US 5,495,436 A · Anti-fuse ROM programming circuit

Abstract

A "charge-kicker" programming circuit for programming anti-fuse links in integrated-circuit memory devices permits smaller feature sizes and a correspondingly lower breakdown voltage by using reduced internal voltage levels to generate a gate voltage for a series pass transistor. A series pass transistor gates a high voltage programming signal (typically 13 volts) to a high-voltage programming line. Selection circuits steer the high voltage programming signal to various columns of anti-fuse elements. A fixed voltage, insufficient to turn on the series pass transistor is applied to the gate terminal of the series pass transistor. An alternating voltage is applied directly onto the gate terminal of the series pass transistor through a capacitor so that the peaks of the alternating voltage turn on the series pass transistor which gates the programming voltage to the main high voltage programming line for the anti-fuse memory array.

Claims15

Dependent claims

An on-chip programming circuit for programming anti-fuse elements of an integrated-circuit ROM, comprising:

a series pass transistor for directing a high voltage programming voltage to a high-voltage programming line for anti-fuse elements;
means for providing a fixed voltage to the gate terminal of the series pass transistor, wherein the fixed voltage is insufficient to turn on the series pass transistor;
means for directly superimposing an alternating voltage directly onto the gate terminal of the series pass transistor wherein the peaks of the alternating voltage superimposed on the gate terminal of the series pass transistor turn on the series pass transistor to apply the programming voltage to the main high voltage programming line of an anti-fuse memory array;
wherein the means for directly superimposing an alternating voltage directly onto the gate terminal of the series pass transistor includes a capacitor having one terminal connected to the gate terminal of the series pass transistor and having another terminal connected to an alternating voltage source.

1 more element

An on-chip programming circuit for programming anti-fuse elements of an integrated-circuit ROM, comprising:

an input terminal for the programming circuit at which is provided a programming voltage;
an output terminal of the programming circuit;
a first series transistor having a drain terminal connected to the input terminal of the programming circuit and having a source terminal connected to the output terminal of the programming circuit;
a saturated transistor having a drain terminal connected to the input terminal of the programming circuit, having a source terminal connected to the gate terminal of the first series transistor, and having a gate terminal to which is applied a positive voltage source so that the second saturated transistor remains in the saturated mode of operation;
an oscillator input terminal;
a series capacitor having a first terminal connected to the oscillator input terminal and a second terminal connected to the gate terminal of the series transistor;
an oscillator circuit connected to the oscillator input terminal and providing an alternating voltage signal through the series capacitor directly to the gate terminal of the first series transistor, where the oscillator provides a peak voltage sufficient to turn on the first series transistor so that the programming voltage is applied to the output terminal of the circuit voltage during the positive peaks of the oscillator voltage.

4 more elements

Dependencies are inferred from the claim text.

Anti-fuse ROM programming circuit

Life of this patent

Anti-fuse ROM programming circuit

Life of this patent

Abstract

Claims15