Output driving circuit, clock chip, and electronic device

A clock chip, including:

• a clock signal generating circuit, configured to generate a high-speed clock signal;
• and
• an output driving circuit, including a low-voltage push-pull module, an impedance calibration module, and an output isolation module, wherein the output driving circuit is configured to input the high-speed clock signal and output a target high-speed clock signal,
• wherein the low-voltage push-pull module is connected to a low-voltage bias voltage and is configured to receive and process the high-speed clock signal, and to output an intermediate signal having a target level, wherein the low-voltage push-pull module includes one or more push-pull units, each including a low-voltage transistor pair including a first low-voltage transistor,
• wherein the output isolation module is connected between an output terminal of the low-voltage push-pull module and an output terminal of the output driving circuit, and includes output isolation units each including a first high-voltage transistor, wherein the output isolation module is configured to be turned on when the output driving circuit works normally, and to output the intermediate signal as the target high-speed clock signal,
• wherein the impedance calibration module is configured to calibrate an output impedance of the output driving circuit, so that the output impedance of the output driving circuit is substantially constant;
• the impedance calibration module includes:
• a reference voltage generating circuit configured to generate a reference voltage;
• a calibration voltage generating circuit configured to generate a calibration voltage negatively correlated with the output impedance;
• and an impedance calibration circuit configured to adjust a control voltage according to the reference voltage and the calibration voltage;
• wherein the calibration voltage generating circuit includes a third low-voltage transistor, a second high-voltage transistor, and a third resistor connected in series between the low-voltage bias voltage and ground;
• a connection point between the second high-voltage transistor and the third resistor outputs the calibration voltage, and the second high-voltage transistor receives the control voltage output by the impedance calibration circuit,
• wherein the third low-voltage transistor and the first low-voltage transistor are of the same type, the second high-voltage transistor and the first high-voltage transistor are of the same type, an overall size of the third low-voltage transistor and the second high-voltage transistor is 1/N of that of the first low-voltage transistor and the first high-voltage transistor, and a ratio of a resistance of the third resistor to N is a target output impedance of the output driving circuit.

An electronic device, including:

• a signal generating circuit, configured to generate a high-speed signal;
• and
• an output driving circuit, including a low-voltage push-pull module, an impedance calibration module, and an output isolation module, wherein the output driving circuit is configured to input the high-speed signal and output a target high-speed signal,
• wherein the low-voltage push-pull module is connected to a low-voltage bias voltage and is configured to receive and process the high-speed signal, and to output an intermediate signal having a target level, wherein the low-voltage push-pull module includes one or more push-pull units, each including a low-voltage transistor pair including a first low-voltage transistor,
• wherein the output isolation module is connected between an output terminal of the low-voltage push-pull module and an output terminal of the output driving circuit, and includes output isolation units each including a first high-voltage transistor, wherein the output isolation module is configured to be turned on when the output driving circuit works normally, and to output the intermediate signal as the target high-speed signal,
• wherein the impedance calibration module is configured to calibrate an output impedance of the output driving circuit, so that the output impedance of the output driving circuit is substantially constant;
• the impedance calibration module includes:
• a reference voltage generating circuit configured to generate a reference voltage;
• a calibration voltage generating circuit configured to generate a calibration voltage negatively correlated with the output impedance;
• and an impedance calibration circuit configured to adjust a control voltage according to the reference voltage and the calibration voltage;
• wherein the calibration voltage generating circuit includes a third low-voltage transistor, a second high-voltage transistor, and a third resistor connected in series between the low-voltage bias voltage and ground;
• a connection point between the second high-voltage transistor and the third resistor outputs the calibration voltage, and the second high-voltage transistor receives the control voltage output by the impedance calibration circuit,
• wherein the third low-voltage transistor and the first low-voltage transistor are of the same type, the second high-voltage transistor and the first high-voltage transistor are of the same type, an overall size of the third low-voltage transistor and the second high-voltage transistor is 1/N of that of the first low-voltage transistor and the first high-voltage transistor, and a ratio of a resistance of the third resistor to N is a target output impedance of the output driving circuit.