Power-on control circuit and integrated circuit having multiple power domains

Patent metadata

Field	Value
Publication number	US-12562739-B2
Application number	US-202418735128-A
Country	US
Kind code	B2
Filing date	Jun 5, 2024
Priority date	Jun 5, 2024
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

A power-on control circuit includes a signal processing circuit, a first level shifter and a voltage tracking circuit. The signal processing circuit is configured to generate a power-on control signal according to a first tracking signal operative in a first power domain of the integrated circuit. The first level shifter is configured to generate the first tracking signal according to a second tracking signal operative in a second power domain of the integrated circuit. The second power domain is different from the first power domain. The voltage tracking circuit is powered by a first supply voltage operative in the first power domain and a second supply voltage operative in the second power domain. The voltage tracking circuit is configured to, when the second supply voltage is ready, track the first supply voltage according to the power-on control signal, and accordingly generate the second tracking signal.

First claim

What is claimed is:

1 . A power-on control circuit for an integrated circuit, the power-on control circuit comprising:
a signal processing circuit, configured to generate a power-on control signal according to a first tracking signal operative in a first power domain of the integrated circuit; a first level shifter, coupled to the signal processing circuit, the first level shifter being configured to generate the first tracking signal according to a second tracking signal operative in a second power domain of the integrated circuit, the second power domain being different from the first power domain; and a voltage tracking circuit, coupled to the first level shifter, and powered by a first supply voltage operative in the first power domain and a second supply voltage operative in the second power domain, wherein the voltage tracking circuit is configured to, when the second supply voltage is ready, track the first supply voltage according to the power-on control signal, and accordingly generate the second tracking signal.

2 . The power-on control circuit of claim 1 , wherein when the power-on control signal at a first logic level, the voltage tracking circuit is configured to generate the second tracking signal by detecting if the first supply voltage reaches a first threshold level to become ready for use; when the power-on control signal at a second logic level different from the first logic level, the voltage tracking circuit is configured to generate the second tracking signal by detecting if the first supply voltage reaches a second threshold level to become unready for use.

3 . The power-on control circuit of claim 1 , wherein the voltage tracking circuit comprises:
an output terminal; a supply terminal coupled to the second supply voltage; and a reference terminal coupled to a reference voltage; wherein when the second supply voltage is ready and the first supply voltage is unready, the voltage tracking circuit is configured to turn on a circuit path between the supply terminal and the output terminal according to the power-on control signal, control a conduction status of a circuit path between the output terminal and the reference terminal according to the first supply voltage, and generate the second tracking signal at the output terminal.

4 . The power-on control circuit of claim 3 , wherein when the first supply voltage reaches a threshold level to turn on the circuit path between the output terminal and the reference terminal, the second tracking signal transitions from a first logic level to a second logic level.

5 . The power-on control circuit of claim 3 , wherein when each of the first supply voltage and the second supply voltage is ready, the voltage tracking circuit is configured to turn off the circuit path between the supply terminal and the output terminal according to the power-on control signal.

6 . The power-on control circuit of claim 1 , wherein the voltage tracking circuit comprises:
a second level shifter, powered by the first supply voltage and the second supply voltage, the second level shifter being configured to convert the first supply voltage into the second tracking signal, wherein the second tracking signal is provided at an output terminal of the second level shifter; and a first switch, arranged to selectively couple the second supply voltage to the output terminal of the second level shifter according to the power-on control signal.

7 . The power-on control circuit of claim 6 , wherein when the second supply voltage is ready and the first supply voltage is unready, the first switch is turned on; when each of the first supply voltage and the second supply voltage is ready, the first switch is turned off.

8 . The power-on control circuit of claim 6 , wherein the second level shifter comprises:
an inverter circuit, powered by the first supply voltage, wherein an input terminal of the inverter circuit is coupled to the first supply voltage; and a latch circuit, powered by the second supply voltage, wherein a first output terminal of the latch circuit is coupled to the output terminal of the second level shifter, a first input terminal of the latch circuit is coupled to an output terminal of the inverter circuit, and a second input terminal of the latch circuit is coupled to the input terminal of the inverter circuit.

9 . The power-on control circuit of claim 8 , wherein a supply terminal of the latch circuit is coupled to the second supply voltage, and the first switch is selectively coupled between the supply terminal and the first output terminal of the latch circuit according to the power-on control signal; the second level shifter comprises:
a second switch, selectively coupled between a second output terminal of the latch circuit to a reference voltage according to the power-on control signal, wherein when one of the first switch and the second switch is turned on, the other of the first switch and the second switch is turned off.

10 . The power-on control circuit of claim 6 , wherein the second level shifter comprises:
an inverter circuit, powered by the first supply voltage, wherein an input terminal of the inverter circuit is coupled to the first supply voltage; and a current mirror circuit, powered by the second supply voltage, wherein an output terminal of the current mirror circuit is coupled to the output terminal of the second level shifter, a first input terminal of the current mirror circuit is coupled to an output terminal of the inverter circuit, and a second input terminal of the current mirror circuit is coupled to the input terminal of the inverter circuit.

11 . The power-on control circuit of claim 1 , wherein the voltage tracking circuit comprises:
an inverter circuit, powered by the first supply voltage, wherein an input terminal of the inverter circuit is coupled to the first supply voltage; a latch circuit, powered by the second supply voltage, wherein a first output terminal of the latch circuit is arranged to provide the second tracking signal, a first input terminal of the latch circuit is coupled to an output terminal of the inverter circuit, and a second input terminal of the latch circuit is coupled to the input terminal of the inverter circuit; and a switch, selectively coupled between a second output terminal of the latch circuit and a reference voltage according to the power-on control signal.

12 . The power-on control circuit of claim 1 , wherein the first level shifter comprises an inverter circuit powered by the first supply voltage; the inverter circuit is configured to generate the first tracking signal by inverting the second tracking signal.

13 . An integrated circuit having multiple power domains, comprising:
an input/output (I/O) circuit controlled by a power-on control signal, the I/O circuit comprising a first signal generator circuit powered by a first supply voltage and a second supply voltage, wherein the first signal generator is configured to receive an input signal, and generate an output signal according to the power-on control signal; the first supply voltage and the input signal are operative in a first power domain of the integrated circuit; the second supply voltage and the output signal are operative in a second power domain of the integrated circuit; and a power-on control circuit, coupled to the first signal generator circuit and configured to generate the power-on control signal, the power-on control circuit comprising:
a second signal generator circuit, configured to generate the power-on control signal according to a tracking signal operative in the second power domain; and
a voltage tracking circuit, coupled to the seco

Assignees

• M31 Tech Corp

Inventors

• Tsai Ming-Yen
• Chao Tze-Hsiang

Classifications

• H03K19/018521 Primary

  of complementary type, e.g. CMOS · CPC title

• H03K19/0013

  in field effect transistor circuits · CPC title

• H03K19/0016 Primary

  by using a control or a clock signal, e.g. in order to apply power supply · CPC title