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3.3V converter delivers 3W from Li-ION battery : 11/05/98 EDN-Design
Ideas / (added 11/05) Lithium-ion batteries are rapidly gaining popularity in portable applications because of their superior
energy density, low self-discharge rate, and high cell voltage. When you use one Li-ion battery to power a 3.3V dc/dc converter; however, you
encounter a problem, because the battery voltage can be higher or lower than 3.3V. When fully charged, a Li-ion cell has approximately 4.2V
output; when fully discharged, the voltage is approximately 2.5V. Therefore, you cannot use a simple buck or boost topology with a single
inductor to generate a regulated 3.3V output. Some designs boost the voltage to approximately 4.3V and then use a low-dropout regulator to
produce the 3.3V. This approach is inefficient, and efficiency is a crucial consideration in battery-powered applications. The circuit in
Figure 1 offers a solution to the problem.... |
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4MHz Monolithic Synchronous Step-Down Regulators Bring High Efficiency to
Space-Sensitive Applications: DN304 - Design Notes (Linear Technology) (app note added 6/06) |
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60V High Efficiency Buck Switching Regulators in SO-8: DN202 -
Design Notes (Linear Technology) (app note added 1/06) |
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60V/3A Step-Down DC/DC Converter Maintains High Efficiency over a Wide Input Range:
DN301 - Design Notes (Linear Technology) (app note added 1/06) |
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Add an auxiliary Voltage to a Buck regulator: 10/31/02 EDN Design Ideas
/ (added 1/05) You often need more than one regulated output voltage in a system. A frequently used and reasonably simple way to
create this auxiliary output voltage is to add a second winding to the output inductor, creating a coupled inductor or a transformer, followed
by a diode to rectify (peak-detect) this output voltage.... |
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AN-1146: Designing a Multi-Phase Asynchronous Buck Regulator using the LM2639:
National Semiconductor Application Note 27 Mar2000 (app note added 7/02) |
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AN-1197: Selecting Inductors for Buck Converters: National Semiconductor
- Application Note (app note added 7/06) |
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AN-1253: Wide-Input, High Voltage Buck Converter: National Semiconductor
- Application Note (app note added 2/06) |
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AN-1319: Analysis and Design of a Hysteretic Constant Frequency Buck Regulator
using the LM5007: National Semiconductor - Application Note (app note added 7/06) |
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AN-6003 / 'Shoot-through' in Synchronous Buck Converters: Fairchild
Application Notes / (app note added 6/06) |
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AN-6005 / Synchronous buck MOSFET loss calculations with Excel model:
Fairchild Application Notes / (app note added 6/06) |
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AN793: Power Management in Portable Applications: Understanding the Buck Switchmode
Power Converter: Microchip Application Note - Published 18-Jul-01 (app note added 2/06) |
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AN874: Buck Configuration High-Power LED Driver: Microchip Application
Note - Published 4-Jan-06 (app note added 6/06) |
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AN968: Simple Sychronous Buck Regulator: MCP1612: Microchip Application
Note - Published 14-Jan-05 (app note added 2/06) |
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Analysis and Design of a Hysteretic Constant Frequency Buck Regulator using the
LM5007: National Semiconductor - Application Note (app note added 7/06) |
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AN-H48: Buck-Based LED Drivers using the HV9910: Supertex Semiconductors
(app note added 6/06) |
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Boost Controller Drives Buck Converter: 02/03/97 EDN Design Ideas /
(added 3/05) -- By adding an external Switching Transistor, you can use a step up dc/dc Converter to step down voltages to produce
an efficient Battery Powered Power Supply, this example Circuit can step down inputs as Low as2V to Outputs as Low as1.25V, with efficiency as
high as 80% |
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Buck Boost Regulator Suits Battery Operation: 09/04/03 EDN Design Ideas
/ (added 1/05) A buck/boost converter can step a voltage up or down. Such a converter is appropriate for battery-powered
applications. One application derives a regulated 14.1V at 1A from 12V solar panels with 9 to 18V variation. In this type of battery
application, efficiency is an important factor; hence, this design uses an inexpensive synchronous-rectifier-based MC33166/7 circuit.... |
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Buck Configuration High-Power LED Driver: Microchip Application Note -
Published 4-Jan-06 (app note added 6/06) |
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Buck Converter Chargers also Provides System Power: 05/22/97 EDN Design
Ideas / (added 4/02) -- Switching Regulator provides the charge voltage setpoint with Current regulation, and second Switching Regulator
provides5V System Power -- Many systems require long-time operation during periods of power loss. Often, a gel or wet-cell lead-acid battery
is the best choice because of high capacity and relatively low cost. The battery charges during normal operation and powers the system during
power loss. These systems require a circuit to charge the battery as well as to regulate the system's VCC. The design must provide a
