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30 VPP MONO CLASS-D AUDIO AMPLIFIER FOR PIEZO/CERAMIC SPEAKERS
Description
The PAM8902H is a mono, Class-D audio amplifier with integrated
boost convertor designed for piezo and ceramic speakers.The
PAM8902H is capable of driving a ceramic/ piezo speaker with
30Vpp(10.6Vrms) from a 3.6V power supply.The PAM8902H's Boost
converter operates at a fixed frequency of 1.5MHz , and provides a
17.5V supply with a minimum number of external components.
PAM8902H features an integrated audio low pass filter that rejects
high frequency noise thus improving audio fidelity. And three gain
modes of 21dB, 26dB and 32.5dB easy for using.PAM8902H also
provides thermal ,short, under and over voltage protection.
The PAM8902H is available in a 16-ball 1.95mm x 1.95mm CSP
package and 16-pin QFN4x4 package.
Features
Pin Assignments
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PAM8902H
• Supply Voltage Range From 2.5V to 5.5V
• 30 V
• Integrated Boost Converter Generates 17.5V Supply
• Programmable Soft-Start
• Small Boost Converter Inductor
• Selectable Gain of 21dB, 26dB, and 32.5dB
• Selectable Boost Output Voltage of 8V, 12V, and 17.5V
• Low Shutdown Current: <1µA
• Build in Thermal , OCP ,OVP,Short Protection
• Available in Space Saving Packages:
Output Load Voltage From a 2.5V Supply
PP
16-ball 1.95mmx1.95mm CSP Package
16-pin QFN4x4 Package
Applications
Wireless or Cellular Handsets
Portable DVD Player
Personal Digital Assistants (PDAs )
Electronic Dictionaries
Digital Still Cameras
PAM8902H
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Typical Applications Circuit
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PAM8902H
Pin Descriptions
Pin Name Bump (CSP) Pin Number (QFN) Function
PVCC A1 16 Audio Amplifier Power Supply
VOUT A2 1 Boost Convertor Output
SW A3 2 Boost Convertor Switching Node
PGND1 A4 4 Boost Convertor Power Ground
OUT+ B1 15 Positive Differential Audio Output
VSET B2 3 Boost Convertor Output Voltage Setting (8V,12V,17.5V)
COMP B3 5 Boost Convertor compensation
AVDD B4 6 Power Supply
OUT- C1 14 Negative Differential Audio Output
GSET C2 11 Amplifier Gain setting ( 21dB , 26dB , 32.5dB)
VCM C3 7 Common Mode bypass Cap
AGND C4 8 Analog Ground
PGND2 D1 13 Class D Power Ground
ENA D2 12 Whole chip Enable
INN D3 10 Negative Differential Audio Input
INP D4 9 Positive Differential Audio Input
PAM8902H
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Functional Block Diagram
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PAM8902H
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 6.0
Input Voltage
Storage Temperature -65 to 150
Maximum Junction Temperature 150
Soldering Temperature 250, 10sec
Recommended Operating Conditions (@T
Parameter Rating Unit
Supply Voltage Range 2.5 to 5.5 V
Ambiient Temperature Range -40 to +85
Junction Temperature Range -40 to +125
PAM8902H
Document number: DSxxxxx Rev. 1 - 0
= +25°C, unless otherwise specified.)
A
-0.3 to V
DD
+0.3
= +25°C, unless otherwise specified.)
