AN2383 datasheet(22/39 Pages) STMICROELECTRONICS

Part #	AN2383

Description	A single plate induction cooker with the ST7FLITE09Y0

PDF	39 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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22 / 39 page

Measurements at PWM frequency

AN2383

22/39

Doc ID 12433 Rev 3

6.2

Working level 1

Figure 13.

System working at level 1

Level 1 is the first and the lowest power working level. The PWM signal frequency,

previously set to 60 kHz, smoothly decreases until the working current for level 1 is reached.

As seen before, the PWM frequency is not constant and is adjusted in real-time to keep the

current level constant. Natural changes such as the iron dilatation or the water warming up,

slightly modify the resonant frequency and therefore the current delivered.

For the 22 cm-diameter iron pot used for the test, level 1 means a PWM frequency of around

48.5 kHz, but variations of several kilohertz are possible and necessary in order to keep the

current level constant.

In this test, level 1 features a 40 ampere peak-to-peak current (I-PLATE, 20 ampere per

division).

PVM

UP-G

LW-G

I - PLATE

AN2383 Datasheet(PDF) 22 Page - STMicroelectronics