IRPLLED1 International Rectifier, IRPLLED1 Datasheet - Page 10

• 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 addition of the COUT is essentially increasing the amount of energy that can be stored in the output stage,
which also means it can supply current for an increased period of time. Therefore by slowing down the di/dt
transients in the load, the frequency is effectively decreased.
With the COUT capacitor added to the circuit the inductor current is no longer identical to that seen in the load. The
inductor current has a triangular shape, where as the load will see the same basic trend in the current, but all sharp
corners become rounded with peaks significantly reduced, as can be seen in Fig. 14 and 13.
www.irf.com
Fig. 14 Iout = 350mA, Vin = 100V, Vout = 16.85V, L = 470uH, COUT = 33uF
400
350
300
250
200
150
100
50
0
0
Fig. 13 Iout = 350mA, Vout = 16.8V, L = 470uH
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RD-0608
Capacitance (uF)
20
30
40
50
40V
100V
160V
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