AU2001257544A1 - A process control transmitter having an externally accessible dc circuit common - Google Patents

A process control transmitter having an externally accessible dc circuit common

Info

Publication number
AU2001257544A1
AU2001257544A1 AU2001257544A AU5754401A AU2001257544A1 AU 2001257544 A1 AU2001257544 A1 AU 2001257544A1 AU 2001257544 A AU2001257544 A AU 2001257544A AU 5754401 A AU5754401 A AU 5754401A AU 2001257544 A1 AU2001257544 A1 AU 2001257544A1
Authority
AU
Australia
Prior art keywords
process control
control transmitter
externally accessible
circuit common
common
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
AU2001257544A
Inventor
Richard L. Nelson
Weston Roper
Brian L Westfield
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rosemount Inc
Original Assignee
Rosemount Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rosemount Inc filed Critical Rosemount Inc
Publication of AU2001257544A1 publication Critical patent/AU2001257544A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G08SIGNALLING
    • G08CTRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
    • G08C19/00Electric signal transmission systems
    • G08C19/02Electric signal transmission systems in which the signal transmitted is magnitude of current or voltage
AU2001257544A 2000-05-15 2001-05-04 A process control transmitter having an externally accessible dc circuit common Abandoned AU2001257544A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US09/571,111 US6504489B1 (en) 2000-05-15 2000-05-15 Process control transmitter having an externally accessible DC circuit common
US09571111 2000-05-15
PCT/US2001/014521 WO2001088643A2 (en) 2000-05-15 2001-05-04 A process control transmitter

Publications (1)

Publication Number Publication Date
AU2001257544A1 true AU2001257544A1 (en) 2001-11-26

Family

ID=24282370

Family Applications (1)

Application Number Title Priority Date Filing Date
AU2001257544A Abandoned AU2001257544A1 (en) 2000-05-15 2001-05-04 A process control transmitter having an externally accessible dc circuit common

Country Status (5)

Country Link
US (1) US6504489B1 (en)
JP (1) JP3859515B2 (en)
AU (1) AU2001257544A1 (en)
DE (1) DE10196182B4 (en)
WO (1) WO2001088643A2 (en)

Families Citing this family (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7134354B2 (en) * 1999-09-28 2006-11-14 Rosemount Inc. Display for process transmitter
US6484107B1 (en) * 1999-09-28 2002-11-19 Rosemount Inc. Selectable on-off logic modes for a sensor module
US7430746B2 (en) * 2001-03-23 2008-09-30 Endress & Hauser Process Solutions Ag Method for operating a field transmitter
JP3753057B2 (en) * 2001-12-04 2006-03-08 株式会社日立製作所 Gas flow measuring device
US7773715B2 (en) * 2002-09-06 2010-08-10 Rosemount Inc. Two wire transmitter with isolated can output
US6904476B2 (en) 2003-04-04 2005-06-07 Rosemount Inc. Transmitter with dual protocol interface
US7330695B2 (en) 2003-12-12 2008-02-12 Rosemount, Inc. Bus powered wireless transmitter
US8145180B2 (en) * 2004-05-21 2012-03-27 Rosemount Inc. Power generation for process devices
US8160535B2 (en) 2004-06-28 2012-04-17 Rosemount Inc. RF adapter for field device
US7262693B2 (en) * 2004-06-28 2007-08-28 Rosemount Inc. Process field device with radio frequency communication
US7200503B2 (en) 2004-12-29 2007-04-03 Endrss + Hauser Flowtec Ag Field device electronics fed by an external electrical energy supply
US8452255B2 (en) 2005-06-27 2013-05-28 Rosemount Inc. Field device with dynamically adjustable power consumption radio frequency communication
US8000841B2 (en) * 2005-12-30 2011-08-16 Rosemount Inc. Power management in a process transmitter
US7525419B2 (en) * 2006-01-30 2009-04-28 Rosemount Inc. Transmitter with removable local operator interface
DE102006024742A1 (en) 2006-05-26 2007-12-06 Siemens Ag transmitters
US8847571B2 (en) 2008-06-17 2014-09-30 Rosemount Inc. RF adapter for field device with variable voltage drop
US8929948B2 (en) * 2008-06-17 2015-01-06 Rosemount Inc. Wireless communication adapter for field devices
JP5232299B2 (en) * 2008-06-17 2013-07-10 ローズマウント インコーポレイテッド RF adapter for field devices with loop current bypass
US8694060B2 (en) * 2008-06-17 2014-04-08 Rosemount Inc. Form factor and electromagnetic interference protection for process device wireless adapters
CN102084307B (en) * 2008-06-17 2014-10-29 罗斯蒙特公司 RF adapter for field device with low voltage intrinsic safety clamping
US8626087B2 (en) * 2009-06-16 2014-01-07 Rosemount Inc. Wire harness for field devices used in a hazardous locations
US9674976B2 (en) 2009-06-16 2017-06-06 Rosemount Inc. Wireless process communication adapter with improved encapsulation
US8334788B2 (en) * 2010-03-04 2012-12-18 Rosemount Inc. Process variable transmitter with display
KR101155898B1 (en) * 2010-05-12 2012-06-20 삼성모바일디스플레이주식회사 Organic light emitting display and driving method thereof
US10761524B2 (en) 2010-08-12 2020-09-01 Rosemount Inc. Wireless adapter with process diagnostics
US9310794B2 (en) 2011-10-27 2016-04-12 Rosemount Inc. Power supply for industrial process field device
KR20150142943A (en) * 2014-06-12 2015-12-23 삼성디스플레이 주식회사 Organic light emitting display device
US10461562B2 (en) 2017-06-27 2019-10-29 Rosemount Inc. Field device charging power regulation
US10480985B2 (en) * 2017-09-29 2019-11-19 Rosemount Tank Radar Ab Explosion proof radar level gauge
DE102019215409B4 (en) * 2019-10-08 2022-10-06 Festo Se & Co. Kg Field device coupling device and field device

