PAM PAM8610

PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Key Features
General Description
n 10W@10%THD / Channel Output into a 8 Ω
Load at 13V
n Low Noise: -90dB
n Over 90% Efficiency
n 32Step DC Volume Control from -75dB to 32dB
n With Shutdown/Mute/Fade Function
n Over Current , Thermal and Short-Circuit
Protection
n Low THD+N
n Low Quiescent Current
n Pop noise suppression
n Small Package Outlines: Thin 40-pin QFN
6mm*6mm Package
n Pb-Free Package (RoHS Compliant)
The PAM8610 is a 10W (per channel) stereo
class-D audio amplifier with DC Volume Control
which offers low THD+N (0.1%), low EMI, and
good PSRR thus high-quality sound
reproduction. The 32 steps DC volume control
has a +32dB to -75dB range.
The PAM8610 runs off of a 7V to 15V supply at
much higher efficiency than competitors’ Ics.
The PAM8610 only requires very few external
components, significantly saving cost and board
space.
The PAM8610 is available in a 40pin QFN
6mm*6mm package.
Applications
n
n
n
n
n
Flat monitor /LCD TVS
Multi-media speaker System
DVD players, game machines
Boom Box
Music instruments
1μF
1μF
10 μ F
PGNDR
ROUTP
BSRP
ROUTP
BSRN
ROUTN
PVCCR
10 μ F
ROUTN
PGNDR
GND
PVCCR
1μF
1μF
PVCCR
GND
PVCCR
Typical Application
1μF
RINN
RINP
1μF
GND
1μF
1μF
VCLAMPR
RINN
RINP
GND
SHUTDOWN
SD
AVDD
AGND
VREF
V2P5
GND
1μF
VOLUME
PAM8610
VOLUME
AVCC
REFGND
MUTE
AGND1
AGND
FADE
ROSC
LINP
COSC
LINN
VCLAMPL
GND
VCC
100nF
10 μ F
MUTE
GND
GND
120K
220pF
PGNDL
PVCCL
GND
PVCCL
10 μ F
GND
1μF
1μF
PVCCL
GND
GND
1μF
1μF
10 μ F
LOUTP
LOUTP
BSLP
LOUTN
1μF
BSLN
1μF
PGNDL
LINN
1μF
PVCCL
LINP
LOUTN
FADE
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
1
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Block Diagram
BSRN
PVCCR
Driver
_
-
RINN
RINP
PGNDR
PAM
Modulation
+
_
+
+ -
BSRP
PVCCR
+
Driver
VOLUME
FADE
ROUTN
ROUTP
PGNDR
Gain
Adjust
Feedback
System
AVCC
AGND
ROSC
osc
COSC
on/off
Depop
AVDD
SD
Thermal
Short Circuit
Protection
Biases &
References
LDO
V2P5
BSLN
MUTE
PVCCL
Driver
LINN
LINP
-
+
+ -
_
PGNDL
BSLP
PVCCL
PAM
Modulation
+
_
LOUTN
+
Driver
LOUTP
PGNDL
Feedback
System
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
2
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Pin Configuration & Marking Information
PGNDR
PVCCR
ROUTN
ROUTN
BSRN
BSRP
ROUTP
ROUTP
PVCCR
PGNDR
Top View
6mm*6mm QFN
40
39
38
37
36
35
34
33
32
31
RINN
1
30
VCLAMPR
RINP
2
29
SD
AVDD
3
28
AGND
VREF
4
27
V2P5
26
AVCC
VOLUME
5
REFGND
6
PAM8610
XATYWWLL
25
MUTE
10
21
VCLAMPL
13
14
15
16
17
18
19
20
PGNDL
LINN
PVCCL
COSC
LOUTP
22
LOUTP
9
BSLP
LINP
BSLN
ROSC
LOUTN
23
LOUTN
8
12
FADE
PVCCL
24
11
7
PGNDL
AGND1
AGND
X: Internal Code
A: Assembly Code
T: Testing Code
Y: Year
WW: Week
LL: Internal Code
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
3
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Pin Descriptions
Pin Number
Name
Function
1
RINN
Negative differential audio input for right channel
2
RINP
Positive differential audio input for right channel
3
AVDD
5V Analog VDD
4
VREF
Analog reference for gain control section
5
VOLUME
6
REFGND
7
AGND1
DC voltage that sets the gain of the amplifier
Ground for gain control circuitry. Connect to AGND. If using a DAC to control the
volume, connect the DAC ground to this terminal.
