1.3 W Audio Amplifier with Fast Turn On Time

NCP2892 Series
1.3 Watt Audio Power
Amplifier with Fast Turn On
Time
The NCP2892 is an audio power amplifier designed for portable
communication device applications such as mobile phone
applications. The NCP2892 is capable of delivering 1.3 W of
continuous average power to an 8.0 BTL load from a 5.0 V power
supply, and 1.0 W to a 4.0 BTL load from a 3.6 V power supply.
The NCP2892 provides high quality audio while requiring few
external components and minimal power consumption. It features a
low−power consumption shutdown mode, which is achieved by
driving the SHUTDOWN pin with logic low.
The NCP2892 contains circuitry to prevent from “pop and click”
noise that would otherwise occur during turn−on and turn−off
transitions.
For maximum flexibility, the NCP2892 provides an externally
controlled gain (with resistors), as well as an externally controlled
turn−on time (with the bypass capacitor). When using a 1 F bypass
capacitor, it offers 100 ms wake up time.
Due to its excellent PSRR, it can be directly connected to the
battery, saving the use of an LDO.
This device is available in a 9−Pin Flip−Chip CSP (Lead−Free).
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MARKING
DIAGRAMS
A1
9−Pin Flip−Chip CSP
FC SUFFIX
CASE 499E
A3
MAxG
AYWW
C1
A1
MAx
A
Y
WW
G
= Specific Device Code
X = NCP2892A
Z = NCP2892B
= Assembly Location
= Year
= Work Week
= Pb−Free Package
PIN CONNECTIONS
Features
•
•
•
•
•
•
•
•
•
•
9−Pin Flip−Chip CSP
1.3 W to an 8.0 BTL Load from a 5.0 V Power Supply
Excellent PSRR: Direct Connection to the Battery
“Pop and Click” Noise Protection Circuit
Ultra Low Current Shutdown Mode: 10 nA
2.2 V−5.5 V Operation
External Gain Configuration Capability
External Turn−on Time Configuration Capability:
100 ms (1 F Bypass Capacitor)
Up to 1.0 nF Capacitive Load Driving Capability
Thermal Overload Protection Circuitry
This is a Pb−Free Device*
A1
A2
A3
INM
OUTA
INP
B1
B2
B3
VM_P
VM
Vp
C1
C2
C3
BYPASS
OUTB SHUTDOWN
(Top View)
ORDERING INFORMATION
Typical Applications
See detailed ordering and shipping information in the package
dimensions section on page 15 of this data sheet.
• Portable Electronic Devices
• PDAs
• Wireless Phones
*For additional information on our Pb−Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques Reference
Manual, SOLDERRM/D.
© Semiconductor Components Industries, LLC, 2006
September, 2006 − Rev. 3
1
Publication Order Number:
NCP2892/D
NCP2892 Series
Rf
20 k
Vp
1 F
Cs
AUDIO
INPUT
Ci
Ri
INM
47 nF
20 k
INP
−
+
Vp
OUTA
R1
20 k
Vp
−
+
BYPASS
Cbypass
8
R2
20 k
OUTB
1 F
SHUTDOWN
VIH
SHUTDOWN
CONTROL
VM_P
VM
VIL
Figure 1. Typical Audio Amplifier Application Circuit with Single Ended Input
Rf
20 k
Vp
1 F
Cs
Ci
Ri
47 nF
20 k
+
AUDIO
INPUT
INM
−
+
INP
Ci
Ri
Vp
Vp
−
47 nF
20 k
20 k
−
+
Rf
BYPASS
Cbypass
R1
20 k
8
R2
20 k
OUTB
1 F
SHUTDOWN
VIH
OUTA
SHUTDOWN
CONTROL
VM_P
VM
VIL
Figure 2. Typical Audio Amplifier Application Circuit with a Differential Input
This device contains 671 active transistors and 1899 MOS gates.
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2
NCP2892 Series
PIN DESCRIPTION
Pin
Type
Symbol
Description
A1
I
INM
A2
O
OUTA
A3
I
INP
B1
I
VM_P
B2
I
VM
Core Analog Ground.
B3
I
Vp
Positive analog supply of the cell. Range: 2.2 V−5.5 V.
C1
I
BYPASS
C2
O
OUTB
C3
I
SHUTDOWN
Negative input of the first amplifier, receives the audio input signal. Connected to the
feedback resistor Rf and to the input resistor Rin.
