Driver circuit, corresponding device and system

A device, comprising:

• a circuit including:
• a differential transconductance amplifier having a first input node, a second input node, and an output node, the output node being coupled to the second input node via a feedback line;
• a supply node and a drive node configured to be coupled to a transistor current operative to provide a current path between the supply node and the drive node, the supply node being configured to be coupled to a power supply source;
• a control node coupled to the output node of the differential transconductance amplifier and the control terminal of the transistor;
• a Zener diode arrangement having a cathode coupled to the supply node and an anode coupled to the first input node of the differential transconductance amplifier;
• a pull-up component coupled in parallel with the Zener diode arrangement;
• and
• an enable switch having a first terminal coupled to the first input node and a second terminal coupled to a ground node, the enable switch being switchable between:
• a conductive state during which the first input node is coupled to the supply node via the Zener diode arrangement in a reverse-bias configuration, and the differential transconductance amplifier performs controlled current discharging of the control node rendering the transistor conductive;
• and
• a non-conductive state during which the first input node is pulled up to the supply node via the pull-up component, and the differential transconductance amplifier performs controlled current charging of the control node rendering the transistor non-conductive;
• and
• the transistor arranged with the current path therethrough coupling the supply node and the drive node.

A system, comprising:

• a circuit, including:
• a differential transconductance amplifier having a first input node, a second input node, and an output node, the output node being coupled to the second input node via a feedback line;
• a supply node configured to be coupled to a power supply source;
• a drive node;
• a transistor having a first conductive terminal coupled to the supply node, a second conductive terminal coupled to the drive node, and a control terminal, the transistor being operative to provide a current path between the supply node and the drive node;
• a control node coupled to the output node of the differential transconductance amplifier and the control terminal of the transistor;
• a Zener diode arrangement having a cathode coupled to the supply node and an anode coupled to the first input node of the differential transconductance amplifier;
• a pull-up component coupled in parallel with the Zener diode arrangement;
• an enable switch having a first terminal coupled to the first input node and a second terminal coupled to a ground node, the enable switch being switchable between:
• a conductive state during which the first input node is coupled to the supply node via the Zener diode arrangement in a reverse-bias configuration, and the differential transconductance amplifier performs controlled current discharging of the control node rendering the transistor conductive;
• and
• a non-conductive state during which the first input node is pulled up to the supply node via the pull-up component, and the differential transconductance amplifier performs controlled current charging of the control node rendering the transistor non-conductive;
• load drive circuitry including:
• first and second circuit output nodes;
• and
• a first load transistor having a first conduction terminal coupled to the intermediate said drive node and a second conduction terminal coupled to the first circuit output node, and a second load transistor having a first conduction terminal coupled to the second circuit output node and a second conduction terminal coupled to the ground node;
• and
• a load coupled to the first and second circuit output nodes.

A method, comprising:

• operating a switch to set a first voltage to either:
• a clamp voltage representative of a difference between a supply voltage and a voltage drop across a Zener diode arrangement, or a pull-up voltage to the supply voltage;
• receiving, by the differential transconductance amplifier at a first input, the first voltage;
• receiving, by the differential transconductance amplifier at a second input, a feedback voltage representative of an output voltage provided at an output of the differential transconductance amplifier;
• comparing, by the differential transconductance amplifier, the first voltage to the feedback voltage;
• and
• sinking or sourcing controlled current, by the differential transconductance amplifier at the output, to operate a transistor in a conductive state or non-conductive state based on the comparing.