Product category:
Power Supply ICs and Controllers
News Release from: Torex Semiconductor | Subject: XC9128/XC9129 Series
Edited by the Electronicstalk Editorial
Team on 30 April 2008
Step-up convertors raise voltages
efficiently
The XC9128/29 series from Torex deliver efficiencies up to 93% over the entire load range, and can supply 500mA to a 3.3V load from a 1.8V battery supply.
The XC9128/XC9129 Series of synchronous step-up DC/DC convertors from Torex Semiconductor allow engineers to achieve efficient step-up circuits from input voltages as low as 0.8V These two series are suitable for a variety of battery-powered portable and handheld device applications, such as digital audio players, digital still cameras and video equipment
This article was originally published on Electronicstalk on 28 Aug 2008 at 8.00am (UK)
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The XC9128/29 Series feature a 200mohm (typical) N-channel driver transistor and a synchronous 200mohm (typical) P-channel switching transistor built-in.
The XC9128/29 series from Torex deliver efficiencies up to 93% over the entire load range, and can supply 500mA to a 3.3V load from a 1.8V battery supply.
Additionally, the 1.2MHz fixed switching frequency helps minimise design footprint by enabling the use of extremely small inductors and capacitors.
Output voltage can be freely set within a range from 1.8 to 5.3V using a reference voltage supply of 0.45V and an external resistor ladder.
The input voltage range is 0.8 to 5.3V.
The mode pin allows designers to select between PWM control and PFM/PWM automatic switching control.
In the PWM/PFM automatic switching mode, the XC9128/29 Series switch from PWM to PFM to reduce switching loss when load current is small.
However, when load current is large, the control switches automatically to PWM so that high efficiency is achievable over a wide range of load conditions.
In addition, the XC9128 Series incorporates an AEN (adapter enable) pin that allows the device to also be used to provide a fast power supply backup solution when the IC is used together with an additional power source, such as an AC adapter.
The AEN pin monitors the external power source and can quickly sense if that power supply fails, providing immediate back-up.
The XC9128 Series also features a flag output (FO) pin for monitoring the IC's operation.
The XC9128/29 Series offer a variety of safety features including thermal shutdown and over current limit protection, and soft start that can be set internally to typically 5ms.
Specified over the -40 to +85C temperature range, the XC9128 Series is available in compact MSOP-10 and USP-10B packages, whereas the XC9129 Series is housed in SOP-8 packages.
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