ON Semiconductor Confidential Design Note – DN06071/D Device Application Input Voltage Output Voltage Output Current Topology DC-DC 9-16V 3.3V 0.01-9A Buck NCP3030B Table 1: Buck Power Supply Characteristic Input Voltage Output Voltage Output Current Oscillator Frequency (NCP3030B) Output Voltage Ripple Load Regulation Iout = 0.02-9A, Vin= 9V NCP3030 Iout = 0.02-9A, Vin= 18V NCP3030 Min 9 3.33 .01 2.1 Typ 12 3.265 3 2.4 86 Max 16 3.28 9 2.7 Unit V V A MHz mVpk-pk 0.99 0.78 mV/A Circuit Description The PCB for the NCP3030 is a 2-layer board for use in applications up to 50W. The synchronous buck converter uses voltage mode control, which can also be compensated externally with a transconductance amplifier. The soft-start time is fixed. The NCP3030 demonstration board is a flexible design allowing the use of electrolytic capacitors or ceramic capacitors. Also Q1 and Q3 (MOSFET’s) footprints allows the use of SOIC-8NB, SO8-FL, u8FL and D-PAK packages. Performance The following figures show typical performance of the NCP3030 demonstration boards. Efficiency vs Output Current and Input Voltage 90 87.5 Vin= 9 V 85 82.5 80 Vout = 12 V Efficiency (%) 77.5 75 72.5 Vout = 16 V 70 67.5 65 NCP3030B Vout = 3.3 V Typical Application Circuit 62.5 60 57.5 55 52.5 50 0 1 2 3 4 5 6 7 8 9 Iout (A) Figure 1: NCP3030B Efficiency at 9V-16.0V with a 3.3V Output Voltage Rev 0 - Dec, 2010 ON Semiconductor Confidential Figure 2: NCP3030B Load Regulation Line Regulation 3.37 3.36 3.35 1A V‐Out (V) 2A 3A 4A 3.34 5A 6A 7A 3.33 8A 9A 3.32 3.31 9 10 11 12 13 14 15 16 V‐In (V) Figure 3: NCP3030B Line Regulation Figure 4: Startup Waveforms (NCP3030B) Input = 12 V, Output = 3.3 V, Load = 5 A, CH4 (Purple) = VIN, CH2 (Red) = VOUT, CH3 (Green) = VHSDR, CH1 (Blue) =SWN CH1 = CH3 = CH4: 10.0 V/div; CH2: 2.0 V/div; Time Scale: 400 μs/div Rev 0 - Dec, 2010 ON Semiconductor Confidential Figure 5: Shutdown Waveforms (NCP3030B) Input = 12 V, Output = 3.3 V, Load = 5 A, CH4 (Purple) = VIN, CH2 (Red) = VOUT, CH3 (Green) = VHSDR, CH1 (Blue) =SWN CH1 = CH3 = CH4: 10.0 V/div; CH2: 2.0 V/div; Time Scale: 400 μs/div Figure 6: Switching Waveforms (NCP3030B) Input = 12 V, Output = 3.3 V, Load = 9 A, CH4 (Purple) = VIN, CH2 (Red) = VOUT, CH3 (Green) = VHSDR, CH1 (Blue) =SWN CH1 = CH3: 5.0 V/div; CH2: 10 mV/div; CH4:100mV/div Time Scale: 200 ns/div Figure 7: Startup into Current Limit (NCP3030B) Input = 12 V, Output = 3.3 V, Load = 5 A, CH4 (Purple) = VIN, CH2 (Red) = VOUT, CH3 (Green) = VHSDR, CH1 (Blue) =SWN CH1 = CH3 = CH4: 10.0 V/div; CH2: 2.0 V/div; Time Scale: 400 μs/div Rev 0 - Dec, 2010 ON Semiconductor Confidential Schematics Figure 8: NCP3030 Demo Board Schematic Rev 0 - Dec, 2010 ON Semiconductor Confidential Item 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Bill Of Materials Quantity Reference 5 CR1,C1A,Q2,Q4,R6 2 C1,C13 3 C2,C11,C12 2 C14,C3 1 C5 1 C7 1 C8 1 C9 1 C10 1 C17 1 D2 1 L1 1 Q1 1 Q3 1 R1 1 R2 1 R3 1 R4 1 R5 2 R11,R8 1 R9 1 R10 1 R12 1 R18 1 U1 Part Not Placed 470uF 22uF 1uF 1.0uF 20pF 16nF 0.1uF 1.2nF 1nF MBRM130L 2.2uH NTMFS4935N NTTFS4930N 22.1K 6.98K 3.9K 100 0 0 10.0K 3 16.92K 20 NCP3030 Table 1: NCP3030 Demo Board Bill Of Materials © 2010 ON Semiconductor. Disclaimer: ON Semiconductor is providing this design note “AS IS” and does not assume any liability arising from its use; nor does ON Semiconductor convey any license to its or any third party’s intellectual property rights. This document is provided only to assist customers in evaluation of the referenced circuit implementation and the recipient assumes all liability and risk associated with its use, including, but not limited to, compliance with all regulatory standards. ON Semiconductor may change any of its products at any time, without notice. Design note created by Tim Kaske and Ed Mejia, e-mail: [email protected] ; [email protected] Rev 0 - Dec, 2010