Abstract: A power supply system (200) has a QFN leadframe with leads and a pad (201, switch node terminal); a pad surface having a portion recessed with a depth (270) and an outline suitable for attaching a semiconductor chip. A first FET chip (220) is vertically stacked to the opposite pad surface. A clip (240) is vertically stacked on the first FET chip and tied to a lead (202, grounded output terminal). A second FET chip (210) has its source terminal attached to the recessed portion and its drain (210a, input terminal) and gate (210b) terminals co-planar with the un-recessed portion. A driver-and-controller chip (230) is attached to the clip. Packaging compound (290) encapsulates the parts but leaves a pad surface and the drain and gate terminals of the second FET chip un-encapsulated.

Abstract: A power supply system has a QFN leadframe with leads and a pad. The pad surface facing a circuit board has a portion recessed with a depth and an outline suitable for attaching side-by-side the sync and the control FET semiconductor chips. The input terminal of the control FET and the grounded output terminal of the sync FET are coplanar with the un-recessed portion of the pad (switch node terminal) so that all terminals can be directly attached to contacts of a circuit board. A driver-and-control chip is vertically stacked to the opposite pad surface and encapsulated in a packaging compound.

Abstract: A power supply system (200) has a QFN leadframe with leads and a pad (201). The pad surface facing a circuit board has a portion recessed with a depth (270) and an outline suitable for attaching side-by-side the sync (210) and the control (220) FET semiconductor chips. The input terminal (220a) of the control FET and the grounded output terminal (210a) of the sync FET are coplanar with the un-recessed portion of the pad (switch node terminal) so that all terminals can be directly attached to contacts of a circuit board. A driver-and-control chip (230) is vertically stacked to the opposite pad surface and encapsulated in a packaging compound (290).

Abstract: An integrated circuit (“IC”) assembly includes an IC die with a metallization layer on a top surface thereof. A plurality of lead wires are bonded at first end portions thereof to the metallization layer. A conductive layer is attached to the metallization layer and covers the first ends of the lead wires.

Abstract: A power supply system (200) has a QFN leadframe with leads and a pad (201). The pad surface facing a circuit board has a portion recessed with a depth (270) and an outline suitable for attaching side-by-side the sync (210) and the control (220) FET semiconductor chips. The input terminal (220a) of the control FET and the grounded output terminal (210a) of the sync FET are coplanar with the un-recessed portion of the pad (switch node terminal) so that all terminals can be directly attached to contacts of a circuit board. A driver-and-control chip (230) is vertically stacked to the opposite pad surface and encapsulated in a packaging compound (290).

Abstract: A power supply system (200) has a QFN leadframe with leads and a pad (201, switch node terminal); a pad surface having a portion recessed with a depth (270) and an outline suitable for attaching a semiconductor chip. A first FET chip (220) is vertically stacked to the opposite pad surface. A clip (240) is vertically stacked on the first FET chip and tied to a lead (202, grounded output terminal). A second FET chip (210) has its source terminal attached to the recessed portion and its drain (210a, input terminal) and gate (210b) terminals co-planar with the un-recessed portion. A driver-and-controller chip (230) is attached to the clip. Packaging compound (290) encapsulates the parts but leaves a pad surface and the drain and gate terminals of the second FET chip un-encapsulated.

Abstract: An integrated circuit (“IC”) assembly includes an IC die with a metallization layer on a top surface thereof. A plurality of lead wires are bonded at first end portions thereof to the metallization layer. A conductive layer is attached to the metallization layer and covers the first ends of the lead wires.

Abstract: A packaged multi-output converter (200) comprising a leadframe with a chip pad (201) as ground terminal and a plurality of leads (202) including the electrical input terminal (203); a first FET chip (sync chip, 220) with its source terminal affixed to the leadframe and on its opposite surface a first drain terminal (221) positioned adjacent to a second drain terminal (222), the drain terminals connected respectively by a first (241) and a second (242) metal clip to a first (204) and second (205) output lead; a second FET chip (control chip, 211), positioned vertically over the first drain terminal, with its source terminal attached onto the first clip; a third FET chip (control chip, 212), positioned vertically over the second drain terminal, with its source terminal attached onto the second clip; and the drain terminals (213, 214) of the second and third chips attached onto a third metal clip (260) connected to the input lead (203).

Abstract: An integrated circuit (“IC”) assembly includes an IC die with a metallization layer on a top surface thereof. A plurality of lead wires are bonded at first end portions thereof to the metallization layer. A conductive layer is attached to the metallization layer and covers the first ends of the lead wires.

Abstract: A power FET (100) comprising a leadframe including a pad (110), a first lead (111), and a second lead (112); a first metal clip (150) including a plate (150a), an extension (150b) and a ridge (150c), the plate and extension spaced from the leadframe pad and the ridge connected to the pad; a vertically assembled stack of FET chips in the space between the plate and the pad, the stack including a first n-channel FET chip (120) having the drain terminal on one surface and the source and gate terminals on the opposite surface, the drain terminal attached to the pad, the source terminal attached to a second clip (140) tied to the first lead; and a second n-channel FET chip (130) having the source terminal on one surface and the drain and gate terminals on the opposite surface, the source terminal attached to the second clip, its drain terminal attached to the first clip; wherein the drain-source on-resistance of the FET stack is smaller than the on-resistance of the first FET chip and of the second FET chip.