Negative output of the NCP2892. Connected to the load and to the feedback resistor Rf.
Positive input of the first amplifier, receives the common mode voltage.
Power Analog Ground.
Bypass capacitor pin which provides the common mode voltage (Vp/2).
Positive output of the NCP2892. Connected to the load.
The device enters in shutdown mode when a low level is applied on this pin.
MAXIMUM RATINGS (Note 1)
Rating
Symbol
Value
Unit
Vp
6.0
V
Op Vp
2.2 to 5.5 V
2.0 V = Functional Only
−
Input Voltage
Vin
−0.3 to Vcc +0.3
V
Max Output Current
Iout
500
mA
Power Dissipation (Note 2)
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
(Note 3)
°C/W
Supply Voltage
Operating Supply Voltage
ESD Protection
Human Body Model (HBM) (Note 4)
NCP2892A
NCP2892B
Machine Model (MM) (Note 5)
Latchup Current at TA = 85°C (Note 6)
−
V
8000
6000
>250
−
±100
mA
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. Maximum electrical ratings are defined as those values beyond which damage to the device may occur at TA = +25°C.
2. The thermal shutdown set to 160°C (typical) avoids irreversible damage on the device due to power dissipation. For further information see
page 10.
3. The RJA is highly dependent of the PCB Heatsink area. For example, RJA can equal 195°C/W with 50 mm2 total area and also 135°C/W with
500 mm2. For further information see page 10. The bumps have the same thermal resistance and all need to be connected to optimize the power
dissipation.
4. Human Body Model, 100 pF discharge through a 1.5 k resistor following specification JESD22/A114.
5. Machine Model, 200 pF discharged through all pins following specification JESD22/A115.
6. Maximum ratings per JEDEC standard JESD78.
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3
NCP2892 Series
ELECTRICAL CHARACTERISTICS Limits apply for TA between −40°C to +85°C (Unless otherwise noted).
Characteristic
Supply Quiescent Current
Symbol
Conditions
Min
(Note 7)
Typ
Max
(Note 7)
Idd
Unit
Vp = 2.6 V, No Load
Vp = 5.0 V, No Load
−
−
1.5
1.7
4
mA
Vp = 2.6 V, 8 Vp = 5.0 V, 8 −
−
1.7
1.9
5.5
Common Mode Voltage
Vcm
−
−
Vp/2
−
V
Shutdown Current
ISD
TA = +25°C
TA = −40°C to +85°C
−
0.01
0.5
1.0
A
Shutdown Voltage High
VSDIH
−
1.2
−
−
V
Shutdown Voltage Low
VSDIL
−
−
−
0.4
V
Turning On Time (Note 9)
TWU
Cby = 1 F
−
90
−
ms
Turning Off Time
TOFF
−
−
1.0
−
s
Output Impedance in Shutdown Mode
NCP2892A
NCP2892B
ZSD
−
−
−
100
10
−
−
k
1.6
2.12
−
−
V
4.0
3.85
4.15
1.6
2.20
−
−
V
4.0
3.85
4.50
Vp = 2.6 V, RL = 4.0 THD + N < 0.1%
Vp = 2.6 V, RL = 8.0 THD + N < 0.1%
Vp = 5.0 V, RL = 8.0 THD + N < 0.1%
−
0.36
−
W
Vp = 2.6 V, RL = 4.0 THD + N < 0.1%
Vp = 2.6 V, RL = 8.0 THD + N < 0.1%
Vp = 5.0 V, RL = 8.0 THD + N < 0.1%
−
PDmax
Vp = 5.0 V, RL = 8.0 −
Output Offset Voltage
VOS
Vp = 2.6 V
Vp = 5.0 V
−30
Signal−to−Noise Ratio
SNR
Vp = 2.6 V, G = 2.0
10 Hz < F < 20 kHz
Vp = 5.0 V, G = 10
10 Hz < F < 20 kHz
−
−
Output Swing
Output Swing
Rms Output Power
Rms Output Power
NCP2892A
NCP2892B
NCP2892A
NCP2892B
Maximum Power Dissipation (Note 9)
Positive Supply Rejection Ratio
Efficiency
Vloadpeak
Vloadpeak
PO
PO
PSRR V+
Vp = 2.6 V, RL = 8.0 Vp = 5.0 V, RL = 8.0 (Note 8)
TA = +25°C
TA = −40°C to +85°C
Vp = 2.6 V, RL = 8.0 Vp = 5.0 V, RL = 8.0 (Note 8)
TA = +25°C
TA = −40°C to +85°C
0.28
−
−
1.08
0.40
−
0.30
−
−
1.20
−
0.65
W
30
mV
84
−
dB
77
−
G = 2.0, RL = 8.0 Vpripple_pp = 200 mV
Cby = 1.0 F
Input Terminated with 10 F = 217 Hz
Vp = 5.0 V
Vp = 3.0 V
Vp = 2.6 V
−
−
−
−64
−72
−73
−
−
−
F = 1.0 kHz
Vp = 5.0 V
Vp = 3.0 V
Vp = 2.6 V
−
−
−
−64
−74
−75
−
−
−
Vp = 2.6 V, Porms = 320 mW
Vp = 5.0 V, Porms = 1.0 W
−
−
48
63
−
−
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4
W
dB
%
NCP2892 Series
ELECTRICAL CHARACTERISTICS Limits apply for TA between −40°C to +85°C (Unless otherwise noted).
