A
f
Description
The PAM8302A is a 2.5W Class-D mono audio amplifier. Its low
THD+N feature offers high quality sound reproduction. The new
filterless architecture allows the device to drive speakers directly
instead of using low-pass output filters, therefore saving system cost
and PCB area.
With the same number of external components, the efficiency of the
PAM8302A is much better than that of Class-AB cousins. It can
optimize battery life thus is ideal for portable applications.
The PAM8302A is available in MSOP-8, SOP-8, DFN3x3-8 and
DFN2x2-8 packages.
Features
Product Line o
Diodes Incorporated
PAM8302A
2.5W FILTERLESS CLASS-D MONO AUDIO AMPLIFIER
Pin Assignments
2.5W Output at 10% THD with a 4 Load and 5V Power Supply
Filterless, Low Quiescent Current and Low EMI
High Efficiency up to 88%
Superior Low Noise
Short Circuit Protection
Thermal Shutdown,
Few External Components to Save Space and Cost
MSOP-8, SOP-8, DFN3x3-8 and DFN2x2-8 Packages Available
Pb-Free Packages
Applications
PMP/MP4
GPS
Portable Speakers
Walkie Talkie
Handsfree phones/Speaker Phones
Cellular Phones
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
1 of 14
www.diodes.com
April 2013
© Diodes Incorporated
A
f
Typical Applications Circuit
Product Line o
Diodes Incorporated
PAM8302A
Functional Block Diagram
Absolute Maximum Ratings (@T
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.
Parameter Rating Unit
Supply Voltage at No Input Signal 6.0
Input Voltage
Maximum Junction Temperature 150
Storage Temperature -65 to +150
Soldering Temperature 300, 5sec
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
= +25°C, unless otherwise specified.)
A
-0.3 to V
+0.3
DD
www.diodes.com
2 of 14
V
°C
April 2013
© Diodes Incorporated
A
f
Product Line o
Diodes Incorporated
PAM8302A
Recommended Operating Conditions (@T
= +25°C, unless otherwise specified.)
A
Parameter Rating Unit
Suppy Voltage Range 2.0 to 5.5 V
Operation Temperature Range -40 to +85 °C
Junction Temperature Range -40 to +125 °C
Thermal Information
Parameter Package Symbol Max Unit
SOP-8
Thermal Resistance (Junction to Ambient)
MSOP-8 180
DFN3x3-8 4739
JA
DFN2x2-8 80
Electrical Characteristics (@T
= +25°C, VIN = 3.6V, VO = 1.8V, CIN = 10µF, C
A
Parameter Symbol Test Conditions Min Typ Max Units
Supply Voltage Range
Quiescent Current
Shutdown Current
V
I
I
SHDN
DD
Q
2.0 5.5 V
No Load 4 8 mA
V
= 0V
SHDN
f = 1kHz, R
= 4,
L
THD+N = 10%
f = 1kHz, RL = 4,
Output Power
P
O
THD+N = 1%
f = 1kHz, RL = 8,
THD+N = 10%
f = 1kHz, RL = 8,
THD+N = 1%
Peak Efficiency f = 1kHz 85 88 %
= 8, PO = 0.1W, f = 1kHz
R
L
Total Harmonic Distortion Plus Noise THD+N
RL = 8, PO = 0.5W, f = 1kHz
RL = 4, PO = 0.1W, f = 1kHz
RL = 4, PO = 0.5W, f = 1kHz
Gain
G
V
Power Supply Ripple Rejection PSRR
No Inputs, f = 1kHz, V
Dynamic Range DYN f = 20 to 20kHz 85 90 dB
Signal to Noise Ratio SNR f = 20 to 20kHz 75 80 dB
Noise
Oscillator Frequency
Drain-Source On-State Resistance
SHDN Input High
SHDN Input Low
f
R
DS(ON)
V
V
V
OSC
SH
SL
N
No A-Weighting 180 300
A-Weighting 120 200
IDS = 100mA
Over Temperature Protection OTP Junction Temperautre 120 135 °C
Over Temperature Hysterisis OTH 30 °C
115
°C/W
= 10µF, L = 4.7µH, unless otherwise specified.)