Abstract: A power transistor module including a power transistor with a first common power node, and a split control node. A first clip is connected to a portion of a second power node so that current through a first control segment of the control node is directed through a first transistor portion and through the first clip. A second clip is connected to another portion of the second power node so that current through a second control segment is directed through a second transistor portion and through the second clip. A ratio of an area of the first transistor portion to a combined area of the first and second portions is 5 percent to 75 percent. A shunt is coupled in series to the first clip. The shunt may be directly electrically connected to the first portion of the power transistor.

Abstract: A power transistor module including a power transistor with a first common power node, and a split control node. A first clip is connected to a portion of a second power node so that current through a first control segment of the control node is directed through a first transistor portion and through the first clip. A second clip is connected to another portion of the second power node so that current through a second control segment is directed through a second transistor portion and through the second clip. A ratio of an area of the first transistor portion to a combined area of the first and second portions is 5 percent to 75 percent. A shunt is coupled in series to the first clip. The shunt may be directly electrically connected to the first portion of the power transistor.

Abstract: A method and structure for a dual heat dissipating semiconductor device. A method includes attaching a drain region on a first side of a die, such as a power metal oxide semiconductor field effect transistor (MOSFET) to a first leadframe subassembly. A source region and a gate region on a second side of the die are attached to a second leadframe subassembly. The first leadframe subassembly is attached to a third leadframe subassembly, then the device is encapsulated or otherwise packaged. An exposed portion of the first leadframe subassembly provides an external heat sink for the drain region, and the second leadframe subassembly provides external heat sinks for the source region and the gate region, as well as output leads for the gate region. The third leadframe subassembly provides output leads for the drain region.

Abstract: A method and structure for a dual heat dissipating semiconductor device. A method includes attaching a drain region on a first side of a die, such as a power metal oxide semiconductor field effect transistor (MOSFET) to a first leadframe subassembly. A source region and a gate region on a second side of the die are attached to a second leadframe subassembly. The first leadframe subassembly is attached to a third leadframe subassembly, then the device is encapsulated or otherwise packaged. An exposed portion of the first leadframe subassembly provides an external heat sink for the drain region, and the second leadframe subassembly provides external heat sinks for the source region and the gate region, as well as output leads for the gate region. The third leadframe subassembly provides output leads for the drain region.

Abstract: A clip-less packaged semiconductor device includes at least one semiconductor die having bottom and top surfaces each having at least one electrode. A leadframe comprising a sheet of conductive material having top and bottom surfaces, the top surface being substantially planar, the bottom surface having a recessed region having a thickness less than the thickness of the sheet of conductive material formed in the sheet and defining a plurality of planar lead contacts, is electrically coupled to the top surface of the die at its bottom surface in the recessed region. An encapsulating layer partially encloses the leadframe and die, wherein the encapsulating layer occupies portions of the recessed region not occupied by the die, wherein the bottom surface of the die and the plurality of leadframe contacts are exposed through the encapsulating layer at least at the bottom surface of the packaged semiconductor device.

Abstract: A clip-less packaged semiconductor device includes at least one semiconductor die having bottom and top surfaces each having at least one electrode. A leadframe comprising a sheet of conductive material having top and bottom surfaces, the top surface being substantially planar, the bottom surface having a recessed region having a thickness less than the thickness of the sheet of conductive material formed in the sheet and defining a plurality of planar lead contacts, is electrically coupled to the top surface of the die at its bottom surface in the recessed region. An encapsulating layer partially encloses the leadframe and die, wherein the encapsulating layer occupies portions of the recessed region not occupied by the die, wherein the bottom surface of the die and the plurality of leadframe contacts are exposed through the encapsulating layer at least at the bottom surface of the packaged semiconductor device.

Abstract: An IC device includes an MOS device having a gate terminal, a source terminal and a drain terminal, the gate terminal being operatively coupled to an input of the IC device, the drain terminal being operatively coupled to an output of the IC device, and the source terminal being coupled to a negative voltage supply. The IC device further includes a bias generator operatively coupled to the gate terminal of the MOS device, the bias generator generating a bias voltage and/or a bias current for biasing the MOS device at a substantially constant quiescent operating point. The bias generator is configured such that the bias voltage and/or bias current varies as a function of a junction temperature of the MOS device. In this manner, the bias generator accurately tracks one or more operating conditions of the MOS device, thereby improving the performance of the device.

Abstract: A power amplifier circuit whose performance is optimized by operating its stages in substantially close to a Class B mode by reducing quiescent current during low driver signal levels. As the driver signal amplitude increases, the operation of the amplifier is configured to dynamically adjust to be in a Class AB mode, thereby increasing the power efficiency of the overall circuit at kiw drive levels. A further enhancement to the power amplifier circuit includes a temperature compensation circuit to adjust the bias of the amplifier so as to stabilize the performance in a wide temperature range.

Abstract: To provide a quality control test for quality of vaccines against a pathogen, a test to determine the presence of antibodies against the pathogen to determine the status of protection of individuals in a herd or a vaccine against the pathogen, in one technique for pathogens having a delayed introduction of protective antibodies, sera from an infected animal is obtained before the eliciting of neutralizing antibodies and after the eliciting of neutralizing antibodies. The two sera are used to remove the non-neutralizing epitopes from the mixture of neutralizing epitopes and non-neutralizing epitopes to obtain pure neutralizing epitopes such as for example by affinity chromatography.

Abstract: A power amplifier circuit is disclosed, whose power efficiency is optimized by operating its stages in substantially close to a Class B mode by reducing the quiescent current during low driver signal levels. As the driver signal amplitude increases, the amplifier is dynamically biased to operate in a Class AB mode. A further enhancement to the power amplifier circuit includes a temperature compensation circuit to adjust the bias of the amplifier so as to stabilize the performance over a wide temperature range.