Characteristic
Thermal Shutdown Temperature (Note 10)
Total Harmonic Distortion
Symbol
Conditions
Typ
Max
(Note 7)
Unit
140
160
180
°C
Vp = 2.6, F = 1.0 kHz
RL = 4.0 AV = 2.0
PO = 0.32 W
−
−
−
−
0.04
−
−
−
−
%
Vp = 5.0 V, F = 1.0 kHz
RL = 8.0 AV = 2.0
PO = 1.0 W
−
−
−
−
0.02
−
−
−
−
Tsd
THD
Min
(Note 7)
7. Min/Max limits are guaranteed by design, test or statistical analysis.
8. This parameter is guaranteed but not tested in production in case of a 5.0 V power supply.
9. See page 12 for a theoretical approach of this parameter.
10. For this parameter, the Min/Max values are given for information.
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5
NCP2892 Series
TYPICAL PERFORMANCE CHARACTERISTICS
10
10
Vp = 2.5 V
RL = 8 f = 1 kHz
AV = 2
NCP2892B
0.1
NCP2892B
0.1
0.01
0.01
0.001
0.001
0
50
100
150
200
250
300
350
0
400
100
200
300
400
500
600
700
Pout, POWER OUT (mW)
Pout, POWER OUT (mW)
Figure 3. THD + N versus Power Out
Figure 4. THD + N versus Power Out
10
10
NCP2892A
Vp = 3.6 V
RL = 8 f = 1 kHz
AV = 2
0.1
0.01
NCP2892A
Vp = 4.2 V
RL = 8 f = 1 kHz
AV = 2
1
THD + N (%)
1
THD + N (%)
NCP2892A
Vp = 3.2 V
RL = 8 f = 1 kHz
AV = 2
1
THD + N (%)
THD + N (%)
1
NCP2892A
NCP2892B
0.1
0.01
NCP2892B
0.001
0.001
0
100
200
300
400
500
600
700
800
0
200
Pout, POWER OUT (mW)
600
800
1000
1200
Pout, POWER OUT (mW)
Figure 5. THD + N versus Power Out
Figure 6. THD + N versus Power Out
10
10
Vp = 5 V
RL = 8 f = 1 kHz
AV = 2
Vp = 3.6 V
RL = 4 f = 1 kHz
AV = 2
NCP2892A
1
THD + N (%)
1
THD + N (%)
400
0.1
0.01
NCP2892A
0.1
NCP2892B
0.01
NCP2892B
0.001
0
200
400
600
800
1000
1200 1400
0.001
1600
0
200
400
600
800
1000
Pout, POWER OUT (mW)
Pout, POWER OUT (mW)
Figure 7. THD + N versus Power Out
Figure 8. THD + N versus Power Out
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6
1200
NCP2892 Series
TYPICAL PERFORMANCE CHARACTERISTICS
1700
10
RL = 8 f = 1 kHz
AV = 2
1300
Vp = 2.5 V
RL = 8 Pout = 100 mW
AV = 2
NCP2892B
THD+N < 10%
1
1100
900
NCP2892A
700
THD + N (%)
OUTPUT POWER (mW)
1500
0.1
THD+N < 1%
500
0.01
300
100
2.5
3.0
3.5
4.0
4.5
0.001
5.0
10
100
POWER SUPPLY (V)
Figure 9. Output Power versus Power Supply
100,000
10
Vp = 3 V
RL = 8 Pout = 150 mW
AV = 2
1
THD + N (%)
1
THD + N (%)
10,000
Figure 10. THD + N versus Frequency
10
0.1
0.01
Vp = 3.3 V
RL = 8 Pout = 250 mW
AV = 2
0.1
0.01
0.001
10
100
1000
10,000
0.001
10
100,000
100
FREQUENCY (Hz)
1000
10,000
100,000
FREQUENCY (Hz)
Figure 11. THD + N versus Frequency
Figure 12. THD + N versus Frequency
10
10
Vp = 5 V
RL = 8 Pout = 250 mW
AV = 2
1
THD + N (%)
1
THD + N (%)
1000
FREQUENCY (Hz)
0.1
