User Manual EV6550DHAT (CML Microcircuits) - 4
| Manufacturer | CML Microcircuits |
| Description | Raspberry Pi HAT for CMX655D |
| Pages / Page | 12 / 4 — Raspberry Pi Compatibility. Power Supplies. Figure 2 40-way GPIO … |
| File Format / Size | PDF / 1.1 Mb |
| Document Language | English |
Raspberry Pi Compatibility. Power Supplies. Figure 2 40-way GPIO Connector Power Pins
Text Version of Document
Raspberry Pi HAT for CMX655D EV6550DHAT
3 Raspberry Pi Compatibility
The EV6550DHAT has been designed from the offset to offer HAT compatibility and to meet the requirements of the HAT definition. Further details of the format and its requirements can be found on the Raspberry Pi Foundations website: www.raspberrypi.org
4 Power Supplies
EV6550DHAT by default takes power from the Raspberry PI GPIO pins: PAVDD Supply: The CMX655D integrated Power Amplifier requires most of the power. A regulator, LM1117DT-3V3, is fitted to the HAT PCB and sources 5V from the GPIO connector supply, routing 3.3V to the PAVDD pin via an on-board LDO regulator. There are options to use external supply via links and pads if required. ADVDD_3V3 Supply: The remaining CMX655D power by default is supplied via a low current regulator, LP2985IM5X-3.3. An alternative 3V3 supply is available from the Raspberry PI GPIO 3.3V pins via a decoupling inductor to reduce the digital noise from the Raspberry Pi supply. The regulator and capacitor should be removed and a suitable inductor mounted to use this option. The resulting 3.3V is routed to the CMX655D low powered circuits via the CMX655D VDD_AD1 and VDD_AD2 pads. There are options to use an external supply via links and pads. 3V3 1 2 5V 4 5V 6 GND GND 9 14 GND 3V3 17 20 GND GND 25 30 GND 34 GND GND 39
Figure 2 40-way GPIO Connector Power Pins
Note: The 3.3V Raspberry Pi pins are limited to a maximum of 50mA, which is sufficient for operation of the CMX655D and associated components. The 5V supply has greater current sourcing capability and as such by default is used to supply the PA via a small regulator. However, the amount of current that can be sourced from the 5V pin is very dependent of what other USB peripheral devices are mounted as well as processor power consumption. For a 4 Ohm speaker load typically 400mA can be drawn from the 5V rail at maximum signal level. Should there be an issue it is recommended that an external 3.3V supply is used to power the PA, there are links and pads available for this change. Note: If an external PAVdd supply is to be used instead of the PAVdd regulator, the PAVdd regulator must be disconnected (0Ω link removed) from the supply. 2019 CML Microsystems Plc 4 UM6550DHAT/1 Document Outline User Manual Front Page 1 Introduction 2 CMX655D Ultra-low Power Voice Codec 3 Raspberry Pi Compatibility 4 Power Supplies 5 Handling Precautions 6 Quick Start 6.1 Mounting The EV6550DHAT To The Raspberry Pi 6.2 Software Installation 6.3 GUI Description and Board Operation 7 Supplied Source Code 8 GUI ‘C’ Source Files and Modification 9 Troubleshooting 10 Additional Hardware Information 10.1 Hardware Test Points End of Document
3 Raspberry Pi Compatibility
The EV6550DHAT has been designed from the offset to offer HAT compatibility and to meet the requirements of the HAT definition. Further details of the format and its requirements can be found on the Raspberry Pi Foundations website: www.raspberrypi.org
4 Power Supplies
EV6550DHAT by default takes power from the Raspberry PI GPIO pins: PAVDD Supply: The CMX655D integrated Power Amplifier requires most of the power. A regulator, LM1117DT-3V3, is fitted to the HAT PCB and sources 5V from the GPIO connector supply, routing 3.3V to the PAVDD pin via an on-board LDO regulator. There are options to use external supply via links and pads if required. ADVDD_3V3 Supply: The remaining CMX655D power by default is supplied via a low current regulator, LP2985IM5X-3.3. An alternative 3V3 supply is available from the Raspberry PI GPIO 3.3V pins via a decoupling inductor to reduce the digital noise from the Raspberry Pi supply. The regulator and capacitor should be removed and a suitable inductor mounted to use this option. The resulting 3.3V is routed to the CMX655D low powered circuits via the CMX655D VDD_AD1 and VDD_AD2 pads. There are options to use an external supply via links and pads. 3V3 1 2 5V 4 5V 6 GND GND 9 14 GND 3V3 17 20 GND GND 25 30 GND 34 GND GND 39
Figure 2 40-way GPIO Connector Power Pins
Note: The 3.3V Raspberry Pi pins are limited to a maximum of 50mA, which is sufficient for operation of the CMX655D and associated components. The 5V supply has greater current sourcing capability and as such by default is used to supply the PA via a small regulator. However, the amount of current that can be sourced from the 5V pin is very dependent of what other USB peripheral devices are mounted as well as processor power consumption. For a 4 Ohm speaker load typically 400mA can be drawn from the 5V rail at maximum signal level. Should there be an issue it is recommended that an external 3.3V supply is used to power the PA, there are links and pads available for this change. Note: If an external PAVdd supply is to be used instead of the PAVdd regulator, the PAVdd regulator must be disconnected (0Ω link removed) from the supply. 2019 CML Microsystems Plc 4 UM6550DHAT/1 Document Outline User Manual Front Page 1 Introduction 2 CMX655D Ultra-low Power Voice Codec 3 Raspberry Pi Compatibility 4 Power Supplies 5 Handling Precautions 6 Quick Start 6.1 Mounting The EV6550DHAT To The Raspberry Pi 6.2 Software Installation 6.3 GUI Description and Board Operation 7 Supplied Source Code 8 GUI ‘C’ Source Files and Modification 9 Troubleshooting 10 Additional Hardware Information 10.1 Hardware Test Points End of Document