Family Cites Families (129)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3701280A (en) 1970-03-18 1972-10-31 Daniel Ind Inc Method and apparatus for determining the supercompressibility factor of natural gas
US3968694A (en) 1975-04-21 1976-07-13 Geophysical Research Corporation Gauge for remotely indicating the pressure of a subterranean formation
US4120206A (en) 1977-01-17 1978-10-17 Rosemount Inc. Differential pressure sensor capsule with low acceleration sensitivity
US4125027A (en) 1977-11-04 1978-11-14 Geophysical Research Corporation Gauge for remotely indicating the pressure of a subterranean formation
US4238825A (en) 1978-10-02 1980-12-09 Dresser Industries, Inc. Equivalent standard volume correction systems for gas meters
US4250490A (en) 1979-01-19 1981-02-10 Rosemount Inc. Two wire transmitter for converting a varying signal from a remote reactance sensor to a DC current signal
JPS5937716Y2 (en) 1979-01-31 1984-10-19 日産自動車株式会社 semiconductor differential pressure sensor
GB2085597B (en) 1980-10-17 1985-01-30 Redland Automation Ltd Method and apparatus for detemining the mass flow of a fluid
FR2496884A1 (en) 1980-12-24 1982-06-25 Flopetrol Etu Fabric PRESSURE MEASURING PROBE
US4377809A (en) 1981-04-27 1983-03-22 Itt Liquid level system
US4485673A (en) 1981-05-13 1984-12-04 Drexelbrook Engineering Company Two-wire level measuring instrument
US4414634A (en) 1981-07-17 1983-11-08 The Scott & Fetzer Company Fluid flow totalizer
US4446730A (en) 1982-04-26 1984-05-08 Quintex Research International, Inc. Specific gravity independent gauging of liquid filled tanks
US4598381A (en) 1983-03-24 1986-07-01 Rosemount Inc. Pressure compensated differential pressure sensor and method
USD287827S (en) 1983-09-06 1987-01-20 Rosemount Inc. Head for a differential pressure measuring and transmitting housing
US4677841A (en) 1984-04-05 1987-07-07 Precision Measurement, Inc. Method and apparatus for measuring the relative density of gases
US4562744A (en) 1984-05-04 1986-01-07 Precision Measurement, Inc. Method and apparatus for measuring the flowrate of compressible fluids
US4528855A (en) 1984-07-02 1985-07-16 Itt Corporation Integral differential and static pressure transducer
JPS6122222A (en) 1984-07-11 1986-01-30 Hitachi Ltd Semiconductor pressure transducer
US4602344A (en) 1984-10-25 1986-07-22 Air Products And Chemicals, Inc. Method and system for measurement of liquid level in a tank
US4653330A (en) 1985-07-15 1987-03-31 Rosemount Inc. Pressure transmitter housing
USD297314S (en) 1985-07-15 1988-08-23 Rosemount Inc. Pressure transmitter housing
GB2179156B (en) 1985-08-14 1990-08-22 Ronald Northedge Flow meters
EP0214801A1 (en) 1985-08-22 1987-03-18 Parmade Instruments C.C. A method of monitoring the liquid contents of a container vessel, monitoring apparatus for use in such method, and an installation including such apparatus
USD296995S (en) 1985-09-27 1988-08-02 Rosemount Inc. Pressure transmitter housing
NL8503192A (en) 1985-11-20 1987-06-16 Ems Holland Bv GAS METER.
US4617607A (en) 1985-12-10 1986-10-14 Kavlico Corporation High pressure capacitive transducer
USD297315S (en) 1985-12-16 1988-08-23 Rosemount Inc. Compact differential pressure transmitter
US5051937A (en) 1986-05-05 1991-09-24 Texas Instruments Incorporated Low cost high precision sensor
JPS6333663A (en) 1986-07-28 1988-02-13 Yamatake Honeywell Co Ltd Flow speed measuring apparatus
US4783659A (en) 1986-08-22 1988-11-08 Rosemount Inc. Analog transducer circuit with digital control
