Motorola Corporation

Philippe B Bauser

Arthur J Edwards

Alexis Marquot

Craig T Swift

A high voltage protection circuit ( ) in a non-volatile memory includes a first transistor ( ) and a second transistor ( ) each formed in their own separate wells. A high voltage supply (Vhv) is provided at the drain of the second transistor ( ). The source ( ) of second transistor ( ) is connected to the drain of first transistor ( ) and to well ( ), and the gate of the second transistor ( ) is connected to Vdd, the main power supply to the chip. By forming the transistors in their own separate wells with the source of the second transistor ( ) connected to its own well, breakdown of the circuit is governed by the sum of BVdss of the first transistor ( ) and a gate induced breakdown (BVind) of the second transistor ( ). With this circuit use of even a low Vdd (e.g. <3V) on the gate of the second transistor ( ) is sufficient to protect against unwanted exposure to Vhs or to prevent leakage so that a higher stand-off voltage need not be generated and routed to the circuit.

High voltage protection circuit

A memory system (20) comprising a memory array (22) having a plurality of memory cells (42) arranged in rows and columns. Each memory cell (42) has a control terminal. A voltage controller (26) provides to the control terminal of a memory cell a first verify voltage signal (Vabse) during a first verify cycle or a second verify voltage signal (Vabsp) during a second verify cycle. The first verify voltage signal (Vabse) having a predetermined voltage level that corresponds substantially to a threshold voltage level of a memory cell in the array in a first state and the second verify voltage signal (Vabsp) having a predetermined voltage level that corresponds substantially to a threshold voltage level of a memory cell in the array in a second state.

Memory system, method for verifying data stored in a memory system after

A signal coupler for incorporating in a smartcard or a base device comprises an optocoupling arrangement for exchanging power or data signals between the demountable device and the base device, thereby eliminating problems associated with wear of metal contacts and allowing convenient manufacture.

Signal coupler

A phase winding detector (50) is preferably used to detect alternator (11) rotation in an alternator charging system (10). The detector (50) receives a single winding phase output signal (at 39) and utilizes a sampling apparatus (71, 74, 76) to provide a sampled phase output signal (at 75). A comparison circuit (70) provides an output by comparing the phase output signal with the sampled phase output signal, whereby a detection of variation in the phase output signal is provided (at terminals 85, 87 and 51). After initial detection of variation of the phase winding output signal, preferably additional circuitry (77, 79, 83) results in comparing the phase winding signal with a fixed reference threshold (V.sub.ref). Detection of a phase winding output signal is implemented without use of a substantial DC blocking capacitor and is implemented by monitoring only one input signal terminal.

Phase winding detector and alternator charging system

A thermally dependent self-modifying voltage source (115) is constructed with a first reference circuit (301) having a control input (311), a primary output (117) dependent on the control input, and a thermally dependent secondary output (303). The thermally dependent self-modifying voltage source also includes a thermally dependent reference (309) with an output (307). The thermally dependent secondary output (303) of the first reference circuit (301) and output (307) of the thermally dependent reference (309) are coupled to inputs of an amplifier (305). The amplifier (305) has an output (313) coupled to the control input (311) of the first reference circuit (301), wherein the primary output (117) of the first reference circuit is dependent on the amplified difference between the thermally dependent secondary output (303) of the first reference circuit and the output (307) of the thermally dependent reference (309). Preferably, the primary output (117) is used in a voltage regulator (121) for use in alternator based battery charging system (100).

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Ornex, France

Philippe B Bauser