On-chip LDO cuts smart card interface noise

Edited by the Electronicstalk editorial team Nov 18, 2003

Three new low-cost smart card interface ICs feature outstanding noise and current performance for use in conditional access, payment and identification environments.

Three new low-cost smart card interface ICs feature outstanding noise and current performance for use in conditional access, payment and identification environments.

Manufactured by TDK Semiconductor Corp, the 73S8024R, 73S8004R and 73S8010R provide a stable, low-noise interface compliant with the ISO7816 standard between any host microcontroller and a smart card.

The 73S8024R and 73S8004R implement the control interface between card and host as dedicated digital I/Os, whereas the 73S8010R implements a standard I2C interface bus for interfacing with the host.

All three new smart cart interface ICs translate the digital signals from the host to analogue signals recognised by the smart card, and vice versa.

These devices also provide a stable 3 or 5V power source to the smart card from an on-chip low-dropout voltage regulator, yielding a 10x improvement in noise performance over existing solutions that employ step-up DC/DC convertors.

Use of the LDO regulator also results in much a smaller die size than is currently available with competing devices, leading to smaller packages that reduce board space requirements and ultimately lower interface IC costs.

"As security concerns increase around the world, there has been a significant acceleration in smart card technology leading to increasing requirements for improved card terminal characteristics", said Jean-Christophe Doucet, Product Manager at TDK Semiconductor.

"Our new smart card interface ICs set a new noise and current performance standard in the marketplace and enable the high frequency operation (up to 20MHz) and high current draw (at least 90mA) that match the performance demanded by 32bit processor cards or SAMs (secure access modules) that are becoming increasingly common in the smart card world".

Doucet noted that the new TDK Semiconductor smart card interface ICs would find immediate application in advanced set-top boxes, digital TVs and personal video recorders for conditional access to audio/video content, pay-per-view events or movies, and other premium services.

"We see the same increases in capability being demanded in new generations of high-performance smart card terminals used in payment and digital identification systems", he added.

These three new TDK Semiconductor smart card interface ICs support ISO7816-3 and EMV2000 (EMV4.0) electrical requirements and are the most protected devices of their class in the market.

Additional card protection features are provided to guard against hardware faults and guarantee emergency card deactivation in the event of card extraction, card overcurrent, supply voltage failure, LDO regulator failure and device overheating.

Supply voltage faults can optionally be adjusted to match same operating voltage range as the host microcontroller.

Other on-chip resources include: a crystal oscillator and circuitry for card clock generation up to 20MHz; an LDO voltage regulator capable of supplying a high current of up to 90mA; and a complete set of buffers for data I/O.

Only a single external capacitor is required for operation.

Samples are available now from Pulsar Electronics for the 73S8024R, 73S8004R and the 73S8010R smart card interface ICs in either SO28 or MLF32 packages - the latter providing the smallest footprint for this type of device on the market.

Production quantities will be available in Q1 2004.

Prices for the devices start at $1.20 each in quantities of 25,000.

A demo board is also available.