US4745810A (en) 1986-09-15 1988-05-24 Rosemount Inc. Flangeless transmitter coupling to a flange adapter union
US5187474A (en) 1986-10-02 1993-02-16 Rosemount Inc. Digital converter apparatus for improving the output of a two-wire transmitter
DE3635165A1 (en) 1986-10-16 1988-04-21 Wabco Westinghouse Fahrzeug HOUSING DEVICE WITH PRESSURE COMPENSATION
IT1196831B (en) 1986-12-10 1988-11-25 Mario Turatti REMOTE CONTROL TRANSMITTER DEVICE
US4798089A (en) 1987-03-12 1989-01-17 Rosemount Inc. Isolator apparatus
US4833922A (en) 1987-06-01 1989-05-30 Rosemount Inc. Modular transmitter
US5070732A (en) 1987-09-17 1991-12-10 Square D Company Modular sensor device
US4818994A (en) 1987-10-22 1989-04-04 Rosemount Inc. Transmitter with internal serial bus
US4850227A (en) 1987-12-22 1989-07-25 Delco Electronics Corporation Pressure sensor and method of fabrication thereof
US5000047A (en) 1988-03-29 1991-03-19 Nippondenso Co., Ltd. Pressure sensor
USD317266S (en) 1988-04-22 1991-06-04 Rosemount Inc. Pressure transmitter housing
USD318432S (en) 1988-04-22 1991-07-23 Rosemount Inc. Pressure transmitter housing
US4930353A (en) 1988-08-07 1990-06-05 Nippondenso Co., Ltd. Semiconductor pressure sensor
FR2637075B1 (en) 1988-09-23 1995-03-10 Gaz De France METHOD AND DEVICE FOR INDICATING THE FLOW OF A COMPRESSIBLE FLUID FLOWING IN A REGULATOR, AND VIBRATION SENSOR USED FOR THIS PURPOSE
US5035140A (en) 1988-11-03 1991-07-30 The Boeing Company Self cleaning liquid level detector
US4866989A (en) 1988-11-07 1989-09-19 Chrysler Motors Corporation Pressure transducer with a sealed sensor
USD317269S (en) 1989-02-13 1991-06-04 Rosemount Inc. Temperature transmitter housing
US4958938A (en) 1989-06-05 1990-09-25 Rosemount Inc. Temperature transmitter with integral secondary seal
US5162725A (en) 1989-08-21 1992-11-10 Alnor Instrument Company Modular metering instrument including multiple sensing probes
US5028746A (en) 1989-08-31 1991-07-02 Rosemount Inc. Cable protector for wound cable
US4970898A (en) 1989-09-20 1990-11-20 Rosemount Inc. Pressure transmitter with flame isolating plug
DE3934577A1 (en) 1989-10-17 1991-04-18 Philips Patentverwaltung POWER SUPPLY DEVICE WITH INRED CURRENT LIMITATION
JPH03148028A (en) 1989-11-02 1991-06-24 Matsushita Electric Ind Co Ltd Piezoelectric pressure sensor
US4980675A (en) 1990-01-09 1990-12-25 Spectrum Associates Temperature compensatible pressure monitor and sensor construction
US5060108A (en) 1990-01-25 1991-10-22 Texas Instruments Incorporated Packaging and sealing for pressure transducer
ATE112086T1 (en) 1990-03-28 1994-10-15 Landis & Gyr Business Support PROCEDURE FOR SELF-CALIBRATION OR RE-CALIBRATION OF MEASUREMENTS OF A PHYSICAL DIMENSION.
USD329619S (en) 1990-06-08 1992-09-22 Rosemount Limited Terminal housing for industrial thermometer
US5212645A (en) 1990-07-19 1993-05-18 General Electric Company Flexible real-time, multi-tasking architecture for tool condition monitoring
US5094109A (en) 1990-12-06 1992-03-10 Rosemount Inc. Pressure transmitter with stress isolation depression
DE4108610A1 (en) 1991-03-16 1992-09-17 Bosch Gmbh Robert TRANSMITTER STAGE
US5157972A (en) 1991-03-29 1992-10-27 Rosemount Inc. Pressure sensor with high modules support
USD342456S (en) 1991-04-18 1993-12-21 Rosemount Inc. Decorative cap for a process transmitter
DE9109176U1 (en) 1991-07-25 1991-09-19 Centra-Buerkle Gmbh, 7036 Schoenaich, De
US5227782A (en) 1991-08-14 1993-07-13 Rosemount Inc. Hydrostatic interface unit
US5198631A (en) 1991-09-11 1993-03-30 General Electric Company Pressure responsive control device
