2.4 V, Vripple = 200 mV pk−pk, RL =16 ,
G = 1 (0 dB)
Figure 35. PSRR − Input Grounded with 10 Vp = 5.0 V, Vripple = 200 mV pk−pk, RL = 16 ,
G = 1 (0 dB)
−10
−10
−20
−20
NCP2809B
−30
NCP2809B
−30
−40
PSRR (dB)
−40
PSRR (dB)
1000
G=4
−50
−60
G=1
−70
−80
G=4
−50
−60
G=1
−70
−80
−90
−90
−100
−100
−110
−110
10
100
1000
10000
100000
10
100
FREQUENCY (Hz)
1000
10000
100000
FREQUENCY (Hz)
Figure 37. PSRR − Input Grounded with 10 Vp = 5.0 V, Vripple = 200 mV pk−pk, RL = 16 ,
G = 1 (0 dB) and G = 4 (12 dB)
Figure 36. PSRR − Input Grounded with 10 Vp = 2.4 V, Vripple = 200 mV pk−pk, RL =16 ,
G = 1 (0 dB) and G = 4 (12 dB)
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NCP2809 Series
TYPICAL CHARACTERISTICS
Figure 38. Turning–On Time/Vp = 5.0 V
and F = 100 Hz
Ch1 = OUT_R, Ch2 = VMC and Ch3 = Shutdown
Figure 39. Turning–On Time Zoom/Vp = 5.0 V
and F = 400 Hz
Ch1 = OUT_R, Ch2 = VMC and Ch3 = Shutdown
Figure 40. Turning–Off Time/Vp = 5.0 V
and F = 100 Hz
Ch1 = OUT_R, Ch2 = VMC and Ch3 = Shutdown
Figure 41. TurningOff Time Zoom/Vp = 5.0 V
and F = 400 Hz
Ch1 = OUT_R, Ch2 = VMC and Ch3 = Shutdown
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NCP2809 Series
APPLICATION INFORMATION
Current Limit Protection Circuitry
The maximum output power of the circuit (POrms =
135 mW, VP = 5.0 V, RL = 16 ) requires a peak current in
the load of 130 mA.
In order to limit excessive power dissipation in the load
when a short−circuit occurs, the current limit in the load is
fixed to 250 mA. The current in the output MOS transistors
is real−time monitored, and when exceeding 250 mA, the
gate voltage of the corresponding MOS transistor is clipped
and no more current can be delivered.
Detailed Description
The NCP2809 power audio amplifier can operate from
2.6 V to 5.0 V power supply. It delivers 24 mWrms output
power to a 16 load (VP = 2.4 V) and 131 mWrms output
power to a 16 load (VP = 5.0 V).
The structure of NCP2809 is basically composed of two
identical internal power amplifiers; NCP2809A has a fixed
internal gain of 0 dB and the gain can be set externally with
the NCP2809B.
Internal Power Amplifier
The output Pmos and Nmos transistors of the amplifier are
designed to deliver the specified output power without
clipping. The channel resistance (Ron) of the Nmos and Pmos
transistors does not exceed 3.0 when driving current.
The structure of the internal power amplifier is
composed of three symmetrical gain stages, first and
medium gain stages are transconductance gain stages in
order to maximize bandwidth and DC gain.
Thermal Overload Protection Circuitry
Internal amplifiers are switched off when temperature
exceeds 160°C, and will be switched back on only when the
temperature goes below 140°C.
NCP2809 is a stereo power audio amplifier.
If the application requires a Single Ended topology with
output coupling capacitors, then the current provided by
the battery for one output is as following:
• VO(t) is the AC voltage seen by the load. Here we
consider a sine wave signal with a period T and a peak
voltage VO.
• RL is the load.
Turn−On and Turn−Off Transitions
A Turn−on/off transition is shown in the following plot
corresponding to curves in Figures 38 to 41.
