STMicroelectronics, a provider of semiconductor products for electronics application, has introduced a new IC, STBP120 for cell phones and mobile devices that will help combat the environmental impact of battery chargers discarded.
The company claims that the new IC protects the charging-control circuitry inside cellphones and other battery-powered portable equipment in case the external charger applies an excessive voltage. Reportedly, a number of variants are available which are suitable for a range of charging-voltage levels.
Reportedly, organisations including the Chinese government and the GSM Association are proposing standard battery-charger connectors and voltages to allow standard chargers for mobile phones. In addition to reducing discarded chargers, standard chargers are also expected to allow charging from a PC or laptop USB port.
According to the company the new product monitors the voltage from the connected charger when implemented inside a battery-powered product. If the detected voltage exceeds a preset threshold, an internal solid-state switch is opened, thereby preventing the over-voltage from damaging the internal circuitry. The company said there are four variants spanning threshold values from 5.375V to 6.02V, allowing to optimise for USB chargers at up to 5.25V or other chargers at higher voltages up to 6.8V.
Reportedly, each device will protect against over-voltages as high as 28V. In normal operation the internal switch, an N-channel MOSFET, has very low resistance of 90 milliOhms to promote efficiency and minimise heat dissipation, said company.
The company added that other features include a fault-indicator output, soft-start capability to limit inrush current to the charging circuitry, and a thermal shutdown to protect against excessive temperature.
The device can reportedly save pc-board space and component count in many other types of products where over-voltage protection is normally implemented using a discrete transient-voltage suppressor and a fuse. The over-voltage threshold can also be set more accurately than when using discrete devices, said company.
Reportedly, the new IC is delivered in an ultra-small 2 x 2.5mm, 10-lead TDFN package, and is in production priced at $0.37 in quantities of 1000 units.
