U211B2 Datasheet, PDF (7/20 Pages) TEMIC Semiconductors – Phase Control Circuit - General Purpose Feedback

V
Mains
Supply
V_GT
95 10716
p/2
p
3/2p
2p
Trigger
Pulse
t_p
t_pp = 4.5 t_p
V_L
Load
Voltage
I_L
ö
Load
Current
F
Figure 6. Explanation of terms in phase relationship
U211B2/ B3
Design Calculations for Mains Supply
The following equations can be used for the evaluation of the series resistor R₁ for worst case conditions:
+ R_1max
0.85
V_Mmin
2
– V_Smax
I_tot
+ R_1min
V_M – V_Smin
2 I_Smax
+ P_(R1max)
(V_Mmax – V_Smin)²
2 R₁
where:
V_M = Mains voltage
V_S = Supply voltage on Pin 3
I_tot = Total DC current requirement of the circuit
= I_S + I_p + I_x
I_Smax = Current requirement of the IC in mA
I_p = Average current requirement of the triggering pulse
I_x = Current requirement of other peripheral components
R₁ can be easily evaluated from the figures 20 to 22.
TELEFUNKEN Semiconductors
Rev. A1, 29-May-96
7 (20)