In today’s rapidly evolving power electronics landscape, the demand for efficient and compact power conversion solutions has never been higher. As leading-edge DSPs, FPGAs, and CPUs continue to operate at lower supply voltages while drawing more current, selecting the right PWM controller has become increasingly complex. Voltages below 1V are now standard, while intermediate bus voltages remain stable or even rise in certain applications. Meanwhile, system frequencies are steadily increasing to support smaller inductors and capacitors, with switching frequencies moving from 500kHz last year to 1MHz this year.
In high-voltage systems requiring low output voltages, power supply designers often face tough choices—either using costly modules or implementing two-level DC/DC solutions that increase complexity and size. This article explores the trends shaping narrow on-time point-of-load (POL) conversion and compares them to traditional current mode control architectures. It also introduces a hybrid valley current mode (VCM) architecture with adaptive slope compensation, highlighting its ability to handle wide input and output voltage ranges. The new 60V synchronous buck controller exemplifies this technology, enabling stable operation at low duty cycles and direct step-down from 48V to 1V.
The need for narrow on-time conversion is driven by several factors, including the push for higher switching frequencies to improve power density. Many modern power supplies operate at 1MHz, and in automotive infotainment systems, frequencies must exceed 1.8MHz to avoid interference. At 1MHz, a 12V to 1V conversion still requires an on-time of about 83ns, pushing the limits of traditional controllers.
Low duty cycle operation presents significant challenges. While ideal buck converters can theoretically produce any output voltage below Vin, real-world limitations such as reference voltage, internal losses, and minimum on-time constraints come into play. The minimum on-time of a controller determines how low the output voltage can go, especially at high switching frequencies. For example, at 600kHz, a 12V to 1V conversion becomes difficult due to the short on-time required.
Peak current mode control, though widely used, struggles with very narrow on-times due to the blanking time needed to avoid false triggering from MOSFET turn-on ringing. Valley current mode control offers an alternative by detecting current during the off-time of the upper MOSFET, avoiding the ringing issue. However, it faces its own challenges, such as subharmonic oscillations and poor linearity.
To address these issues, adaptive slope compensation in valley current mode has emerged as a powerful solution. This technique prevents subharmonic oscillations across all duty cycles, enabling stable operation at very high frequencies. The ISL8117 60V synchronous buck controller, for instance, combines valley current sensing, low-side MOSFET Rdson, and adaptive slope compensation to deliver exceptional performance. It supports input voltages from 4.5V to 60V and output voltages from 0.6V to 54V, with a minimum on-time of just 40ns. This allows for high-frequency conversions, such as 1V from a 12V or 48V bus.
With only 10 components required, the ISL8117 simplifies design and achieves up to 98% efficiency and 1.5% output accuracy. Its low pin count and layout-friendly design further enhance performance by minimizing cross-talk and improving thermal management. In applications sensitive to noise, the controller can synchronize with external clock sources to reduce radiated and beat frequency noise.
In summary, while each control method has its trade-offs, innovations like the ISL8117 demonstrate how advanced architectures can overcome traditional limitations. By eliminating intermediate conversion stages, these controllers enable higher power density, reduced system cost, and improved reliability—making them essential for next-generation power supply designs.
Slide Switch
Slide Switches
The Slide Switches is used to switch the circuit by turning the switch handle to turn the circuit on or off. It is different from our other serious switches, for example, Metal Switches, Automotive Switches, LED light Switches, Push button Switches, Micro Switches, The commonly used varieties of Miniature Slide Switches are single pole double position, single pole three position, double pole double position and bipolar three position. It is generally used for low voltage circuits, featuring flexible slider action, stable and reliable performance. Mainly used in a wide range of instruments, fax machines, audio equipment, medical equipment, beauty equipment, and other electronic products.
The Mini Slide Switches are divided into: low-current slide switches (right), and high-current slide switches (left). Small current slide switches are commonly used in electronic toys, digital communications. High current is generally used in electrical appliances, machinery, etc.
It can divided into 4 types modals, respectively are:
1. High-current sealed switch
Its rated current is as high as 5A, and it is sealed with epoxy resin. It is a large current sealed switch. It has a variety of terminal forms, contact materials are silver, gold, switching functions. Therefore, there are many types of subdivisions. Widely used in electrical appliances and machinery
2. Single sided snap-on surface mount type slide switch
The actuator is operated on the side and the pins are patch-type, so it is a unilateral spring-back surface mount type slide switch. Widely used in communications, digital audio and video
3.4P3T in-line slide switch
The contact form is 4P3T and the pin is in-line. It is 4P3T in-line slide switch. 4P3T determines that it has 8 pairs of pins. At the same time, there are two pairs of brackets that support, fix, and ground. Widely used in building automation, electronic products
4.Long actuator jacking type slide switch
Actuator 12mm, and located at the top of the switch, it is a long actuator jacking type slide switch. Widely used in digital audio and video, various instruments / instrumentation equipment
Slide Switches,Micro Slide Switch,2 Position Slide Switch,Momentary Slide Switch
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