In recent years, with the implementation of new national standards and the emergence of new application scenarios such as balanced cars, scooters, and shared electric bicycles, the electric and two wheeled vehicle markets have ushered in a new development trend. Lithium batteries are increasingly sought after by manufacturers due to their high energy density and multiple cycles. For different application scenarios, users often need to choose different  BMS architecture, such as electric motorcycle, needs to achieve higher power and use multiple AFE cascades to support more battery strings; The charging and discharging currents of electric bicycles vary greatly, requiring separate charging and discharging circuit paths to optimize costs. Therefore, the safety of widely used lithium batteries also requires stricter monitoring and protection by the Battery Management System (BMS).

The latest product from Suming Semiconductor; The SiLM266x series can flexibly meet the monitoring and protection needs of lithium batteries in different application scenarios, providing reliability and design flexibility for battery system protection. SiLM2660/61 is a low-power, high side N-channel FET driver used for battery charging/discharging system control. The high side protection function prevents the grounding pin of the system from being disconnected, ensuring continuous communication between the battery pack and the host system. SiLM2660 integrates PACK+voltage monitoring and control, supporting host sensing of PACK+voltage; And it has an additional PFET control output, allowing for low current pre charging of deeply discharged batteries. The SiLM266x series provides  The simplified version of SiLM2660, SiLM2661, does not have pre charging and battery PACK+voltage detection functions, and is packaged in SOP8. SiLM2660 is packaged in TSSOP-16. It can be widely used in various scenarios in the industrial and energy fields, such as electric bicycles, electric scooters, electric motorcycles, energy storage systems and uninterruptible power supplies, portable medical systems, wireless base station battery systems, lead-acid backup batteries, 12V to 48V battery packs, etc.

Figure 1 Typical application diagram of SiLM2661

Figure 2 Typical application diagram of SiLM2661

The SiLM266x series has an independent enable input interface, allowing for independent control of battery charging and discharging FETs on and off. For certain application scenarios, such as when the charging and discharging currents of electric bicycles differ significantly, separate charging and discharging circuit paths can be set to optimize costs. The charging current of general electric vehicle lithium battery packs is smaller than the discharge current. If using the same charging and discharging port scheme, it is necessary to choose more charging MOSFETs than the actual demand, which will cause unnecessary waste. In addition, whether charging or discharging, all current needs to pass through the charging and discharging MOSFETs, which will generate more losses and heat, and to some extent reduce the effective capacity of the battery. The charging and discharging scheme can be selected separately according to the actual charging and discharging current requirements; The number and model of MOSFETs and discharge MOSFETs, whether charging or discharging, only pass through the first level MOSFET, resulting in less loss and heat generation. The SiLM266x series supports both the same port charging and discharging solutions and different port charging and discharging solutions to meet different customer needs.

Figure 3. Charging and discharging special interface scheme

Product characteristics

·&Nbsp; High Edge; NFET driver
Has extremely short opening and closing time for quick battery protection

·&Nbsp; Pre charging; PFET drive
Provide current limiting pre charging function for deeply depleted battery packs (only applicable to SiLM2660)

·&Nbsp; Independent enabling control for charging and discharging
1. Allow independent control of battery charging and discharging FETs for their conduction and shutdown;
2. Support configurable universal and independent charging and discharging path management.

·&Nbsp; Scalable charge pump based on external capacitors
Suitable for multiple  NFET parallel drive

·&Nbsp; Withstand high voltage
The absolute highest voltage can reach  100V

·&Nbsp; Configurable battery pack voltage detection function
Flexible monitoring and protection of lithium batteries in different scenarios (only applicable to SiLM2660)

·&Nbsp; low power consumption
Normal mode: 40 μ A
Standby mode: less than  ten μ A

·&Nbsp; Optional packaging
SiLM2660: TSSOP-16
SiLM2661: SOP8