PAM8902HKER - Diodes Incorporated

A Product Line of
Diodes Incorporated
PAM8902H
30 VPP MONO CLASS-D AUDIO AMPLIFIER FOR PIEZO/CERAMIC SPEAKERS
Description
Pin Assignments
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
•
•
Supply Voltage Range From 2.5V to 5.5V
30 VPP Output Load Voltage From a 2.5V Supply
•
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:
ƒ
16-ball 1.95mmx1.95mm CSP Package
ƒ
16-pin QFN4x4 Package
Applications
ƒ
Wireless or Cellular Handsets
ƒ
Portable DVD Player
ƒ
Personal Digital Assistants (PDAs )
ƒ
Electronic Dictionaries
ƒ
Digital Still Cameras
PAM8902H
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PAM8902H
Typical Applications Circuit
Pin Descriptions
Pin Name
PVCC
VOUT
SW
PGND1
OUT+
VSET
COMP
AVDD
OUTGSET
VCM
AGND
PGND2
ENA
INN
INP
Bump (CSP)
A1
A2
A3
A4
B1
B2
B3
B4
C1
C2
C3
C4
D1
D2
D3
D4
PAM8902H
Document number: DSxxxxx Rev. 1 - 0
Pin Number (QFN)
16
1
2
4
15
3
5
6
14
11
7
8
13
12
10
9
Function
Audio Amplifier Power Supply
Boost Convertor Output
Boost Convertor Switching Node
Boost Convertor Power Ground
Positive Differential Audio Output
Boost Convertor Output Voltage Setting (8V,12V,17.5V)
Boost Convertor compensation
Power Supply
Negative Differential Audio Output
Amplifier Gain setting ( 21dB , 26dB , 32.5dB)
Common Mode bypass Cap
Analog Ground
Class D Power Ground
Whole chip Enable
Negative Differential Audio Input
Positive Differential Audio Input
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PAM8902H
Functional Block Diagram
Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.)
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
Supply Voltage
Input Voltage
Storage Temperature
Maximum Junction Temperature
Soldering Temperature
Rating
6.0
-0.3 to VDD +0.3
-65 to 150
150
250, 10sec
Unit
V
°C
Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.)
Parameter
Supply Voltage Range
Ambiient Temperature Range
Junction Temperature Range
PAM8902H
Document number: DSxxxxx Rev. 1 - 0
Rating
2.5 to 5.5
-40 to +85
-40 to +125
Unit
V
°C
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Thermal Information
Parameter
Symbol
Thermal Resistance
(Junction to Ambient)
θJA
Thermal Resistance
(Junction to Case)
θJC
Package
CSP
QFN4x4-16
CSP
QFN4x4-16
Maximum
90
52
72
30
Unit
°C/W
°C/W
Electrical Characteristics (@TA = +25°C, VDD = 3.6V, CL = 1µF, VSET Float, unless otherwise specified.)
Symbol
VDD
IQ
Parameter
Conditions
Input Voltage
Quiescent Current
Min
Typ
2.5
Max
Unit
5.5
V
mA
EN > 1.2V, VSET = High
EN > 1.2V, VSET = Floating
EN > 1.2V, VSET = GND
30
10
5
48
18
12
1.0
ISD
Shutdown Current
EN = 0V
0.1
TWU
Wake-Up Time
EN From Low to High
40
VEH
Chip Enable
VEL
Chip Disable
1.2
0.4
VH
GSET/VSET High
VDD -0.5
VDD
VF
GSET/VSET Floating
1
VDD -1
VL
GSET/VSET Low
0
0.5
UVLO
Under Voltage Lockout Threshold
VDD From High to Low
2.2
UVLOH
OTP
Under Voltage Lockout Hysteresis
VDD From Low to High
0.2
OTPH
µA
mS
V
V
V
Thermal Shutdown Threshold
150
°C
Thermal Shutdown Lockout Hysteresis
30
°C
Boost Converter
VSET = GND, No Load
7.2
8.0
8.8
V
Output Voltage
VSET = NC, No Load
10.8
12.0
13.2
V
16
17.5
19
CL
Current Limit
Average Input Current
RLS
Low Side MOSFET RDS(ON)
IO = 50mA
fOSCB
Boost Switching Frequency
V O1
V O2
VSET = AVDD, No Load
V O3
1.0
V
A
Ω
0.5
1.1
1.5
1.9
MHz
225
375
475
KHz
50
mV
Class-D
fOSCD
Class-D Amplifier Switching Frequency
Input AC-GND
CMRR
Common Mode Reject Ratio
VIN = ±100mV, VDD = 3.6V
60
VOS
Output Offset Voltage
Output Offset Voltage
5
RP
RDS(ON)
High Side
Low Side
1.5
0.6
GSET = AVDD, VO = 1VRMS
32.5
GSET = AVDD, VO = 1VRMS
26
GSET = AVDD, VO = 1VRMS
21
AV1
AV2
Closed-Loop Voltage Gain
AV3
dB
Ω
Ω
dB
PSRR
Power Supply Reject Ratio
200m VPP Supply Ripple @ 217Hz
70
THD+N
Total Harmonice Distortion Plus Noise
VO = 5VRMS