Analog GND
Input for controlling volume ramp rate when cycling SD or during power-up. A
8
FADE
logic low on this pin places the amplifier in fade mode. A logic high on this pin
allows a quick transition to the desired volume setting.
9
LINP
Positive differential audio input for left channel
10
LINN
Negative differential audio input for left channel
11,20
PGNDL
Power ground for left channel H-bridge
12,19
PVCCL
Power supply for left channel H-bridge, not connected to PVCCR or AVCC.
13,14
LOUTN
Class-D 1/2-H-bridge negative output for left channel
15
BSLN
Bootstrap I/O for left channel, negative high-side FET
16
BSLP
Bootstrap I/O for left channel, positive high-side FET
17,18
LOUTP
Class-D 1/2-H-bridge positive output for left channel
21
VCLAMPL Internally generated voltage supply for left channel bootstrap capacitors.
I/O for charge/discharging currents onto capacitor for ramp generator triangle
22
COSC
23
ROSC
Current setting resistor for ramp generator. Nominally equal to 1/8*VCC
24,28
AGND
Analog GND
25
MUTE
A logic high on this pin disables the outputs and a logic low enables the outputs.
26
AVCC
High-voltage analog power supply (7V to 15V)
27
V2P5
29
SD
30
wave biased at V2P5
2.5V Reference for analog cells, as well as reference for unused audio input
when using single-ended inputs.
Shutdown signal for IC (low= shutdown, high =operational). TTL logic levels with
compliance to VCC.
VCLAMPR Internally generated voltage supply for right channel bootstrap capacitors.
31,40
PGNDR
Power ground for right channel H-bridge
32,39
PVCCR
Power supply for right channel H-bridge, not connected to PVCCL or AVCC.
33,34
ROUTP
Class-D 1/2-H-bridge positive output for right channel
35
BSRP
Bootstrap I/O for right channel, positive high-side FET
36
BSRN
Bootstrap I/O for right channel, negative high-side FET
37,38
ROUTN
Class-D 1/2-H-bridge negative output for right channel
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
4
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Absolute Maximum Ratings
These are stress ratings only and functional operation is not implied . Exposure to absolute
maximum ratings for prolonged time periods may affect device reliability . All voltages are with
respect to ground .
Supply Voltage V DD .........................-0.3V to16.5V
Input Voltage Range V I:
MUTE,VREF,VOLUME, FADE ................0V to 6.0V
SD ....................................................-0.3V to V DD
RINN,RINP,LINN,LINP......................-0.3V to 6.0V
Junction Temperature Range,T J......-40°C to 125 °C
Storage Temperature.....................-65 °C to150 °C
Lead Temperature1,6mm(1/16 inch) from case for
5 seconds.................................................260 °C
Recommended Operating Conditions
Supply Voltage (V DD)............................7V to 15V
Maximum Volume Control Pins, Input Pins
Voltage................................................0V to 5.0V
High Level Input Voltage: SD .................2.0V to V DD
MUTE , FADE ...2.0V to 5V
Low Level Input Voltage: SD ...................0 to 0.3V
MUTE , FADE .....0 to 0.3V
Ambient Operating Temperature......-20 °C to 85 °C
Thermal Information
Parameter
Thermal Resistance
(Junction to Case)
Thermal Resistance
(Junction to Ambient)
Package
Symbol
Maximum
QFN 6mm*6mm
θJC
7.6
Unit
°C/W
QFN 6mm*6mm
θJA
18.1
The Exposed PAD must be soldered to a thermal land on the PCB.