In order to eliminate “pop and click” noises during
transitions, output power in the load must be slowly
established or cut. When logic high is applied to the
shutdown pin, the bypass voltage begins to rise
exponentially and once the output DC level is around the
common mode voltage, the gain is established slowly
(50 ms). This way to turn−on the device is optimized in
terms of rejection of “pop and click” noises.
The device has the same behavior when turned−off by a
logic low on the shutdown pin. During the shutdown mode,
amplifier outputs are connected to the ground.
A theoretical value of turn−on and off times at 25°C is
given by the following formula.
Cby: Bypass Capacitor
R: Internal 300 k resistor with a 25% accuracy
Ton = 0.95 * R * Cby
Toff = R * Cby * Ln(Vp/1.4)
Ip(t)
VO/RL
T/2
T
TIME
So, the total power delivered by the battery to the device is:
PTOT + Vp
Ipavg
Ipavg + 1
2
ŕ 0 RVoL sin(t)dt + .RVoL
Vp.Vo
PTOT +
.RL
The power in the load is POUT.
Shutdown Function
The device enters shutdown mode when shutdown signal
is low. During the shutdown mode, the DC quiescent
current of the circuit does not exceed 600 nA.
V 2
POUT + O
2RL
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NCP2809 Series
The dissipated power by the device is
The power in the load is POUT
PD + PTOT * POUT
V 2
POUT + O
2RL
ƪVP * V2Oƫ
V
PD + o
RL
The dissipated power by the device is
PD + PTOT * POUT
At a given power supply voltage, the maximum power
dissipated is:
V
PD + o
RL
VP2
PDmax +
22.RL
At a given power supply voltage, the maximum power
dissipated is:
Of course, if the device is used in a typical stereo
application, each load with the same output power will give
the same dissipated power. Thus the total lost power for the
device is:
V
PD + o
RL
2VP2
PDmax +
2.RL
Of course, if the device is used in a typical stereo
application, each load with the same output power will give
the same dissipated power. Thus the total lost power for the
device is:
ƪ2VP * VOƫ
And in this case, the maximum power dissipated will be:
V 2
PDmax + P
2.RL
V
PD + o
RL
.VO
2VP
4VP2
PDmax +
2.RL
If the application requires a NOCAP scheme without
output coupling capacitors, then the current provided by
the battery for one output is as following:
• Vo(t) is the AC voltage seen by the load. Here we
consider a sine wave signal with a period T and a peak
voltage VO.
• RL is the load.
In NOCAP operation, the efficiency is:
+
VO/RL
T
TIME
So, the total power delivered by the battery to the device is:
PTOT + Vp
Ipavg + 1
.VO
4VP
Gain−Setting Selection
With NCP2809 Audio Amplifier family, you can select
a closed−loop gain of 0db for the NCP2809A and an
external gain setting with the NCP2809B. In order to
optimize device and system performance, NCP2809 needs
to be used in low gain configurations. It minimizes THD+N
values and maximizes the signal−to−noise ratio, and the
amplifier can still be used without running into the
bandwidth limitations.
NCP2809A can be used when a 0 dB gain is required.
Adjustable gain is available on NCP2809B.
Ip(t)
T/2
ƪ4VP * VOƫ
And in this case, the maximum power dissipated will be:
In single ended operation, the efficiency is:
+
ƪ2VP * V2Oƫ
Ipavg
2Vo
ŕ 0 RVoL sin(t)dt + .R
L
2Vp.Vo
PTOT +
.RL
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NCP2809 Series
With Output Coupling Capacitor
NCP2809 Amplifier External Components
However, when using a low cost jack connector (with
third connection to ground), the headset amplifier requires
very few external components as described in Figure 43.
