100 V CoolGaN™ power transistor IGB110S10S1 in combination with MERUS™ IRS20957S audio controller IC. CoolGaN™ Infineon’s CoolGaN™ solution offers unmatched quality that operate at higher switching speeds resulting in lower power losses, higher efficiency paving the way for smaller and lighter power supplies with the same power supplies with the same size but increased power capability.
Infineon Technologies. The design of the Evaluation Boards and Reference Boards has been tested by Infineon Technologies only as described in this document. The design is not qualified in terms of safety requirements, manufacturing and operation over the entire operating temperature range or lifetime.
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Safety precautions Safety precautions Note: Please note the following warnings regarding the hazards associated with development systems. Table 1 Safety precautions Warning: The DC link potential of this board is up to 1000 VDC. When measuring voltage waveforms by oscilloscope, high voltage differential probes must be used.
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Table of contents Table of contents About this document ........................1 Important notice ..........................2 Safety precautions .......................... 3 Table of contents ..........................4 REF_Audio_GaNb_750W overview .................... 6 Features ..............................
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Table of contents Bill of Materials ........................45 Summary ..........................51 References ............................ 52 Revision history..........................53 Disclaimer............................. 54 User guide V 1.0 2025-04-11...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC REF_Audio_GaNb_750W overview REF_Audio_GaNb_750W overview The REF_Audio_GaNb_750W features the 100 V CoolGaN™ transistors combined with the MERUS™ IRS20957S class D audio driver ICs. This two-channel design is scalable up to 375 W x 2 channel at 2 Ω without heatsink. The design includes all the required power supplies and connectors for ease of use and lab bench evaluation.
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC REF_Audio_GaNb_750W overview Figure 2 Simplified block diagram of REF_Audio_GaNb_750W reference board Features Overcurrent protection (OCP) • Overvoltage protection (OVP) • Undervoltage protection (UVP) • Overtemperature protection (OTP) •...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC REF_Audio_GaNb_750W overview Table 2 Electrical specifications Condition Min. Typ. Max. Note Supply voltage ± 27 V ± 36 V ± 40 V – Power supply current at ±...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC REF_Audio_GaNb_750W overview Following are the main board connections: Although the board includes all the house-keeping power supplies, use the connectors (X1, X2, X3) if • separate low-voltage (LV) supply is of interest The external clock input at X7 is optional and it’s recommended to use the self-oscillating clock by setting •...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC REF_Audio_GaNb_750W overview Table 2 Function description of the main REF_Audio_GaNb_750W board connections Designator Function Note X1, X2, X3 External LV supply Optional LV supply, not required for operation Bipolar DC power supply >12-16 AWG preferred X5, X6...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC REF_Audio_GaNb_750W overview 1.4.1 Features Floating PWM input enables easy half bridge implementation • Programmable bidirectional overcurrent protection with self-reset function • Programmable preset dead-time for improved THD performance •...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Board setup Board setup The board can be set up for two main load configurations: Two-channel single-ended (SE) configuration • Single-channel bridge tied load (BTL) configuration •...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Board setup One-channel BTL configuration wiring setup Perform the following steps to set up the board for the one-channel BTL configuration wiring setup: 1. Connect 4 Ω > 800 W capable load to output connectors (P1 and P2) 2.
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio analyzer setup Audio analyzer setup 3.1.1 Two-channel single-ended configuration Perform the following steps to set up the Audio Precision for two-channel single-ended operation as shown in Figure Output Configuration settings: Connection: Analog Unbalanced...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio analyzer setup Figure 7 Typical analyzer setup for SE operation of REF_Audio_GaNb_750W 3.1.2 One-channel BTL configuration Perform the following steps to set up the Audio Precision for one-channel single-ended operation as shown in Figure Output Configuration settings: Connection: Analog Unbalanced...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio analyzer setup Verify Connections settings: Waveform: Sine • Check the Levels Track Ch1 box and set the Ch as 1 V • Frequency: 1 kHz •...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Reference board operations Reference board operations Test setup 1. For SE, connect 2 > 400 W capable dummy loads according to Figure 5 2. For BTL, connect 4 > 800 W capable dummy load according to Figure 6 3.
