US 8,797,776 B2Granted

Diode-less full-wave rectifier for low-power on-chip AC-DC conversion

AssigneeHong Kong Applied Science and Technology Research Institute Company Limited

InventorsKwok Kuen (David) Kwong, Chun Fai Wong, Leung Ling (Alan) Pun, Ho Ming (Karen) Wan

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Abstract

A bridge rectifier operates on low A.C. input voltages such as received by a Radio-Frequency Identification (RFID) device. Voltage drops due to bridge diodes are avoided. Four p-channel transistors are arranged in a transistor bridge across the A.C. inputs to produce an internal power voltage. Another four diode-connected transistors form a start-up diode bridge that generates a comparator power voltage and a reference ground. The start-up diode bridge operates even during initial start-up before the comparator and boost drivers operate. A comparator receives the A.C. input and controls timing of voltage boost drivers that alternately drive gates of the four p-channel transistors in the transistor bridge with voltages boosted higher than the peak A.C. voltage. Substrates are connected to the power voltage on the power-voltage half of the bridge and to the A.C. inputs on the ground half of the bridge to fully shut off transistors, preventing reverse current flow.

Claims20

Dependent claims

A transistor-based bridge rectifier comprising:

a first alternating input;
a second alternating input;
a start-up diode bridge connected between the first alternating input and the second alternating input, for generating a comparator power voltage on a comparator power node and having a reference ground node;
a comparator, receiving the comparator power voltage from the start-up diode bridge, the comparator for comparing the first alternating input to a comparator reference to generate a timing signal;
a first boost driver, controlled by the timing signal, for generating a first gate signal, the first gate signal being boosted to a voltage greater than a peak voltage of the first alternating input;
a second boost driver, controlled by the timing signal, for generating a second gate signal, the second gate signal being boosted to a voltage greater than the peak voltage of the first alternating input;
a first forward transistor, having a transistor gate receiving the first gate signal, for conducting current between the first alternating input and an internal power node;
a first reverse transistor, having a transistor gate receiving the second gate signal, for conducting current between the first alternating input and an internal ground node;
a second forward transistor, having a transistor gate receiving the second gate signal, for conducting current between the second alternating input and the internal power node;
and
a second reverse transistor, having a transistor gate receiving the first gate signal, for conducting current between the second alternating input and the internal ground node.

8 more elements

A transistor rectifier comprising:

a pair of alternating-voltage inputs having a first phase and a second phase;
a comparator for comparing one of the pair of alternating inputs to a reference;
a first voltage booster, controlled by the comparator, for generating a first gate signal that alternates between a boosted voltage that exceeds a peak voltage of the pair of alternating-voltage inputs, and a ground;
a second voltage booster, controlled by the comparator, for generating a second gate signal that alternates between a boosted voltage that exceeds a peak voltage of the pair of alternating-voltage inputs, and the ground;
a first transistor having a gate controlled by the first gate signal to conduct during the first phase and switched to isolate during the second phase, the first transistor conducting between a first one of the pair of alternating-voltage inputs and an internal power node during the first phase;
a second transistor having a gate controlled by the first gate signal to conduct during the first phase and switched to isolate during the second phase, the second transistor conducting between an internal ground node and a second one of the pair of alternating-voltage inputs during the first phase;
a third transistor having a gate controlled by the second gate signal to conduct during the second phase and switched to isolate during the first phase, the third transistor conducting between the second one of the pair of alternating-voltage inputs and the internal power node during the second phase;
a fourth transistor having a gate controlled by the second gate signal to conduct during the second phase and switched to isolate during the first phase, the fourth transistor conducting between the internal ground node and the first one of the pair of alternating-voltage inputs during the second phase;
a first diode-connected transistor having a gate and a drain connected together, for conducting between the first one of the pair of alternating-voltage inputs and a comparator power node;
a second diode-connected transistor having a gate and a drain connected together, for conducting between a comparator ground node and the second one of the pair of alternating-voltage inputs during the first phase;
a third diode-connected transistor having a gate and a drain connected together, for conducting between the second one of the pair of alternating-voltage inputs and the comparator power node during the second phase;
and
a fourth diode-connected transistor having a gate and a drain connected together, for conducting between the comparator ground node and the first one of the pair of alternating-voltage inputs during the second phase;
wherein the comparator power node is connected as a power input to the comparator.

11 more elements

A full-wave transistor-bridge rectifier comprising:

alternating input means for receiving an Alternating-Current (AC) signal between a first AC line and a second AC line, the AC signal having a peak voltage;
compare means for comparing a first AC voltage on the first AC line to a reference voltage;
first voltage boost means, controlled by the compare means, for generating a first gate signal that alternated between a boosted voltage that is above the peak voltage and a ground;
second voltage boost means, controlled by the compare means, for generating a second gate signal that alternated between a boosted voltage that is above the peak voltage and a ground;
first transistor means, controlled by the first gate signal, for conducting during a first phase and for isolating during a second phase of the AC signal, the first transistor means for conducting between the first AC line and an internal power node during the first phase;
second transistor means, controlled by the first gate signal, for conducting during the first phase and for isolating during the second phase, the second transistor means conducting between an internal ground and the second AC line during the first phase;
third transistor means, controlled by the second gate signal, for conducting during the second phase and for isolating during the first phase, the third transistor means conducting between the second AC line and the internal power node during the second phase;
fourth transistor means, controlled by the second gate signal, for conducting during the second phase and for isolating during the first phase, the fourth transistor means conducting between the internal ground and the first AC line during the second phase;
first diode-connected transistor means, having a gate and a drain connected together, for conducting between the first AC line and a comparator power node during the first phase;
second diode-connected transistor means, having a gate and a drain connected together, for conducting between a comparator ground and the second AC line during the first phase;
third diode-connected transistor means, having a gate and a drain connected together, for conducting between the second AC line and the comparator power node during the second phase;
and
fourth diode-connected transistor means, having a gate and a drain connected together, for conducting between the comparator ground and the first AC line during the second phase;
wherein the compare means is powered by the comparator power node and receives the comparator ground.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/652,474Filed 16 Oct 2012
Published: US 2014/0104909 A117 Apr 2014
Granted: 5 Aug 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H02M 7/219
Using semiconductor devices only: in a bridge configuration
H02M 7/2195
In a bridge configuration: the switches being synchronously commutated at the same frequency of the AC input voltage
Y02B 70/10
Technologies for an efficient end-user side electric power management and consumption: technologies improving the efficiency by using…
H02M
Apparatus for conversion between ac and ac, between ac and dc, or