0.01
Vp = 2.5 V
RL = 4 Pout = 100 mW
AV = 2
0.1
0.01
0.001
10
100
1000
10,000
0.001
10
100,000
FREQUENCY (Hz)
100
1000
10,000
FREQUENCY (Hz)
Figure 13. THD + N versus Frequency
Figure 14. THD + N versus Frequency
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7
100,000
NCP2892 Series
TYPICAL PERFORMANCE CHARACTERISTICS
−10
−10
Vp = 3.6 V
RL = 8 Vripple = 200 mVpk−pk
Input to Gnd
Cbypass = 1 F
PSRR (dB)
−30
−30
−40
AV = 8
−50
−60
−40
AV = 8
−50
−60
AV = 2
−70
−80
Vp = 5 V
RL = 8 Vripple = 200 mVpk−pk
Input to Gnd
Cbypass = 1 F
−20
PSRR (dB)
−20
10
100
AV = 2
−70
−80
10,000
1000
10
100
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 15. PSRR @ Vp = 3.6 V
Single Ended Audio Input to Ground
Figure 16. PSRR @ Vp = 5 V
Single Ended Audio Input to Ground
−10
−10
Vp = 3.6 V
RL = 8 Vripple = 200 mVpk−pk
Input to Gnd
Cbypass = 1 F
PSRR (dB)
−30
Vp = 5 V
RL = 8 Vripple = 200 mVpk−pk
Input to Gnd
Cbypass = 1 F
−20
−30
PSRR (dB)
−20
−40
AV = 4
−50
−60
−40
AV = 4
−50
−60
AV = 1
AV = 1
−70
−80
10
100
1000
−70
−80
10,000
10
100
FREQUENCY (Hz)
10,000
Figure 18. PSRR @ Vp = 5 V
Differential Audio Input to Ground
0
−10
RL = 8 AV = 2
Vripple = 200 mVpk−pk
Inputs Floating
Cbypass = 1 F
−30
−20
−40
−50
VP = 5 V &
VP = 3.6 V
−60
Vp = 5 V
RL = 8 F = 217 Hz
AV = 2
Vripple = 200 mVpk−pk
Cbypass = 1 F
−10
PSRR (dB)
−20
PSRR (dB)
1000
FREQUENCY (Hz)
Figure 17. PSRR @ Vp = 3.6 V
Differential Audio Input to Ground
−30
−40
−50
−60
−70
−80
10,000
1000
−70
10
100
1000
10,000
−80
−5
−4
−3
−2
−1
0
1
2
3
DC OUTPUT VOLTAGE (V)
FREQUENCY (Hz)
Figure 20. PSRR @ DC Output Voltage
Figure 19. PSRR @ Vp = 3.6 V
Single Ended Audio Input Floating
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8
4
5
NCP2892 Series
TYPICAL PERFORMANCE CHARACTERISTICS
180
120
160
Vbat = 5.5 V
110
100
120
Turn ON (ms)
Turn ON (ms)
140
100
80
60
Vbat = 3.6 V
90
80
Vbat = 2.5 V
70
40
60
20
0
0
400
1200
800
50
−50
2000
1600
25
50
75
100
125
Cbypass (nF)
TEMPERATURE (°C)
Figure 22. TON versus Temperature @ Vbat = 3.6 V,
Cbypass = 1 mF
0.7
PD, POWER DISSIPATION (W)
94
92
Turn ON (ms)
0
Figure 21. TON versus Cbypass @ Vbat = 3.6 V,
TA = +255C
96
90
88
86
84
82
80
78
76
2.5
3.0
3.5
4.0
4.5
5.0
0.6
0.5
0.4
Vp = 5 V
RL = 8 F = 1 kHz
THD + N < 0.1%
0.3
0.2
0.1
0
5.5
0
0.2
0.4
0.6
0.8
1
Vbat, (V)
Pout, OUTPUT POWER (W)
Figure 23. TON vs. Vbat @ Cbypass = 1 mF,
TA = +255C
Figure 24. Power Dissipation versus Output
Power
0.3
1.2
0.25
PD, POWER DISSIPATION (W)
PD, POWER DISSIPATION (W)
−25
0.25
0.2
0.15
Vp = 3.3 V
RL = 8 F = 1 kHz
THD + N < 0.1%
0.1
0.05
0
0.2
0.15
Vp = 3 V
RL = 8 F = 1 kHz