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Reference board operations External sync clock function 1. Monitor VS1 and VS2 switching frequency 2. Adjust R44A and R44B on the board to change the self-oscillating frequency to 20-30% higher than the desired external clock 3.
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio performance Audio performance This section shows the results of the audio performance of REF_Audio_GaNb_750W that can be achieved using the 100 V CoolGaN™ transistors in combination with the MERUS™ IRS20957S class D audio driver ICs. Total harmonic distortion - THD+N Test conditions: ±40 V...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio performance Test conditions: ±36 V • Input signal = 1 kHz • Load impedance = 2 Ω • = 1 MHz • Figure 11 Power vs.
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio performance Test conditions: ±36 V • Input signal = 1 kHz • Load impedance = 4 Ω • = 1 MHz • Figure 12 Power vs.
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio performance Test conditions: ±36 V • Output power = 1 W • Load impedance = 4 Ω • = 1 MHz • Figure 13 THD+N at 4 Ω...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio performance Test conditions: ±36 V • Output power = 1 W • Load impedance = 2 Ω • = 1 MHz • Figure 14 THD+N at 2 Ω...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio performance Frequency response Test conditions: ±36 V • Output power = 1 W • Load impedance = 4 Ω • = 1 MHz • Figure 15 Frequency response 4 Ω...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio performance Test conditions: ±36 V • Output power = 1 W • Load impedance = 2 Ω • = 1 MHz • Figure 16 Frequency response 2 Ω...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio performance Noise floor Test conditions: ±36 V • No input signal • Load impedance = 2 Ω • = 1 MHz • Figure 17 Noise floor idle User guide V 1.0...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Audio performance Test conditions: ±36 V • Output = 1 V at 1 kHz • Load impedance = 2 Ω • = 1 MHz • Figure 18 Noise floor 1 V output...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Efficiency Efficiency Efficiency Figure 19 Figure 20 show the efficiency characteristics of REF_Audio_GaNb_750W. The high efficiency is achieved by the following factors: Low conduction loss due to the CoolGaN™ offering low R •...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Efficiency Test conditions: ±36 V • Input signal = 1 kHz • Load impedance = 2 Ω • = 1 MHz • Figure 20 Total power efficiency 2 Ω load User guide V 1.0 2025-04-11...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Thermal performance Thermal performance Test conditions: Input signal = 1 kHz • Table 4 Peak power without heatsink Load ±V 10% THD+N power Duration (minutes) case 4 Ω...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Thermal performance Table 6 1/8 power without heatsink Load 1/8 Power Max rise Duration (minutes) ±V 2 Ω 36 V 47 W 60ºC 30 minutes <60ºC PCB temperature rise Figure 23 1/8 Power P = 47 W with 2 Ω...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC 400 kHz variant of REF_Audio_GaNb_750W 400 kHz variant of REF_Audio_GaNb_750W The REF_Audio_GaNb_750W reference board is optimized for a 1 MHz switching frequency by default, which enables the use of smaller output filter inductors, resulting in a compact and power-dense solution.