US5248167A (en) 1991-09-12 1993-09-28 Rosemount Inc. Interchangeable process connection resistant to installation errors
US5236202A (en) 1991-09-23 1993-08-17 Rosemount Inc. Spring loaded resin seal
US5245333A (en) 1991-09-25 1993-09-14 Rosemount Inc. Three wire low power transmitter
US5287746A (en) 1992-04-14 1994-02-22 Rosemount Inc. Modular transmitter with flame arresting header
JPH0694561A (en) 1992-09-11 1994-04-05 Matsushita Electric Ind Co Ltd Piezoelectric type pressure sensor
US5369386A (en) 1992-11-13 1994-11-29 Elsag International B.V. Removable magnetic zero/span actuator for a transmitter
US5436824A (en) 1992-12-10 1995-07-25 Rosemount Inc. Inrush current limiter in a magnetic flowmeter
US5469150A (en) 1992-12-18 1995-11-21 Honeywell Inc. Sensor actuator bus system
US5353200A (en) 1993-02-24 1994-10-04 Rosemount Inc. Process transmitter with inner conductive cover for EMI shielding
US5416723A (en) * 1993-03-03 1995-05-16 Milltronics Ltd. Loop powered process control transmitter
CN1058568C (en) 1993-04-23 2000-11-15 罗斯蒙德公司 Pressure isolator assembly for sanitary processing
EP0639039A1 (en) 1993-08-11 1995-02-15 Awag A. Widmer AG Process for the program control of lights or blinds
US5471885A (en) 1993-08-11 1995-12-05 Wagner; William B. Self-contained digital electronic force gage with interchangeable force sensor modules
US5574848A (en) 1993-08-24 1996-11-12 National Semiconductor Corporation Can interface selecting one of two distinct fault recovery method after counting a predetermined number of recessive bits or good can frames
US5606513A (en) 1993-09-20 1997-02-25 Rosemount Inc. Transmitter having input for receiving a process variable from a remote sensor
WO1995008759A1 (en) 1993-09-24 1995-03-30 Rosemount Inc. Pressure transmitter isolation diaphragm
US5515038A (en) * 1993-11-15 1996-05-07 Camco International Inc. Data transmission system
USD358784S (en) 1993-11-19 1995-05-30 Rosemount Inc. Flowmeter instrument
US5381355A (en) 1993-12-17 1995-01-10 Elsag International N.V. Method for filtering digital signals in a pressure transmitter
CN1141679A (en) 1994-02-23 1997-01-29 罗斯蒙德公司 Field transmitter for storing information
US5502659A (en) 1994-06-06 1996-03-26 Endress+Hauser, Inc. Method and apparatus for calibrating moisture sensors
US5546804A (en) 1994-08-11 1996-08-20 Rosemount Inc. Transmitter with moisture draining housing and improved method of mounting RFI filters
US5583294A (en) 1994-08-22 1996-12-10 The Foxboro Company Differential pressure transmitter having an integral flame arresting body and overrange diaphragm
US5669713A (en) 1994-09-27 1997-09-23 Rosemount Inc. Calibration of process control temperature transmitter
US5764928A (en) 1994-09-30 1998-06-09 Rosemount Inc. Microprocessor communication protocol in a multiprocessor transmitter
US5710552A (en) 1994-09-30 1998-01-20 Rosemount Inc. Barrier device
US5656782A (en) 1994-12-06 1997-08-12 The Foxboro Company Pressure sealed housing apparatus and methods
USD366000S (en) 1994-12-06 1996-01-09 Karas Edwin L Pressure transmitter housing
USD366218S (en) 1994-12-23 1996-01-16 Rosemount Inc. Temperature transmitter housing
US5498079A (en) 1994-12-23 1996-03-12 Rosemount Inc. Temperature transmitter
US5650936A (en) 1994-12-30 1997-07-22 Cd Power Measurement Limited Power monitor apparatus and method with object oriented structure
EP0823045A1 (en) 1995-04-28 1998-02-11 Rosemount Inc. Mounting assembly for a pressure transmitter
