US 9,810,744 B2
Resonant inductive sensing with reduced noise folding
George P. Reitsma, Redwood City, CA (US)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Dec. 30, 2014, as Appl. No. 14/585,285.
Claims priority of provisional application 61/922,897, filed on Jan. 2, 2014.
Prior Publication US 2015/0188522 A1, Jul. 2, 2015
Int. Cl. G01R 27/02 (2006.01); G01R 33/00 (2006.01); G01R 33/06 (2006.01); H03K 5/1252 (2006.01)
CPC G01R 33/0023 (2013.01) [G01R 33/063 (2013.01); H03K 5/1252 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A circuit suitable for use in resonant inductive sensing, comprising:
input/output nodes coupleable to an inductive resonator;
drive circuitry to drive excitation current pulses out of the input/output nodes with a modulation period synchronized with a resonator oscillation frequency; and
pulse shaping circuitry to pulse shape the excitation current pulses so that each pair of excitation current pulses within the modulation period are identical.