CXLB7296 is a high-end power management chip designed specifically for modern portable devices, packaged in DFN4x4-28. This chip integrates complete charging management, boost conversion, and system control functions, and only requires a single inductor to achieve bidirectional power flow. The control architecture of its patent eliminates the current detection resistor required for traditional constant current control, significantly improving system efficiency and reducing overall costs.
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[ CXLB7296 ]"
CXLB7296: Deep technical analysis of innovative single inductor bidirectional power management chip
In today's increasingly popular portable electronic devices, efficient and compact power management solutions have become the core of product design. CXLB7296, as an advanced power management chip that integrates 3A switch charging, 2.4A boost output, and intelligent power metering, provides unprecedented integration and performance for mobile power banks, smartphones, and tablet devices through innovative single inductor bidirectional architecture and charge pump technology.
Product Core Overview
CXLB7296 is a high-end power management chip designed specifically for modern portable devices, packaged in DFN4x4-28. This chip integrates complete charging management, boost conversion, and system control functions, and only requires a single inductor to achieve bidirectional power flow. The control architecture of its patent eliminates the current detection resistor required for traditional constant current control, significantly improving system efficiency and reducing overall costs.
The chip has a built-in microcontroller function that supports button control, automatic load detection, and precise power metering, providing a complete solution for charging and discharging applications with a single USB port. Whether it's a power bank, smartphone, or tablet device, CXLB7296 can provide excellent performance and reliability.
Core technical characteristics
Innovative power architecture
• Single inductor bidirectional conversionThe same inductor achieves charging and discharging functions, greatly saving space
• Charge pump technologyRealize extremely fast input voltage protection response
• 20V input withstand voltageProvide powerful overvoltage protection capability
• Non sensing resistor designPatent control scheme improves efficiency and reduces costs
Efficient charging management system
• high-current chargingSupport up to 3A charging current, quickly restore battery energy
• Dual voltage optionSupports two battery charging voltages of 4.2V and 4.35V
• Intelligent charging management: Includes the entire process of pre charging, constant current charging, and constant voltage charging
• Precise termination controlProgrammable charging termination current threshold
Stable boost output performance
• 5V boost outputProvide stable output voltage of 5.0V-5.1V
• 2.4A output capabilityMeet the charging needs of most USB devices
• High conversion efficiencyThe overall efficiency can reach up to 95%
• Intelligent load detectionAutomatically identify the status of load insertion
Comprehensive system functionality
• Four light battery level displayIntuitive battery level visual feedback
• Flashlight functionIntegrated LED driver capability
• temperature monitoringNTC thermistor input ensures a safe temperature range
• Button controlSupport one click activation of boost and flashlight functions
Detailed technical parameters
Charging mode characteristics
• Input voltage range：4.5V-5.5V
• Input voltage withstand: Maximum 20V
• Charging termination voltage: 4.2V (default) or 4.35V (configurable)
• Pre charge threshold3.0V (with 200mV hysteresis)
• Pre charging current：200mA
• Fast charging currentUp to 3A (set through resistance)
Boost mode characteristics
• output voltage：5.0V-5.1V
• output currentMaximum 2.4A
• switching frequency：0.8MHz-1.2MHz
• quiescent current: 100μ A (boost mode)
• Turn off the current: 30μ A (idle mode)
Power device parameters
• High end PMOS Rdson：55mΩ
• Low end NMOS Rdson：50mΩ
• maximum duty cycle：90%
• short circuit protection4A hiccup mode protection
Comprehensive protection mechanism guarantees
Electrical protection function
• Input Overvoltage Protection: 20V tolerance
• Output short circuit protectionHiccup mode, 25ms on/750ms off
• Charge pump protection300mV hysteresis voltage protection
• ESD protection: 2kV HBM, 200V MM grade
Thermal Management and Safety
• Thermal regulation threshold：85℃
• Thermal shutdown protection160 ℃ shutdown, 130 ℃ recovery
• NTC temperature monitoringSupports a temperature range of 52% -13%
• Multiple fault protectionEnsure the safety of the system under various abnormal conditions
Detailed explanation of pin functions
Power pin group
• SW（2,3,27）Switch pin, connected to power inductor
• OUT（4,5,6）USB 5V output/charging input pin
• BATT（26）Battery voltage detection pin
• PGND（1,28）: Power ground pin
Control and monitoring pins
• BUTT（13）Key detection pins, control boost and flashlight functions
• ENBST（15）Manual forced boost control pin
• NTC（22）Battery temperature monitoring input
• ISET（23）Charging current setting pin
Electricity metering and display
• LED1-4（17-20）Four segment battery indicator light
• LDO1V（21）: 1V LDO output, used for voltage division of electricity meter resistors
• FLASH（16）Flashlight LED driver pin
Typical Application Design Guidelines
Power inductor selection
Recommend using saturated current greater than 5A and DC resistance less than 50mΩ The power inductance is selected based on the operating frequency and maximum current requirement.
