The CXLB73335 is a complete single lithium ion/lithium polymer battery charge management chip in a compact SOT23-6 package. The biggest highlight is that it integrates the reverse connection protection function of the positive and negative poles of the battery, thus fundamentally avoiding the risk of circuit damage caused by incorrect battery installation. The chip supports a wide range of programmable charging current from 10mA to 600mA and is compatible with USB ports and standard power adapter, greatly simplifying the charging circuit design.
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[ CXLB73335 ]"
CXLB73335 single lithium battery charger chip: provides efficient and safe battery management solutions for portable devices
In today's era of highly dependent on portable electronic devices, the safe and efficient charging of lithium batteries has become a key link in product design. As a complete single lithium battery charger chip, CXLB73335 has become an ideal choice for all kinds of portable devices due to its high integration, multiple protection mechanisms and flexible application design. This article will deeply analyze the functional features, working principles and application suggestions of CXLB73335 to help engineers better understand and apply the chip.
I. Product Overview
CXLB73335 is a single lithium battery charger chip that supports programmable charging current from 10mA to 600mA, with the reverse connection protection function of the positive and negative poles of the battery. It adopts three-stage Charging Control of eliminating current, constant current and constant voltage, and has built-in thermal regulation circuit, which can automatically optimize the charging current under different ambient temperatures to ensure the safety and stability of the charging process. Its SOT23-6 package is small in size and few peripheral components, which is very suitable for portable devices with limited space, such as smart wearable devices, Bluetooth headphones, mobile power supplies, etc.
Second, the core features
· Wide range charging current adjustable: the charging current can be easily set through an external resistor to meet various requirements from low-power devices to large-capacity batteries.
· Battery reverse connection protection: When the positive and negative poles of the battery are connected in reverse, the chip automatically enters the protection state without charging current output, effectively preventing battery and circuit damage.
· Temperature monitoring and protection: Supports external NTC thermistor to monitor the battery temperature in real time to avoid potential safety hazards caused by over-temperature or low-temperature charging.
· Power supply adaptive function: When the input voltage is low, the charging current is automatically reduced to ensure the stable operation of the system when the USB or small power adapter is powered.
· High Precision voltage control: Float-charge pressure accuracy reaches ± 1%, ensuring accurate battery charging voltage and extending battery life.
· Multiple working modes: supports current elimination charging, constant current charging, constant voltage charging and automatic recharging, and the whole charging process is controllable.
III. Working principle and charging process
CXLB73335 adopt constant current/constant voltage (CC/CV) charging algorithm. The charging process is divided into three stages:
·Discharge charging stage: When the battery voltage is lower than 2.9V, the chip is precharged with a small current of about 20% of the set current to wake up the battery and raise its voltage to a safe range.
·Constant current charging stage: After the battery voltage rises above the elimination threshold, the chip charges quickly with the set current.
·Constant voltage charging stage: When the battery voltage is close to 4.2V, it turns to constant voltage charging, and the current decreases gradually. When the current drops to 1/10 of the set value, the charging automatically terminates and enters the standby mode.
4. Typical application circuit
CXLB73335 the peripheral circuit is simple, and only a few components are needed to realize the complete charging function. In typical applications, we recommend that you connect a 10CF ceramic capacitor to each of the VCC and BAT pins for filtering and voltage stabilization. If high current charging is required (for example, more than 500mA), a 0.3Ω ~ 0.6Ω dissipation resistor can be connected in series at the VCC terminal to improve system stability and heat dissipation performance.
V. Battery temperature monitoring design
The chip is connected to the external NTC thermistor through the TS pin to realize temperature monitoring. The internal threshold values are 45% and 80% of VCC respectively. When the TS voltage exceeds this range, the charging is suspended until the temperature returns to normal. Users can select appropriate divider resistance R1 and R2 through simple calculation according to battery specifications and temperature ranges to realize customized temperature protection strategies.
VI. Status indication and system integration
CXLB73335 CHRG pin with open drain output can directly drive LED or connect MCU for charging status monitoring. The CHRG output is low when charging, and the high resistance state is output when it is full or abnormal. In addition, the chip also supports manual shutdown mode, which can enter the low power consumption state by disconnecting the PROG resistor, and the static current is lower than 95μa.
VII. Suggestions on thermal management and reliability
Due to the SOT23-6 small package, heat dissipation design should be paid attention to in high-current applications. Suggestions:
·Try to expand the chip grounding area by copper foil in PCB layout;
·Avoid arranging other heating components around the charger;
·Select the appropriate dissipation resistor according to the actual input voltage;
·The input voltage is recommended to be about 4.8V to achieve the best charging efficiency.
VII. Wide range of applications
CXLB73335 applicable to all kinds of single lithium battery power supply equipment, including but not limited:
·Smart watches, wristbands and other wearable devices
·Bluetooth headset, speaker and other audio products
·Portable Medical Equipment
·Mobile power supply, charging set
·Handheld instrument and intelligent hardware
VIII. Conclusion
CXLB73335 has become the preferred solution for charging management of single lithium battery due to its high integration, multiple protection mechanisms and flexible design options. It can provide safe, efficient and reliable charging performance in consumer electronics, medical equipment and industrial applications. Welcome to our official websitejtm-ic.comGet more product information, technical support and sample application.
IX. Summary of this article: CXLB73335 is a comprehensive, safe and reliable single lithium battery charger chip, suitable for all kinds of portable electronic devices. It supports many practical functions such as reverse connection protection, temperature monitoring, and adjustable current. With simple peripheral circuits, it can greatly improve product safety and user experience. For more information and application support, visitjtm-ic.com.
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