DC-DC converter drive circuit which has step up mode and step down mode
AssigneeNEC Electronics Corporation
InventorKazuo Henmi
Life of this patent
Estimating the term…
Abstract
A switching signal for load power control undergoes a logic change on the basis of a reference power supply potential by a controller responding to a load power feed control sense signal, and a reference signal. The sense signal in a first operation mode is converted from a load power feed state feedback signal varying on the basis of an input power supply potential into a signal varying on the basis of the reference power supply potential to be fed to the controller. On the other hand, a load power feed state feedback signal varies on the basis of the reference power supply potential in a second operation mode, and the load power feed state feedback signal is used as the sense signal to be fed to the controller.
Claims16
A DC-DC converter drive circuit, comprising:
- a controller that generates a switching signal for controlling a power supply to a load circuit provided between an input power supply potential and a reference power supply potential by responding to a sense signal and a reference signal, the switching signal undergoing a logic change on a basis of the reference power supply potential;
- step-down operation feedback means for receiving a first feedback signal varying on a basis of the input power supply potential from the load circuit in a step-down operation mode to convert the first feedback signal into a signal varying on the basis of the reference power supply potential, and feeding the signal varying as the sense signal, to the controller;
- and
- boost operation mode feedback means for receiving a second feedback signal varying on the basis of the reference power supply potential from the load circuit in a boost operation mode, and feeding the second feedback signal as the sense signal to the controller.
A DC-DC converter drive circuit, comprising on a semiconductor chip:
- an amplification circuit which includes a first node coupled to a first external terminal, and a second node applied with a reference voltage, to produce a first signal;
- a control circuit which responds to the first signal, to output a control signal;
- a drive circuit which outputs a drive signal in response to the control signal;
- and
- a sense amplifier which includes an input coupled to a second external terminal and an output coupled to the first node, and activated by a mode signal.
Dependencies are inferred from the claim text.