Stmicroelectronics S.r.l.

Stmicroelectronics International N.v.

Riccardo Zurla

Marco Pasotti

Marcella Carissimi

Laura Capecchi

Guido Torelli

Alessandro Cabrini

Flavio Giovanni Volpe

Riccardo Vignali

An in-memory computation device includes a word line activation circuit that receives an input signal indicative of input values and provides activation signals each as a function of the input value. The in-memory computation device further includes a memory array, a biasing circuit generating a bias voltage and a digital detector. The memory array has memory cells coupled to a bit line and each to a word line. Each memory cell stores a computational weight. In response to an activation signal, a cell current flows through each memory cell as a function of the bias voltage, the activation signal and the computational weight. A bit line current flows through the bit line as a function of a summation of the cell currents. The digital detector is coupled to the bit line, samples the bit line current and, in response, provides an output signal.

In-memory computation device having improved drift compensation

A voltage regulator receives a reference voltage and generates a regulated voltage using a MOSFET having a gate terminal configured to receive a control voltage. A charge pump receives the regulated voltage and generates a charge pump voltage in response to an enable signal and a clock signal generated in response to the enable signal. The voltage regulator further includes a first switched capacitor circuit coupled to the gate terminal and configured to selectively charge a first capacitor with a first current and impose a first voltage drop on the control voltage in response to assertion of the enable signal. The voltage regulator also includes a second switched capacitor circuit coupled to the gate terminal and configured to selectively charge a second capacitor with a second current and impose a second voltage drop on the control voltage in response to one logic state of the clock signal.

Voltage regulator circuit for a switching circuit load

An in-memory computation circuit includes a memory array with memory cells arranged in a matrix in rows and columns. Groups of memory cells store computational weights for an in-memory compute (IMC) operation that is performed with a first multiply and accumulate (MAC) elaboration to produce a first analog signal and a second MAC elaboration to produce a second analog signal. An analog-to-digital converter circuit operates to: increment a count value in a counter circuit in response to the first analog signal; convert the count value in the counter circuit to a negated count value; and increment the count value in the counter circuit starting from the negated count value in response to the second analog signal.

In-memory computation system with built-in subtraction mode for handling matrix vector multiplication of signed feature data and signed computational weight data

A current-generator circuit includes an output-current generator circuit having a control branch to be coupled to a control current generator and adapted to provide a control current pulse and a driver electrically coupled between the control branch and the output leg. A compensation circuit includes a first compensation branch configured to generate a compensation current pulse that is a function of the control current pulse and a second compensation branch coupled in a current mirror configuration with the first compensation branch to receive the compensation current pulse. The second compensation branch includes a resistive block having an electrical resistance that is a function of a resistance of an output load. The second compensation branch is electrically coupled to the control branch and the driver is electrically coupled to the control branch and to the output leg.

Current-generator circuit

A phase-change memory device, comprising: a memory array of PCM cells, a variable current generator, and a sense amplifier. The current generator comprises a reference array of PCM cells programmed in SET resistance state. The phase-change memory device further comprises a decoder for addressing each cell of the reference array so that a respective plurality of SET current signals is generated through the plurality of reference cells; and a controller configured to receive at input said SET current signals, select a number of SET current signals having the lowest current values among the plurality of SET current signals, calculate a mean value of said lowest current values, and adjust the reference current to be lower than said mean value.

Single-ended phase-change memory device and reading method

A current mirror includes an input transistor and an output transistor, wherein the sources of the input and output transistor are connected to a supply voltage node. The gates of the input and output transistors are connected through a switch. A first current source is coupled to the input transistor to provide an input current. A copy transistor has a source connected to the supply node and a gate connected to the gate of the input transistor at a mirror node. A second current source is coupled to the copy transistor to provide a copy current. A source-follower transistor has its source connected to the mirror node and its gate connected to the drain of the copy transistor. Charge sharing at the mirror node occurs in response to actuation of the switch and the source-follower transistor is turned on in response thereto to discharge the mirror node.

Analog boost circuit for fast recovery of mirrored current

A current mirror includes an input transistor and an output transistor, wherein the sources of the input and output transistor are connected to supply voltage node. The gates of the input and output transistor are connected through a switch. A first current source is coupled to the input transistor to provide an input current. A copy transistor has a source connected to the supply node and a gate connected to the gate of the input transistor at a mirror node. A second current source is coupled to the copy transistor to provide a copy current. A source-follower transistor has its source connected to the mirror node and its gate connected to the drain of the copy transistor. Charge sharing at a mirror node occurs in response to actuation of the switch and the source-follower transistor is turned on in response thereto to discharge the mirror node.

According to an embodiment, an operational amplifier includes a first amplifier stage coupled between an input node and an intermediate node, a second amplifier stage coupled between the intermediate node and an output node, a compensation capacitor having a first terminal coupled to the intermediate node and a second terminal, and a compensation amplifier coupled between the output node and the second terminal. The compensation amplifier has a positive gain greater than one.

Growing community of inventors

Milan, Italy

Riccardo Zurla