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Jinxin Electronics 12V Electronic Water Pump Solution
Electronic water pumps are an important part of the on-board thermal management system and are used to dissipate heat in the automotive water cooling system. At present, the water pump solution on the market is dominated by BLDC brushless motor, and silky adjustment, precise control and high cost performance have become the focus of customers' attention.
In response to the above market demands, Jinxin Electronics launched a power 40-200W/12V electronic water pump, which uses PWM/LIN communication for speed regulation and fault feedback. Using a single-resistor sine wave scheme, the circuit is simple, and it has the advantages of stable control and low cost. Jinxin Electronics can provide cost-effective electronic water pump control board solutions based on the company's ADM16F03A2 DSP as the main control chip.
Figure 1 Product prototype
ADM16F03A2 Introduction
ADM16F03A2 is an improved 16-bit DSP for brushless motor control, integrating LDO and 6NMOS pre-drive modules, equipped with 150MHz main frequency 16-bit DSP processing core + acceleration computing unit, event manager, SPI and SCI modules, 12-bit ADC, and built-in op-amp, voltage comparator and LIN transceiver. It can form a control core and support multi-mode brushless motor control such as inductive, non-inductive, square wave, and sine wave. The following table is an introduction to resources for ADM16F03A2 motor control.
Master architecture | 16-bit fixed-point DSP |
Frequency | 150MHz |
Storage resources | 8KB SARAM、64KBFlash |
Single power supply | 4.5-40V |
Communication interface | SCI (Configured as LIN Interface) |
peripheral |
|
Simulate peripherals | OPA+3PGA+5 comparator + temperature sensor |
Integrated configuration | 12V-LDO、6NMOS预驱、LIN-PHY |
Motor drive method | Sensive/non-inductive square waves Sensible/non-inductive string waves |
encapsulation | QFN56 package |
Temperature range Vehicle Regulation Certification | -40-125°C AEC-Q100 |
Table 1 ADM16F03A2 Motor control related resources
At the same time, the ADM16F03A2 supports JTAG online simulation, and supports the fast programming mode of at least four wires in the serial SCI mode. The following is a layout diagram of ADM16F03A2 chip pin definitions:
Figure 2 Chip pin definition layout
ADM16F03A2 application advantages
ADM16F03A2 is a highly integrated, high-performance BLDC/PMSM controller packaged in QFN56 that allows users to design motor control systems for the best price/performance ratio, ADM16F03A2 with built-in modules such as six NMOS Pre-Drivers, op-amps, PGAs, comparators, high-speed ADCs, SCIs, SPIs, and LINs. At the same time, it adopts a high-performance 16-bit CPU with 64KB FLASH embedded in it and a maximum operating frequency of 150MHz, which can meet the application requirements of high-performance brushless motor control and simplify the hardware cost of the system. It is suitable for BLDC/PMSM motor square wave, SVPWM/SPWM, FOC drive control.
Hardware module introduction
The circuit module mainly includes: input anti-reverse bus capacitor input part, ADM16F03A2 minimum system, power bridge circuit, ADC bus sampling circuit, single-resistance sampling op amp sampling circuit, bootstrap circuit and PWM/LIN communication feedback circuit.
• Input anti-reverse bus capacitor input section
The input passes through the N tube to achieve anti-reaction function. CE1, L1, and CE2 are used to form π filtering. It can effectively reduce the interference of the power supply.
Figure 3 Anti-reverse bus circuit
• ADM16F03A2 minimal system
ADM16F03A2 minimum system is shown in the figure below, including JTAG interface, serial port, SPI, PWM module, ADC module, etc.
The op amp OP1 that comes with the system can be configured as a differential mode for bus current sampling through the peripheral resistor, and the output result of the op amp OP1OUT can be connected to COMP0 for hardware overcurrent protection, and different comparison levels can be set inside COMP0, and once the threshold is triggered, the PWM signal can be directly blocked.
When an offline programming program is required, the pad is tested with 5V, TX, RX, IOPE4, and GND signals, and fast offline programming can be achieved with the help of the offline programming tool of the core.
Figure 4 Schematic diagram of chip and interface
• Power bridge circuitry
The power bridge circuit adopts the configuration of NMOS for both upper and lower tubes, and a total of 6 NMOS form a three-phase H-half-bridge drive circuit.
The single sampling resistor is 0.005R, and the op-amp input is input to the chip port sampling for calculation through the independent op-amp circuit of the differential trace to the OP1 of the ADM16F03A2.
Fig.5 Schematic diagram of the power bridge circuit
• ADC bus voltage sampling circuit
ADC sampling bus sampling circuit, the value of the bus voltage is sent to the AD port of the chip for voltage division, and it participates in the operation of FOC.
Fig.6 Schematic diagram of AD bus voltage sampling
• Single-resistor sampling op-amp sampling circuit
The internal independent op amp OP1 group is used for differential op amp 15 times, which is sent to port A0 for overcurrent protection and to port A4 for constant power control.
Figure 7 Op amp partial circuit
• Bootstrap circuit
The 12V voltage of the VDRV is output from the inside of the chip and given to the bootstrap circuit part, so that the drive voltage of the upper bridge can be raised, so that the upper bridge can be controlled.
Fig.8 Bootstrap circuit part
• PWM/LIN communication feedback circuit
The chip is integrated with a LIN chip, which is compatible with recognizing PWM, and can communicate speed regulation and feedback faults through input PWM/LIN. Enables LIN_EN pins to turn LIN communication on and off.
Figure 9 PWM/LIN communication circuit
Scenario description
It adopts a single-resistor sine wave, the circuit is simple and the cost is low. Non-inductive FOC, power closed-loop, speed closed-loop. All kinds of protection (over-under-voltage, over-current, blockage, phase loss, power) and other characteristics.
Specifications
Voltage: DC12V
Power: 40-200W
A variety of protection measures: over-current protection, short-circuit protection, over-voltage protection, under-voltage protection, blocking protection, phase loss protection, power protection, starting protection, etc.
This solution uses the non-inductive single-resistor FOC algorithm, bus voltage ADC detection, and controls different rotational speeds and fault feedback functions through PWM/LIN. It has the characteristics of strong load capacity, low noise, and stable waveform control.
Technical support
Jinxin Electronics can provide customers with the schematic diagram, PCB reference board diagram, source code, and software and hardware development technical support corresponding to the above solution, if you need to know more about the details of the solution, please call 0731-88731027.