Only two external coupling capacitors are needed. The
main concern is in output coupling capacitors, because of
the value and consequently the size of the components
required. Purpose of these capacitors is biasing DC voltage
and very low frequency elimination. Both, coupling
capacitor and output load form a high pass filter. Audible
frequency ranges from 20 Hz to 20 kHz, but headset used
in portable appliance has poor ability to reproduce signals
below 75 or 100 Hz. Input coupling capacitor and input
resistance also form a high pass filter. These two first order
filters form a second order high pass filter with the same
−3 dB cut off frequency. Consequently, the following
formula must be respected:
Input Capacitor Selection (Cin)
The input coupling capacitor blocks the DC voltage at
the amplifier input terminal. This capacitor creates a
high−pass filter with the internal Rinternal resistor of 50 k,
the cut−off frequency of which is given by:
1
fc +
2 * * Rin * Cin
(eq. 1)
The size of the capacitor must be large enough to couple
in low frequencies without severe attenuation. However a
large input coupling capacitor requires more time to reach
its quiescent DC voltage (VP/2) and can increase the
turn−on pops.
An input capacitor value of 100 nF performs well in
many applications (With Rinternal =50 k).
Bypass Capacitor Selection (Cbypass)
The bypass capacitor Cby provides half−supply filtering
and determines how fast the NCP2809 turns on.
A proper supply bypassing is critical for low noise
performance and high power supply rejection ratio.
Moreover, this capacitor is a critical component to
minimize the turn−on pop noise. A 1.0 F bypass capacitor
value should produce clickless and popless shutdown
transitions. The amplifier is still functional with a 0.1 F
capacitor value but is more sensitive to “pop and click”
noises.
Thus, for optimized performances, a 1.0 F ceramic
bypassing capacitor is recommended.
2
1
50 k
Cin
[
2
1
RL
Cout
(eq. 2)
Like for loudspeaker amplifier, the input impedance
value for calculating filters cut off frequency is the
minimum input impedance value at maximum output
volume.
To obtain a frequency equal to when frequency is 5 times
the cut off frequency, attenuation is 0.5 dB. So if we want
a ±0.5 dB at 150 Hz, we need to have a –3 dB cut off
frequency of 30 Hz:
f−3dB w
2
Cout w
2
Without Output Coupling Capacitor
As described in Figure 42, the internal circuitry of the
NCP2809 device eliminates need of heavy bypassing
capacitors when connecting a stereo headset with 3
connecting points. This circuitry produces a virtual ground
and does not affect either output power or PSRR.
Additionally, eliminating these capacitors reduces cost and
PCB place.
However, user must take care to the connection between
pin REF_I and ground of the headset: this pin is the ground
reference for the headset. So, in order to improve
crosstalk performances, this pin must be plugged
directly to the ground pin of the headset connector.
1
RL
1
RL
Cout
f−3dB
(eq. 3)
(eq. 4)
With RL = 16 , and f−3dB = 30 Hz formula (4) shows that
Cout ≥ 330 F.
With Cout = 220 F, ±0.5 dB attenuation frequency will
be 225 Hz with a –3.0 dB cut off frequency of 45 Hz.
Following this, the input coupling capacitor choice is
straightforward. Using formula (2) input coupling
capacitor value would be 68 nF for a 220 F output
coupling capacitor and 100 nF for a 330 F output coupling
capacitor.
When using the NCP2809 with this configuration, pins
REF_I and OUT_I must be left unconnected
(see Figure 43).