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
5
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Electrical Characteristic
T A=25 °C , V DD=12V,R L=8 Ω (unless otherwise noted)
Parameter
Supply Voltage
Continuous Output Power
Symbol
condition
V DD
Po
Quiescent Current
Supply Quiescent Current in
shutdown mode
Drain-source on-state
resistance
Power Supply Ripple Rejection
Ratio
MAX
Units
7.0
12
15
V
5
THD+N=1.0%,f=1kHz,RL=8Ω
8
THD+N=10%,f=1kHz,RL=8Ω,
THD+N=10%,f=1kHz,R L=4Ω( N ot e )
Noise
TYP
THD+N=0.1%,f=1kHz,RL=8Ω
V DD= 13 V
Total Harmonic Distortion plus
MIN
W
10
15
P O=5W, f=1kHz, RL =8Ω
0.1
IDD
(no load)
20
30
mA
ISD
SHUTDOWN=0V
4
10
μA
THD+N
rds(on)
PSRR
V CC=12V
High side
200
IO=1A
Low side
200
TJ=25℃
Total
400
1VPP ripple, f=1kHz, Inputs
ac-coupled to ground
%
mΩ
-60
dB
Oscillator Frequency
fOSC
ROSC=120kΩ, C O S C = 22 0 pF
250
kHz
Output Integrated Noise Floor
Vn
20Hz to 22 kHz, A-weighting
-90
dB
Crosstalk
CS
P O=3W, R L=8Ω, f=1kHz
-80
dB
80
dB
Signal to Noise Ratio
Output offset voltage
SNR
Maximum output at THD+N< 0.5%,
f=1kHz
|V OS|
INN and INP connected together
30
mV
2.5V Bias voltage
V2P5
No Load
2.5
V
Internal Analog supply Voltage
AV DD
V DD=7V to 15V
Over Temperature Shutdown
OTS
150
°C
Thermal Hysteresis
OTH
40
°C
(measured differentially)
5
5.5
V
Note: Heat sink is required for high power output.
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
6
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Table 1. DC Volume Control
Step
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Volume
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
Gain (dB)
-75
-40
-30
-20
-10
-5
0
5
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Rf (kΩ)
0.40
1.26
3.92
11.90
20.22
33.33
52.47
77.49
83.02
88.65
94.37
100.12
105.87
111.58
117.21
122.74
128.12
133.33
138.35
143.15
147.71
152.04
156.11
159.92
163.49
166.80
169.86
172.69
175.30
177.68
179.87
200.00
Ri (kΩ)
200.00
199.60
198.74
196.08
188.10
179.78
166.67
147.53
122.51
116.98
111.35
105.63
99.88
94.13
88.42
82.79
77.26
71.88
66.67
61.65
56.85
52.29
47.96
43.89
40.08
36.51
33.20
30.14
27.31
24.70
22.32
20.13
Note:
Volume: DC voltage on Volume pin
Rf: Internal pre-amplifier feedback resistance
Ri: Internal pre-amplifier input resistance
Calculation Gain=20log (5XRf/Ri), there is one dB tolerance from device to device.
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
7
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Typical Performance Characteristics
V DD=12V,R L=8 Ω, Gv=24dB, Τ Α=25 °C, unless otherwise noted.
1. THD +N vs. Power
4. THD+N vs Frequency
100
10
50
5
V DD=15V
20
10
2
V DD=12V
5
1
2
%
V DD=7V
1
%
0.5
0.2
Po=3W
Po=1W
0.5
0.2
0.1
0.05
0.1
Po=5W
0.02
0.01
10m
20m
50m
100m
200m
500m
1
2
5
0.04
20
10
50
100
200
W
500
1k
2k
5k
10k 20k
5k
10k
20k
5k
10k
20k
Hz
5. THD+N vs Frequency (Po=1W)
2. THD +N vs. Power
100
10
50
5
20
10
5
f=10kHz
2
%
2
1
f=500Hz
1
%
0.5
V DD=12V
V DD=7V
0.5
0.2
0.1
f=100Hz
0.2
0.05
0.1
0.02
0.01
10m
20m
50m
100m
200m
500m
1
2
5
V DD=15V
0.06
20
10
50
100
200
W
500
1k
2k
Hz
3. THD +N vs. Power
6. THD+N vs Frequency (Po=3W)
100
10
50
5
20
10
2
5
1
2
%
Gv=32dB
1
%
0.5
Gv=18dB
Gv=32dB
0.5
0.2
0.2
0.1
0.1
Gv=12dB
0.05
Gv=18dB
0.02
0.01
10m
20m
50m
100m 200m
500m
1
2
5
0.05
0.03
20
10
W
Gv=12dB
50
100
200
500
Hz
1k
2k
Power Analog Microelectronics , Inc
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08/2008 Rev 1.2
8
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Typical Performance Characteristics
V DD=12V,R L=4 Ω, Gv=24dB, Τ Α=25 °C, unless otherwise noted.
