5.5 KiB
HubAudio
Power Management Architecture
Document: Power Management Design Specification
Revision: 0.1
Status: Design Phase
1. Overview
The HubAudio platform requires a sophisticated power management architecture.
The system combines:
- ESP32-S3 high performance MCU with WiFi
- ADAU1467 professional audio DSP
- Si4684 FM/DAB receiver
- Bluetooth audio transmitter
- Bluetooth audio receiver
- battery operation
- remote monitoring capability
The power system is therefore not considered a simple voltage regulator stage, but a complete energy management subsystem.
2. Design Philosophy
The selected architecture follows these principles:
- single intelligent PMIC
- integrated battery management
- multiple independent power rails
- I2C monitoring
- controlled power sequencing
- ability to disable unused subsystems
- separated digital and audio power domains
3. Selected Main PMIC
Texas Instruments TPS65217CRSLR
The TPS65217 is selected as the main power management IC.
Reasons for selection:
- integrated Li-Ion battery charger
- power path management
- multiple switching regulators
- LDO outputs
- I2C configuration
- programmable sequencing
- fault monitoring
Although originally designed for embedded processor systems, its architecture is suitable for HubAudio due to the need for multiple controlled power domains.
4. Power Tree
Proposed architecture:
USB-C / External Power
|
|
TPS65217CRSLR
|
+----------------+----------------+
| | |
DCDC1 DCDC2 DCDC3
| | |
3.3V_DIGITAL 3.3V_AUDIO 5V
| |
| |
ESP32-S3 Audio/RF domain
|
Ferrite filtering
|
+-----------+-----------+
| | |
ADAU1467 Si4684 Bluetooth
5. Power Domains
5.1 Digital Domain
Voltage:
3.3V_DIGITAL
Consumers:
- ESP32-S3
- EEPROM
- logic peripherals
- communication interfaces
Requirements:
- high transient capability
- low impedance supply
Main concern:
ESP32-S3 WiFi current peaks.
5.2 Audio / RF Domain
Voltage:
3.3V_AUDIO
Consumers:
- ADAU1467
- Si4684
- BT1035
- Bluetooth RX module
This rail must be isolated from digital noise.
Recommended:
3.3V_AUDIO
|
ferrite bead
|
audio devices
5.3 5V Domain
Possible consumers:
- DAC
- amplifier
- future peripherals
This rail is kept independent from sensitive audio electronics.
6. Battery Management
The TPS65217 provides:
- Li-Ion charging
- battery monitoring
- power path control
- protection mechanisms
Battery:
Single cell Li-Ion
3.7V nominal
4.2V charged
7. Power Monitoring
7.1 Decision
The TPS65217 already provides battery management.
An additional current monitor is not required for system operation.
However, HubAudio benefits from detailed subsystem monitoring.
A dedicated I2C power monitor is therefore added for the audio domain.
8. Selected Current Monitor
Texas Instruments INA226
The INA226 is selected as the default power monitoring device.
Purpose:
Measure the audio subsystem consumption.
Monitored rail:
TPS65217
|
3.3V_AUDIO
|
INA226
|
ADAU1467 Si4684 Bluetooth
9. INA226 Functions
The INA226 provides:
- bus voltage measurement
- shunt voltage measurement
- current measurement
- power calculation
- I2C communication
The ESP32-S3 can periodically read:
Voltage
Current
Power
Example:
{
"audio_voltage":3.30,
"audio_current":180,
"audio_power":0.59
}
10. INA228 Evaluation
The INA228 has been evaluated as an alternative.
Advantages:
higher resolution ADC
higher precision
energy accumulation
advanced power analysis
Typical application:
laboratory measurements
industrial systems
precision battery analysis
For HubAudio:
Not selected as default.
Reason:
The additional precision is not necessary because:
battery management is already handled by TPS65217
audio subsystem consumption does not require laboratory accuracy
11. Future Compatibility
The PCB should allow optional replacement:
INA226 footprint compatible with INA228 evaluation.
Possible versions:
Standard
TPS65217
+
INA226
Engineering / Pro Version
TPS65217
+
INA228
12. I2C Monitoring Bus
The power monitoring devices share the system I2C bus.
Example:
ESP32-S3
|
I2C
+---- EEPROM
|
+---- ADAU1467
|
+---- INA226
|
+---- TPS65217
13. Power Sequencing
Startup sequence:
Battery connected
|
TPS65217 initialization
|
3.3V_DIGITAL enabled
|
ESP32-S3 boot
|
Module detection
|
Enable audio domain
|
Initialize DSP
|
Enable RF modules
14. Controlled Shutdown
The ESP32-S3 can disable:
Bluetooth TX
Bluetooth RX
Si4684
ADAU1467
Example:
Standby:
ESP32-S3 ON
WiFi ON
Audio OFF
Radio OFF
Bluetooth OFF
15. PCB Layout Requirements
Critical:
Switching regulators
Keep away from:
ADAU1467
DAC
RF sections
Audio supply
Use:
short traces
filtering
dedicated return paths
Decoupling
Every IC requires local decoupling.
Additional filtering is required for:
DSP supply
RF supply
16. Final Decision
The HubAudio power architecture is:
TPS65217CRSLR
+
Separate audio power domain
+
INA226 monitoring
+
Optional INA228 upgrade
This provides:
professional power management
battery operation
remote diagnostics
future scalability
END DOCUMENT
---