US 7,030,591 B2 · Integrated circuit implementing protection switch for battery charging and discharging with enhanced reverse voltage protection

Abstract

A battery charging, discharging, and protection switch circuit with enhanced reverse voltage protection is achieved. The circuit comprises, first, field effect transistor (FET) switches having gate, source, drain, and bulk. The FET switches may comprise either NMOS devices or PMOS devices. Second, means of controlling the FET switch's gate and bulk are included. The FET switch gate voltage determines the OFF and ON state of said FET switches. The bulk is switchable coupled between the battery terminal and the load terminal. To achieve high voltage breakdown limits the FET switch is realized with cascaded MOSFETs, where as a novelty here under certain operating conditions, i.e. the battery charger coupled in reverse condition—one FET is working as a source follower. All the necessary MOSFET switches are integrated onto a single chip, together with its controller logic. To form these MOSFETs within a single IC together with the other circuit elements is much less expensive. The circuit of the invention is manufactured with CMOS deep well technology.

Claims35

Dependent claims

A circuit for storing electrical energy, and consuming or supplying this energy with intrinsic protection features, comprising:

a means for the storage of electrical energy;
a means for, on the one hand, the consumption of electrical energy or
a means for, on the other hand, the supply of electrical energy;
and
a means manufactured as integrated circuit for secure connection of said energy storage means with said energy consumption or supply means, whereby a switchable and controllable flow of energy between said energy storage means and said energy consumption or supply means is made possible in conjunction with protection against damaging or destructive operational conditions during said connection with said energy flowing, and where the flow of energy is controlled by means of integrated controllable switches contained within an integrated switching circuit block—establishing said secure connection—and said integrated switching circuit block being controlled by an integrated controller circuit block sensing and monitoring both said stored electrical energy and said consumed or supplied electrical energy and generating and delivering control signals for said integrated switching circuit block.

2 more elements

A circuit for battery charging and discharging with intrinsic protection features, comprising:

a battery with two terminals, called the one and the other battery terminals, each being either of the positive or the negative terminal type;
a load or charger two-pole device with two terminals each;
a first FET switch having gate, source, drain, and a separate bulk, wherein said drain is coupled to one battery terminal;
a second FET switch having gate, source, drain, and a separate bulk, wherein said drain is coupled to said first FET switch source to thereby form a mid node and wherein said source is coupled to a load or charger terminal;
and
a means for controlling said first and second FET gates together with said separate bulks wherein the gate voltages of said first and second FET switches determine the OFF and ON states of said first and second FET switches, and wherein said first FET separate bulk is switchable coupled between said one battery terminal and said mid node, and wherein said second FET separate bulk is switchable coupled between said mid node and said load or charger terminal and wherein another additional controllable switch is connected between said other battery terminal and said mid node.

3 more elements

Dependencies are inferred from the claim text.

Integrated circuit implementing protection switch for battery charging and discharging with enhanced reverse voltage protection

Life of this patent

Integrated circuit implementing protection switch for battery charging and discharging with enhanced reverse voltage protection

Life of this patent

Abstract

Claims35