7. THD +N vs. Power
10. THD+N vs Frequency
10
100
50
5
V DD=15V
20
10
5
2
V DD=12V
Po=1W
2
%
1
V DD=7V
1
%
Po=3W
0.5
0.5
0.2
0.2
0.1
0.05
0.1
Po=5W
0.02
0.01
10m
20m
50m
100m
200m
500m
1
2
5
10
0.05
20
20 30
50
100
200
500
1k
2k
5k
10k
20k
10k
20k
10k
20k
Hz
W
11. THD+N vs Frequency (Po=1W)
8. THD +N vs. Power
10
100
50
5
20
10
f=10kHz
5
2
f=500Hz
2
%
V DD=7V
1
1
%
V DD=15V
0.5
0.5
0.2
0.2
0.1
f=100Hz
0.05
0.1
V DD=12V
0.02
0.01
10m
20m
50m
100m
200m
500m
1
2
5
10
0.05
20
20
50
100
200
500
1k
2k
5k
Hz
W
9. THD +N vs. Power
12. THD+N vs Frequency (Po=3W)
10
100
50
5
20
10
2
5
1
2
%
Gv=32dB
1
%
0.5
Gv=18dB
Gv=32dB
0. 5
0.2
0. 2
0.1
0. 1
Gv=12dB
0.05
Gv=18dB
Gv=12dB
0.05
0.02
0.01
10m
20m
50m
100m
200m
500m
1
2
5
10
0.02
20
20
50
100
200
500
1k
2k
5k
Hz
W
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
9
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Typical Performance Characteristics
V DD=12V,R L=8 Ω, Gv=24dB, Τ Α=25 °C, unless otherwise noted.
13. Power Supply Ripple Rejection
16. Noise Floor
+0
+0
-10
-10
-20
-20
-30
-40
-30
-50
-40
d
B
-60
d
B
V
-50
-70
-80
-60
-90
-70
-100
-110
-80
-120
-130
-90
-140
-100
10
20
50
100
200
500
1k
2k
5k
10k
20k
-150
20
50k 100k
50
100
200
500
1k
2k
5k
10k
20k
1k
2k
5k
10k
20k
8
9
Hz
Hz
14. Crosstalk
17. CMRR
+0
-50 T
-55
-10
-60
-20
-65
-30
-70
d
B
-75
d
B
r
-80
A
L to R
-40
-50
-85
-60
-90
-70
R to L
-95
-100
20
50
100
200
500
1k
2k
5k
10k
-80
20
20k
50
100
200
500
Hz
Hz
18. Efficiency vs Power
15. Frequency Response (Vo=1.0Vrms)
A
100
+4
90
+3
80
+2
70
+1
60
Efficiency(%)
d
B
r
+5
+0
-1
50
40
-2
30
-3
20
-4
10
-5
20
0
50
100
200
500
1k
2k
5k
10k
20k 30k
0
Hz
1
2
3
4
5
6
7
10
Output Power(W)
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
10
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Typical Performance Characteristics
V DD=12V,R L=8 Ω, Gv=24dB, Τ Α=25 °C, unless otherwise noted.
19. Output Power vs Supply Voltage
21.Gain vs DC voltage
18
16
THD+N=10%
12
Gain (dB)
Output Power (W)
14
10
8
6
THD+N=1%
4
2
0
7
8
9
10
11
12
13
14
0
15
0.4
0.8
1.2
1.6
2
2.4
2.8
Volume Voltage (V)
Supply Voltage (V)
22.Power Dissipation vs. Output Power
20. Quesicent Current vs Supply Voltage
4
25
Power Dissipation(W)
Quiescent Current (mA)
3.5
20
15
10
5
3
2.5
2
1.5
1
0.5
0
0
7
8
9
10
11
12
Supply Voltage (V)
13
14
15
0
3
6
Output Power (W)
Two channels driven
9
12
Note:
PCB information for power dissipation measurement.
