Reference Voltage Test Control for Low-Voltage Trimming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor integrated circuits face issues during internal voltage trimming tests, particularly when the external voltage is lower than the internal circuit voltage, leading to potential current flow from the internal circuit to the outside, which can cause problems during normal voltage trimming tests.
Innovation Solution
A test control circuit and reference voltage generating circuit are designed to include a test mode control unit, decoding portion, trimming signal adjusting portion, and reference voltage generation block, which output adjusted trimming signals to prevent current flow by reducing internal reference voltages and generating an internal reference voltage at a low level during voltage trimming tests, even when the external voltage is lower than the internal circuit voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional voltage trimming test is performed without voltage level adjustment, then normal voltage trimming test operation is achieved, but current flows from internal circuit to outside when external voltage is lower than internal circuit voltage
Solution Approach 1:
The patent applies preliminary action by adjusting the voltage level of trimming signals before they are applied to the internal circuit during voltage trimming tests. The test control circuit detects when external voltage is lower than internal circuit voltage and preemptively reduces the trimming signal voltage levels to prevent current flow from the internal circuit to the outside, thereby eliminating the harmful effect before it can occur.
2Object-generated harmful factors
If voltage level of trimming signals is adjusted to prevent current flow, then current flow to outside is prevented, but test time increases due to additional voltage level adjustment
Solution Approach 1:
The patent implements feedback by having the test control circuit continuously monitor the external voltage level and automatically adjust the trimming signal voltage levels in response. When the circuit detects that external voltage is lower than internal circuit voltage, it automatically reduces the trimming signal levels to prevent current flow, and can restore normal levels when conditions change, thereby minimizing additional test time while ensuring current flow prevention.
3Device complexity
If conventional test control circuit operates without voltage adjustment, then simple operation is maintained, but internal circuit may operate outside safe voltage range
Solution Approach 1:
The patent applies self-service by enabling the test control circuit to automatically monitor external voltage levels and adjust trimming signal voltage levels without requiring external intervention. The circuit autonomously determines when voltage adjustment is needed and performs the adjustment itself, maintaining safe operating conditions while keeping the operation transparent and simple from the user perspective.
Data Source
AI summary
A test control circuit according to an embodiment of the invention includes a test mode control unit that outputs a control signal according to a voltage trimming test signal, a decoding portion that receives the control signal and outputs a decoding signal, and a trimming signal adjusting portion that receives the decoding signal and outputs a trimming signal adjusted by a low level test signal.