Thursday, June 26, 2008

Fingerprint Sensor and Blackfin Processor Enhance Biometric Identification

The need for effective, efficient security is manifest in today’s world. Individuals must be identified to allow or prohibit access to secure areas—or to enable them to use a computer. Biometric signatures identify individuals by measuring unique physical and behavioral characteristics using: a sensor, feature extraction, pattern matching, and decision making—allowing a user’s claimed identity to be authenticated or rejected.

Wednesday, June 04, 2008

Volume 42, Number 1, 2008 Print Edition

In this issue:

2 -- Editors’ Notes and Product Introductions
3 -- Cooking Inductively: ADI iCoupler Technology Isolates the Hob and the User Interface
6 -- Analog-to-Digital Converter Clock Optimization
13 -- High-Side Current Sensing: Difference Amplifier vs. Current-Sense Amplifier


Subscribe at http://www.analog.com/library/analogDialogue/subscribe.html

Open-Loop Calibration Techniques for Digital-to-Analog Converters

In principle, you give a digital input to a DAC and it provides an accurate output. In reality, the accuracy of the output voltage is subject to gain and offset errors from the DAC and other components in the signal chain. The system designer must compensate for these errors in order to get an accurate output voltage.

Noise Figure and Logarithmic Amplifiers [The Wit and Wisdom of Dr. Leif—6]

Log amps are uniquely equipped as RF measurement elements at frequencies from near-dc up to 12 GHz because of their wide dynamic range, temperature stability, excellent log conformance, and ease of use—with measurements provided directly in decibels. Noise figure is a valuable metric when log amps are used in the signal path, as it indicates the system's ability to extract information in the presence of noise.