AMG-LM302 Datasheet, PDF (20/23 Pages) alpha microelectronics gmbh – Ballast Controller for Metal Halide Lamps

AMG-LM302
Ballast Controller for Metal Halide Lamps
6) Over voltage and PFC ready voltage divider
7) PFC current sense resistor (6.2-PFC-9):
R_{Pof 2}
R_{Pof 1} + R_{Pof 2}
=
2.5
V_{PFC _ OV}
R _{pk _ PFC}
≤
V_{CS _ cl}
I_{PK _ PFC}
=
1.75
I_{PK _ PFC}
11.3. Calculating HID Parameters
1) Biasing resistor:
2) Lamp voltage divider:
3) CDM current sense resistor:
4) Power scale resistor:
R_ISET = 510kΩ
R_VOUTC
R_VOUTC + R_VOUTB
=
1
100
R_VOUTA = 10kΩ
R _ML
=
V_IOUTi
I _overdrive
=
0.625
I _overdrive
R_Mp
=
3.906 ⋅ 10⁶
P_Lamp ⋅ R_ML
5) Oscillator capacitor:
( ) ^{COP =}
I_{COP _ up} ⋅ I_{COP _ down}
F_OSC ⋅ (I_{COP _ down} − I_{COP _ up} ) ⋅ V_{COP _ thH} − V_{COP _ thL}
6) Upper true voltage threshold:
COP =
12.6
F_OSC ⋅ R_ISET
R_td
=
1.25 ⋅ 10⁷
V_{OUT _ th}
for ^VOUT _ th ^{= 160V}
7) Lower true voltage threshold:
R _tu
=
1.25 ⋅ 10⁷
V_{OUT _ th}
8) Bridge dead time capacitor
CDT ≈ 1.67 ⋅ 10^{− 5} ⋅ t_DT
9) Capacitor and resistor for frequency compensation at FPWMo=31kHz
R_Q = 100kΩ
R_F = tbd
C_F1 = tbd
C_{F 2} = tbd
for ^VOUT _ th ^{= 50V}
AMG-LM302 Revision: A
29. Jul. 2010 © All rights reserved Page 20 of 23