1. The PCB size is 74mm * 68mm with 1.2mm thickness,
two layers and Fr4.
2. 16 vias at the thermal land on the PCB with 0.5mm
diameter.
3. The size of exposed copper is 10mm*10mm with
3oz thickness.
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
11
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Test Setup for Performance Testing
PAM8610 Demo Board
Load
AP
+OUT
AP System One
Generator
Input
Low Pass
Filter
GND
-OUT
AP System One
Analyzer
AUX-0025
VDD
Power Supply
Notes
1. The AP AUX-0025 low pass filter is necessary for class-D amplifier measurement with AP analyzer.
2. Two 22μH inductors are used in series with load resistor to emulate the small speaker for efficiency
measurement.
Application Information
Power and Heat Dissipation
If the rated workable junction temperature is
150°C, the relationship between ambient
temperature and permitted P loss is shown in below
diagram.
Choose speakers that are able to stand large
output power from the PAM8610. Otherwise,
speaker may suffer damage.
10
Heat dissipation is very important when the
device works in full power operation. Two factors
affect the heat dissipation, the efficiency of the
device that determines the dissipation power, and
the thermal resistance of the package that
determines the heat dissipation capability.
9
8
Ploss(W)
7
In operation, some of power is dissipated to the
resistors.
6
5
4
3
2
Power Dissipation: P loss=(Po*(1- η)/η)* 2
1
0
The PAM8610’s efficiency is 90% with 10W ouput
and 8 Ω load. The dissipation power is 2.22W.
0
20
40
60
80
100
Ta
Thermal resistance of junction to ambient of the
QFN package is 18.1°C/W and the junction
temperature Tj=P loss* θ jA+Ta, where Ta is ambient
temperature. If the ambient temperature is 85°C,
the QFN’s junction temperature
From the diagram, it can be found that when the
device works at 10W/8 Ω load the dissipation
power is 1.1W per channel, 2.2W total, the
permitted ambient temperature is over 100°C.
This is proven by actual test. The PAM8610 can
work in full output power under 85°C ambient
temperature.
Tj=2.22*18.1+85=125°C
w h i c h i s l o w e r t h a n 1 5 0 ° C ra t e d j u n c t i o n
temperature.
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
12
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Heat Dissipation in PCB design
Consideration for EMI
Generally, class-D amplifiers are high efficiency
and need no heat sink. For high power ones that
has high dissipation power, the heat sink may also
not necessary if the PCB is carefully designed to
achieve good heat dissipation by the PCB itself.
Filters are not required if the traces from the
amplifier to the speakers are short (<20cm). But
most applications require a ferrite bead filter as
shown in below figure. The ferrite bead filter
reduces EMI of around 1MHz and higher to meet
the FCC and CE's requirements. It is
recommended to use a ferrite bead with very low
impedances at low frequencies and high
impedance at high frequencies (above 1MHz).
Dual-Side PCB
To achieve good heat dissipation , the PCB’s
copper plate should be thicker than 0.035mm and
the copper plate on both sides of the PCB should
be utilized for heat sink.
Ferrite Bead
OUTP
OUT+
The thermal pad on the bottom of the device
should be soldered to the plate of the PCB, and
via holes, usually 9 to 16, should be drilled in the
PCB area under the device and deposited copper
on the vias should be thick enough so that the
heat can be dissipated to the other side of the
plate. There should be no insulation mask on the
other side of the copper plate. It is better to drill
more vias on the PCB around the device if
possible.
200pF
Ferrite Bead
OUTN
OUT200pF
The EMI characteristics are as follows after
employing the ferrite bead.
Vertical Polarization
4-layer PCB
If it is 4-layer PCB, the two middle layers of
grounding and power can be employed for heat
dissipation, isolating them into serval islands to
avoid short between ground and power.
