IRS2158DSTRPBF International Rectifier, IRS2158DSTRPBF Datasheet - Page 26

• 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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PCB Layout Considerations
In order to successfully utilize the IRS2158D in a ballast design, it is necessary to follow the following PCB
layout guidelines. This can avoid possible interference and ground loop issues that can occur in the ballast
circuit. These connection techniques also prevent high current ground loops from interfering with sensitive
timing component operation and allow the entire control circuit to reject common-mode noise due to output
switching.
Figure 10 and Figure 11 show the control section of typical ballast designed around the IRS2158D, where
the IC is located in the center. In this design all SMD devices are mounted under the PCB with discrete
devices on top.
1) The signal ground (pin 12) should only be connected to the power ground at one single point to prevent
2) The point described in (1) should be where the grounds of the current sense resistors for both the half
3) The VCC decoupling capacitor should be placed as close to the IRS2158D VCC (pin 13) and COM (pin
4) The devices; CPH, RMIN, CVCO, CT and CCS should all be located as close to the IRS2158D as
5) The ground connections from the devices listed in (4) should be connected back to the COM pin of the
6) The charge pump diode connection to ground should be made to the power ground not the signal ground.
7) The power factor correction section (if used) should be kept apart from the ballast control as shown in the
ground loops from forming.
bridge MOSFETs and the lamp current feedback both meet.
12) as possible with the shortest possible traces.
possible with traces to the relevant pins being
IRS2158D through the shortest possible traces. These should be connected back to the COM pin of the
IC without joining the power ground trace at any point. In the example shown above the power ground
trace runs along the lower side of the board on the bottom Copper layer
example above. the power factor correction section is at the left side of the PCB.
Figure 10: Critical traces on the bottom side of the PCB
Figure 11: Critical traces on the top side of the PCB
WITH FIRST FILTER
STAR POINT AT IC COM
CHARGE PUMP
RESISTOR
SIGNAL GROUND
SENSITIVE TIMING
COMPONENTS
IRS2158D
VCC DECOUPLING
CAPACITOR
26
as short as possible.
SECOND FILTER RESISTOR
AND CVCC
CURRENT SENSE
SENSE RESISTOR
GROUNDS JOIN HERE
LAMP CURRENT
SIGNAL AND POWER
HALF BRIDGE
RESISTOR
© 2009 International Rectifier
IRS2158D(S)