IRPLLED1 International Rectifier, IRPLLED1 Datasheet - Page 24

• Manufacturer Part Number: IRPLLED1
• Description: BOARD EVALUATION FOR IRS2540PBF
• Manufacturer: International Rectifier

Specifications of IRPLLED1

• Current - Output / Channel: 1.5A
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 24V
• Features: Dimmable
• Voltage - Input: 50 ~ 170V
• Utilized Ic / Part: IRS2540PBF
• Core Chip: IRS2540, IRS2541, IRS25401
• Topology: Buck (Step Down)
• No. Of Outputs: 1
• Output Current: 1.5A
• Output Voltage: 500mV
• Dimming Control Type: PWM
• Development Tool Type: Hardware - Eval/Demo Board
• Lead Free Status / RoHS Status: Contains lead / RoHS compliant by exemption

The yellow waveform shows the output voltage and the red waveform shows the VS switching waveform. In this
example there is no output capacitor. When the output goes above the over voltage threshold the VCC voltage
shown in blue is quickly pulled below VCCUV- and then gradually charges back up to VCCUV+ through RS1. If an
output capacitor is connected then VCC is pulled almost to zero by IC3 and the systems takes longer to re-start.
The values of the divider resistor ROV1 and ROV2 are calculated as follows:
Let ROV2 = 10K
www.irf.com
V
R
R
out
OV
OV
1
1
=
=
≈
2
120
V
5 .
out
⋅
2
(
k
R
5 .
R
Ω
OV
OV
2
R
1
−
+
OV
R
R
2
OV
OV
2
2
)
=
32
Fig. 30 Open Circuit Fault Signals, with Clamp
V
2
⋅
5 .
10
k
Ω
V
out
−
RD-0608
10
=
k
2
Ω
5 .
=
⋅
(
118
R
OV
k
R
1
Ω
+
OV
R
2
OV
2
)
24