Horizontal Polarization
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
13
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Volume Control
Shutdown Operation
A DC volume control section is integrated in
PAM8610, controlling via VREF, VOLUME and
VREFGND terminals. The voltage on VOLUME
pin, without exceeding VREF, determines internal
amplifier gain as listed in Table 1.
The PAM8610 employs a shutdown operation
mode to reduce supply current to the absolute
minimum level during periods of non-use to save
power. The SD input terminal should be held high
during normal operation when the amplifier is in
use. Pulling SD low causes the outputs to mute
and the amplifier to enter a low-current state. SD
should never be left unconnected to prevent the
amplifier from unpredictable operation.
If a resistor divider is used to fix gain of the
amplifier, the VREF terminal can be directly
connected to AVDD and the resistor divider
connected across VREF and REFGND. For fixed
gain, the resistor divider values are calculated to
center the voltage given in the Table 1.
For the best power-off pop performance, the
amplifier should be set in shutdown mode prior to
removing the power supply voltage.
FADE Operation
Internal 2.5V Bias Generator Capacitor
Selection
The FADE terminal is a logic input that controls
the operation of the volume control circuitry
during transitions to and from the shutdown state
and during power-up.
The internal 2.5V bias generator (V2P5) provides
the internal bias for the preamplifier stage. The
external input capacitors and this internal
reference allow the inputs to be biased within the
optimal common-mode range of the input
preamplifiers.
A logic low on this terminal will set the amplifier in
fade mode. During power-up or recovery from the
shutdown state (a logic high is applied to the SD
terminal), the volume is smoothly ramped up from
the mute state, -75dB, to the desired volume set
by the voltage on the volume control terminal.
Conversely, the volume is smoothly ramped down
from the current state to the mute state when a
logic low is applied to the SD terminal. A logic high
on this pin disables the volume fade effect during
transitions to and from the shutdown state and
during power-up. During power-up or recovery
from the shutdown state (a logic high is applied to
the SD terminal), the transition from the mute
state, -75dB, to the desired volume setting is less
than 1ms. Conversely, the volume ramps down
from current state to the mute state within 1ms
when a logic low is applied to the SD terminal.
The selection of the capacitor value on the V2P5
terminal is critical for achieving the best device
performance. During startup or recovery from
shutdown state, the V2P5 capacitor determines
the rate at which the amplifier starts up. When the
voltage on the V2P5 capacitor equals 0.75 x
V2P5, or 75% of its final value, the device turns
on and the class-D outputs start switching. The
startup time is not critical for the best de-pop
performance since any heard pop sound is the
result of the class-D output switching-on other
than that of the startup time. However, at least a
0.47µF capacitor is recommended for the V2P5
capacitor.
MUTE Operation
Another function of the V2P5 capacitor is to filter
high frequency noise on the internal 2.5V bias
generator.
The MUTE pin is an input for controlling the output
state of the PAM8610. A logic high on this pin
disables the outputs and low enables the outputs.
This pin may be used as a quick disable or enable
of the outputs without a volume fade.
Power Supply Decoupling, C S
The PAM8610 is a high-performance CMOS audio
amplifier that requires adequate power supply
decoupling to ensure the output total harmonic
distortion (THD) as low as possible. Power supply
decoupling also prevents oscillations caused by
long lead between the amplifier and the speaker.
The optimum decoupling is achieved by using two
capacitors of different types that target different
types of noise on the power supply leads. For
higher frequency transients, spikes, or digital
For power saving, the SD pin should be used to
reduce the quiescent current to the absolute
minimum level. The volume will fade, increasing
or decreasing slowly, when leaving or entering the
shutdown state if the FADE terminal is held low. If
the FADE terminal is held high, the outputs will
transit very quickly. Refer to the FADE operation
section.
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
14
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Differential Input
hash on the line, a good low equivalent-seriesresistance (ESR) ceramic capacitor, typically 1μF,
is recommended, placing as close as possible to
the device’s VCC lead. To filter lower-frequency
noises, a large aluminum electrolytic capacitor of
10μF or greater is recommended, placing near the
audio power amplifier. The 10μF capacitor also
serves as a local storage capacitor for supplying
current during large signal transients on the
amplifier outputs.
