US 11,893,435 B2
Internal voltage generation circuit of smart card and smart card including the same
Eunsang Jang, Hwaseong-si (KR); Junho Kim, Seoul (KR); and Inhyuk Kim, Hanam-si (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed on Apr. 16, 2021, as Appl. No. 17/232,298.
Claims priority of application No. 10-2020-0077690 (KR), filed on Jun. 25, 2020; and application No. 10-2020-0108026 (KR), filed on Aug. 26, 2020.
Prior Publication US 2021/0406631 A1, Dec. 30, 2021
Int. Cl. G05B 19/00 (2006.01); G05B 23/00 (2006.01); G06F 7/00 (2006.01); G06F 7/04 (2006.01); G06T 1/00 (2006.01); G06T 7/00 (2017.01); G08B 29/00 (2006.01); G08C 19/00 (2006.01); H04B 1/00 (2006.01); H04B 3/00 (2006.01); H04Q 1/00 (2006.01); H04Q 9/00 (2006.01); G06K 19/07 (2006.01); G06K 19/077 (2006.01); H02M 3/335 (2006.01)
CPC G06K 19/0718 (2013.01) [G06K 19/077 (2013.01); G06K 19/0715 (2013.01); G06K 19/0723 (2013.01); H02M 3/33507 (2013.01); H02M 3/33584 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An internal voltage generation circuit of a smart card configured to perform a fingerprint authentication, the internal voltage generation circuit comprising:
a first contact switch configured to selectively switch a contact voltage received from an external card reader to a first node based on a first switching enable signal, in a contact mode;
a second contact switch configured to selectively switch the contact voltage to a second node based on a second switching enable signal, in the contact mode;
a switched capacitor converter configured to step down a contactless voltage induced by an electromagnetic wave received from the card reader to provide a contactless mode first driving voltage to the first node;
a bidirectional switched capacitor converter, connected to the first node and the second node, the bidirectional switched capacitor converter configured to:
in a contactless mode, step down the contactless mode first driving voltage at the first node to provide a contactless mode second driving voltage to the second node; and
in the contact mode, either step down a contact mode first driving voltage at the first node to provide a contact mode second driving voltage to the second node, or boost a contact mode second driving voltage at the second node based on a level of the contact voltage to provide a boosted voltage to the first node;
a mode selector configured to output a first mode signal and a second mode signal, the first mode signal designating one of the contact mode and the contactless mode, the second mode signal designating one of a plurality of sub-modes of the contact mode, the mode selector further configured to select a highest voltage among the contact voltage, the contactless voltage and the contactless mode first driving voltage or the contact mode first driving voltage to output the selected voltage as a control voltage; and
a control signal generator configured to generate a first power-down signal that enables/disables the switched capacitor converter, a second power-down signal that enables/disables the bidirectional switched capacitor converter, the first switching enable signal and the second switching enable signal, based on the first mode signal and the second mode signal.