Product category:
Power Supply ICs and Controllers
News Release from: Torex Semiconductor | Subject: XC9101/02
Edited by the Electronicstalk Editorial
Team on 11 June 2001
DC/DC controller saves with ceramic
capacitors
The XC9101/02 is Torex Semiconductor's third-generation step-up DC/DC convertor controller and is ideal for a wide range of handheld applications.
The XC9101/02 is Torex Semiconductor's third-generation step-up DC/DC convertor controller and is ideal for a wide range of handheld applications from mobile and cordless phones, palm top computers and games consoles, to digital cameras and laptops Employing the very latest current/voltage multiple feedback technique means that ceramic capacitors can be used to stabilise the XC9101/02's output rather than the tantalums required by most DC/DC controller ICs
This article was originally published on Electronicstalk on 5 Sep 2008 at 8.00am (UK)
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LDOs save power in many ways
LDO regulators are compatible with low-ESR ceramic capacitors, which give added output stability, and include built-in overcurrent protection and thermal shutdown circuits.
This brings significant savings in terms of both space and cost.
Current sense, clock frequency and amplifier feedback gain can all be externally regulated giving designers a very high level of flexibility allowing these characteristics to be exactly tailored to closely match the parameters of a particular application.
With an input voltage range of 2.0 to 20V the new DC/DC controllers can be configured to produce stable power supplies with output currents up to 3A and output voltages between 2.2 and 16V, selectable in 0.1V steps to an accuracy of +/-2.5%.
Switching frequency can be set externally (using a resistor and capacitor) from 100 to 600kHz.
The higher maximum frequency together with the built-in current limit circuit, which limits the amount of current flowing through the external inductor, allows designers to safely use much smaller inductors than previously possible.
The device's clock synchronisation pin allows the switching frequency to be carefully matched to another frequency present within the design, thus reducing noise.
The gain controller pin can be used to set the device's transient response characteristic.
If the controller IC responds too quickly, unwanted noise can be generated.
By careful adjustment this noise is easily eliminated.
Both the XC9101 and XC9102 step-up DC/DC controllers achieve pulsewidth modulation via the multiple feedback signals of the devices' output voltage and coil current.
The XC9102 additionally is able to automatically switch to pulse frequency modulation under light load conditions, thus enabling it to maintain low ripple and high efficiencies over a wider load range.
Other notable features of the new devices include soft start and 'shutdown' where current consumption reduces to less than 0.5mA.
The XC9101/02 is available in an MSOP-8A package with an operating temperature range of -40 to +85C.
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