Bidirectional HV Switch Circuit With Programmable Resistance Modules
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Solution Overview
Problem
Existing high voltage bidirectional power switches require large area HV devices/switches for resistance programming/trimming, leading to integration challenges and potential device breakdowns under high voltage/current conditions.
Innovation Solution
A high voltage bidirectional power switch circuit design that includes a HV block with two series-connected HV transistors and a parallel resistance network of switchable resistance modules, each with precision resistors, biasing resistors, and body bias control, using switchable current sources to manage transistor bias and enable/disable the switches, allowing bidirectional current flow and voltage blocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If large area HV devices/switches are used for resistance programming and trimming, then accurate programmable resistance is achieved, but device area increases and integration becomes difficult
Solution Approach 1:
The resistance network is divided into multiple switchable resistance modules connected in parallel, each module containing precision resistors and control circuitry. This segmentation allows accurate resistance programming through selective switching of smaller resistance units rather than requiring a single large HV device, thereby achieving precise resistance control while reducing overall device area and improving integrability.
2Measurement precision
If large area HV switches are used, then resistance trimming capability is achieved, but device breakdown risk increases under high voltage/current conditions
Solution Approach 1:
The resistance trimming function is distributed across multiple switchable resistance modules rather than concentrated in a single large HV switch. Each module operates at lower voltage stress levels, reducing the risk of device breakdown while collectively providing the full resistance trimming range and accuracy through parallel configuration and selective switching.
Solution Approach 2:
The patent introduces a body bias control circuit as an intermediary element that controls the bias of body diodes in the resistance switching transistors. This intermediary control mechanism enables precise resistance trimming through gradual bias adjustment rather than direct high-voltage switching, reducing stress on HV devices and preventing breakdown while maintaining trimming accuracy.
3Reliability
If conventional HV switch design is used, then high voltage blocking capability is achieved, but integration on chip becomes challenging
Solution Approach 1:
The high voltage blocking function is segmented into two series-connected HV transistors in the HV block, each handling a portion of the voltage stress. This segmentation allows the use of smaller, more integrable transistor devices while collectively achieving the required high voltage blocking capability, thereby enabling chip integration without sacrificing voltage handling performance.
Solution Approach 2:
The body bias control circuit serves as an intermediary that enables precise control of the resistance switching transistors through bias adjustment rather than direct high-voltage signal manipulation. This intermediary control approach allows standard CMOS fabrication processes to be used, improving ease of manufacture and chip integration while maintaining high voltage blocking capability through the series-connected HV transistor structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves accurate programmable/trimmable resistance with bidirectional power switch functionalities, supporting high voltages and currents without requiring large HV switches, thus enabling integration on a chip and preventing device breakdowns.
Implementation Method 1
a precision resistor connected (or coupled) in series with a conduction channel of a resistance switching transistor
Implementation Method 2
a body bias control circuit configured to control a bias of body diodes of the resistance switching transistor
Implementation Method 3
a switchable sourcing current source comprising a first current source and a first source switch connected in series between a positive voltage supply terminal and the control terminal of the resistance switching transistor
Data Source
AI summary
The present disclosure relates to a high voltage bidirectional power switch circuit that includes a high voltage block coupled to a first terminal; and a resistance network including modules connected in parallel with each other between the high voltage block and a second terminal. Each module includes a precision resistor connected in series with a conduction channel of a resistance switching transistor; a first biasing resistor connected between a first conduction channel terminal and a control terminal of the resistance switching transistor; a second biasing resistor connected between a second conduction channel terminal and the control terminal; a body bias control circuit configured to control a bias of body diodes of the resistance switching transistor; a switchable sourcing current source; and a switchable sinking current source. Switches of the switchable sourcing current source and the switchable sinking current source receive switching signals to control the resistance switching transistor.