IR21591 International Rectifier, IR21591 Datasheet - Page 22

• Manufacturer Part Number: IR21591
• Description: IC BALLAST CONTROL DIM 16-DIP
• Manufacturer: International Rectifier
• Type: Ballast Controllerr

Specifications of IR21591

• Frequency: 30 ~ 230 kHz
• Current - Supply: 10mA
• Voltage - Supply: 12.5 V ~ 15.6 V
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Output: -

IR2159/IR21591
Should the peak voltage on pin CS exceed 1.6V
at any time during dimming, the IR2159 enters
FAULT mode and the high and low-side driver
outputs, HO and LO, are both turned off . Cycling
the supply voltage on VCC below or the voltage
on pin SD will reset the IR2159 to preheat (PH)
mode (see STATE DIAGRAM).
Lamp Requirements
Before selecting component values for the ballast
output stage and the programmable inputs of the
IR2159, the following lamp requirements must first
be defined:
22
Variable
V
I
V
Cath
P
V
V
I
ph
P
t
100
100
ign
1
1
ph
ph
max
%
%
min
%
%
Table I, Typical lamp requirements
Filament pre-heat current
Filament pre-heat time
Maximum lamp pre-heat voltage
Lamp ignition voltage
Lamp power at 100% brightness
Lamp voltage at 100% brightness
Lamp power at 1% brightness
Lamp voltage at 1% brightness
Minimum cathode heating current
Ballast Design
Description
( S )
Units
Arms
Arms
Vpp
Vpp
Vpp
Vpp
W
W
s
Ballast Output Stage
The components comprising the output stage are
selected using a set of equations. Different ballast
operating frequencies and their respective
voltages and currents are calculated.
The inductor and capacitor values are obtained
using equations (2) through (7). The results of
these equations reveal the location of each
operating frequency and the corresponding
voltages and currents. For a given L, C, DC bus
voltage, and pre-heat current, the resulting voltage
over the lamp during pre-heat is given as:
The resulting operating frequency during pre-heat
is given as:
The resulting operating frequency during ignition
is given as:
The total load current during ignition is given as:
V
I
ph
ign
f
f
ign
ph
2
f
1
2
ign
V
CV
2
DC
CV
I
1
ph
ph
ign
LC
2
4
V
V
2
ign
DC
8
C
L
I
2
ph
1
2
[Hz]
[App] (5)
[Hz]
2
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V
DC
(4)
(2)
(3)