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NCP2809 Series
VP
1 F
CS
VP
20 k
CI
AUDIO
INPUT
20 k
IN_L
390 nF
VP
BYPASS
Cbypass
OUT_L
+
16 +
−
VMC
BRIDGE
1 F
CI
AUDIO
INPUT
BYPASS
−
+
−
OUT_I
−
REF_I
+
−
IN_R
16 +
OUT_R
20 k
390 nF
20 k
SHUTDOWN
SHUTDOWN
CONTROL
VIH
VM
VIL
Figure 42. Typical Application Schematic Without Output Coupling Capacitor
VP
1 F
CS
VP
20 k
CI
AUDIO
INPUT
20 k
IN_L
390 nF
VP
BYPASS
Cbypass
OUT_L
Cout
+
−
VMC
BRIDGE
OUT_I
+
+
−
IN_R
20 k
−
NC
−
REF_I
390 nF
220 F
+
16 1 F
CI
AUDIO
INPUT
BYPASS
−
+
OUT_R
NC
220 F
+
16 +
Cout
20 k
SHUTDOWN
SHUTDOWN
CONTROL
VIH
VIL
VM
Figure 43. Typical Application Schematic With Output Coupling Capacitor
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NCP2809 Series
DEMONSTRATION BOARD AND LAYOUT GUIDELINES
VP
VP
J4
1 F
C1
VM1
VM1
VP
C2
20 k
1 IN_R
390 nF
VP
U1
7
2
−
3 +
BYPASS
+
20 k
16 1
OUT_R
1
OUT_I
8
REF_I
4
OUT_L
6
−
10
J3 & U2
J2
3 BYPASS
VM1
VMC
BRIDGE
1 F
C3
3
+
2
−
VM1
C4
3
+
2 −
5 IN_L
−
20 k
390 nF
VP
R1
1
16 20 k
+
100 k
2 SHUTDOWN
SHUTDOWN
CONTROL
J1
VM
9
VM1
VM1
VP
VP
J10
1 F
C5
VM2
VM2
VP
C6
20 k
1 IN_R
390 nF
VP
U3
7
BYPASS
+
20 k
2
−
3 +
1
16 OUT_R
10
+
C9
−
220 F
J9 & U4
J8
3 BYPASS
1 F
C7
VM2
3
+
2
−
VMC
BRIDGE
1
OUT_I
8
REF_I
4
OUT_L
6
VM2
C8
5 IN_L
1
20 k
390 nF
VP
R2
3
+
2 −
NC
NC
VM2
C10
+
220 F
20 k
100 k
2 SHUTDOWN
SHUTDOWN
CONTROL
J7
VM
VM2
9
VM2
Figure 44. Schematic of the Demonstration Board for Micro10 Device
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VM2
−
16 +
NCP2809 Series
TOP LAYER
BOTTOM LAYER
Figure 45. Demonstration Board for Micro10 Device – PCB Layers
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NCP2809 Series
Table 1. Bill of Material
Item
Part Description
Ref.
PCB
Footprint
Manufacturer
Manufacturer
Reference
1
NCP2809 Audio Amplifier
U1,U3
Micro10
ON Semiconductor
NCP2809
2
SMD Resistor 100 K
R1,R2
0805
Vishay−Draloric
D12CRCW Series
3
Ceramic Capacitor 390 nF 50 V Z5U
C2,C4,
C6,C8
1812
Kemet
C1812C394M5UAC
4
Ceramic Capacitor 1.0 F 16 V X7R
Optimized Performance
C1,C3,
C5,C7
1206
Murata
GRM42−6X7R105K16
5
Tantalum Capacitor 220 F 10 V
C9,C10
−
Kemet
T495X227010AS
6
I/O Connector. It can be plugged by
BLZ5.08/2 (Weidmüller Reference)
J4,J10
−
Weidmüller
SL5.08/2/90B
7
I/O Connector. It can be plugged by
BLZ5.08/3 (Weidmüller Reference)
J2,J3,
J8,J9
−
Weidmüller
SL5.08/3/90B
8
3.5 mm PCB Jack Connector
U2,U4
−
Decelect−Forgos
IES 101−3
9
Jumper Header Vertical Mount
2*1, 2.54 mm
J1,J7
−
−
−
PCB LAYOUT GUIDELINES
How to Optimize the Accuracy of VMC
How to Optimize THD+N Performances
The main innovation of the NCP2809 stereo NOCAP
audio amplifier is the use of a virtual ground that allows
connecting directly the headset on the outputs of the device
saving DC−blocking output capacitors. In order to have the
best performances in terms of crosstalk, noise and supply
current, the feedback connection on the virtual ground
amplifier is not closed internally. To reach this goal of
excellence, one must connect OUT_I and REF_I as close
as possible from the middle point of the output jack
connector. The most suitable place for this connection is
directly on the pad of this middle point.
