Feedback network for low-drop-out generator

A circuit, comprising:

• a differential amplifier having an inverting input terminal, a power reference terminal, and output terminal;
• a feedback network comprising:
• a chain of resistance sets coupled in series and having a first end terminal coupled to the output terminal of the differential amplifier and a second end terminal coupled to the power reference terminal of the differential amplifier,
• respective nodes coupled between successive ones of the resistance sets,
• a feedback terminal coupled to the inverting input terminal of the differential amplifier,
• a set of switches configured to electrically couple a given one of the respective nodes to the feedback terminal,
• a controller configured to control the set of switches so as to electrically couple the given one of the respective nodes to the feedback terminal,
• a first resistance set of the chain adjacent the first end terminal comprising two resistance subsets coupled in series at an intermediate node between the two resistance subsets, and
• a first programmable current generator having a current output directly connected to the intermediate node between the two resistance subsets and being configured to produce a controlled value of current at the current output terminal flowing into or out of the intermediate node.

An integrated circuit comprising:

• a first circuit comprising:
• a first differential amplifier having an inverting input terminal, a power reference terminal, and output terminal,
• a first feedback network comprising:
• a chain of resistance sets coupled in series and having a first terminal coupled to the output terminal of the first differential amplifier and a second end terminal coupled to the power reference terminal of the first differential amplifier,
• respective nodes coupled between successive ones of the resistance sets,
• a feedback terminal coupled to the inverting input terminal of the first differential amplifier,
• a set of switches capable of electrically coupling a given node to the feedback terminal,
• a controller configured to control the set of switches so as to electrically couple the given node to the feedback terminal,
• a first resistance set of the chain adjacent the first end terminal comprising two resistance subsets coupled in series, with an intermediate node coupled between the two resistance subsets, and
• a first programmable current generator having a current output terminal coupled to the intermediate node and being configured to produce a controlled value of current flowing at the current output terminal, and
• a second circuit comprising:
• a second differential amplifier having an inverting input terminal, a power reference terminal, and output terminal,
• a second feedback network comprising:
• a chain of resistance sets coupled in series and having a first terminal coupled to the output terminal of the second differential amplifier and a second end terminal coupled to the power reference terminal of the second differential amplifier,
• respective nodes coupled between successive ones of the resistance sets,
• a feedback terminal coupled to the inverting input terminal of the second differential amplifier,
• a set of switches capable of electrically coupling a given node to the feedback terminal,
• a controller configured to control the set of switches so as to electrically couple the given node to the feedback terminal,
• a first resistance set of the chain adjacent the first end terminal comprising two resistance subsets coupled in series, with an intermediate node coupled between the two resistance subsets, and
• a first programmable current generator having a current output coupled to the intermediate node and being configured to produce a controlled value of current flowing at the current output terminal;
• wherein the first programmable current generator of the first circuit and the first programmable current generator of the second circuit each comprise respective digital-to-analog converters, the digital-to-analog converter of the first programmable current generator being formed adjacent the digital-to-analog converter of the second programmable current generator;
• wherein the chain of the resistance sets of the first circuit and the chain of the resistance sets of the second circuit are formed spaced apart from the digital-to-analog converter of the first programmable current generator and the digital-to-analog converter of the second programmable current generator;
• wherein the first differential amplifier of the first circuit and the second differential amplifier of the second circuit are formed spaced apart from the digital-to-analog converter of the first programmable current generator and the digital-to-analog converter of the second programmable current generator.

A circuit, comprising:

• a differential amplifier having a first input, a second input and an output;
• a string of series connected resistors coupled between a first node and a second node, wherein each adjacent pair of resistors in said string are connected an intermediate node;
• a switching circuit configured to selectively connect a selected intermediate node to the second input of the differential amplifier;
• a first resistor and a second resistor connected in series at a first current node, said first and second resistors coupled between the output of the differential amplifier and the first node of the string of series connected resistors;
• and
• a first programmable current generator having a current output terminal directly connected to the first current node and being configured to produce a controlled value of current at the current output terminal flowing into or out of the first current node.