Application of N9000 high-performance modular battery simulator in AFE chip test

AFE chip is a front-end integrated circuit used for analog signal acquisition and processing. It can amplify, filter, sample, quantize and process the input signal to facilitate the analysis of the back-end MCU (processor). At present, AFE chips have been widely used in many industries such as electric vehicles, energy storage, 3C electronics, etc.
Taking electric vehicles and energy storage as examples, AFE chips are the core components of automotive BMS and energy storage BMS. The rapid development of electric vehicles, energy storage and other industries has driven the growth of demand in the AFE chip market. Its performance directly determines the accuracy and reliability of BMS operation. Therefore, AFE chip testing has also become the focus of chip manufacturers, which puts high demands on the functional configuration, channel station configuration, test synchronization and accuracy of related test equipment.

Multi-function requirements
AFE chips usually have the following functions:
1) Single cell voltage acquisition;
2) Cell temperature acquisition;
3) Cell balancing;
4) State estimation: SOC, SOH, etc.;
5) Abnormal alarm and protection: protection against overcharge, over discharge, over temperature, collection line break, etc.
Therefore, the test equipment related to the AFE chip needs to have multiple functions such as single cell voltage simulation, temperature simulation, state simulation, fault simulation, cell balancing, etc., and try to integrate them into a single device.

Requirements for multi-channel high-speed synchronization
Under the development trend of high power and high voltage related industries such as 5MWh energy storage and 800V electric vehicles, more battery strings have become an inevitable trend. At present, the number of battery strings for outdoor energy storage and industrial and commercial energy storage can reach up to 416S, and the number of battery strings for 800V platform electric vehicles can reach up to 192S. In the case of multiple battery string design, high-speed synchronous acquisition and upload of multi-channel data has also become one of the important performances of AFE chips. The synchronization time of battery voltage measurement of mainstream AFE chips on the market is generally less than 1ms.
Therefore, the test equipment related to the AFE chip needs to ensure the synchronization of voltage output and the timeliness of communication command response during the test process.

High-precision requirements
The single-cell voltage acquisition accuracy of the AFE chip directly determines the accuracy of functions such as cell balancing, state estimation, and overcharge protection. Therefore, the chip is constantly developing and improving in terms of acquisition accuracy. At present, the voltage acquisition accuracy of the mainstream automotive-grade AFE chip in the world can reach up to 0.5mV, while the sleep power consumption is generally at the μA level.
Therefore, for the test equipment of the AFE chip, its single-cell voltage simulation accuracy should be better than 0.16mV, and it should have the measurement function of μA-level leakage current.

NGI solution
In response to the above test requirements, NGI launched theN9000 series of high-performance multi-channel modular battery simulators, which have several major features of functional modularization, high-speed synchronous control, and high precision, which can perfectly match the AFE chip test requirements:
Modular design
4U space integrates 36-channel single-cell simulation function modules, 36-channel fault simulation function modules, and 36-channel temperature simulation function modules. The space occupied by the same number of channels is 45% of the traditional solution.
High-speed synchronous control
Command response ≤1ms; 200+ channel synchronization ≤200μs, matching the requirements of synchronous acquisition and testing of mainstream AFE chips.
High precision
Test accuracy can reach 0.1mV, matching the high-precision development trend of AFE.At present, NGI's high-performance battery simulator has been widely used in global leading AFE chip companies such as NXP.