A powerful MCU born for Bluetooth, singing and finding the way to master

  Since BluetoothLE was introduced to the Bluetooth standard, it has grown at an alarming rate. Its fast and sensitive skills make up for the shortcomings of classic Bluetooth and are very popular among manufacturers. According to the Bluetooth Alliance, by 2022, low-power Bluetooth single-mode chips will account for more than a third of all Bluetooth chip shipments.

Dialog Semiconductor has also invested in this market very early. According to Mark de Clercq, Director of Dialog's Low-Power Connectivity Business Unit, its Bluetooth low-power SoC shipments have reached 250 million units and have been implemented in the global market. Second place.

Mark de Clercq, Director, Low Power Connectivity Business Unit, Dialog Semiconductor

The wide product line is the guarantee of Dialog's high shipments. There are small front-end low-power products for simple applications and a more integrated product line for high-end products. However, the most anticipated by Dialog is the recently launched DA1469x series, which is known as the "unique" product.

Learned wireless MCU

The DA1469x is the world's first mass-produced ARM Cortex-M33-based wireless MCU. It features a software configurable protocol engine and supports the latest Bluetooth 5.1 standard while integrating an advanced built-in power management unit. It also has a unique combination of analog and digital peripherals.

To address the three main functions of the IoT target application: sensing, processing, and communication, it is configured with three processors, each of which can perform its respective functions in an optimal manner.

The core processing unit selects the ARM Cortex-M33 application processor, the latest product in the ARM Cortex-M family, including floating point units, memory protection units and DSP expansion engines. In order to fully utilize the potential of the M33, its memory is scalable and users are free to choose.

Many developers are concerned about code security, and the DA1469x is equipped with an executable QSPI flash memory that allows customers to execute code safely.

This MCU "has a stunt", it can be said that it integrates various functions that can be thought of at present: there is a built-in display controller to realize a rich user interface, a built-in backlight white LED driver, and an internal touch controller. There is also a fully autonomous stepper motor controller. In addition, it supports two channels of audio input and output, built-in ERM and LRA drivers to provide tactile feedback to the user.

At the front end of the analog interface, there are two ADCs: one with high data rate and a slightly lower accuracy; one with high accuracy, but with a slightly lower sampling rate.

In order to optimize power and control so many interfaces, a second core micro DSP is required. It is software programmable, fully autonomous, and the client can control the interface through a digital serial interface without the need for other functions on the chip to be active.

The last core is the logo of the chip, which is responsible for the wireless connection part, which is the ARM Cortex-M0+. It has a software programmable protocol engine that also supports the latest Bluetooth 5.1 standard as well as the 2.4GHz proprietary protocol. The radio front end has a maximum output power of +6dBm and a receiving sensitivity of -97dBm. The available power replaces the coverage. The RF design can be accomplished by integrating all components of the external front end, including an integrated balun, a 50Ω matched single RF IO pin, and a single PCB layout antenna.

Dialog started with the development of power management chips, so this MCU is also a strong point in power management. The chip native support includes rechargeable batteries such as lithium polymer batteries, lithium-ion batteries, button batteries, etc. All internal power management is done on-chip. For some complex systems, the DA1469x can also power external devices via DC/DC. Most notably, it has seven independent power domains that can be powered when the customer needs it. For example, when Bluetooth is applied, only the Bluetooth-related power domain will supply power. The chip will also allocate power according to the function.

There are two great tricks

The traditional Bluetooth field is audio transmission, but this skill may also be robbed, and the DA1469x can also transfer Hi-Fi audio.

Dialog developed a demo for real wireless stereo TWS audio system with Bluetooth low energy technology with DA1469x, users can clearly receive Hi-Fi sound quality music. Mark de Clercq calls this a true stereo. "We have a transmitter that transmits audio streams over two channels, one for the left ear and one for the right ear. The left and right channels are not communicating with each other. This is analogous to classic Bluetooth. This is a big difference. In this demonstration, two separate channels are used to transmit the audio stream, which can be synchronized to a time difference of 1ms, ensuring a true stereo experience."

However, he also said that the transmission of Hi-Fi audio through BLE is still in a proof-of-concept phase, and there is still a need for protocol enhancements, while the chip also needs to reduce power consumption to extend battery life. But the potential to transmit Hi-Fi audio over BLE has been well documented.

Another trick is the positioning function, which is also a new addition to the new Bluetooth 5.1 standard, applying angle of arrival (AoA) and exit angle (AoD) for homing. Applications such as indoor positioning, item tracking, access control, keyless unlocking, etc. will all benefit from this feature of the new 5.1 standard.

Mark de Clercq explains how the angle of arrival (AoA) works. "We assume that there is a transmitter transmitting a serial signal. The receiver has multiple antennas, each receiving a signal. Two different antennas receiving signals When there is a phase difference, analyze the phase difference to form the angle of the beam to determine the direction of the receiver relative to the transmitter."

The key to this application is the design of the antenna. Dialog provides a very clear application note and an antenna reference design that allows the customer to mimic these designs and ensure that the designed performance is optimal.

Developer's gospel

Developers often find headaches when developing Bluetooth-related products, because development is far more difficult than imagination.

Dialog provides a complete software development kit to solve the user's troubles. There are three main toolkits, the first is the pre-configured Eclipse integrated development environment and SDK, followed by a development kit SmartSnippets Studio, and finally the Connection Manager for debugging, protocol analysis and testing.

It is reported that the SmartSnippets Bluetooth protocol stack is a relatively mature protocol stack, and customers have developed a variety of products with this tool. This stack supports the latest Bluetooth standard specifications and also supports a number of other features that enable customers to make better application development.

Mark de Clercq added: "The Dialog Bluetooth protocol stack is integrated into a very comprehensive software development kit that provides all the tools for engineers to develop applications without the need for engineers to get too involved in the software. In addition to systems, LLDs, and middleware, there is a set of application-level APIs that allow engineers to enjoy these functions without having to control each part individually. Dialog also has a series of software examples that allow engineers to accelerate application development."

"In conjunction with software tools, Dialog also offers a complete hardware development kit that allows customers to develop their own software on the hardware. The hardware development kit includes a motherboard that integrates many important features and features; and a daughter board, daughter board There is the DA1469x on this product," Mark de Clercq said.

Dialog's expectation for this product is "to provide customers with the opportunity to develop next product cycle", so it uses the latest 55nm ULP process. According to Mark de Clercq, the series has been in volume production, samples and development kits are available through global distributor partners, and all software tools are available on the official website.