THD + N < 0.1%
0.1
0.05
0
0
0.1
0.2
0.3
0.4
0.5
0
Pout, OUTPUT POWER (W)
0.1
0.2
0.3
Pout, OUTPUT POWER (W)
Figure 25. Power Dissipation versus Output
Power
Figure 26. Power Dissipation versus Output
Power
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9
0.4
NCP2892 Series
TYPICAL PERFORMANCE CHARACTERISTICS
700
PD, POWER DISSIPATION (mW)
0.35
RL = 4 0.3
0.25
0.2
RL = 8 0.15
0.1
Vp = 2.6 V
F = 1 kHz
THD + N < 0.1%
0.05
PCB Heatsink Area
600
200 mm2
500
50 mm2
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
500 mm2
400
300
200
PDmax = 633 mW
for Vp = 5 V,
RL = 8 100
0
0
0
0.4
20
40
60
Pout, OUTPUT POWER (W)
Maximum Die Temperature 150°C
RL = 8 160
Vp = 5 V
120
Vp = 4.2 V
100
80
Vp = 3.3 V
60
40
Vp = 2.6 V
50
100
100
120
140
160
Figure 28. Power Derating − 9−Pin Flip−Chip CSP
180
140
80
TA, AMBIENT TEMPERATURE (°C)
Figure 27. Power Dissipation versus Output
Power
DIE TEMPERATURE (°C) @
AMBIENT TEMPERATURE 25°C
PD, POWER DISSIPATION (W)
0.4
150
200
PCB HEATSINK AREA
250
(mm2)
Figure 29. Maximum Die Temperature versus
PCB Heatsink Area
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10
300
NCP2892 Series
TYPICAL PERFORMANCE CHARACTERISTICS
Ch1 = OUTA
Ch2 = OUTB
Ch3 = Shutdown
Math1 = Ch1−Ch2: Differential
Signal seen by the Load
Ch1 = OUTA
Ch2 = OUTB
Ch3 = Shutdown
Math1 = Ch1−Ch2: Differential
Signal seen by the Load
Figure 30. Zero Pop Noise Turn On Sequence with
Differential Input to Ground; Cin = 100 nF, Rin = 24 W,
Rf = 100 kW, Cbyp = 1 mF, RL = 8 W
Figure 31. Zero Pop Noise Turn On Sequence with
Differential Audio Source; Cin = 100 nF, Rin = 24 W,
Rf = 100 kW, Cbyp = 1 mF, RL = 8 W
Ch1 = OUTA
Ch2 = OUTB
Ch3 = Shutdown
Math1 = Ch1−Ch2: Differential
Signal seen by the Load
Ch1 = OUTA
Ch2 = OUTB
Ch3 = Shutdown
Math1 = Ch1−Ch2: Differential
Signal seen by the Load
Figure 32. Zero Pop Noise Turn Off Sequence with
Differential Input to Ground; Cin = 100 nF, Rin = 24
W, Rf = 100 kW, Cbyp = 1 mF, RL = 8 W
Figure 33. Zero Pop Noise Turn Off Sequence with
Differential Audio Source; Cin = 100 nF, Rin = 24 W,
Rf = 100 kW, Cbyp = 1 mF, RL = 8 W
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11
NCP2892 Series
APPLICATION INFORMATION
Detailed Description
is no audible pop click noise, especially when the input cut
off frequency is higher than 100 Hz.
The NCP2892 audio amplifier can operate under 2.6 V
until 5.5 V power supply. With less than 1% THD+N, B
version can deliver up to 1.2 W rms output power to an
8.0 load (Vp = 5.0 V). If application allows to reach 10%
THD+N, then 1.6 W can be provided using a 5.0 V power
supply.