Capacitor configuration scheme
• Input capacitor：2× 22-F MLCC capacitor, located near the OUT pin
• output capacitorMLCC capacitors with appropriate capacitance to ensure stability
• Charge pump capacitorChoose the appropriate capacity value based on the working frequency
Best Practices for PCB Layout
Optimized PCB layout is crucial for performance:
• Power path：Cout、 Inductors and Cin are placed according to the recommended layout
• thermal designConnect the heat dissipation pad to the back ground plane through the through-hole
• Signal IntegritySimulate signal lines away from power switch nodes
• Grounding strategySeparate layout of power ground and analog ground, single point connection
Deep analysis of application scenarios
High end mobile power bank
CXLB7296 performs excellently in mobile power applications:
• high integrationSingle chip completes all power management functions
• High current support3A charging and 2.4A discharging meet the fast charging requirements
• intelligent controlAutomatic load detection and power display
• compact designDFN4x4-28 packaging greatly saves space
Smartphones and tablets
Unique advantages in smart devices:
• Single port designSame USB port for charging and OTG functions
• Efficient Charging3A charging significantly reduces charging time
• system integrationSeamless integration with the host processor
• Space optimizationExtremely small board area suitable for compact layout
Other portable devices
Wide applicability:
• Portable medical equipment
• Industrial handheld terminal
• IoT devices
• Consumer electronics products
Summary of Performance Advantages
Technological Leadership
• Leading industry in single inductor bidirectional power architecture
• Charge pump technology achieves fast voltage protection
• Innovative design of current free detection resistor
Performance Excellence
• Charging and boosting dual-mode high efficiency
• High current output capability
• Accurate system control and monitoring
Application flexibility
• Wide range operating voltage
• Rich control and display interfaces
• Adapt to multiple battery types
Reliability assurance
• Comprehensive protection mechanism
• Industrial grade temperature range
• Excellent EMI characteristics
Design validation and measured performance
In practical application testing, CXLB7296 demonstrated excellent performance:
Efficiency test data
• charging efficiencyUnder 3A charging current, the efficiency exceeds 92%
• Boosting efficiencyUnder 2A output current, the efficiency remains above 90%
• Light load efficiencyExtremely low static current consumption in standby mode
Thermal performance
• Excellent temperature control during normal operation
• The thermal protection mechanism responds promptly and accurately
• Good heat dissipation capability under compact packaging
Dynamic response characteristics
• Fast and stable transient response of load
• Mode switching without impact
• Stable and reliable startup process
Design points and troubleshooting
Common design considerations
• Inductance saturationEnsure that the saturation current of the inductor is greater than the peak switching current
• Layout optimizationStrictly follow the recommended layout to reduce EMI issues
• thermal managementEnsure adequate heat dissipation in high temperature environments
Troubleshooting Guide
• Startup failureCheck VDD voltage and enable signal
• inefficientVerify the selection and layout of power devices
• stability issueCheck the compensation network and feedback loop
Conclusion
CXLB7296 provides an ideal power management solution for modern portable devices with its innovative single inductor bidirectional architecture, efficient charge pump technology, and complete system integration. Whether in power banks, smartphones, or other portable devices, this chip can provide excellent performance, reliability, and user experience.
With the increasing demand for power management in portable devices, CXLB7296 will continue to play an important role in the field of power management due to its high integration, high efficiency, and high reliability.
For detailed technical information, sample applications, or design support for CXLB7296, please visit the JTM-IC official website;jtm-ic.comOur professional technical team will provide you with comprehensive technical support and services.
article authorJTM-IC Technical Team
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