current-limited voltage to the battery for charging and still develop system VCC in the charge or the discharge condition..... |
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Buck Converter Handles Battery Backup System: 04/24/03 EDN Design Ideas
/ (added 12/04) A synchronous buck converter is inherently bidirectional. That is, it transfers energy from input to output as a
buck regulator when the output voltage is low, but, when the output voltage is high, the converter acts as a boost regulator, transferring
power from output to input. This Design Idea shows how to use this bidirectional energy transfer to automatically recharge a battery when the
mai...... |
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Buck converter works efficiently from phone line: 02/15/00 EDN-Design
Ideas / (added 2/06) |
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Buck IC Boosts Battery Voltage for White LED: 04/24/03 EDN Design Ideas
/ (added 1/05) White-light LEDs are finding their way into many markets that incandescent bulbs once served. Flashlights are among
the newer applications in which reliability, ruggedness, and ability to control the power draw of the LEDs make these devices attractive. With
incandescent bulbs, the power management for the device is a simple on-off switch.... |
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Buck or Boost: Rugged Fast 60V Synchronous Controller Does Both: DN370 -
Design Notes (Linear Technology) (app note added 1/06) |
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Buck Reference Design: This reference design is a buck converter that can
deliver up to 2A of continuous current at -24 V from an input range of -35 V to -75 V. By referencing the UCC3813 controller to the negative
input rail, the N-channel MOSFET is easily driven. This design achieves a peak efficiency greater than 95%. The UCC3813 provides current mode
control for excellent line and load transient response. (added 3/05) |
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Buck regulator and two inductors make dual Polarity converter: 03/20/03
EDN Design Ideas / (added 1/05) A common problem for power-supply designers is to create a compact, dual-polarity step-down
converter. If space and cost are not concerns, the obvious solution is a pair of dc/dc converters, one for each output. But space and cost are
almost always issues for communications, data-acquisition, and disk-drive applications.... |
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Buck regulator forms high Power inverting5V supply: 04/01/04 EDN Design
Ideas / (added 1/05) Configuring a step-down switching-converter IC as an inverter yields an efficient, high-power, -5V
supply that can of deliver currents as high as 4.5A at the 12V input or 3.2A at the 5V input (Figure 1). Conventional inverting power supplies
do their switching using a p-channel MOSFET (Figure 2). That configuration works well at lower currents, but has limited use above
approximately 2A, depend...... |
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Buck Regulator Generates Flexible VTT for PECL: 08/15/97 EDN Design Ideas
/ (added 07/02) -- Circuit to generate Output which can both Source and Sink Current -- The positive emitter-coupled logic (PECL) in
most high-speed clock-distribution and -recovery circuits requires a termination voltage, VTT, that imposes special requirements on the VTT
supply. First, the typical switching thresholds for PECL must refer to VDD instead of ground (VOL=VDD1.32V+400 mV, and VOH=VDD1.32400 mV).
The level of VTT, typically at VDD2V, is slightly below VOL to ensure that the open-emitter outputs always source current (Figure 1a). Unlike
most power-supply voltages, therefore, the supply must regulate VTT with respect to VDD instead of ground.... |
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Buck regulator operates Without a dedicated clock: 08/21/03 EDN Design
Ideas / (added 1/05) Most switching regulators rely on a dedicated clock oscillator to determine the switching frequency of
operation. A dedicated oscillator circuit within the power controller usually generates the clock signal. A class of hysteretic switching
regulators can actually operate at a relatively fixed frequency without a clock, even with changing input-line and output-loading
conditions.... |
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Buck Regulator Terminates Fast Data Buses: 07/20/95 EDN-Design Ideas /
(added 3/03) |
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Buck Regulator uses Step Up Controller: 11/09/95 EDN-Design Ideas /
(added 3/03) |
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Buck/Boost Reference Design: This reference design presents an
alternative to the typical boost power regulator. A buck converter IC is used to generate a higher voltage needed by the white light LED power
from a Ni-Cd battery. This circuit operates by turning the high switch on, connecting the battery voltage across the inductor. Once sufficient
energy is stored in the inductor, the high side switch is turned off. The inductor current drives the switching node negative and energy is
delivered through the low side into the output capacitor. This is essentially a lossless switching event. Also, since the high side and low
side switches are MOSFET's, voltage drop can be very low as compared to a diode implementation so efficiency can be high. Regulation is
achieved by monitoring the current through the LED with a current sense resistor and comparing it to an internal 0.45 volt reference within
the converter IC. Current and thereby, illumination is varied by modifying the current sense resistor voltage. (added 3/05) |
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Buck-Based LED Drivers using the HV9910: Supertex Semiconductors (app
note added 6/06) |