To get the best THD+N level on the headset speakers, the
traces of the power supply, ground, OUT_R, OUT_L and
OUT_I need the lowest resistance. Thus, the PCB traces for
these nets should be as wide and short as possible.
You need to avoid ground loops, run digital and analog
traces parallel to each other. Due to its internal structure,
the amplifier can be sensitive to coupling capacitors
between Ground and each output (OUT_R, OUT_L and
OUT_I). Avoid running the output traces between two
ground layers or if traces must cross over on different
layers, do it at 90 degrees.
ORDERING INFORMATION
Device
Marking
Package
Shipping†
NCP2809ADMR2
MAE
Micro10
4000 Tape & Reel
NCP2809ADMR2G
MAE
Micro10
(Pb−Free)
4000 Tape & Reel
NCP2809BDMR2
MAC
Micro10
4000 Tape & Reel
NCP2809BDMR2G
MAC
Micro10
(Pb−Free)
4000 Tape & Reel
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
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NCP2809 Series
PACKAGE DIMENSIONS
Micro10
CASE 846B−03
ISSUE D
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSION “A” DOES NOT INCLUDE MOLD
FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE
BURRS SHALL NOT EXCEED 0.15 (0.006)
PER SIDE.
4. DIMENSION “B” DOES NOT INCLUDE
INTERLEAD FLASH OR PROTRUSION.
INTERLEAD FLASH OR PROTRUSION
SHALL NOT EXCEED 0.25 (0.010) PER SIDE.
5. 846B−01 OBSOLETE. NEW STANDARD
846B−02
−A−
−B−
K
D 8 PL
0.08 (0.003)
PIN 1 ID
G
0.038 (0.0015)
−T−
SEATING
PLANE
M
T B
S
A
DIM
A
B
C
D
G
H
J
K
L
S
C
H
MILLIMETERS
MIN
MAX
2.90
3.10
2.90
3.10
0.95
1.10
0.20
0.30
0.50 BSC
0.05
0.15
0.10
0.21
4.75
5.05
0.40
0.70
L
J
SOLDERING FOOTPRINT*
10X
1.04
0.041
0.32
0.0126
3.20
0.126
8X
0.50
0.0196
10X
4.24
0.167
5.28
0.208
SCALE 8:1
mm Ǔ
ǒinches
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
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INCHES
MIN
MAX
0.114
0.122
0.114
0.122
0.037
0.043
0.008
0.012
0.020 BSC
0.002
0.006
0.004
0.008
0.187
0.199
0.016
0.028
NCP2809 Series
NOCAP is a trademark of Semiconductor Components Industries, LLC (SCILLC).
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any
liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental
damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over
time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under
its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body,
or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death
may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees,
subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of
personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part.
SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT:
N. American Technical Support: 800−282−9855 Toll Free
Literature Distribution Center for ON Semiconductor
USA/Canada
P.O. Box 61312, Phoenix, Arizona 85082−1312 USA
Phone: 480−829−7710 or 800−344−3860 Toll Free USA/Canada Japan: ON Semiconductor, Japan Customer Focus Center
2−9−1 Kamimeguro, Meguro−ku, Tokyo, Japan 153−0051
Fax: 480−829−7709 or 800−344−3867 Toll Free USA/Canada
Phone: 81−3−5773−3850
Email: [email protected]
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ON Semiconductor Website: http://onsemi.com
Order Literature: http://www.onsemi.com/litorder
For additional information, please contact your
local Sales Representative.
NCP2809/D
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