DE69629024T2 (en) 1995-04-28 2004-04-22 Rosemount Inc., Eden Prairie PRESSURE CONVERTER WITH MOUNTING ARRANGEMENT WITH HIGH PRESSURE INSULATOR
US5677476A (en) 1996-02-06 1997-10-14 Endress + Hauser Conducta Gesellschaft Fuer Mess- Und Regeltechnik Mbh & Co. Sensor and transmitter with multiple outputs
US5665899A (en) 1996-02-23 1997-09-09 Rosemount Inc. Pressure sensor diagnostics in a process transmitter
DE19611944C2 (en) 1996-03-26 2003-03-27 Daimler Chrysler Ag Integrated circuit for coupling a micro-controlled control unit to a two-wire bus
US5668322A (en) 1996-06-13 1997-09-16 Rosemount Inc. Apparatus for coupling a transmitter to process fluid having a sensor extension selectively positionable at a plurality of angles
KR100237316B1 (en) 1996-08-01 2000-01-15 박호군 Sputtering target for forming magnetic thin film and the manufacturing method thereof
US6006338A (en) 1996-10-04 1999-12-21 Rosemont Inc. Process transmitter communication circuit
US5954526A (en) 1996-10-04 1999-09-21 Rosemount Inc. Process control transmitter with electrical feedthrough assembly
JPH10115536A (en) 1996-10-14 1998-05-06 Denso Corp Composite sensor
US6519546B1 (en) * 1996-11-07 2003-02-11 Rosemount Inc. Auto correcting temperature transmitter with resistance based sensor
US5988203A (en) 1997-10-01 1999-11-23 Hutton; Peter B. Two-piece manifold
US5823228A (en) 1997-02-05 1998-10-20 Keystone International Holdings Corp. Valve manifold
US6059254A (en) 1997-03-27 2000-05-09 Rosemount Inc. Process instrument mount
DE19713240C2 (en) 1997-03-29 1999-01-28 Endress Hauser Gmbh Co Procedure for automatic address assignment in a CAN network
DE19716137C1 (en) 1997-04-17 1998-10-22 Siemens Ag Module for connecting actuators and / or sensors
US6131467A (en) 1997-05-09 2000-10-17 Fujikoki Corporation Pressure sensor including a joint for connecting a housing and connector case together
US6111888A (en) 1997-05-27 2000-08-29 Micro Motion, Inc. Deterministic serial bus communication system
US5983727A (en) 1997-08-19 1999-11-16 Pressure Profile Systems System generating a pressure profile across a pressure sensitive membrane
EP0903651B1 (en) 1997-09-18 2003-04-23 Endress + Hauser GmbH + Co. KG Measuring device / bus system interface and adapter therefor
DE59706255D1 (en) 1997-10-10 2002-03-14 Wika Alexander Wiegand Gmbh Process for manufacturing a pressure transmitter and pressure transmitter
DE19755516A1 (en) 1997-12-13 1999-06-17 Conducta Endress & Hauser Measuring device for liquid and / or gas analysis and / or for measuring moisture in liquids and / or gases
US6140952A (en) 1997-12-26 2000-10-31 Rosemount Inc. Delta sigma circuit with pulse width modulated offset
US6151557A (en) 1998-01-13 2000-11-21 Rosemount Inc. Friction flowmeter with improved software
US6233532B1 (en) 1998-01-14 2001-05-15 Dover Associates, Inc. Sensor assembly
US5948988A (en) 1998-05-27 1999-09-07 Honeywell Inc Pressure transducer with flame arrester
US5973942A (en) 1998-07-10 1999-10-26 Rosemount Inc. Start up circuit for DC powered field instrument
JP3013843B1 (en) 1998-10-16 2000-02-28 日本精機株式会社 Pressure sensor
DE29903260U1 (en) 1999-02-23 2000-04-13 Siemens Ag Transmitter
US6295875B1 (en) 1999-05-14 2001-10-02 Rosemount Inc. Process pressure measurement devices with improved error compensation
US6321166B1 (en) 1999-08-05 2001-11-20 Russell N. Evans Noise reduction differential pressure measurement probe
US6311568B1 (en) 1999-09-13 2001-11-06 Rosemount, Inc. Process flow device with improved pressure measurement feature

