Switched tank-transformer based high step-down ratio DC-DC converter
A DC-DC converter circuit includes a switched tank converter configured to output a switching waveform. The DC-DC converter circuit further includes a transformer coupled to the switched tank converter to receive the switching waveform output by the switched tank converter across a primary winding of the transformer.
1. A DC-DC converter circuit comprising:
a switched tank converter configured to output a switching waveform;
a transformer coupled to the switched tank converter to receive the switching waveform output by the switched tank converter across a primary winding of the transformer; and
wherein the switched tank converter comprises an interleaved switch tank converter.
2. The DC-DC converter circuit of claim 1 , wherein the switched tank converter provides a portion of a conversion ratio of the DC-DC converter circuit, and the transformer provides a remaining portion of the conversion ratio.
3. The DC-DC converter circuit of claim 1 , wherein the interleaved switch tank converter comprises a first tank circuit, a second tank circuit, and a plurality of switches for coupling the first tank circuit and the second tank circuit.
4. The DC-DC converter circuit of claim 3 , wherein the first tank circuit comprises a first inductor and a first capacitor coupled to the first inductor, and wherein the second tank circuit comprises a second inductor and a second capacitor coupled to the second inductor.
5. The DC-DC converter circuit of claim 1 , further comprising a resonant capacitor tuned to series resonate with a leakage inductance of the transformer at a switching frequency of the switching waveform.
6. The further of claim 1 , wherein the transformer comprises a plurality of transformer circuits coupled in parallel.
7. A system comprising:
a DC-DC converter configured to receive an input signal and generate an output signal, wherein the DC-DC converter comprises:
a switched tank converter configured to output a switching waveform;
a transformer coupled to the switched tank converter to receive the switching waveform output by the switched tank converter across a primary winding of the transformer;
a synchronous rectifier coupled to the DC-DC converter and configured to rectify the output signal generated by the DC-DC converter;
an integrated circuit (IC) device coupled to the synchronous rectifier to receive the rectified output signal; and
wherein the switched tank converter comprises an interleaved switch tank converter.
8. The system of claim 7 , wherein the switched tank converter provides a portion of a conversion ratio of the DC-DC converter, and the transformer provides a remaining portion of the conversion ratio.
9. The system of claim 8 , wherein the interleaved switch tank converter comprises a first tank circuit, a second tank circuit, and a plurality of switches for coupling the first tank circuit and the second tank circuit.
10. The system of claim 9 ,
wherein the first tank circuit comprises a first inductor and a first capacitor coupled to the first inductor, and
wherein the second tank circuit comprises a second inductor and a second capacitor coupled to the second inductor.
11. The system of claim 7 , wherein the DC-DC converter further comprises a resonant capacitor tuned to series resonate with a leakage inductance of the transformer at a switching frequency of the switching waveform.
12. The system of claim 7 , wherein the transformer comprises a plurality of transformer circuits coupled in parallel.
13. A method of operating a converter circuit comprising a switched tank converter and a transformer coupled to the switched tank converter, the method comprising:
receiving an input signal at the switched tank converter;
during a first phase, controlling the switched tank converter to apply a voltage of a first polarity across a primary winding of the transformer;
during a second phase, controlling the switched tank converter to apply a voltage of a second polarity across the primary winding of the transformer, wherein the second polarity is opposite of the first polarity;
providing an output signal at a secondary winding of the transformer; and
the converter circuit drawing current from the input signal during both the first phase and the second phase.
14. The method of claim 13 , wherein controlling the switched tank converter to apply the voltage of the first polarity across the primary winding comprises controlling a plurality of first switches to be on and controlling a plurality of second switches to be off.
15. The method of claim 14 , wherein controlling the switched tank converter to apply the voltage of the second polarity across the primary winding comprises controlling the plurality of first switches to be off and controlling the plurality of second switches to be on.
16. The method of claim 13 , wherein the switched tank converter provides a portion of a conversion ratio of the converter circuit, and the transformer provides a remaining portion of the conversion ratio.
17. The method of claim 13 , wherein controlling the switched tank converter to apply the voltage of the first polarity during the first phase and controlling the switched tank converter to apply the voltage of the second polarity during the second phase cause a switching waveform to be applied across the primary winding of the transformer.