The first NFC configuration ICs with integrated CLO

Operation modes
The NLM0011 operates in two modes: configuration mode (passive) and lighting mode (active)

In configuration mode, where the LED driver is not powered (no V_CC applied to the NFC IC), the NFC IC is powered by the RF field sent from the NFC reader. Parameters stored in the non-volatile memory (NVM) can be configured wirelessly via the NFC interface.

In lighting mode, as soon as the LED driver is under power (V_CC applied to the NFC IC), a PWM output is generated according to the stored PWM parameters. During the active mode, the NFC interface is disabled.

PWM parameters
The products in Infineon’s NFC-PWM series generate a PWM signal with a fixed amplitude at 2.8 V. Thanks to the integrated voltage regulator (LDO), the level and the stability of the external supply voltage do not influence that. The adjustment of the DC-voltage level is achieved by modifying the PWM duty cycle. The signal output is produced by an internal clock, derived from an internal oscillator running at a frequency of 27.12 MHz. The duty-cycle accuracy is better than 0.1 percent. The PWM resolution depends on the selected PWM frequency: 15 bit @ 1 kHz or 10 bit @ 30 kHz.

CLO implementation
The CLO is a quasi-control system (self-regulating system) that fights the natural degradation of an LED’s light output. This technology maintains the luminous flux constant by regulating the LED current over the life of an LED. The NLM0011 has an integrated operation time counter (OTC), which automatically records the accumulated operation time. An 8-point CLO table is integrated to store the degradation curve of the LED module. The LED luminaire manufacturers program this curve according to the LED selection. As soon as the CLO table is programmed, the duty cycle of the PWM signal is then automatically adjusted to compensate for the LED degradation. The actual duty cycle, as a function of the actual operating time, is calculated by linear interpolation between two neighbored reference points. The NLM0011 is continuously counting the operation time and is continuously interpolating the duty-cycle correction factor, which is then multiplied with the nominal duty-cycle value to get the actual duty-cycle value.