Other

Phyworks Limited

Motorola Corporation

Fingerprint Cards Anacatum IP Ab

Nicholas Weiner

Rolf Sundblad

David Carling

Anthony Spencer

Peter Almers

Benjamin Willcocks

Paul A Denny

Mui-Chwee Tong

Circuitry for characterising a test impedance of a test load, the test load coupled between a sense node and a first driver node, the circuitry comprising: driver circuitry configured to apply a time-varying test stimulus between the first driver node and a second driver node, the test stimulus varied in step changes at a one or more of signal events; a reference load coupled between the second driver node and the sense node, the reference load having a programmable impedance comprising: a first programmable capacitance; a programmable resistance connected in series with the first programmable capacitance to form a series combination; and a first integrator configured to integrate a sense voltage derived from the sense node to generate a first integrated signal.

Impedance measurement

Circuitry for characterising a test impedance of a test load, the test load coupled between a sense node and a first driver node, the circuitry comprising: driver circuitry configured to apply a time-varying test stimulus between the first driver node and a second driver node, the test stimulus varied in step changes at one or more signal events; a reference load coupled between the second driver node and the sense node, the reference load having a programmable impedance; and a first integrator configured to integrate a voltage derived from the sense node to generate a first integrated signal; and measurement circuitry configured to derive one or more characteristics of the test impedance based on the programmable impedance and the first integrated signal.

A method of controlling operation of a field-powered biometric device comprising biometric acquisition circuitry, processing circuitry controllable to transition between a first functional state having a first power consumption and a second functional state having a second power consumption lower than the first power consumption, and power management circuitry. The method comprises the steps of monitoring, by the power management circuitry, a property indicative of a supply voltage to the processing circuitry; controlling, when the monitored property indicates that the supply voltage has fallen to a first threshold voltage, the processing circuitry to transition from the first functional state to the second functional state; and controlling, when the monitored property indicates that the supply voltage has increased to a second threshold voltage higher than the first threshold voltage, the processing circuitry to transition from the second functional state to the first functional state.

Field-powered biometric device, and method of controlling a field-powered biometric device

A method of equalizer adaptation involves comparing equalizer output values with a center threshold, and with at least one of a pair of outer thresholds, and adapting the equalizer in order to increase the degree of eye opening. The values of the outer thresholds are adapted such that a fixed proportion of equalizer output values lie between the outer thresholds, and the equalizer coefficients are adapted such the separation of the outer thresholds is increased. The equalizer coefficients are adapted on the basis of equalizer output values which lie between the pair of outer thresholds.

Receiver

A switching circuit, for use in soft-decision Extended Hamming Code decoding, allows the detection of pairs of received bits having 'low confidence' and whose position-ids SUM to the syndrome of the received code signal, when the occurrence of an even (and non-zero) number of errors is detected.

Switching circuit for decoder

In a Viterbi decoder, a branch metrics unit (,) receives samples and provides a branch metric to a first and second adder (,and,) that adds the branch metric to a first and second path metric from a path metrics memory (,). Concurrently, a comparator (,) compares the first and second path metrics and provides a select signal to a multiplexor (,) to select the output of the first or second adder (,or,). The selection signal is also provided to a path memory unit (,) which provides a detected symbol sequence. The output of the first or second adder (,or,) is selected by the multiplexor (,) and provided to the path metric memory (,) as an updated path metric.

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Bristol, United Kingdom

Nicholas Weiner