IRS2158DSTRPBF International Rectifier, IRS2158DSTRPBF Datasheet - Page 24

• Manufacturer Part Number: IRS2158DSTRPBF
• Description: IC BALLAST CTRL 600V 16-SOIC
• Manufacturer: International Rectifier
• Type: Fluorescent Lamp Driverr

Specifications of IRS2158DSTRPBF

• Frequency: 42.5 ~ 48.5 kHz
• Current - Supply: 3.5mA
• Current - Output: 260mA
• Voltage - Supply: 11.5 V ~ 15.6 V
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SOIC (3.9mm Width)
• For Use With: IRPLDIM3 - KIT DES FLUOR BALLAST IRS2158D
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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Ballast Design Equations
Note: The results from the following design equations can differ slightly from actual measurements due to IC
tolerances, component tolerances, and oscillator over- and under-shoot due to internal comparator response
time.
Step 1: Program Deadtime
The deadtime is programmed with the timing resistor RDT at the DT pin. The deadtime is given by:
Step 2: Program Run Frequency
The run frequency is programmed with the timing resistor RMIN at the FMIN pin. The run frequency is
given as:
[Hz] (3)
[Ohms]
Step 3: Program Preheat Frequency
The preheat frequency is programmed with timing resistors RMIN and RPH. The timing resistors are
connected in parallel for the duration of the preheat time. The preheat frequency is therefore given as:
[Hertz]
Step 4: Program Preheat Time
The preheat time is defined by the time it takes for the external capacitor on pin CPH to charge up to
2/3*VCC. An external resistor (RCPH) connected to VCC charges capacitor CPH. The preheat time is
therefore given as:
(4)
(5)
f
OSCPH
t
C =
DT
t
T
PH
= 1500
=
1500
f
=
t
OSCRUN
DT
R
R
. 2
CPH
MIN
15
⋅
C
⋅
T
=
⋅
C
=
C
PH
5
3
. 2
T
⋅
⋅
15
⎛
⎜ ⎜
⎝
⎛
⎜ ⎜
⎝
(
3
5
24
. 2
⋅
or
⋅
C
15
(
(
T
R
R
⋅
MIN
⋅
1
MIN
⎛
⎜
⎝
[Seconds]
f
3
5
OSCRUN
[Farads]
1
+
1
⋅
⋅
R
R
R
PH
MIN
PH
[Seconds] (6)
⋅
)
)
C
+
+
T
1500
1500
)
(1)
(2)
−
1500
⎞
⎟
⎠
⎞
⎟ ⎟
⎠
⎞
⎟ ⎟
⎠
© 2009 International Rectifier
IRS2158D(S)