STEVAL-ILL004V1 STMicroelectronics, STEVAL-ILL004V1 Datasheet - Page 14

• Manufacturer Part Number: STEVAL-ILL004V1
• Description: EVAL BOARD PHASE CONTROL DIMMER
• Manufacturer: STMicroelectronics
• Type: Power Management: Lighting and Ballast Controllerr

Specifications of STEVAL-ILL004V1

• Design Resources: STEVAL-ILL004V1 Gerber Files STEVAL-ILL004V1 Bill of Material STEVAL-ILL004V1 Schematic
• Contents: Fully Assembled Evaluation Board
• Product: Display Modules
• For Use With/related Products: ST7FLITE09
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 497-5081

Universal motor speed control
2.3.4
Note:
14/38
Figure 9.
Gate-limiting resistor calculation
Connecting the resistor between the microcontroller and the gate of the TRIAC is
recommended. This will limit the maximum driving current coming from the microcontroller.
The following TRIAC parameters (from the datasheet) must be used to determine the
resistor’s value:
●
●
The resistor’s voltage drop is about 3 V because the rest of the supply voltage (V
TRIAC and microcontroller. To ensure that the TRIAC’s gate opens under any
circumstances, the maximum current going through the resistor should be at least the same
or higher than the gate-triggering current. For example, a BTB16-600CW TRIAC with a
maximum current of 40 mA would require the following resistor value:
Equation 11
It is better to connect two I/O pins in parallel to drive the BTB16-600CW and keep the
recommended current capability from the high sink outputs of the microcontroller (20 mA).
BTB16 TRIAC is assembled on the evaluation board with a gate-limiting resistor of 47 Ω
which allows to fully open the TRIAC.
If an ACST6-7S TRIAC is used in the design, only one I/O pin from the microcontroller and a
gate-limiting resistor of 180 Ω are required to guarantee the TRIAC’s opening under any
circumstances.
TRIAC gate-triggering current (i.e., the BTB16-600CW is 35 mA and the ACST6-7S is
10 mA)
The maximum I/O port driving current (the ST7FLITE09 is capable of high sink outputs,
the maximum being 50 mA of current, but the recommended value is 20 mA).
ZCD circuit actual waveforms
R
=
V
-------------- -
I
MAX
GT
=
---------- -
0.04
3
=
75Ω
CC
) is in the
AN2263