US 6,150,714 A · Current sense element incorporated into integrated circuit package lead frame

Abstract

An electronic device includes a conductive member disposed within an insulative package. The conductive member is formed from a lead frame used to form the interconnection pins for the device. The conductive member includes an elongated, folded sense element portion having a known resistance. The sense element portion is disposed between two sets of conductive lead portions extending from the conductive member forming pins used to provide a current to the device for sensing. An integrated circuit disposed within the package includes a differential amplifier having differential inputs connected to bond pads on the integrated circuit. The bond pads are connected to spaced-apart tap points of the sense element via conductive bond wires, so that the combination of the sense element and the differential amplifier forms a trans-impedance amplifier. The gain of the differential amplifier is controlled to be proportional to the magnitude of a reference voltage generated by a bandgap voltage reference circuit. The reference voltage varies with temperature such that the overall gain of the trans-impedance amplifier is constant over temperature. The nominal gain of the differential amplifier is established by an on-chip resistance, which is trimmed using fuse-programmable trim cells that are programmed via operational package pins during a pre-operation trim procedure.

Claims11

Dependent claims

An electronic device, comprising:

an insulative package having a plurality of conductive leads extending therefrom, one or more of the conductive leads being commonly connected and serving as sense element input leads, and one or more of the conductive leads being commonly connected and serving as sense element output leads;
a conductive sense element disposed within the package, the conductive sense element being connected between the sense element input and output leads, the conductive sense element having a known resistance between first and second spaced-apart tap points disposed thereon;
and
an integrated circuit disposed within the package, the integrated circuit including first and second bond pads and a differential amplifier having differential inputs connected respectively to the bond pads, each bond pad being electrically connected to a corresponding tap point of the sense element, the differential amplifier being operative to generate an output voltage substantially proportional to the magnitude of the current flowing through the sense element over an operating temperature range of the device.

1 more element

An electronic device, comprising:

an insulative package;
a conductive member disposed within the package, the conductive member including a sense element portion disposed between a first plurality of conductive lead portions extending from the conductive member and a second plurality of conductive lead portions extending from the conductive member, the conductive lead portions forming external interconnection pins of the electronic device, the conductive sense element portion having a known resistance between first and second spaced-apart tap points located thereon;
an integrated circuit disposed within the package, the integrated circuit having a differential amplifier formed thereon having differential inputs connected to first and second bond pads on the integrated circuit, each bond pad being connected to a corresponding tap point of the sense element via a conductive bond wire, the differential amplifier having a gain proportional to the magnitude of a reference voltage supplied thereto;
and
a reference voltage generator circuit operative to generate the reference voltage such that the product of the differential amplifier gain and the resistance between the tap points of the sense element portion of the conductive member over the operating temperature range is substantially constant.

2 more elements

Dependencies are inferred from the claim text.

Current sense element incorporated into integrated circuit package lead frame

Life of this patent

Current sense element incorporated into integrated circuit package lead frame

Life of this patent

Abstract

Claims11