The differential input stage of the amplifier
eliminates noises that appear on the two input
lines of the channel. To use the PAM8610 with a
differential source, connect the positive lead of
the audio source to the INP input and the negative
lead from the audio source to the INN input. To
use the PAM8610 with a single-ended source, acground the INP input through a capacitor equal in
value to the input capacitor on INN and apply the
audio source to the INN input. In a single-ended
input application, the INP input should be acgrounded at the audio source other than at the
device input for best noise performance.
Selection of C OSC and R OSC
The switching frequency is determined by the
values of components connected to ROSC (pin
23) and COSC (pin 22) and calculated as follows:
Using low-ESR Capacitors
f OSC = 2 π / (R OSC * C OSC)
The frequency may varies from 225kHz to 275kHz
by adjusting the values of R OSC and C OSC. The
r e c o m m e n d e d v a l u e s a r e C O S C = 2 2 0 p F,
R OSC=120k Ω for a switching frequency of 250kHz.
Low-ESR capacitors are recommended
throughout this application section. A real (with
respect to ideal) capacitor can be modeled simply
as a resistor in series with an ideal capacitor. The
voltage drop across this resistor minimizes the
beneficial effects of the capacitor in the circuit.
The lower the equivalent value of this resistance
the more the real capacitor behaves as an ideal
capacitor.
BSN and BSP Capacitors
The full H-bridge output stages use NMOS
transistors only. They therefore require bootstrap
capacitors for the high side of each output to turn
on correctly. A at least 220nF ceramic capacitor,
rated for at least 25V, must be connected from
each output to its corresponding bootstrap input.
Specifically, one 220nF capacitor must be
connected from xOUTP to xBSP, and another
220nF capacitor from xOUTN to xBSN. It is
r ecommended to use 1 μ F BST capacitor to
replace 220nF (pin15, pin16, pin35 and pin36)
for lower than 100Hz applications.
Short-circuit Protection
The PAM8610 has short circuit protection circuitry
on the outputs to prevent damage to the device
when output-to-output shorts, output-to-GND
shorts, or output-to-VCCshorts occur. Once a
short-circuit is detected on the outputs, the output
drive is immediately disabled. This is a latched
fault and must be reset by cycling the voltage on
the SD pin to a logic low and back to the logic high
state for normal operation. This will clear the
short-circuit flag and allow for normal operation if
the short was removed. If the short was not
removed, the protection circuitry will again
activate.
VCLAMP Capacitors
To ensure that the maximum gate-to-source
voltage for the NMOS output transistors not
exceeded, two internal regulators are used to
clamp the gate voltage. Two 1μF capacitors must
be connected from VCLAMPL and VCLAMPR to
ground and must be rated for at least 25V. The
voltages at the VCLAMP terminals vary with V CC
and may not be used to power any other circuitry.
Thermal Protection
Thermal protection on the PAM8610 prevents
damage to the device when the internal die
temperature exceeds 150°C. There is a ±15
degree tolerance on this trip point from device to
device. Once the die temperature exceeds the set
thermal point, the device enters into the shutdown
state and the outputs are disabled. This is not a
latched fault. The thermal fault is cleared once the
temperature of the die is reduced by 40°C. The
device begins normal operation at this point
without external system intervention.
Internal Regulated 5-V Supply (AVDD)
The AVDD terminal is the output of an internallygenerated 5V supply, used for the oscillator,
preamplifier, and volume control circuitry. It
requires a 0.1μF to 1μF capacitor, placed very
close to the pin to Ground to keep the regulator
stable. The regulator may not be used to power
any external circuitry.
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
15
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Ordering Information
PAM8610 X X
Shipping
Package Type
Part Number
PAM8610TR
Marking
PAM8610
XATYWWLL
Package Type
Standard Package
QFN 6mm*6mm
3,000 units/Tape & Reel
Please consult PAM sales office or authorized distributors for more details.
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
16
PAM8610
10W Stereo Class-D Audio Power Amplifier with DC Volume Control
Outline Dimension
40pin QFN
QFN
Unit: Millimeter
Power Analog Microelectronics , Inc
www.poweranalog.com
08/2008 Rev 1.2
17