IRAUDAMP9
1.7 kW / 2-Ω Single Channel
Class D Audio Power Amplifier
Using the IRS2092S and IRFB4227
By
Israel Serrano and Jun Honda
CAUTION:
International Rectifier recommends the following guidelines for safe operation and
handling of IRAUDAMP9 demo board:
•
Always wear safety glasses when operating demo board
•
Avoid physical contact with exposed metal surfaces when operating the demo board
•
Turn off demo board when placing or removing measurement probes
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IRAUDAMP9 REV 1.0
Page 1 of 39
TABLE OF CONTENTS
PAGE
INTRODUCTION............................................................................................................................................... 3
SPECIFICATIONS ............................................................................................................................................ 3
CONNECTION SETUP AND DESCRIPTION ............................................................................................... 5-6
TEST PROCEDURES ...................................................................................................................................... 6
PERFORMANCE AND TEST GRAPHS ....................................................................................................... 7-9
IRAUDAMP9 OVERVIEW .............................................................................................................................. 10
FUNCTIONAL DESCRIPTIONS................................................................................................................... 100
C
LASS
D O
PERATION
................................................................................................................................... 100
Gate Driver Buffer Stage………………………………………………………………………………………… 11
P
OWER
S
UPPLIES AND
PSRR........................................................................................................................ 12
B
US
P
UMPING
............................................................................................................................................... 12
H
OUSE
K
EEPING
P
OWER
S
UPPLY
................................................................................................................... 13
I
NPUT
............................................................................................................................................................ 13
O
UTPUT
........................................................................................................................................................ 13
H
IGH
O
UTPUT
P
EAK
S
HUTDOWN
(HOPS) C
IRCUIT
......................................................................................... 13
G
AIN
S
ETTING
/ V
OLUME
C
ONTROL
................................................................................................................ 14
E
FFICIENCY
................................................................................................................................................... 14
O
UTPUT
F
ILTER
D
ESIGN AND
P
REAMPLIFIER
................................................................................................... 15
S
ELF
-O
SCILLATING
PWM M
ODULATOR
.......................................................................................................... 16
A
DJUSTMENTS OF
S
ELF
-O
SCILLATING
F
REQUENCY
......................................................................................... 16
S
WITCHES AND
I
NDICATORS
........................................................................................................................... 16
S
TARTUP AND
S
HUTDOWN
............................................................................................................................. 17
S
TARTUP AND
S
HUTDOWN
S
EQUENCING
........................................................................................................ 17
P
ROTECTION
S
YSTEM
O
VERVIEW
................................................................................................................... 20
Ouput Over-Current Protection (OCP).................................................................................................... 20
Low-side Current Sensing ................................................................................................................. 20
High-side Current Sensing ................................................................................................................ 21
Input Bus Over-Voltage Protection (OVP) .............................................................................................. 21
Input Bus Under-Voltage Protection (UVP)............................................................................................. 22
Speaker DC-Offset- Protection (DCP) .................................................................................................... 21
Offset Null (DC Offset) Adjustment ......................................................................................................... 21
Over-Temperature Protection (OTP) ...................................................................................................... 22
Thermal Considerations .......................................................................................................................... 22
S
HORT
C
IRCUIT
P
ROTECTION
R
ESPONSE
....................................................................................................... 23
S
CHEMATIC
D
IAGRAMS
.................................................................................................................................. 25
IRAUDAMP9 FABRICATION BILL OF MATERIALS (BOM)....................................................................... 30
IRAUDAMP9 PCB SPECIFICATIONS........................................................................................................... 34
REVISION CHANGES DESCRIPTIONS........................................................................................................ 39
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IRAUDAMP9 REV 1.0
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Introduction
The IRAUDAMP9 reference design is a single-channel 1.7-kW ( @ 2Ω load) half-bridge Class D audio
power amplifier. This reference design demonstrates how to use the IRS2092S Class D audio controller and
external gate buffer
,
to implement protection circuits, and design an optimum PCB layout using the
IRFB4227 (x 2 Pairs) TO-220 MOSFETs. This reference design may require additional heatsink or fan for
normal operation (one-eighth of continuous rated power). The reference design provides all the required
housekeeping power supplies for ease of use. The 1-channel design is capable of delivering higher than its
rated power with provision of larger heat sink ( Rth <2° C / W).