The structure of the NCP2892 is basically composed of
two identical internal power amplifiers; the first one is
externally configurable with gain−setting resistors Rin and
Rf (the closed−loop gain is fixed by the ratios of these
resistors) and the second is internally fixed in an inverting
unity−gain configuration by two resistors of 20 k. So the
load is driven differentially through OUTA and OUTB
outputs. This configuration eliminates the need for an
output coupling capacitor. The NCP2892A has around
100 and the NCP2892B has around 10 k output
impedance in the shutdown mode.
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 100 nA. In this
configuration, the output impedance is 10 k on each
output.
Current Limit Circuit
The maximum output power of the circuit (Porms =
1.0 W, Vp = 5.0 V, RL = 8.0 ) requires a peak current in
the load of 500 mA.
In order to limit the excessive power dissipation in the
load when a short−circuit occurs, the current limit in the
load is fixed to 800 mA. The current in the four output MOS
transistors are real−time controlled, and when one current
exceeds 800 mA, the gate voltage of the MOS transistor is
clipped and no more current can be delivered.
Internal Power Amplifier
The output PMOS and NMOS transistors of the amplifier
were designed to deliver the output power of the
specifications without clipping. The channel resistance
(Ron) of the NMOS and PMOS transistors does not exceed
0.6 when they drive current.
The structure of the internal power amplifier is
composed of three symmetrical gain stages, first and
medium gain stages are transconductance gain stages to
obtain maximum bandwidth and DC gain.
Thermal Overload Protection
Internal amplifiers are switched off when the
temperature exceeds 160°C, and will be switched on again
only when the temperature decreases fewer than 140°C.
The NCP2892 is unity−gain stable and requires no
external components besides gain−setting resistors, an
input coupling capacitor and a proper bypassing capacitor
in the typical application.
The first amplifier is externally configurable (Rf and
Rin), while the second is fixed in an inverting unity gain
configuration.
The differential−ended amplifier presents two major
advantages:
− The possible output power is four times larger (the
output swing is doubled) as compared to a single−ended
amplifier under the same conditions.
− Output pins (OUTA and OUTB) are biased at the same
potential Vp/2, this eliminates the need for an output
coupling capacitor required with a single−ended
amplifier configuration.
The differential closed loop−gain of the amplifier is
Turn−On and Turn−Off Transitions
A cycle with a turn−on and turn−off transition is
illustrated with plots that show both single ended signals on
the previous page.
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
instantaneously. 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 it is turned−off
by a logic low on the shutdown pin. During the shutdown
mode, amplifier outputs are connected to the ground.
When a shutdown low level is applied, with 1 F bypass
capacitor, it takes 65 ms before the DC output level is tied
to Ground on each output. However, no audio signal will be
provided to the BTL load only 1 s after the falling edge on
the shutdown pin.
With 1 F bypass capacitor, turn on time is set to 90 ms.
This fast turn on time added to a very low shutdown current
saves battery life and brings flexibility when designing the
audio section of the final application.
NCP2892 is a zero pop noise device when using a
differential audio input. In case of a single ended one, there
R
V
given by Avd + 2 * f + orms .
Rin
Vinrms
Output power delivered to the load is given by
Porms +
(Vopeak)2
(Vopeak is the peak differential
2 * RL
output voltage).
When choosing gain configuration to obtain the desired
output power, check that the amplifier is not current limited
or clipped.
The maximum current which can be delivered to the load
is 500 mA Iopeak +
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12
Vopeak
.
RL
NCP2892 Series
Gain−Setting Resistor Selection (Rin and Rf)
large input coupling capacitor requires more time to reach
its quiescent DC voltage (Vp/2) and can increase the
turn−on pops when a single ended audio input is used.
An input capacitor value between 33 nF and 220 nF
performs well in many applications (With Rin = 22 K).
Rin and Rf set the closed−loop gain of the amplifier.
In order to optimize device and system performance, the
NCP2892 should be used in low gain configurations.
The low gain configuration minimizes THD + noise
values and maximizes the signal to noise ratio, and the
amplifier can still be used without running into the
bandwidth limitations.
A closed loop gain in the range from 2 to 5 is
recommended to optimize overall system performance.
