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Description
The PAM8301 is a 1.5W Class-D mono audio amplifier. Its low
THD+N feature offers high quality sound reproduction. The new
filterless architecture allows the device to drive speaker 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
PAM8301 is much better than that of Class-AB cousins. It can
optimize battery life thus is ideal for portable applications.
The PAM8301 is available in TSOT26 package.
Features
1.5W Output at 10% THD with a 8Ω 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
Tiny TSOT26 Package
Pb-Free Package
Typical Applications Circuit
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FILTERLESS CLASS-D MONO AUDIO AMPLIFIER
Pin Assignments
Top View
TSOT26
Applications
PMP/MP4
GPS
Portable Speakers
Walkie Talkie
Handsfree Phones/Speaker Phones
Cellular Phones
PAM8301
PAM8301
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Pin Descriptions
Pin
Number
1 OUT2 GND
3 IN
4 SD
5 VDD
6 OUT+
Pin
Name
Negative Output
Ground
Input
Shutdown, Active Low
Power Supply
Positive Output
Functional Block Diagram
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PAM8301
Function
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 Range
Maximum Junction Temperature 150
Storage Temperature -65 to +150
Soldering Temperature 300, 5sec
Recommended Operating Conditions (@T
Parameter Rating Unit
Supply Voltage Range 2.5 to 5.5 V
Operation Temperature Range -40 to +85 °C
Junction Temperature Range -40 to +125 °C
PAM8301
Document number: DSxxxxx Rev. 1 - 3
= +25°C, unless otherwise specified.)
A
-0.3 to V
+0.3
DD
= +25°C, unless otherwise specified.)
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V
°C
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PAM8301
Thermal Information
Parameter Package Symbol Max Unit
Thermal Resistance (Junction to Ambient) TSOT26
Thermal Resistance (Junction to Case) TSOT26
Electrical Characteristics (@T
Symbol Parameter Test Conditions Min Typ Max Units
VDD
I
SHDN
VSH
VSL
R
DS(ON)
PO
THD+N Total Harmonic Distortion Plus Noise
PSRR AC Power Supply Ripple Rejection
GV
VN
f
OSC
SNR Signal to Noise Ratio f = 20 to 20kHz 78 dB
OTP Over Temperature Protection 135 °C
OTH Over Temperature Hysterisis 30 °C
Supply Voltage Range
Quiescent Current No Load 4 8 mA
IQ
Shutdown Current
SHDN Input High
SHDN Input Low
Drain-Source On-State Resistance
Output Power f = 1kHz
Gain
Output Noise
Oscillator Frequency
η Peak Efficiency f = 1kHz 85 88 %
= +25°C, VDD = 5V, Gain = 24dB, RL = 8Ω, unless otherwise specified.)
A
V
= 0V
SHDN
IDS = 100mA
= 8Ω, PO = 200mW
R
L
RL = 8Ω, PO = 0.5W
No Inputs, f = 1kHz, V
No A-Weighting 180
A-Weighting 120
θ
JA
θ
JC
= 200mV
PP
250
130
1 µA
P MOSFET 0.45
N MOSFET 0.20
THD+N = 1% 1.2
THD+N = 10% 1.5
°C/W
2.5 5.5 V
1.2
0.4
W
0.2
0.3
45 50 dB
24 dB
200 250 300 kHz
%
µV
V
Ω
PAM8301
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Typical Performance Characteristics (@T
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= +25°C, unless otherwise specified.)
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PAM8301
PAM8301
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Typical Performance Characteristics (cont.) (@T
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= +25°C, unless otherwise specified.)
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PAM8301
PAM8301
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Typical Performance Characteristics (cont.) (@T
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= +25°C, unless otherwise specified.)
A
PAM8301
Application Information
Test Setup for Performance Testing
Notes: 1. The AP AUX-0025 low pass filter is necessary for every 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.
PAM8301
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PAM8301
Application Information (cont.)
Maximum Gain
As shown in block diagram (Page 2), the PAM8301 has two internal amplifier stages. The first stage's gain is externally configurable, while the
second stage's is internally fixed. The closed-loop 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
The PAM8301 sets maximum R
Input Capacitors (CI)
In typical 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, CI and the minimum input impedance RI (10k internal) form a high pass filter with a corner frequency determined by the following
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 low as 100Hz. Equation is reconfigured as follows:
As the input resistance is variable, 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 capacitor 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.
Power Supply Decoupling (CS)
The PAM8301 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, typically 1.0μF is good, placing it as close as possible to the device V
terminal. For filtering lower-frequency noise signals, a 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 PAM8301 contains shutdown circuitry for turn off the amplifier. This shutdow n fe ature turns
the amplifier off when a logic low is applied on the SHDOWN pin. By switching the shutdown pin over to GND, the PAM8301 supply current draw
will be minimized in idle 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 PAM8301 incorporates circuitry to detect low on or off voltage. When the supply voltage drops to 2.1V or below, the PAM8301 goes into a
state of shutdown, and the device comes out of its shutdown state and starts to normal operation by reset the power supply or SD pin.
PAM8301
Document number: DSxxxxx Rev. 1 - 3
= 20*log [2*(RF/RI)]
VD
f
C
C
I
= 80kΩ, minimum RI = 10kΩ, so the maximum closed-gain is 24dB.
F
1
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
DD
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PAM8301
Application Information (cont.)
How to Reduce EMI (Electro Magnetic Interference)
A simple solution is to put an additional capacitor 1000µF 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.
Figure 1: Ferrite Bead Filter to Reduce EMI
Ordering Information
Part Number Part Marking Package Type Standard Package
PAM8301AAF FPXYW TSOT26 3000 Unit/Tape&Reel
PAM8301
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Marking Information
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PAM8301
Top View
TSOT26
Package Outline Dimensions (All dimensions in mm.)
TSOT26
PAM8301
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PAM8301
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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).
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Copyright © 2013, Diodes Incorporated
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IMPORTANT NOTICE
LIFE SUPPORT
PAM8301
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