Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Pull-up circuit for IO circuit

A circuit and power supply technology, applied in the direction of logic circuit, logic circuit coupling/interface using field effect transistor, logic circuit interface device, etc., can solve the problems affecting the normal output of IO circuit, and achieve the effect of preventing backflow

Active Publication Date: 2018-06-05
SEMICON MFG INT (SHANGHAI) CORP +1
View PDF4 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem solved by the present invention is that the existing pull-up circuit used for IO circuits based on fail-safe applications or IO port voltages is higher than the IO power supply voltage input under normal operation. The problem that the pull-up voltage is less than the minimum value specified by the IO logic output high voltage affects the normal output of the IO circuit

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Pull-up circuit for IO circuit
  • Pull-up circuit for IO circuit
  • Pull-up circuit for IO circuit

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0030] Those skilled in the art understand that the existing pull-up circuits for IO circuits generally adopt figure 1 The circuit configuration shown. exist figure 1 In the shown circuit structure, M1 is an NMOS transistor, M2 is a PMOS transistor, REN is a pull-up control signal, net1 is node 1 and is used to connect the source of the NMOS transistor M1 and the drain of the PMOS transistor M2. according to figure 1 The circuit structure shown, when in fail-safe mode (for example, the voltage value VDDIO of the IO power supply is suddenly powered off, while the voltage value of the IO port signal is logic high level), or the input signal voltage value of the IO port is higher than normal When the voltage value of the IO power supply under operation is VDDIO, even if the NMOS transistor M1 is turned on, the voltage value of the net1 is still smaller than the IO power supply voltage by at least the threshold voltage of M1, ensuring that there will be no transition from the IO...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a pull-up circuit for an IO circuit, which comprises an access control module, a pull-up module and a switch module, wherein the access control module and the pull-up module are connected in series between an IO port and an IO power supply; the switch module generates an access control signal according to an IO port signal and a first interface signal; when the IO port isinput or floated, the voltage value of the IO port signal is equal to the voltage value of the first interface signal; the access control signal is larger than or equal to a difference value between the IO port signal and a preset threshold voltage; an access control module is cut off or conducted under the control of the access control signal and a second interface signal; and the voltage value of the second interface signal is equal to the larger one of the voltage value of the IO power supply and the voltage value of the IO port signal. According to the technical scheme, when the voltage value of the IO port signal is larger than the voltage value of the IO power supply, current can be effectively prevented from flowing backwards from the IO port to the IO power supply; and when the IOport is floated, the requirement that the potential at the IO port can be pulled up to always be larger than the minimum value of the IO logic output high voltage is met.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a pull-up circuit for an IO circuit. Background technique [0002] Pull-up application, as a common characteristic of input / output interface (Input / Output, hereinafter referred to as IO) circuit, has been more and more applied to IO circuit to provide input / output high level value of IO circuit. In a typical IO circuit, the voltage of the IO port (PAD) is usually lower than the voltage value of the IO power supply (VDDIO), and the pull-up circuit is generally connected to the input side of the IO port PAD to pull up the voltage value of the IO port signal to It is equal to the voltage value of the IO power supply of the IO circuit. However, in practical applications, if the input voltage of the IO port PAD is greater than the voltage value of the IO power supply, or the IO power supply voltage is suddenly powered off while there is still potential on the IO port PAD, it is ver...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H03K19/0185H03K19/0175
CPCH03K19/017509H03K19/018521
Inventor 耿彦陈捷马晓媛
Owner SEMICON MFG INT (SHANGHAI) CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com