Input AC Ground, A-Weighting
0.3
%
90
dB
SNR
Signal to Noise Ratio
PAM8902H
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PAM8902H
Typical Operating Characteristics
(@TA = +25°C, VDD = 4.2V, Gain = 26dB, CIN = 1µF, CLOAD = 1µF, unless otherwise specified.)
PAM8902H
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PAM8902H
Typical Operating Characteristics (cont.) (@TA = +25°C, VDD = 5V, Gain = 18dB, unless otherwise specified.)
PAM8902H
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PAM8902H
Application Information
Select Boost Convertor Output Voltage
Customer can use VSET pin to set boost converor output voltage between 8V, 12V and 17.5V. VSET pin configuration table as below:
VSET Pin
Configuration
Min
Max
PVCC Voltage
Audio Amplifier Maximum
Output Voltage
Connect to AVDD
AVDD – 0.5V
AVDD
17.5V
11VRMS (VPP = 31.1V)
Floating
1V
AVDD – 1V
12V
5VRMS (VPP = 22.6V)
Connect to GND
GND
0.5V
8V
5VRMS (VPP = 14.1V)
Input Resistance (RI)
The input resistors (RI = RIN + REX) set the gain of the amplifier according to Equation 1 when anti-saturation is inactive.
G = 20 Log [12.8*RF/(RIN+REX)] (dB)
GSET = VDD
GSET
RIN
36.5kΩ
RF
122.6kΩ
GSET = Floating
59kΩ
100kΩ
GSET = GND
82kΩ
77.4kΩ
Where RIN 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 fully differential amplifiers. The balance of the output on the reference voltage depends on matched ratios of the resistors. CMRR, PSRR, and
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 RI minimizes pop noise.
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, CI and the minimum input impedance RI form is a high-pass filter with the corner frequency determined in the follow
equation:
fC =
1
2πR I CI
It is important to consider the value of CI as it directl y affects the low frequency performance of the circuit. For example, when RI is 150kΩ and
the specification calls for a flat bass response are down to 150Hz. Equation is reconfigured as followed:
CI =
1
2πR IFC
When input resistance variation is considered, the CI is 7nF, so one would likely choose a value of 10nF. A further consideration for this
capacitor is the leakage path from the input source through the input network (CI, RI + RF) to the load. This leakage current creates a DC offset
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 VDD/2, which is likely higher than the source DC level. Please note that it is important to confirm the
capacitor polarity in the application.
PAM8902H
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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.
1. VSET = GND or Floating and CL less than 1µF.
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 only 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 shorted 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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PAM8902H
Ordering Information
Part Number
PAM8902HZER
PAM8902HKER
Part Marking
BT
YW
P8902H
XXXYW
Package Type
Standard Package
CSP-16L
3000 Units/Tape&Reel
QFN4x4-16L
3000 Units/Tape&Reel
Marking Information
PAM8902H
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PAM8902H
Package Outline Dimensions (All dimensions in mm.)
CSP-16
PAM8902H
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Package Outline Dimensions (All dimensions in mm.)
QFN4x4-16
PAM8902H
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PAM8902H
IMPORTANT NOTICE
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).
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application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or
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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.
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PAM8902H
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