OUT
1 µA
= 5V
V
DD
VDD = 3.6V
= 5V
V
DD
VDD = 3.6V
V
= 5V
DD
VDD = 3.6V
V
= 5V
DD
VDD = 3.6V
2.25 2.50
1.10 1.25
1.80 2.00
0.86 0.95
1.35 1.50
0.72 0.80
1.15 1.30
0.6 0.65
0.30 0.35
0.45 0.50
0.35 0.40
0.40 0.45
22.5 24.0 25.5 dB
= 200mV
PP
45 50 dB
200 250 300 kHz
P MOSFET 0.45 0.50
N MOSFET 0.20 0.25
1.2
0.4
W
%
µV
V
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
3 of 14
www.diodes.com
April 2013
© Diodes Incorporated
A
f
Typical Performance Characteristics (@T
Diodes Incorporated
= +25°C, unless otherwise specified.)
A
Product Line o
PAM8302A
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
4 of 14
www.diodes.com
© Diodes Incorporated
April 2013
A
f
Typical Performance Characteristics (cont.) (@T
Product Line o
Diodes Incorporated
= +25°C, unless otherwise specified.)
A
PAM8302A
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
www.diodes.com
5 of 14
© Diodes Incorporated
April 2013
A
f
Typical Performance Characteristics (cont.) (@T
Product Line o
Diodes Incorporated
= +25°C, unless otherwise specified.)
A
PAM8302A
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
6 of 14
www.diodes.com
© Diodes Incorporated
April 2013
A
f
Application Information
Test Setup for Performance Testing
Product Line o
Diodes Incorporated
PAM8302A
PAM8302A DUT
Notes: 1. The AP AUX-0025 low pass filter is necessary for every class-D amplifier measurement with AP analyzer.
2. Two 22H inductors are used in series with load resistor to emulate the small speaker for efficiency measurement.
Maximum Gain
As shown in block diagram (Page 2), the PAM8302A has two internal amplifier stages. The first stage's gain is externally con figurable, while the
second stage's is internally fixed. The closedloop gain of the first stage is set by selecting the ratio of RF to RI while the second stage's gain is
fixed at 2x.The output of amplifier one serves as the input to amplifier two, thus the two amplifiers produce signals identical in magnitude, but
different in phase by 180°. Consequently, the differential gain for the IC is
A =20*log [2*(R
The PAM8302A sets maximum R =80k, minimum R
F/RI
)]
=10k, so the maximum closed-gain is 24dB.
I
Input Capacitor (CI)
Intypical application, an input capacitor, CI is required to allow the amplifier to bias input signals to a proper DC level for optimum operation. In
this case, C
equation:
It is important to choose the value of CI as it directly affects low frequency performance of the circuit, for example, when an application requires a
flat bass response as loas as 100Hz,. Equation is reconfigured as follows:
As the input reisitance is varible, for the C
consideration for this capacitor is the leakage path from the input source through the input network (R
creates a DC offset voltage at the input to the amplifier that reduces useful headroom, especially in high gain application. For this reason, a low
leakage tantalum or ceramic capacitor is the best choice. When a polarized capacitior is used, the positive side of the capacitor should face the
amplifier input in most applications as the DC level is held at V
important to confirm the capacitor polarity in the application.
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
and the minimum input impedance RI (10k internal) form a high pass filter with a corner frequeny determind by the following
I
1
f
C
C
I
R2
C
I
I
1
R2
f
I
I
value of 0.16µF, one should actually choose the CI within the range of 0.1µF to 0.22µF. A further
I
, RF, CI) to the load. This leakage current
I
/2, which is likely higher than the source DC level. Please note that it is
DD
7 of 14
www.diodes.com
© Diodes Incorporated
April 2013
A
f
Product Line o
Diodes Incorporated
PAM8302A
Application Information (cont.)
