LDO Current Limiting Circuit for RF Chip High-Current Protection
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Solution Overview
Problem
Radio frequency chips are prone to damage due to high current working conditions, leading to device failure and irreversible damage, necessitating an LDO circuit with a current limiting function to provide stable voltage and protect against high current conditions.
Innovation Solution
An LDO circuit with a current limiting function, incorporating a bandgap reference circuit, error amplifier, power transistor, feedback resistor network, and a current limiting module, which includes a load current mirror, reference current unit, current comparison unit, hysteresis shaping unit, and control current output unit to manage and limit output current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the output power of the radio frequency chip is increased to meet communication technology requirements, then the application performance is improved, but the risk of device damage due to high current working conditions increases
Solution Approach 1:
The patent applies preliminary anti-action by implementing a current limiting function module that proactively prevents high current damage before it occurs. The module includes a current comparison unit that continuously compares the output current with a reference current, and when the output current exceeds the reference current, the hysteresis shaping unit generates a control signal to activate the control current output unit, which then limits the current through the power transistor. This preemptive mechanism stops harmful high current conditions before they can cause device damage, allowing the radio frequency chip to operate at high power levels safely.
2Reliability
If a current limiting function module is added to the LDO circuit to protect against high current conditions, then device reliability is improved, but the circuit complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the current limiting function into distinct modular units: a current comparison unit that compares output current with reference current, a hysteresis shaping unit that processes the comparison signal, and a control current output unit that implements the limiting action. This modular segmentation allows each unit to perform a specific function independently, making the overall complex function manageable and maintainable while integrating seamlessly with the existing LDO circuit structure.
Data Source
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AI summary
Provided are an LDO circuit having a current limiting function, and a chip and an electronic device. The LDO circuit comprises a bandgap reference circuit (101), an error amplifier (102), a power transistor (103), a feedback resistor network (104), and a current limiting function module (105), wherein the current limiting function module (105) comprises a load current mirror unit (107), a reference current unit (108), a current comparison unit (109), a hysteresis shaping unit (110), and a control current output unit (111). The current limiting function module (105) controls the on or off of a negative feedback loop and a current limiting output unit in the LDO circuit by comparing a load current with a reference current, so as to control an output current, thereby providing a stable direct current bias voltage for a radio frequency chip under working conditions such as large power and a complex application environment.