A
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V
°C
°C
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PAM8902H
Thermal Information
Parameter Symbol Package Maximum Unit
Thermal Resistance
(Junction to Ambient)
Thermal Resistance
(Junction to Case)
θ
JA
θ
JC
Electrical Characteristics (@T
= +25°C, VDD = 3.6V, CL = 1µF, V
A
Symbol Parameter Conditions Min Typ Max Unit
VDD
IQ
ISD
TWU
VEH
VEL
VH
VF
VL
UVLO Under Voltage Lockout Threshold
UVLOH
OTP Thermal Shutdown Threshold 150 °C
OTPH
Boost Converter
VO1
VO2
VO3
CL
RLS Low Side MOSFET R
f
OSCB
Class-D
f
OSCD
CMRR Common Mode Reject Ratio
VOS
RP R
AV1
AV2 G
AV3 G
PSRR Power Supply Reject Ratio
THD+N Total Harmonice Distortion Plus Noise
SNR Signal to Noise Ratio Input AC Ground, A-Weighting 90 dB
Input Voltage 2.5 5.5 V
EN > 1.2V, VSET = High 30 48
Quiescent Current
EN > 1.2V, VSET = Floating 10 18
EN > 1.2V, VSET = GND 5 12
Shutdown Current EN = 0V 0.1 1.0 µA
Wake-Up Time EN From Low to High 40 mS
Chip Enable 1.2
Chip Disable 0.4
GSET/VSET High
GSET/VSET Floating 1
GSET/VSET Low 0 0.5
V
DD
Under Voltage Lockout Hysteresis
VDD From Low to High
Thermal Shutdown Lockout Hysteresis 30 °C
VSET = GND, No Load 7.2 8.0 8.8 V
Output Voltage
VSET = NC, No Load 10.8 12.0 13.2 V
VSET = AVDD, No Load 16 17.5 19 V
Current Limit Average Input Current 1.0 A
I
DS(ON)
Boost Switching Frequency 1.1 1.5 1.9 MHz
Class-D Amplifier Switching Frequency Input AC-GND 225 375 475 KHz
= 50mA
O
V
IN
Output Offset Voltage Output Offset Voltage 5 50 mV
DS(ON)
Closed-Loop Voltage Gain
High Side 1.5 Ω
Low Side 0.6 Ω
G
SET
SET
SET
200m V
V
O
CSP 90
QFN4x4-16 52
CSP 72
QFN4x4-16 30
Float, unless otherwise specified.)
SET
VDD -0.5
From High to Low
2.2
0.2
0.5 Ω
= ±100mV, VDD = 3.6V
= AVDD, VO = 1V
= AVDD, VO = 1V
= AVDD, VO = 1V
Supply Ripple @ 217Hz
PP
= 5V
RMS
RMS
RMS
RMS
60 dB
32.5
26
21
70 dB
0.3 %
°C/W
°C/W
mA
V
VDD
VDD -1
V
V
dB
PAM8902H
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Typical Operating Characteristics
(@TA = +25°C, VDD = 4.2V, Gain = 26dB, CIN = 1µF, C
= 1µF, unless otherwise specified.)
LOAD
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PAM8902H
PAM8902H
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Typical Operating Characteristics (cont.) (@T
= +25°C, V
A
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= 5V, Gain = 18dB, unless otherwise specified.)
DD
PAM8902H
PAM8902H
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PAM8902H
Application Information
Select Boost Convertor Output Voltage
Customer can use V
Pin
V
SET
Configuration
Connect to AVDD AVDD – 0.5V AVDD 17.5V
Floating 1V AVDD – 1V 12V
Connect to GND GND 0.5V 8V
Input Resistance (RI)
The input resistors (RI = R
Where R
is a 77.4KΩ internal resistor, REX is the external input resistor, RF is a 122.6KΩ internal resistor. Resistor matching is very important
IN
in fully differential amplifiers. The balance of the output on the reference voltage depends on matched ratios of the resistors . CMRR, PSRR, an d
cancellation of the second harmonic distortion diminish if resistor mismatch occurs. Therefore, it is recommended to use 1% tolerance resistors
or better to keep the performance optimized. Matching is more important than overall tolerance. Resistor arrays with 1% matching can be used
with a tolerance greater than 1%.
Place the input resistors very close to the PAM8902H to limit noise injection on the high-impedance nodes. For optimal performance the gain
should be set to lower. Lower gain allows the PAM8902H to operate at its best, and keeps a high voltage at the input making the inputs less
susceptible to noise. In addition to these features, higher value of R
Input Capacitors (CI)
In the typical application, an input capacitor, CI, is required to allow the amplifier to bias the input signal to the proper DC level for optimum
operation. In this case, C
equation:
It is important to consider the value of C
the specification calls for a flat bass response are down to 150Hz. Equation is reconfigured as followed:
When input resistance variation is considered, the C
capacitor is the leakage path from the input source through the input network (C
voltage at the input to the amplifier that reduces useful headroom, especially in high gain applications. For this reason, a low-leakage tantalum or
ceramic capacitor is the best choice. When polarized capacitors are used, the positive side of the capacitor should face the amplifier input in
most applications as the DC level is held at V
capacitor polarity in the application.
