It's a Switcher - Part 4 News & Analysis 4/21/2003 Post a comment In part 3 of this four-part series, Sanjaya Maniktala examined Buck ICs, the "Type 2s" in his topology. Here, he turns to the sensing schemes that are critical to load regulation. Whether we're looking at negative-to-positive or negative-to-negative transitions, current sensing and better output regulation can be implemented by using an op-amp like an LM324. This final article installment examines where the amplifier can be inserted in the flyback chain.
Analog controller balances power, precision and cost in handhelds News & Analysis 4/21/2003 Post a comment Wearing pulse monitors and other instruments to the health club? Our fascination with gadgets extends from airports and convention centers to the most intimate of settings. These devices have much in common: A CPU and sensor interface that's accurate, cheap, and runs from a coin cell. A Texas Instruments' authority gives details using a glucose meter example.
Duty-cycle is one key to buck converters' output current capability News & Analysis 4/16/2003 Post a comment More thoughts on buck regulators: The most critical factor in DC-DC converter circuits is the load current capability, writes this On Semiconductor apps engineer. Whether you're using an internal or external FET, the sizing of the switch will be a function of its current rating. The overall power supply circuit also depends on the input-output voltage relationship, the inductor value, and switching frequency. Based on one of On's switching regulator circuits, this piece offers advice for picking
It's a Switcher - Part 3 News & Analysis 4/16/2003 Post a comment In part 3 of this four-part series, Sanjaya Maniktala examines Buck ICs, the "Type 2s" in his topology. Here, the Drain/Collector of the FET switch is typically connected to the control sections. Some of the versatility of the LSD cell is lost, he says. But the Type 2 is actually a good choice for positive-to-positive Buck regulators. This article shows how.
Adjacent channel rejection is a key for comparing transient responses of filter Banks News & Analysis 4/9/2003 Post a comment Here's a piece that was ripe for our April 7th Signals feature section on DSP filters. It examines the transient performance of RF filter banks, like those used for radar processing. The better the frequency discrimination - the tuning properties, writes John Lillington, the longer the time it takes to settle. Is there a convergence between fast transient response and sharp spectral filtering? he wonders. How does the plain old FFT fare against Polyphase DFT filter banks? The differences are ill
It's a switcher - Part 2 News & Analysis 4/9/2003 Post a comment By examining the internal architecture of the FET-based LSD cells, it is possible to visualize negative-to-positive and positive-to-negative current transitions. These transitions, explains Sanjaya Maniktala in part two of a four-part tutorial on switching regulator design, are the keys to using switchers efficiently.
It's a Buck; It's a Boost, No! It's a Switcher! News & Analysis 4/2/2003 Post a comment The LSD cell has no hallucinogenic properties, insists Sanjaya Maniktala in this new tutorial article series on switching power supply design. Rather, if you can visualize the inductor (L), the switch (S) and the diode (D) associated with the power FETs, you're in a better position to see how they behave in switchmode regulator designs. There are four LSD cell types: Some are easier to turn on; some are easier to turn off. Guess which support buck typologies, which support boost. Planet Analog i