Semiconductor device
First Claim
Patent Images
1. A semiconductor device comprising:
- a phase locked loop (PLL) that receives a reference clock and derives candidate clocks from the reference clock, wherein each one of the candidate clocks has a different phase;
a multiplexer that receives the candidate clocks and selects a first selected clock from among the candidate clocks in response to a first control value and selects a second selected clock from among the candidate clocks, different from the first selected clock, in response to a second control value;
a phase difference detector that detects a phase difference between the reference clock and the first selected clock;
a phase difference controller generates the second control value in response to the detected phase difference;
a variable delay line that generates a transmission clock in response to the second selected clock; and
a driver that provides transmission data synchronously with the transmission clock.
1 Assignment
0 Petitions
Accused Products
Abstract
A semiconductor device including a PLL providing candidate clocks of different phases in response to a first clock received from a reader via an antenna, a phase difference detector detecting a phase difference between the first clock and a clock from the candidate clocks, a phase difference controller that selects another clock from the candidate clocks, and a driver that provides transmission data synchronously with the another clock to the reader.
-
Citations
9 Claims
-
1. A semiconductor device comprising:
-
a phase locked loop (PLL) that receives a reference clock and derives candidate clocks from the reference clock, wherein each one of the candidate clocks has a different phase; a multiplexer that receives the candidate clocks and selects a first selected clock from among the candidate clocks in response to a first control value and selects a second selected clock from among the candidate clocks, different from the first selected clock, in response to a second control value; a phase difference detector that detects a phase difference between the reference clock and the first selected clock; a phase difference controller generates the second control value in response to the detected phase difference; a variable delay line that generates a transmission clock in response to the second selected clock; and a driver that provides transmission data synchronously with the transmission clock. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A near field communication (NFC) card comprising:
-
an antenna; a clock generator that generates a transmission clock; and a driver that provides transmission data to the antenna synchronously with the transmission clock, wherein the clock generator comprises; a phase locked loop (PLL) that derives candidate clocks from a reference clock, wherein each one of the candidate clocks has a different phase respectively defined by m divisions of the reference clock, where ‘
m’
is a natural number;a multiplexer that receives the candidate clocks and selects a first selected clock from among the candidate clocks in response to a first control value and selects a second selected clock from among the candidate clocks in response to a second control value; a phase difference detector that detects a phase difference between the reference clock and the first selected clock; a phase difference controller generates the second control value in response to the detected phase difference; and a variable delay line that generates the transmission clock in response to the second selected clock. - View Dependent Claims (8, 9)
-
Specification