New Product Recommendation: Zhongwei Aixin has launched the AiP4728X, a single-cell lithium‑ion battery protection chip with ultra‑low on‑resistance.
Product Overview
The AiP4728x is a highly integrated single‑cell lithium‑ion battery protection chip with built-in MOSFETs, combining ultra‑low power consumption, high‑precision monitoring, and comprehensive multi‑dimensional protection. Housed in an ultra‑compact SOT23‑5 package, it requires only one resistor and one capacitor in the external circuitry, making it ideally suited for lithium‑ion‑powered devices such as smart wearables, portable small appliances, and compact energy‑storage systems, thereby delivering efficient and reliable safety protection for the battery.
- Normal operation : Real-time monitoring of battery voltage/current, enabling unrestricted charging and discharging
- Overcharge protection : When the voltage exceeds the threshold, the MOS is turned off, and charging stops.
- Over-discharge protection : When the voltage drops below the threshold, the MOS is turned off, and the system enters low-power mode.
- Overcurrent during charging and discharging : Rapid shutdown upon overcurrent to prevent damage to the battery and equipment.
- Short-circuit protection : 250μs ultra-fast shutdown to prevent extreme risks
- Over-temperature protection : Automatic protection at 160℃, recovery at 110℃, preventing thermal runaway.
- 0V charging : Supports deep‑discharge battery activation, enhancing product usability.
Product Advantages
Built-in 17 mΩ low‑resistance MOS , low conduction loss and minimal heat generation, ensuring greater stability under high-current conditions
Ultra-low power consumption : 2 μA in normal operation, 1.3 μA in over-discharge mode, and only 0.2 μA in sleep mode
All-Scenario Security Protection : Comprehensive protection against overcharging, over-discharging, overcurrent during charging and discharging, short circuits, overheating, and reverse polarity connection.
High-precision voltage detection , with tightly controlled errors and precise, timely protection responses
Supports charging batteries at 0V , deeply discharged batteries can be safely activated
Dual overcurrent and short-circuit rapid protection , fast response and high security
SOT23‑5 small package , Saves board space, ultra‑compact BOM, and mass‑production friendly
Key parameters
Operating current: Normal 2 μA | Over-discharge 1.3 μA | Sleep 0.2 μA
Overcharge protection: threshold voltage ±50 mV
Over-discharge protection: 2.4 V
Overcurrent during charging and discharging: 7 A for charging | 9 A for discharging | 27 A in short circuit
Protection delay: Overcharge 150 ms | Overdischarge 55 ms | Overcurrent 10 ms | Short circuit 250 µs
Over-temperature protection: 160°C shutdown, automatic recovery at 110°C.
Package: SOT23‑5
Pinout Diagram
Pin Description
Protection Trigger Timing Diagram
Overcharge and overdischarge protection
Note: (1) Normal operation (2) Overcharge condition (3) Overdischarge condition
Charge overcurrent and discharge overcurrent protection
Note: (1) Normal operation; (4) Charging overcurrent condition; (5) Discharging overcurrent condition.
Application areas
- Portable fans, beauty devices, and small electric gadgets
- Handheld barcode scanner, LED portable light, compact energy storage
- E-cigarettes, toys, and various single-cell lithium‑ion portable devices
Typical Application Circuit
Minimalist Battery Charge–Discharge Protection Circuit Design
Design of a Battery Protection Circuit Using an RC1 Chip
Minimalist exterior design: R1 = 1 kΩ, C1 = 0.1 μF , must be placed close to the chip; high-current paths are thickened and shortened to optimize thermal performance and reliability.
- Typical Application Solution for AiP4056x + AiP4728x
In this scheme, when a charger is connected, the PMOS transistor turns on while the MOS transistor turns off. The charger can either supply power directly to the load or charge the battery via the AiP4056x; meanwhile, the AiP4728x provides charging protection for the lithium‑ion battery. When the battery reaches the overcharge protection threshold or other abnormal conditions occur, the internal MOS transistor within the chip is turned off, halting further charging.
When the charger is disconnected, the PMOS transistor turns off, and the battery takes over as the power source. If the battery voltage falls below the AiP4728x’s undervoltage protection threshold or other abnormal conditions occur, the AiP4728x triggers undervoltage protection, turning off the internal MOSFETs so that the battery no longer discharges externally. At the same time, the chip enters sleep mode to minimize battery power consumption.
Typical application solution for AiP4056 + AiP4728x
Note:
- The over‑voltage threshold of the lithium‑ion battery protection chip AiP4728x should be slightly higher than the full‑charge voltage threshold of the AiP4056x.
- In this design, the diode has a forward voltage drop of 0.3 V and a current-handling capability of 3 A. Depending on the supply voltage range, the number of diodes can be reduced to a single unit.
- In this design, the PMOS transistor has an overcurrent capability of 2.3 A; please replace it according to the actual required discharge current of the lithium battery.
- In PCB design, high-current traces should be widened and shortened to optimize thermal performance and reliability.
- If the overcharge protection threshold of the AiP4728x is lower than the voltage‑at‑full‑charge point of the AiP4056x, then when the AiP4728x triggers its overcharge protection while the AiP4056x has already reached its full‑charge voltage, the external charging indicator LED on the AiP4056x may exhibit a low‑frequency dimming flash.
Conclusion
With its high integration, low power consumption, comprehensive protection features, and minimalist external circuitry, the AiP4728x has become the preferred domestically produced, cost‑effective solution for single‑cell lithium‑ion battery protection, helping customers accelerate mass production while enhancing product safety and extending battery life.
(Source: Zhongwei Aixin official website)
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