US Patent No. 10,483,753

EMBEDDED BATTERY PROTECTION SYSTEM


Patent No. 10,483,753
Issue Date November 19, 2019
Title Embedded Battery Protection System
Inventorship Shaohua Peng, Shanghai (CN)
Xuguang Zhang, Shanghai (CN)
Assignee BCD Semiconductor Manufacturing Limited, George Town, Grand Cayman (KY)

Claim of US Patent No. 10,483,753

1. A battery control circuit for a mobile device, wherein the mobile device has an embedded battery and is configured for coupling to an external power source, the battery control circuit comprising:first and second high-voltage NMOS transistors coupled in series and configured for connecting between a ground terminal of the embedded battery in the mobile device and a ground terminal of the external power source; and
a battery protection IC (integrated circuit) including:
a power terminal for coupling to a power terminal of the embedded battery and a power terminal of the external power source;
a first ground terminal for coupling to the ground terminal of the external power source; and
a second ground terminal for coupling to the ground terminal of the embedded battery;
wherein the battery protection IC is configured to:
receive a signal from a functional block in the mobile device, the signal having a voltage level relative to the ground terminal of the external power source;
and
in response to the signal, provide one or more control signals having voltage levels relative to the ground terminal of the embedded battery, the control signals being configured to turn on the first and the second high-voltage NMOS transistors to connect the embedded battery to the external power source, or to turn off the first and the second high-voltage NMOS transistors to disconnect the embedded battery from the external power source;
wherein the battery protection IC comprises:
a signal processing circuit configured to receive an input signal having a voltage level relative to the first ground terminal and to provide an output signal having a voltage level relative to the second ground terminal in response to the input signal; and
a logic circuit coupled to the signal processing circuit and configured to provide one or more control signals having voltage levels relative to the second ground terminal in response to the output signal of the signal processing circuit;
wherein the signal processing circuit comprises:
a first circuit coupled between the power terminal and the first ground terminal, the first circuit being configured to receive an input signal having a voltage level relative to the first ground terminal and to provide first and second complementary digital signals in response to the input signal; and
a second circuit coupled between the power terminal and the second ground terminal, the second circuit being configured to provide a digital output signal relative to the second ground terminal in response to the first and second complementary digital signals;
wherein the one or more control signals are configured to turn on a switch device including the first and second high-voltage NMOS transistors between the first ground terminal and the second ground terminal to connect the first ground terminal to the second ground terminal, even when the second ground terminal is electrically floating relative to the first ground terminal.