Also Published As

Publication number Publication date
WO2001088643A3 (en) 2002-05-23
US6504489B1 (en) 2003-01-07
DE10196182B4 (en) 2010-11-11
JP3859515B2 (en) 2006-12-20
WO2001088643A2 (en) 2001-11-22
JP2003533808A (en) 2003-11-11
DE10196182T1 (en) 2003-03-27

Similar Documents

Publication Publication Date Title
AU2001257544A1 (en) A process control transmitter having an externally accessible dc circuit common
AUPR967301A0 (en) A control circuit
AU2001238647A1 (en) Sequential control circuit
AU2001243426A1 (en) Electronic switch
AU2002213294A1 (en) Carrier-based electronic module
AU2003215824A1 (en) Controlling a home electronics system
AU2002337359A1 (en) An autonomous machine
AU2001273367A1 (en) Multiple die industrial process control transmitter
AU2001234308A1 (en) Controlling an electronic device
AU5895699A (en) A switch circuit
EP1193401A3 (en) Multi-pressure ball-poppet control value
AU2001234555A1 (en) Optocoupler for a non-intrinsically safe circuit
AU2001266835A1 (en) Molded electronic assembly
AU4492301A (en) A zero-voltage-switch snubber circuit
AU2001280117A1 (en) Case for electronic parts
AU2002343377A1 (en) Intergrated circuit having a voltage sensor
AUPR580901A0 (en) Electronic gaming machine control
AU2002353265A1 (en) Output driver comprising an improved control circuit
AU6051601A (en) A contactor control circuit
EP1271271A3 (en) Multimedia machine control
AU5963400A (en) Pass-driver circuit for a two-conductor bus-system
AUPP944799A0 (en) Control circuit
AU2002222303A1 (en) A switch for an electronic device
AUPR163500A0 (en) Two-wire controlled switching
AU2001283994A1 (en) Electronic circuit