Direct current DC-DC converter pin lift detection
Embodiments of pin lift detection circuit for a direct current DC-DC converter and DC-DC converters are disclosed. In an embodiment, a pin lift detection circuit for a DC-DC converter includes a current source, a switch connecting the current source to an electrical terminal of the DC-DC converter, a resistive divider connected to the switch and to the electrical terminal of the DC-DC converter, an amplifier connected to the resistive divider, a comparator connected to the amplifier and to the resistive divider, a digital filter connected to the comparator and configured to generate a flag signal in response to a disconnection between the electrical terminal of the DC-DC converter and a load of the DC-DC converter, and a timer circuit configured to generate control signals for the switch, the comparator, and the digital filter.
1 . A pin lift detection circuit for a direct current DC-DC converter, the pin lift detection circuit comprising:
a current source;
a switch connecting the current source to an electrical terminal of the DC-DC converter;
a resistive divider connected to the switch and to the electrical terminal of the DC-DC converter;
an amplifier connected to the resistive divider;
a comparator connected to the amplifier and to the resistive divider;
a digital filter connected to the comparator and configured to generate a flag signal in response to a disconnection between the electrical terminal of the DC-DC converter and a load of the DC-DC converter; and
a timer circuit configured to generate a plurality of control signals for the switch, the comparator, and the digital filter;
wherein the amplifier comprises a first input terminal connected to a reference voltage and a second input terminal configured to receive an output voltage of the resistive divider;
further comprising a second comparator connected to the amplifier and to a control circuit of the DC-DC converter;
wherein the amplifier comprises an output terminal connected to an input terminal of the second comparator; and
wherein the second comparator is configured to cause the control circuit of the DC-DC converter to disable the DC-DC converter in response to the disconnection between the electrical terminal of the DC-DC converter and the load of the DC-DC converter.
2 . The pin lift detection circuit of claim 1 , wherein the second comparator is configured to cause the control circuit of the DC-DC converter to disable a high-side (HS) switch and a low-side (LS) switch of the DC-DC converter in response to the disconnection between the electrical terminal of the DC-DC converter and the load of the DC-DC converter.
3 . The pin lift detection circuit of claim 2 , wherein at least one of the HS switch and the LS switch comprises a bipolar junction transistor (BJT) or a metal-oxide-semiconductor field-effect transistor (MOSFET).
4 . The pin lift detection circuit of claim 3 , wherein an output inductor and an output capacitor are connected between two electrical terminals of the DC-DC converter.
5 . The pin lift detection circuit of claim 1 , wherein the timer circuit is further configured to generate a first control signal to enable or disable the switch and the comparator, and a second control signal to enable or disable the digital filter.
6 . The pin lift detection circuit of claim 5 , wherein a rising or falling edge of the second control signal has a delay with respect to a rising or falling edge of the first control signal.
7 . The pin lift detection circuit of claim 1 , further comprising a resistor-capacitor (RC) circuit that includes a resistor and a capacitor.
8 . A direct current DC-DC converter comprising:
a pin lift detection circuit comprising:
a current source;
a switch connecting the current source to an electrical terminal of the DC-DC converter;
a resistive divider connected to the switch and to the electrical terminal of the DC-DC converter;
an amplifier connected to the resistive divider;
a comparator connected to the amplifier and to the resistive divider;
a digital filter connected to the comparator and configured to generate a flag signal in response to a disconnection between the electrical terminal of the DC-DC converter and a load of the DC-DC converter; and
a timer circuit configured to generate a plurality of control signals for the switch, the comparator, and the digital filter;
a high-side (HS) driver;
an HS switch connected to the HS driver;
a low-side (LS) driver;
an LS switch connected to the LS driver; and
a control circuit connected to the pin lift detection circuit and configured to control the HS driver, the HS switch, the LS driver, and the LS switch;
wherein the amplifier comprises a first input terminal connected to a reference voltage and a second input terminal configured to receive an output voltage of the resistive divider;
wherein the pin lift detection circuit further comprises a second comparator connected to the amplifier and to the control circuit of the DC-DC converter; and
wherein the second comparator is configured to cause the control circuit of the DC-DC converter to disable the HS switch and the LS switch of the DC-DC converter in response to the disconnection between the electrical terminal of the DC-DC converter and the load of the DC-DC converter.
9 . The DC-DC converter of claim 8 , wherein an output inductor and an output capacitor are connected between two electrical terminals of the DC-DC converter.
10 . The DC-DC converter of claim 8 , wherein the timer circuit is further configured to generate a first control signal to enable or disable the switch and the comparator of the pin lift detection circuit, and a second control signal to enable or disable the digital filter.
11 . The DC-DC converter of claim 10 , wherein a rising or falling edge of the second control signal has a delay with respect to a rising or falling edge of the first control signal.
12 . The DC-DC converter of claim 8 , wherein the pin lift detection circuit further comprises a resistor-capacitor (RC) circuit that includes a resistor and a capacitor.
13 . A pin lift detection circuit for a buck direct current DC-DC converter, the pin lift detection circuit comprising:
a current source;
a switch connecting the current source to an electrical terminal of the buck DC-DC converter;
a resistive divider connected to the switch and to the electrical terminal of the buck DC-DC converter;
an amplifier connected to the resistive divider;
a first comparator connected to the amplifier and to the resistive divider;
a digital filter connected to the first comparator and configured to generate a flag signal in response to a disconnection between the electrical terminal of the buck DC-DC converter and a load of the buck DC-DC converter;
a timer circuit configured to generate a plurality of control signals for the switch, the first comparator, and the digital filter; and
a second comparator connected to the amplifier and to a control circuit of the buck DC-DC converter and configured to cause the control circuit of the buck DC-DC converter to disable the buck DC-DC converter in response to the disconnection between the electrical terminal of the buck DC-DC converter and the load of the buck DC-DC converter.