CXLB73273 is a high-performance and highly integrated linear charging management chip, suitable for 1 to 3 lithium ion or lithium polymer batteries. Its input voltage range is 4V ~ 24V, which can withstand up to 38v instantaneous surge voltage and effectively cope with adapter voltage fluctuation or plug-in impact. The chip has a complete charging management process, including three stages: current elimination charging (TC), constant current charging (CC) and constant voltage charging (CV). The charging voltage accuracy is as high as ± 0.5%, the maximum charging current can reach 1A.
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[ CXLB73273 ]"
Today, portable electronic devices are constantly pursuing longer battery life and higher safety, the performance of lithium battery charging management chips is particularly critical. CXLB73273 as a highly integrated linear charger supporting 1 to 3 lithium ion batteries, it not only has an input withstand voltage of up to 38V and a charging voltage accuracy of ± 0.5%, but also supports flexible programmable configuration, it is widely used in scenarios such as electronic cigarette, walkie-talkie charging set, handheld POS machine, wearable device and Bluetooth speaker. This article will systematically introduce its core features, configuration methods and typical applications to help engineers achieve safer and more efficient power supply design.
I. Product Overview
CXLB73273 is a high-performance and highly integrated linear charging management chip, suitable for 1 to 3 lithium ion or lithium polymer batteries. Its input voltage range is 4V ~ 24V, which can withstand up to 38v instantaneous surge voltage and effectively cope with adapter voltage fluctuation or plug-in impact. The chip has a complete charging management process, including three stages: current elimination charging (TC), constant current charging (CC) and constant voltage charging (CV). The charging voltage accuracy is as high as ± 0.5%, the maximum charging current can reach 1A.
CXLB73273 is packaged with ESOP-8, which has good heat dissipation performance and compact layout, and is suitable for portable devices with limited space.
II. Core functions and features
2.1. Flexible battery type and voltage configuration
The chip supports a variety of lithium battery chemical systems, including:
·Standard lithium ion battery: 4.2V, 4.35V, 4.4V
·Lithium iron phosphate battery: 3.6V
·Multiple series batteries: 2s and 3s (to be customized)
Users can set the target charging voltage through the external resistor of the VSET pin, and can also customize the voltage value (step 50mV) at the factory to meet the charging requirements of different battery pack.
2.2. Programmable charging current and cut-off current
The charging current is set by an external resistor (1 kOhm to 40 Kohm) on the ISET pin, ranging from 25mA to 1A. The cut-off current is 1/10 of the constant current by default, and can be customized to 1/20, 1/5, or 1/2.5, with a minimum of 10mA, effectively avoiding overcharging of the battery.
2.3. Multiple security protection mechanisms
·Input overvoltage and undervoltage protection: With 5.8V input overvoltage protection and 4v undervoltage locking function
·Battery overvoltage protection: stops charging when VBAT > CV 200mV
·Temperature Protection: supports NTC thermistor monitoring battery temperature, with three levels of protection: over temperature, medium temperature, and low temperature
·Chip Thermal Management: automatically reduces flow when junction temperature reaches 120 ℃, and turns off output when 150 ℃
·Charging timeout protection: Built-in configurable timer to prevent abnormal charging retention
2.4. Low power consumption design and status indication
In standby mode, the battery leakage current is as low as 1μa, which greatly prolongs the storage time of the device. CHGLED pin supports charging status indication (such as flashing, always on, and off). You can select standard or customization lamp display mode according to product requirements.
3. Typical application scenarios
·Electronic cigarette equipment: CXLB73273 high-precision and high-temperature protection mechanism to ensure the safety and consistency of the battery during frequent charging and discharging
·Handheld POS machine and Interphone: Supports 2s/3S battery pack to adapt to various industrial power environments
·Wearable devices and Bluetooth speakers: small size, low quiescent current characteristics, fit the power consumption and size limits of wearable and audio products
·Customized mobile devices: users can flexibly adapt to different battery systems and charging strategies through resistor configuration or factory customization.
IV. Key parameter Configuration Guide
4.1. Charging current setting
Constant current charging current is determined by the following formula:
For example:
·RISET=1kΩ → ICC= 1A
·RISET=10kΩ → ICC= 0.1A
4.2. Charging voltage setting
Set the target voltage through the VSET pin resistor:
|
R_VSET |
Charging voltage (CV) |
|---|---|
|
1 kOhm |
4.2V |
|
15 Kohm |
4.35V |
|
39 Kohm |
4.4V |
|
75 Kohm |
3.6V |
|
Suspended |
Factory Default (usually 4.2V) |
4.3. Timer configuration
You can set the charging timeout time through the TIMER pin grounding (using the internal clock) or external capacitor (custom frequency) to avoid unlimited charging due to battery abnormalities.
V. Design attention
5.1. Layout suggestions: the pin of VIN and BAT should be arranged with decoupling capacitor nearby. The high current path adopts large area copper laying, and the heat dissipation pad is connected to the ground plane through multiple vias to improve the heat dissipation performance.
5.2. NTC configuration: If the temperature detection function is not used, the NTC pin should be grounded to shield the function.
5.3. Input power selection: Although the chip withstand voltage reaches 38V, it is recommended that the working voltage does not exceed 24V to ensure the long-term stable operation of the system.
VI. Selection and technical support
JTM-IC (official website:jtm-ic.com) provide CXLB73273 full series models, including:
·CXLB73273: standard single battery version
·CXLB73273_2S/3s: customized version of multiple batteries
·CXLB73273_DA: custom light display version
We can provide customers with samples, technical documents and reference designs to help products go on the market quickly.
VII. Definition of packaging and pin functions
8. Schematic diagram of typical applications
Nine, Conclusion
CXLB73273 has become an ideal choice for lithium battery charging management in portable devices due to its high integration, high precision and high reliability. Whether in industrial equipment or consumer electronics, the chip can provide safe, efficient and flexible charging solutions. Welcome to the JTM-IC official website for more details, or contact our technical support team for personalized services.
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