Power Supply Decoupling (CS)
The PAM8302A is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output THD and
PSRR as low as possible. Power supply decoupling affects low frequency response. 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 hash on the line, a
good low equivalent-series-resistance (ESR) ceramic capacitor, typicall 1.0µF is good, placing it as close as possilbe to the device V
For filtering lower frequency noise signals, capacitor of 10µF or larger, closely located to near the audio power amplifier is recommended.
Shutdown Operation
In order to reduce shutdown power consumption, the PAM8032A contains shutdown circuitry for turn to turn off the amplifier. This shutdown
feature turns the amplifier off when a logic low is apllied on the SD pin. By switching the shutdown pin over to GND, the PAM8302A supply
current draw will be minimized inidle mode.
For the best power on/off pop performance, the amplifier should be set in the shutdown mode prior to power on/off operation.
Under Voltage Lock-Out (UVLO)
The PAM8302A incorporates circuitry to detect low on or off voltage. When the supply voltage drops to 2.1V or below, the PAM8302A goes into
a state of shutdown, and the device comes out of its shutdown state to normal operation by reset the power supply or SD pin.
How to Reduce EMI (Electro Magnetic Interference)
A simple solution is to put an additional capacitor 1000F at power supply terminal for power line coupling if the traces from amplifier to speakers
are short (< 20CM). Most applications require a ferrite bead filter as shown at Figure 1. The ferrite filter depresses EMI of around 1MHz and
higher. When selecting a ferrite bead, choose one with high impedance at high frequencies and low impedance at low frequencies.
terminal.
DD
Figure 1. Ferrite Bead Filter to Reduce EMI
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
8 of 14
www.diodes.com
April 2013
© Diodes Incorporated
A
f
Ordering Information
Product Line o
Diodes Incorporated
PAM8302A
Marking Information
Part Number Package Type Standard Package
PAM8302AASCR MSOP-8 2500 Units/Tape&Reel
PAM8302AADCR SOP-8 2500 Units/Tape&Reel
PAM8302AAYCR DFN3x3-8 3000 Units/Tape&Reel
PAM8302ABGCR DFN2x2-8 3000 Units/Tape&Reel
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
9 of 14
www.diodes.com
April 2013
© Diodes Incorporated
A
f
Package Outline Dimensions (All dimensions in mm.)
MSOP-8
Product Line o
Diodes Incorporated
PAM8302A
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
10 of 14
www.diodes.com
April 2013
© Diodes Incorporated
A
f
Package Outline Dimensions (cont.) (All dimensions in mm.)
DFN3x3-8
Product Line o
Diodes Incorporated
PAM8302A
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
11 of 14
www.diodes.com
© Diodes Incorporated
April 2013
A
f
Package Outline Dimensions (cont.) (All dimensions in mm.)
SOP-8
Product Line o
Diodes Incorporated
PAM8302A
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
12 of 14
www.diodes.com
April 2013
© Diodes Incorporated
A
f
Package Outline Dimensions (cont.) (All dimensions in mm.)
DFN2x2-8
Product Line o
Diodes Incorporated
PAM8302A
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
13 of 14
www.diodes.com
April 2013
© Diodes Incorporated
A
f
Product Line o
Diodes Incorporated
PAM8302A
DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
(AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes
without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the
application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or
trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume
all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated
website, harmless against all damages.
Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel.
Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and
hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or
indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.
Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings
noted herein may also be covered by one or more United States, international or foreign trademarks.
This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the
final and determinative format released by Diodes Incorporated.
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express
written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the
labeling can be reasonably expected to result in significant injury to the user.
B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the
failure of the life support device or to affect its safety or effectiveness.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and
acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any
use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related
information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its
representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems.
Copyright © 2012, Diodes Incorporated
www.diodes.com
IMPORTANT NOTICE
LIFE SUPPORT
PAM8302A
Document number: DSxxxxx Rev. 2 - 5
14 of 14
www.diodes.com
April 2013
© Diodes Incorporated
Loading...