1. No category

The Association of Loudspeaker Manufacturers & Acoustics
International presents
How to Develop a Loudspeaker
for iPhone 5 with Digital Audio Interface
Dr. John Oh
Pulsus Technologies
www.almainternational.org
Audio Interface of iPhone 5,
iPad, New iPad, iPod Touch
•  Lightning connector 30-pin -> 8 pin
•  New connector is an active component
with a chip inside
•  Analog audio streaming is not
supported anymore
•  New interface iAP2 has announced, and
older interface is now called iAP1
www.almainternational.org
Implication
•  Existing docking speakers are not
compatible with iPhone 5
•  Converter should be able to convert
USB audio to analog
•  Existing analog docking solutions cannot
be used in the new designs
•  iAP1 based digital docking solutions can
coexist with iAP2 for sometime.
www.almainternational.org
What is iAP2?
•  Will replace iAP1
•  iTunes control
•  USB high-speed audio up to 24bit 192
KHz (iAP1 < 16bit 48KHz)
•  Analog audio removed
•  Both USB host and device mode (iAP1
only support device mode – iPhone is
USB device)
www.almainternational.org
Start Developing Speakers
for MFI
•  Registered as a MFI developer
•  Access MFI portal mfi.apple.com for
resources
•  mfi.avnet.com for compo, such as
lightening connector, Apple
authentication processor
•  Choose mfi audio development system
www.almainternational.org
What’s inside the new
speakers?
•  MCU with USB audio interface (with iAP
Library)
•  Apple authentication chip
•  DSP for digital audio processing
•  Audio CODEC
•  Amplifier
•  Alternative audio sources (Bluetooth,
FM Tuner, DAB , etc.)
www.almainternational.org
PS8645, all-in-one SoC
PS8645 = USB controller + MCU + audio DSP + PWM
modulator + peripherals
www.almainternational.org
System Configuration
General Docking Speaker
www.almainternational.org
• 
• 
• 
• 
• 
• 
• 
• 
8051-based microprocessor with 64kB RAM
Audio inputs
- USB 2.0 full-speed host and device (selectively)
- 3 x stereo AUX and 1 microphone
- 2 x I2S
- 1 x SPDIF (PCM only)
Supports 16~24bit, 8-kHz~96kHz audio streaming
Dual asynchronous sample rate converter with jitter attenuation for low distortion
Fixed audio DSP with 24bit, 192kHz sound processing
- 5-band/ch equalizer
- Digital crossover
- QXpanderⓇ: virtual surround
- Virtual bass
- TuubilizerⓇ : smoothly plays output over the dynamic range without clipping noise
- Loudness volume
4-ch nDDC (Digital-to-Digital Converter) with HD PWM correction
Peripherals
- SPI, I2C, UART, JTAG, IR remote controller, real time clock controller, and 23 GPIOs
Value-added functions:
- Source level detector for lower power consumption
- Device firmware update
www.almainternational.org
Development System
for Rapid Prototyping
PS2022
power amplifier
I2S in
180
Speaker
Optical
USB
AUX
(PC)
1
8
0
Power supply
8-pin/30-pin
connector
Apple
authentication coprocessor
PS8645
www.almainternational.org
Main Features
•  iAP2 ready
- Supports iAP1 and iAP2
- Supports USB host mode and USB device mode
•  Better sound quality
- Full digital audio streaming and amplification
- Extensive audio DSP algorithms
•  Low cost
- PS8645, all-in-one SoC for digital audio docks
•  Faster time-to-market with much less engineering
- Development board for rapid prototyping
- 2.1ch Module that can be immediately used to produce 2.1ch iAP2
docking speakers
- Full SW library of iPod/iPhone/iPad dock functions and peripheral
interfaces
- Easy-to-use GUI SW development tool for real-time speaker tuning
and input configuration
www.almainternational.org
iAP2 ready
•  iAP2 MFi Device
- USB device mode audio
- HID (Human Interface Device)
- Now Playing
- 16bit 32kHz / 44.1kHz / 48kHz
•  iAP2 MFi Host
- HID
- Now Playing
- 24bit adaptive, 44.1kHz / 48kHz
www.almainternational.org
Technical Specification
• 
Audio Input
- 8-pin/30-pin connector for iPod/iPhone/iPad
: Supports both iAP1, iAP2 host, and iAP2 device
- 1 stereo analog input (AUX)
- S/PDIF optical input (PCM only)
- I2S (optional)
• 
Speaker Output
- 2-ch full-range or two-way / 2.1ch
• 
Audio algorithms: QXpanderⓇ, Virtual bass, TuubilizerⓇ, Digital crossover
filter, 5-band EQ
• 
Display: 20 digits x 2rows character VFD
• 
User interfaces:
- Button: Standby, sound mode, volume -, volume +, play/pause, intput
- IR remote control
: Standby, volume -/+, mute, play/pause, previous/next, menu, arrow up/
down, arrow left/right, enter,
source input selection, PC to iPod link control, sound
• 
Supports Apple iPod authentication processor (2.0B / 2.0C)
• 
8V - 17V single power operation
www.almainternational.org
2.1ch module for immediate product
launch
• 
A finished design that can be immediately adopted to mass production
- No additional hardware development or programming is required
• 
Audio inputs
- 8-pin/30-pin connector for iPod/iPhone/iPad
: Supports both iAP1, iAP2 host, and iAP2 device
- 1 stereo analog input (AUX)
• 
Speaker Output
- 2.1-ch configuration: 10Wx2ch + 20Wx1ch (THD+N 1%)
• 
Audio algorithms: QXpanderⓇ, Virtual bass, TuubilizerⓇ, Digital crossover filter, 5-band EQ
• 
Display: 2 sets of LEDs for power mode and sound mode
• 
User interfaces
- Button : Standby, sound mode, volume -, volume +
- IR remote control
: Standby, volume -/+, mute, play/pause, previous/next, menu, arrow up/down, enter,
sound
• 
15V/2.7A single power operation
• 
SNR: >90dB
• 
Small foot print: 120mm x 70mm (Main board)
www.almainternational.org
2.1ch Reference Design
PS2022
power amplifier
1
8
0
Speaker
1
8
0
PS2022
power amplifier
8-pin connector
Apple 2.0c
PS8645
AUX Power supply
www.almainternational.org
2.1ch Reference Design
www.almainternational.org
Firmware development
environment
•  Provides a full library of iAP1 and iAP2 including
digital audio streaming, general purpose peripheral
interfaces, and authentication protocols
•  SDK (Software Development Kit) with full library and
sample source code of all the functions
•  Users can customize the firmware firmware:
- by adopting reference firmware released
- through Pulsus’ SW development support program
•  Industry standard C-compiler
www.almainternational.org
www.almainternational.org
PDK Development Env. for DSP
•  System configuration and
real-time speaker tuning
without DSP programming
- Only through USB
connection to PC/Macs, no
specific equipment is
required
•  Quick adjustment of
equalizer, crossover, and
sound processing
algorithms
www.almainternational.org
PDK
www.almainternational.org
PDK
www.almainternational.org
Dynamic Loudness
www.almainternational.org
Multi-input multi-function high-end docking speaker
www.almainternational.org
Summary
•  New iPhone 5 pure digital Interface
iAP2 has announced.
•  Better sound quality through 24bit
digital audio interface enables
implementation of high quality audio
systems.
•  New development system and SoC
architecture can significantly reduce
development time and cost.
www.almainternational.org