An input resistor (Rin) value of 22 k is realistic in most
of applications, and doesn’t require the use of a too large
capacitor Cin.
Bypass Capacitor Selection (Cby)
The bypass capacitor Cby provides half−supply filtering
and determines how fast the NCP2892 turns on (see
Figure 21). With a differential audio input, the amplifier
will be a zero pop noise device no matter the bypass
capacitor.
With a single ended audio input, this capacitor is a
critical component to minimize the turn−on pop. A 1.0 F
bypass capacitor value (Cin = < 0.39 F) should produce
clickless and popless shutdown transitions. The amplifier
is still functional with a 0.1 F capacitor value but is more
susceptible to “pop and click” noises.
Thus, a 1.0 F bypassing capacitor is recommended.
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 Rin, the cut−off frequency is given by
fc +
1
.
2 * * Rin * Cin
The size of the capacitor must be large enough to couple
in low frequencies without severe attenuation. However a
R2
100 k
C2*
C1
AUDIO
INPUT
R1
INM
100 nF
C5
20 k
Vp 100 nF
20 k
J3
TP1*
1 F
−
+
INP
R5
Vp
R4
100 k
Vp
OUTA
20 k
Vp
8
−
+
BYPASS
20 k
OUTB
J5
C3
1 F
J9
SHUTDOWN
J8
J11
C4
150 k
R3
SHUTDOWN
CONTROL
VM_P
J7
VM
*C2, TP1: Not Mounted
Figure 34. Schematic of the Demonstration Board of the 9−Pin Flip−Chip CSP Device
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13
NCP2892 Series
Silkscreen Layer
Figure 35. Demonstration Board for 9−Pin Flip−Chip CSP Device − PCB Layers
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14
NCP2892 Series
BILL OF MATERIAL
Item
Part Description
Ref.
PCB
Footprint
Manufacturer
Manufacturer
Reference
1
NCP2892 Audio Amplifier
−
−
ON Semiconductor
NCP2892
2
SMD Resistor 20 K
R1, R5
0805
Panasonic
ERJ−6GEYJ203V
3
SMD Resistor 100 K
R2, R4
0805
Panasonic
ERJ−6GEYJ104V
4
SMD Resistor 150 K
R3
0805
Panasonic
ERJ−6GEYJ154V
5
Ceramic Capacitor 100 nF, 100 V X7R
C1, C5
0805
TDK
C2012X7R2A473K
6
Ceramic Capacitor 1.0 F, 10 V X7R
C3, C4
0805
TDK
C2012X7R1A105K
7
Jumper Header Vertical Mount, 2 positions, 100 mils
J8, J9, J12
100 mils
Tyco Electronics / AMP
5−826629−0
8
I/O Connector, 2 positions
J5, J11
200 mils
Phoenix Contact
1757242
9
Jumper Connector
J7
400 mils
Harwin
D3082−B01
10
Not Mounted
C2, TP1
−
−
−
ORDERING INFORMATION
Marking
Package
Shipping†
NCP2892AFCT2G
MAX
9−Pin Flip−Chip CSP
(Pb−Free)
3000/Tape and Reel
NCP2892BFCT2G
MAZ
9−Pin Flip−Chip CSP
(Pb−Free)
3000/Tape and Reel
Device
†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.
NOTE: The NCP2892AFCT2G version requires a lead−free solder paste and should not be used with a SnPb solder paste.
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15
NCP2892 Series
PACKAGE DIMENSIONS
9 PIN FLIP−CHIP
CASE 499E−01
ISSUE A
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETERS.
3. COPLANARITY APPLIES TO SPHERICAL
CROWNS OF SOLDER BALLS.
−A−
4X
D
0.10 C
−B−
DIM
A
A1
A2
D
E
b
e
D1
E1
E
TOP VIEW
A
0.10 C
0.05 C
−C−
MILLIMETERS
MIN
MAX
0.540
0.660
0.210
0.270
0.330
0.390
1.450 BSC
1.450 BSC
0.290
0.340
0.500 BSC
1.000 BSC
1.000 BSC
A2
A1
SIDE VIEW
SEATING
PLANE
D1
e
C
B
e
E1
A
9X
b
1
2
3
0.05 C A B
0.03 C
BOTTOM VIEW
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
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Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada
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ON Semiconductor Website: www.onsemi.com
Order Literature: http://www.onsemi.com/orderlit
For additional information, please contact your local
Sales Representative
NCP2892/D