Semiconductor device, electronic appliance, and vehicle

Patent metadata

Field	Value
Publication number	US-9391603-B2
Application number	US-201314062430-A
Country	US
Kind code	B2
Filing date	Oct 24, 2013
Priority date	Oct 25, 2012
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A semiconductor device has a first chip and a second chip sealed in a single package. The first chip includes a regulator which generates an internal voltage from a supply voltage, a reset circuit which monitors the supply voltage and the internal voltage to generate a reset signal, and a controlled circuit which operates by being supplied with the supply voltage. The second chip includes a controlling circuit which generates a control signal for the controlled circuit by being supplied with the internal voltage. The reset signal is fed to both the controlling circuit and the controlled circuit.

First claim

What is claimed is:

1. A semiconductor device comprising a first chip and a second chip sealed in a single package, wherein:
the first chip includes a regulator which generates an internal voltage from a supply voltage, a reset circuit which monitors the supply voltage and the internal voltage to generate a reset signal, and a controlled circuit which operates by being supplied with the supply voltage,
the second chip includes a controlling circuit which generates a control signal for the controlled circuit by being supplied with the internal voltage, and
the reset signal is fed to both the controlling circuit and the controlled circuit,
wherein the reset circuit includes:
a supply voltage monitor which monitors the supply voltage to generate a supply voltage monitor signal,
a timer which delays the supply voltage monitor signal to generate a delayed supply voltage monitor signal,
an internal voltage monitor which monitors the internal voltage to generate an internal voltage monitor signal, and
a reset signal generator which generates the reset signal according to the delayed supply voltage monitor signal and the internal voltage monitor signal, wherein:

when at least one of the delayed supply voltage monitor signal or the internal voltage monitor signal is at an abnormal-state logic level, the reset signal generator keeps the reset signal at a reset-state logic level, and
when the delayed supply voltage monitor signal and the internal voltage monitor signal are both at a normal-state logic level, the reset signal generator keeps the reset signal at a non-reset-state logic level.

2. The semiconductor device according to claim 1 ,
wherein the controlled circuit is enabled to operate when the reset signal is at a non-reset-state logic level and simultaneously the control signal is at an enabled-state logic level.

3. The semiconductor device according to claim 2 ,
wherein the reset circuit includes
a supply voltage monitor which monitors the supply voltage to generate a supply voltage monitor signal,
a timer which delays the supply voltage monitor signal to generate a delayed supply voltage monitor signal,
an internal voltage monitor which monitors the internal voltage to generate an internal voltage monitor signal, and
a reset signal generator which generates the reset signal according to the delayed supply voltage monitor signal and the internal voltage monitor signal.

4. The semiconductor device according to claim 3 ,
wherein the controlled circuit is a motor driving circuit which drives and controls a motor.

5. The semiconductor device according to claim 4 ,
wherein the motor driving circuit includes
a controller which generates an energizing control signal according to the control signal,
a pre-driver which generates a drive signal according to the energizing control signal, and
a driver which generates a drive current for the motor according to the drive signal.

6. The semiconductor device according to claim 1 ,
wherein the controlled circuit is a motor driving circuit which drives and controls a motor.

7. The semiconductor device according to claim 6 ,
wherein the motor driving circuit includes
a controller which generates an energizing control signal according to the control signal,
a pre-driver which generates a drive signal according to the energizing control signal, and
a driver which generates a drive current for the motor according to the drive signal.

8. The semiconductor device according to claim 7 ,
wherein the motor driving circuit includes a logic gate which performs masking of the energizing control signal or the drive signal according to the reset signal.

9. The semiconductor device according to claim 7 ,
wherein the motor driving circuit includes a power switch which switches a power path to the driver between a conducting state and a cut-off state according to the reset signal.

10. The semiconductor device according to claim 7 ,
wherein the motor driving circuit includes a power switch which switches a power path to the pre-driver between a conducting state and a cut-off state according to the reset signal.

11. An electronic appliance comprising:
the semiconductor device according to claim 6 ; and
a motor which is driven and controlled by the semiconductor device.

12. A vehicle comprising:
the electronic appliance according to claim 11 ; and
a battery which supplies the electronic appliance with a supply voltage.

13. The semiconductor device according to claim 1 ,
wherein the controlled circuit is a motor driving circuit which drives and controls a motor.

14. The semiconductor device according to claim 13 ,
wherein the motor driving circuit includes
a controller which generates an energizing control signal according to the control signal,
a pre-driver which generates a drive signal according to the energizing control signal, and
a driver which generates a drive current for the motor according to the drive signal.

15. The semiconductor device according to claim 2 ,
wherein the controlled circuit is a motor driving circuit which drives and controls a motor.

16. The semiconductor device according to claim 15 ,
wherein the motor driving circuit includes
a controller which generates an energizing control signal according to the control signal,
a pre-driver which generates a drive signal according to the energizing control signal, and
a driver which generates a drive current for the motor according to the drive signal.

Assignees

• Rohm Co Ltd

Inventors

• Fujimura Takashi
• Imamura Muga
• Yuki Hirofumi

Classifications

• H03K17/22 Primary

  Modifications for ensuring a predetermined initial state when the supply voltage has been applied (bi-stable generators H03K3/12) · CPC title

• H02J1/06

  Two-wire DC power distribution systems · CPC title

• H03K2217/0081

  Power supply means, e.g. to the switch driver · CPC title

• Y10T307/469

  Cross-Sectional Technologies · mapped topic

• Y02P80/23

  Cross-Sectional Technologies · mapped topic