Nanochip's 40V automotive-grade multi-channel half-bridge driver NSD830x-Q1 can control cold and hot air easily

On October 8, NOVOSENSE announced the launch of the NSD830x-Q1 series of multi-channel half-bridge automotive-grade driver chips. This series of products includes two products, NSD8308 (8-channel) and NSD8306 (6-channel). Both products integrate multi-channel half-bridge drivers and N-MOS power stages to support a variety of load types.

Figure 1: Motor/LED/inductive load

As shown in Figure 1 above, through SPI configuration, this product can realize full-bridge and half-bridge drive modes, supporting DC brushed motors, bipolar stepper motors, relays and LEDs, etc. In automotive systems, this solution can be widely used in air conditioning damper control, electric rearview mirrors and zone controllers.

Figure 2: Automotive thermal management system

NSD830x-Q1 Product Performance Overview

- Wide operating voltage range: 4.5V-36V (withstand voltage 40V)

- On-resistance (HS + LS): 1.5 Ω

- Peak current 1.3A/1.7A

- Support clock chopping function to meet automotive EMI requirements

- PWM generator supports register configuration of preset frequency and duty cycle

- Load diagnostics

- Undervoltage protection and overvoltage protection

- Operating temperature: -40°C~125°C

- AEC-Q100 qualified

- Package: HTSSOP-24

Figure 3: NSD8306 functional block diagram

NSD830x-Q1 not only provides SPI interface and multi-channel driving mode, but also has a variety of additional features to enable it to support a variety of loads more flexibly:

1. PWM Generator

NSD8308/NSD8306-Q1 is equipped with a PWM generator, which can adjust the PWM frequency and duty cycle by configuring registers, adjust the speed of the DC brushed motor, and dim the LED, thereby reducing the workload of the main control chip and saving I/O resources.

The PWM generator can support a frequency range of 80-2,000Hz and a duty cycle with 8-bit resolution, which means that this series of products can support a duty cycle range of 0-100% and a subdivision range of 0-255.

In the application of brushed DC motors, even if the main control chip does not deeply intervene in the PWM generator, the motor load can achieve soft start and speed regulation functions with the assistance of the PWM generator, and realize simple PWM dimming function in the application of LED loads. As shown in Figure 4, when the register is set to output 100Hz and the duty cycle is 25%/50%/75%, the corresponding channel can accurately match the frequency and duty cycle configured by the register.

2. Output current limiting function

When designing motors and other load systems, small capacitors are connected in parallel at the output to reduce electromagnetic interference or enhance anti-interference capabilities. Compared with traditional overcurrent protection functions, the output current limiting function can ensure that the output stage provides peak current for a longer time to support capacitive loads.

NSD8308/NSD8306-Q1 can provide current limiting protection for both the upper and lower arms of the half-bridge. When a short circuit or overcurrent occurs and the load current exceeds the threshold defined by the chip, the output enters the current limiting mode. Compared with the traditional overcurrent protection function, the current limiting function has a higher tolerance for "false alarms", avoiding transient currents caused by capacitive loads or parasitic parameters from triggering the protection function and affecting the normal operation of the equipment.

Figure 5: Output short-circuit current limiting function

3. Load diagnosis function

Smart cars have increasing requirements for monitoring and diagnosing the working status of the vehicle system load. NSD8308/NSD8306-Q1 can provide intelligent load diagnosis function to allow the vehicle system to determine the load connection status. If a short circuit or open circuit occurs, the external controller can obtain the status information of each independent channel through the register inside the chip.

The diagnostic function of this series of products can fully cover the working status of various loads and support multiple load connection methods, including: half-bridge, full-bridge, high-side and low-side. In offline mode (the drive output is in the off state), it can help the system to realize open circuit diagnosis, battery short circuit diagnosis, and ground short circuit diagnosis; in online mode (the drive output is in the working state), it can realize open circuit diagnosis and current limiting protection. The status and alarm of the corresponding output channel can obtain the information on the corresponding register through SPI, and then report to the main controller.