Integrated Motor Pre-Driver for Drones, Enabling Small, Quiet, and Highly-Efficient Designs
Drones have struggled with reduction of noise, obtaining longer flight times, reducing size, component weight, and safety. Asahi Kasei Microdevices Corporation, (AKM), has now started sampling of an integrated pre-driver IC, the AP1050 for 3-phase brushless motors.
The AP1050 reduces current consumption and drive noise while integrating the functions required for the electric speed controller (ESC), implementing various protection functions while reducing size. It is also possible to build a system that controls multiple motors with one MCU.
This pre-driver IC is designed for battery-powered 3-phase brushless motors. It includes built-in power supplies, which operate motor drive voltages in the range of 8V to 36V. It incorporates a step-down dc-dc converter (10V/500mA, with built-in FET and synchronous rectification) and LDOs to generate the power supply that the motor drive system requires. The bootstrap circuit with dead-time control is embedded and it enables to use N-type MOSFET for both low side and high side. This device is rated for operation from -40 to +105°C and is delivered in a 48-pin QFN (7×7mm).
Key operational features:
- Improved motor Efficiency and lower Driving Noise
The AP1050 adopts the Field Oriented Control, (FOC), method which is vector control using sine waves to drive a motor. High frequency sound from the motor driver is suppressed with this method. In addition, system current can be reduced by about 20% to 30% compared to FOC driven via rectangular wave.
- Size and Weight Reduction by Integration of the IC with various Protection Functions
The AP1050 integrates a system power supply, amplifiers for current sense, A/D converters (ADC), a PWM generator, and pre-drivers. Since the Electric Speed Controller, (ESC), can be configured only with the AP1050, an MUC, and FETs, the system can be made smaller and lighter. The AP1050 even integrates various protection functions, (undervoltage, overvoltage, overcurrent, and thermal shutdown), contributing to increasing system safety.
- Multiple Motors can be controlled by one MCU
In previous systems, the same number of ADCs and PWM generators in the MCU were required, depending on the number of drive motors. By using the AP1050, it is possible to control multiple motors with one MCU and SPI interface. This will reduce the board size and cost.
Summary of specifications:
- Motor Drive Voltage 8V to 36V
- Buck DC-DC 10V/500mA, Built-in FET, Synchronous rectification type
- LDOE 3.3V/200mA (For external circuit and DVDD connection)
- LDOA 5.0V (For AVDD connection)
- VREG 4.83V (For internal analog circuit)
- LDOD 1.88V (For internal digital circuits), With Power Good signal output
- Pre-Driver Built-in bootstrap circuit for high side driver, With Dead Time Control function
- PWM Controller 13-bit setting, PWM waveform mode switching
- VGA +17dB to 28dB, 3dB step, 2ch same setting
- ADC 12-bit, 2ch
- 4-wire serial interface CSB, SCK, SDI, SDO
- PWM cycle input / output INT
- Protection functions
- Undervoltage detection (VIN, VDC, VREG, LDOE, LDOA, LDOD)
- Overvoltage detection (VIN, VDC, LDOE, LDOA, LDOD)
- Overcurrent detection (Buck DC-DC, Pre-Driver)
- Built-in thermal shutdown circuit (TSD)
- Overcurrent protection (OCP)
- Error output 1-Output (ERRB)
- Operation Temperature Range -40 to 105°C（Tj max=150°C）
- Package 48-pin QFN (7×7mm)
You can see the AP1050 and other products from Asahi Kasei Microdevices Corporation at electronica 2018 in Hall C4 Stand 222. They will be represented by Atlantik Elektronik GmbH.