Applications
•
•
•
Pro-Audio amplifiers
Powered speakers
Active Sub-woofers
•
•
P.A. Systems
Car audio amplifiers
Musical Instrument amplifier
Features
Output Power:
Residual Noise:
Distortion:
Efficiency:
Multiple Protection Features:
1.7 kW Single channel (2
Ω
load, 1kHz, THD+N=10%),
290μV, IHF-A weighted, AES-17 filter
0.07% THD+N @ 600W, 2Ω
97% @ 1.7 kW, 2Ω
Output Over-current protection (OCP), high side and low side
Input Over-voltage protection (OVP),
Input Under-voltage protection (UVP),
Output DC-offset protection (DCP),
Over-temperature protection (OTP)
Self-oscillating half-bridge topology with optional clock synchronization
PWM Modulator:
Specifications
General Test Conditions (unless otherwise noted)
Supply Voltages
±75V
Load Impedance
2Ω
Self-Oscillating Frequency
300kHz
Gain Setting
33dB
Electrical Data
IR Devices Used
Notes / Conditions
No input signal, Adjustable
1Vrms
input
yields
sinusoidal output power
1-kW
Typical
Notes / Conditions
IRS2092S Audio Controller and Gate-Driver,
IRFB4227 (x 2 Pairs) TO-220 MOSFETs
Modulator
Self-oscillating, second order sigma-delta modulation, analog input
Power Supply Range
± 48V to ±80V
Bipolar power supply
Output Power CH1: (1% THD+N)
1200W
1kHz Sinewave
Output Power CH1: (10% THD+N)
1700W
1kHz Sinewave
Rated Load Impedance
2
Ω
Non-inductive Resistive load
Idling Supply Current
+67mA , -105mA
No input signal
Total Idle Power Consumption
13.2 W
No input signal
System Efficiency
97%
@ +/- 75V 1.7 kW, 2Ω
94%
@ +/- 75V 1.2 kW, 2Ω
74 %
@ +/- 75V 125 W (1/8 Po-rated), 2Ω
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IRAUDAMP9 REV 1.0
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Audio Performance
THD+N, @ 1W
THD+N, @ 125W
THD+N, @ 250W
THD+N, @ 500W
THD+N, @ 1250W
THD+N, @ 1700W
Dynamic Range
Residual Noise, 22Hz - 20kHz AES17
Damping Factor
Frequency Response : 20Hz-20kHz
Class D
Output
0.024%
0.025%
0.025%
0.049%
1.0 %
10.0%
99.4 dB
290μV
81.9
±1dB
Notes / Conditions
1kHz, +/-75Vbus,
2-ohm load
A-weighted, AES-17 filter,
Single-channel operation
Self-oscillating – 300kHz
AP BW:<10Hz- 20kHz AES17
IHF-A weighted
1kHz, relative to 2Ω load
1W, 2Ω Load
Thermal Performance
Idling
125W (1/8 rated power)
1.2 kW
Physical Specifications
Dimensions
Weight
Typical
T
C
= 56°C
T
C
= 104°C
T
C
= 118°C
Notes / Conditions
No signal input, T
A
=25°C, after 5
min
Continuous @ T
A
=25°C
*requires larger heatsink design
for continuous operation
At OTP shutdown after 130 sec,
T
A
=25°C
7.76”(L) x 5.86”(W) x 2.2”(H)
192 mm (L) x 149mm (W) x 56mm(H)
0.54kgm
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IRAUDAMP9 REV 1.0
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Connection Setup
75V, 18ADC supply
75V,18A DC supply
3000W,Non-inductive Resistors
2-Ohm
J1
G
J3
S3
J8
CH1 Output
VS pins (CH1-O)
S2
Normal
Protection
J7
J6
CH1
Input
Volume
R130
R100
S1
Audio Signal Generator
Figure 1 Typical Test Setup
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IRAUDAMP9 REV 1.0
Page 5 of 39
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