PAM8902H
Document number: DSxxxxx Rev. 1 - 0
pin to set boost converor output voltage between 8V, 12V and 17.5V. V
SET
Min Max PVCC Voltage
+ REX) set the gain of the amplifier according to Equation 1 when anti-saturation is inactive.
IN
G
SET
G
SET
G
SET
G = 20 Log [12.8*RF/(RIN+
G
R
SET
= VDD
= Floating
= GND
R
IN
36.5kΩ 122.6kΩ
59kΩ 100kΩ
82kΩ 77.4kΩ
REX
)] (dB)
pin configuration table as below:
SET
Audio Amplifier Maximum
11V
5V
5V
F
Output Voltage
RMS (VPP
RMS (VPP
RMS (VPP
= 31.1V)
= 22.6V)
= 14.1V)
minimizes pop noise.
I
and the minimum input impedance RI form is a high-pass filter with the corner frequency determined in the follow
I
C
I
=
π
=
π
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1
R2
C
I
I
1
R2
IFC
, RI + RF) to the load. This leakage current creates a DC offset
I
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as it directl y affects the low frequency performance of the circuit. For exampl e, when RI is 150kΩ and
I
C
is 7nF, so one would likely choose a value of 10nF. A further consideration for this
I
/2, which is likely higher than the source DC level. Please note that it is important to confirm the
DD
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PAM8902H
Application Information (cont.)
Decoupling Capacitor
The PAM8902H 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.
The optimum decoupling is achieved by using two different types of capacitors that target on 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
1µF, is placed as close as possible to the device AVDD pin for the best operation. For filtering lower frequency noise signals, a large ceramic
capacitor of 10µF or greater placed near the AVDD supply trace is recommended.
External Schottky Diode
Use external schottky diode can get the best driving capability and efficiency. Since internal power diode has limited driving capability, only in
following conditions customer can remove the external schottky diode to reduce the cost.
= GND or Floating and CL less than 1µF.
1. V
SET
2. The signal frequency less than 4KHz.
3. Haptic application (50-500Hz)
Shutdown Operation
In order to reduce power consumption while not in use, the PAM8902H contains shutdown circuitry amplifier off when a logic low is placed on the
ENA pin. By switching the ENA pin connected to GND, the PAM8902H supply current draw will be minimized in idle mode.
Under Voltage Lock-out (UVLO)
The PAM8902H incorporates circuitry designed to detect supply voltage. When the supply voltage drops to 2.2V or below, the PAM8902H goes
into a state of shutdown, and the device comes out of its shutdown state and restore to normal function onl y when reset the power supply or
ENA pin.
Short Circuit Protection (SCP)
The PAM8902H has short circuit protection circuitry on the outputs to prevent the device from damage when output-to-output shor ted or outputto-GND shorted occurs. When a short circuit occurs, the dev ice goes into a latch state and must be reset by cycling the voltage on the ENA pin
to a logic low and then 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.
Over Temperature Protection (OTP)
Thermal protection on the PAM8902H prevents the device from damage when the internal die temperature exceeds +150°C. There is a 15°C
tolerance on this trip point from device to device. Once the die temperature exceeds the set point, the device will enter the shutdown state and
the outputs are disabled, in this condition both OUT+ and OUT- will become high impedance. This is not a latched fault. The thermal fault is
cleared once the temperature of the die decreased by 30°C. This large hysteresis will prevent motor boating sound well and the device begins
normal operation at this point with no external system interaction.
PAM8902H
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Ordering Information
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PAM8902H
Part Number Part Marking Package Type Standard Package
PAM8902HZER
PAM8902HKER
Marking Information
BT
YW
P8902H
XXXYW
CSP-16L 3000 Units/Tape&Reel
QFN4x4-16L 3000 Units/Tape&Reel
PAM8902H
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Package Outline Dimensions (All dimensions in mm.)
CSP-16
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PAM8902H
PAM8902H
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Package Outline Dimensions (All dimensions in mm.)
QFN4x4-16
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PAM8902H
PAM8902H
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PAM8902H
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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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without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the
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indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.
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This document is written in English but may be translated into multiple languages for reference. Onl y 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:
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1. are intended to implant into the body, or
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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
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Copyright © 2012, Diodes Incorporated
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IMPORTANT NOTICE
LIFE SUPPORT
PAM8902H
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