STWBC2-HP datasheet(15/96 Pages) STMICROELECTRONICS

15 / 96 page

Figure 19. DC-DC buck monitor

Table 9. DC-DC buck monitor operating parameters

Parameter

Value

Division factor from VDD to ADC mux

2.86

LPF

10k Hz 2nd order

2.1.5

Analog demodulators

2.1.5.1

Voltage demodulator

The voltage demodulator detects Rx modulation from the variation of the ringing node voltage.

Figure 20. Voltage demodulator

The ring voltage monitor cell provides the peak-to-peak of the probed voltage (see Ring voltage monitor

(Ring_V)). It provides also a rectification of the ringing voltage. From SPI register, the FW can select on-the-fly

the peak-to-peak or the rectified signal to be demodulated. The selected signal is directly filtered using a HPF

and an LPF to select the band of the useful modulation. This filtered signal is shipped to ADC mux for STM32

acquisition through ADC. The signal is also sent to a comparator in order to provide a direct digital 1bit form of the

modulation to an STM32 GPIO.

Table 10. Voltage demodulator operating parameters

Parameter

Value

Demodulation HPF

2nd order

F0 adjustable by SPI registers to 300 Hz, 450 Hz, 600 Hz, 750 Hz

Frequency tolerance +/-10%

STWBC2-HP

Analog AFE functions

DS13825 - Rev 1.0

page 15/96

STWBC2-HP Datasheet(PDF) 15 Page - STMicroelectronics