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公开(公告)号：JP2000299978A
公开(公告)日：2000-10-24
申请号：JP2000035366
申请日：2000-02-14
Applicant: ANALOG DEVICES INC
Inventor： REDL RICHARD , ERISMAN BRIAN P , AUDY JONATHAN M , REIZIK GABOR
Abstract: PROBLEM TO BE SOLVED: To minimize the capacitor size by maintaining the regulator's output voltage within specified boundaries for large bi-directional step change in load current. SOLUTION: A current sensor 64 at a controllable power stage 50 generates an output signal which varies along with the output current from the power stage 50. A current controller 66 receives the output signal thus generated along with the output 62 from a voltage error amplifier 59 to produce an output 67. In response to the output 67 from the current controller 66, a power circuit 68 generates an output voltage Vout. The output capacitor 56 of the power circuit 68, i.e., a regulator, maintains the output voltage within a boundary specified for the bi-directional step change in load current. Consequently, the capacitor size is minimized and the power circuit 68 can be compensated.
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公开(公告)号：AU3547495A
公开(公告)日：1996-12-24
申请号：AU3547495
申请日：1995-09-06
Applicant: ANALOG DEVICES INC
Inventor： AUDY JONATHAN M
Abstract: An IC temperature sensor with a programmable offset generates an output voltage Vo over a desired temperature range that is a PTAT voltage VPTAT shifted by an offset voltage Voff. A band gap cell generates a basic PTAT voltage across a first resistor to produce a PTAT current IPTAT. A second resistor is connected from the first resistor to a reference voltage terminal to provide voltage gain. A third resistor is connected across the base-emitter junction of a transistor which is connected from the top of the second resistor to an output terminal at which Vo is generated. The transistor's base-emitter voltage provides a portion of Voff. The third resistor reduces the portion of IPTAT that flows through the second resistor to provide the remaining portion of Voff. A current source is positioned between the transistor's emitter and the reference voltage terminal to supply its emitter current and the current for the third resistor. The offset voltage Voff is set by trimming the third resistor until Vo equals a voltage applied to the reference voltage terminal at a lower end of the desired temperature range. The desired gain of VPTAT is then set by trimming the first resistor.
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公开(公告)号：AU2220899A
公开(公告)日：1999-08-02
申请号：AU2220899
申请日：1999-01-11
Applicant: ANALOG DEVICES INC
Inventor： BROKAW A PAUL , AUDY JONATHAN M
Abstract: A low voltage CTAT current source includes a bipolar transistor connected across two series-connected resistors. A voltage developed across the resistors turns on the transistor, making the current through the resistors CTAT. A second transistor supplies the resistor current; its base (if bipolar) is connected to the node between the resistors, which are selected to limit the transistor's base-collector forward bias and collector-emitter voltage to a preselected fraction of the first transistor's Vbe, allowing the CTAT current source to operate with supply voltages of less than two junction voltage drops. A PTAT current can be combined with the CTAT current to create a temperature-compensated current. A low voltage current mirror has the respective bases of a pair of cascoded transistors connected across a resistor which is also connected between the bottom transistor's collector and a programming current. When the transistors are matched, the top transistor's collector-emitter voltage about equals the voltage across the resistor, which is selected to establish a Vce just high enough to avoid saturation and allow the circuit to operate with only two unsaturating Vce's of headroom. The current mirror's lower headroom requirements are advantageously employed in a low voltage differential to single-ended converter circuit, and the current mirror and CTAT current source can be combined in numerous analog circuits to enable their operation at lower supply voltages.
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