Abstract:
Disclosed examples include isolated phase shifted dual active bridge DC to DC converters with a first bridge circuit operative according to a primary side clock signal to provide a primary voltage signal to a transformer primary winding, a second bridge circuit operative according to a secondary side clock signal to convert a secondary voltage signal from a transformer secondary winding to provide an output voltage signal, and a secondary side control circuit that alternately operates in a first mode to regulate the output voltage signal by controlling a phase shift angle between switching transitions of secondary side switching control signals and switching transitions of the secondary side clock signal, and a second mode to discontinue the secondary side switching control signals and synchronize the secondary side clock signal to transitions in the secondary voltage signal while the secondary side switching control signals are discontinued.
Abstract:
An electronic device, which includes an H-bridge circuit and a miniaturized transformer that is coupled to operate at VHF frequency, and a driver circuit for an n-type power transistor of the H-bridge circuit are disclosed. The driver circuit includes a first p-type transistor and an n-type transistor coupled between an upper rail and a lower rail, with an output taken between the drains of the first p-type transistor and the n-type transistor being coupled to a gate of the n-type power transistor. The driver circuit also includes a sample-and-hold capacitor coupled to capture a drain voltage for the first n-type power transistor on a first edge of a control signal for the first n-type power transistor and a comparator coupled to compare the captured drain voltage to a lower rail on a given edge of a clock signal and to provide a comparator value. The driver circuit also includes an up/down counter, which is coupled to receive the comparator value, to adjust a counter value responsive to receiving the comparator value and to output the counter value, and a first timing circuit that is coupled to receive the counter value and to send an adjustable pulse towards a gate of the first p-type transistor and a gate of the n-type transistor.
Abstract:
Described examples include DC to DC converters and systems with switching circuitry formed by four series-connected switches, inductors connected between the ends of the switching circuitry and corresponding output nodes, and with a flying capacitor coupled across interior switches of the switching circuitry and a second capacitor coupled across the ends of the switching circuitry. A control circuit operates the switching circuit to control a voltage signal across the output nodes using a first clock signal and a phase shifted second clock signal to reduce output ripple current and enhance converter efficiency using valley current control. The output inductors are wound on a common core in certain examples.
Abstract:
Disclosed examples include multiple output DC to DC converters with a buck converter including a half bridge switching circuit and transformer primary winding to provide a first output voltage signal, as well as a boost converter to provide an isolated second output voltage signal. The boost converter includes a transformer secondary winding magnetically coupled with the primary winding to provide a boost converter inductor, a switching circuit, an output diode providing the second output voltage signal, and a PWM controller that synchronizes the boost converter switching with the low side switch of the buck converter based on a sensed voltage of the transformer secondary winding.
Abstract:
A semiconductor package is provided that has a transformer formed within a multilayer dielectric laminate substrate. The transformer has a first inductor coil formed in one or more dielectric laminate layers of the substrate, a second inductor coil formed in one or more dielectric laminate layers of the substrate, and an isolation barrier comprising two or more dielectric laminate layers of the multilayer substrate positioned between the first inductor coil and the second inductor coil. The transformer may be mounted on a lead frame along with one or more integrated circuits and molded into a packaged isolation device.