Fuse Disconnect Circuit Using Fault Latch Power From Enable Pin
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Solution Overview
Problem
Existing circuitry designs face challenges in efficiently disconnecting from a power source during fault conditions without increasing cost, size, or complexity, particularly in voltage converter circuits that handle a wide range of supply voltages, risking damage to converter and downstream components.
Innovation Solution
Incorporation of fault latch circuitry that generates a latch supply voltage from an existing pin, using open loop regulator circuitry, voltage clamp circuitry, level shifter circuitry, and latch circuitry to efficiently control fuse circuitry, allowing fault detection and disconnection without requiring additional pins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional pins are added to support fault latch circuitry operation, then fault detection capability is improved, but device complexity and cost increase
Solution Approach 1:
The enable pin of the fuse circuitry is made multi-functional by having it serve both as the enable control for the fuse and as the power source for the fault latch circuitry. This allows the fault detection system to operate without requiring additional dedicated pins, thereby improving reliability through comprehensive fault detection while avoiding increased device complexity
Solution Approach 2:
The fault latch circuitry is designed to derive its operating power from the existing enable pin voltage rather than requiring a separate power source. This self-service approach allows the fault detection system to bootstrap its operation from the existing circuitry, eliminating the need for additional pins and reducing overall device complexity while maintaining full fault detection capability
2Reliability
If additional pins are added to support fault latch circuitry operation, then fault detection capability is improved, but cost increases
Solution Approach 1:
The enable pin is designed to serve dual purposes: controlling the fuse circuitry and powering the fault latch circuitry. This multi-functionality reduces the total pin count required, which directly lowers manufacturing costs while maintaining comprehensive fault detection capability
Solution Approach 2:
The fault latch circuitry bootstraps its operation by drawing power from the existing enable pin voltage. This eliminates the need for additional power source connections and reduces the component count, thereby reducing manufacturing costs while enabling full fault detection functionality
3Object-affected harmful factors
If fuse circuitry is used to disconnect circuitry from power source, then circuitry protection is improved, but device complexity increases
Solution Approach 1:
The fault latch circuitry and fuse control logic are merged into a single integrated unit that shares common components and signaling paths. The fault latch output directly controls the fuse enable pin, eliminating the need for separate control circuitry and reducing overall device complexity while maintaining robust circuitry protection
Solution Approach 2:
The enable pin is made multi-functional to serve both as the fuse control signal and as the power source for fault detection. This consolidation reduces the number of dedicated control pins required, thereby simplifying the device architecture while maintaining comprehensive circuitry protection capabilities
Data Source
AI summary
An example apparatus includes: a supply terminal; fuse circuitry having a first terminal, a second terminal, and an enable terminal, the first terminal of the fuse circuitry coupled to the supply terminal; fault circuitry having an enable terminal and a fault terminal, the enable terminal coupled to the supply terminal, the fault terminal coupled to the enable terminal of the fuse circuitry; and converter circuitry having a terminal coupled to the second terminal of the fuse circuitry.