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC 400 kHz variant of REF_Audio_GaNb_750W Frequency adjustment 1. Monitor VS1 and VS2 switching frequency with an oscilloscope. See Figure 9 2. Adjust R44A and R44B setting VS1 and VS2 to 400 kHz Total harmonic distortion - THD+N Test conditions: ±38 V...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC 400 kHz variant of REF_Audio_GaNb_750W Test conditions: ±38 V • Input signal = 1 kHz • Load impedance = 2 Ω • = 400 kHz •...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC 400 kHz variant of REF_Audio_GaNb_750W Frequency response Test conditions: ±38 V • Output power = 1 W • Load impedance = 2 Ω • = 400 kHz •...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC 400 kHz variant of REF_Audio_GaNb_750W Efficiency Test conditions: ±38 V • Input signal = 1 kHz • Load impedance = 2 Ω • = 400 kHz •...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC 400 kHz variant of REF_Audio_GaNb_750W Figure 28 Peak power P = 400 W with 2 Ω load, ±38 V, no heatsink Table 9 1/8 power without heatsink Load 1/8 Power Duration (minutes)
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Schematics Schematics Figure 29 Signal chain Figure 30 Preamplifier User guide V 1.0 2025-04-11...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Schematics Figure 31 Self-oscillating PWM modulator Figure 32 Class D amplifier stage User guide V 1.0 2025-04-11...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Schematics Figure 33 Class D output stage Figure 34 Channel sync User guide V 1.0 2025-04-11...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Schematics Figure 35 Over-/undervoltage protection Figure 36 Housekeeping power supplies User guide V 1.0 2025-04-11...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC PCB specifications and layout PCB specifications and layout 10.1 PCB specifications Fabricate per ipc-601x series, class 2, and inspect per IPC-A-600 class 2 • U.l. rating: 94 V-0 minimum •...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC PCB specifications and layout 10.2 Layout Figure 37 Layer 1 Figure 38 Layer 2 User guide V 1.0 2025-04-11...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC PCB specifications and layout Figure 39 Layer 3 Figure 40 Layer 4 User guide V 1.0 2025-04-11...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Bill of Materials Bill of Materials Table 5 Bill of materials Part number Designator Description Quantity Vendor 1441142 KNOB Farnell 445-173687-1-ND C11, C15, C18, CAP CER 0.047UF 50V DigiKey C21, C22, C23, X7R 0603...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Bill of Materials Part number Designator Description Quantity Vendor CAP ALUM 10UF 20% C38, C40 C38, C40 Digikey 6.3V SMD CAP CER 220PF 50V X7R C39, C41 C39, C41 Digikey...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Bill of Materials Part number Designator Description Quantity Vendor DIODE SCHOT 30V D10A, D10B D10A, D10B Digikey 200MA PGSOD3233D D11A, D11B, DIODE STANDARD 200V D11A, D11B, D15A, D15B Digikey D15A, D15B 700MA PMDU...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Bill of Materials Part number Designator Description Quantity Vendor TRANS NPN 80V 8A Digikey DPAK TRANS PNP 80V 8A Digikey DPAK Q6, Q7, Q8, Q12A, TRANS NPN 160V 0.6A Q6, Q7, Q8, Q12A, Q12B Digikey...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Bill of Materials Part number Designator Description Quantity Vendor CRCW0603 50 1% 100 Digikey RES 100K OHM 1% Digikey 1/10W 0603 RES SMD 2K OHM 1% Digikey 1/2W 0805 RES SMD 75K OHM 1%...
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Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Bill of Materials Part number Designator Description Quantity Vendor RES 5.6K OHM 1% R82A, R82B R82A, R82B Digikey 1/10W 0603 RES SMD 7.5K OHM 1% R86A, R86B R86A, R86B Digikey...
The REF_Audio_GaNb_750W is a high-performance class D audio amplifier reference board developed by Infineon Technologies. It combines 100 V CoolGaN™ transistors (IGB110S10S1) with the MERUS™ IRS20957S digital audio driver to showcase the superior efficiency, power density, and audio quality achievable with GaN technology.
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC References References [1] Infineon Technologies AG: IGB110S10S1; Available online [2] Infineon Technologies AG: IGB070S10S1; Available online [3] Infineon Technologies AG: IRS20957SPBF; Available online [4] Infineon Technologies AG: 1EDN7116U;...
Class D audio reference board with 100 V CoolGaN™ transistors and MERUS™ IRS20957S audio IC Revision history Revision history Document Date Description of changes revision V 1.0 2025-04-11 Initial release User guide V 1.0 2025-04-11...
For information on the types in question please contact your nearest Published by Infineon Technologies office. Except as otherwise explicitly approved by Infineon Infineon Technologies AG Technologies in a written document signed by 81726 Munich, Germany authorized...
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