DC2603A EVM Test


1. Test Plan

1.1 Basic Test

1.1.1 Switching Frequency

测试条件fsw=583kHz,1000个连续采样点内,最大开关频率584.41kHz,最小开关频率581.69kHz,均值583.03kHz,抖动范围为0.4%

1.1.2 Dual Channel Cross Adjustment

fsw=583kHz,两通道均Enable,低负载模式FCCM,Channel 1 Remote Sense On

V_{IN}/\rm{V} I_{IN}/\rm{A} V_{OUT1}/\rm{V} I_{OUT1}/\rm{A} V_{OUT2}/\rm{V} I_{OUT2}/\rm{A} Efficiency
12.013V 0.18A 3.336V 0A 1.504V 0A 0%
11.874V 6.01A 3.330V 20A 1.504V 0A 93.3%
11.880V 5.79A 3.333V 10A 1.503V 20A 92.1%
11.947V 2.91A 3.336V 0A 1.503V 20A 86.4%
Table1. Vin and Vout test under different load

1.1.3 Efficiency Test

1.5V输出通道峰值效率测试,设定输入电压12V,Disable Channel2,FCCM, Channel2 Remote Sense Amplifier On

V_{IN}/\rm{V} I_{IN}/\rm{A} V_{OUT2}/\rm{V} I_{OUT2}/\rm{A} Efficiency
11.983 0.377 1.504 2.5 83.2
11.955 0.709 1.503 5 88.6
11.980 1.38 1.503 10 90.9
11.835 2.093 1.503 15 91.0
11.768 2.826 1.503 20 90.3
Table2. Vout1 test under different load

Figure1. Efficiency compare with measured result and datasheet result

3.3V输出通道峰值效率测试,设定输入电压12V,Disable Channel1,FCCM

V_{IN}/\rm{V} I_{IN}/\rm{A} V_{OUT1}/\rm{V} I_{OUT1}/\rm{A} Efficiency
11.944 0.824 3.334 2.5 84.69
11.884 1.535 3.334 5 91.38
11.765 3.010 3.332 10 94.09
11.638 4.54 3.330 15 94.54
11.494 6.13 3.329 20 94.50
Table3. Vout2 test under different load

Figure2. Efficiency compare with measured result and datasheet result

1.1.4 Output Voltage Ripple

Channel1 Channel2 Work Mode Output Ripple IIN
1.5V / FCCM 15.7mV 64mA
1.5V / PSM 8.3mV 19mA
1.5V / BM 57.8mV 8mA
/ 3.3V FCCM 25.2mV 143mA
/ 3.3V PSM 14.2mV 50mA
/ 3.3V BM 81.3mV 24mA
Table4. Input Current and Output Ripple vs Work Mode

1.1.5 Soft-Start Waveform

Figure3. Individual Soft-Start vs Track Soft-Start

1.2 Transient Response

1.2.1 Transient Load Schematic

Figure4. On board transient load schematic

1.2.2 VOUT1 Transient setup:

  • IOSTEK CLK: 3.027V peak,200Hz,Duty 5%,20ns rise edge,2.3us fall edge.
  • Load Current:20A High,0A Low,21A/us rise slope,27A/us fall slope.
  • LTM4650:Channel 2 Disable,FCCM

    Figure5. Trans Response on VOUT1 with 20A high and 0A low

    将低电流从0A改到1A,瞬态响应无明显变化,Overshoot与Undershoot峰值,恢复时间等不变.

    1.3 Parallel Multiphase

    1.3.1 Efficiency Test

    V_{IN}/\rm{V} I_{IN}/\rm{A} V_{OUT}/\rm{V} I_{OUT}/\rm{A} Efficiency/%
    11.978 0.431 1.504 2.5 72.83
    11.949 0.750 1.504 5 83.91
    11.894 1.418 1.504 10 89.18
    11.832 2.107 1.504 15 90.49
    11.776 2.804 1.504 20 91.10
    11.714 3.518 1.504 25 91.24
    11.655 4.24 1.503 30 91.24
    11.589 4.99 1.503 35 90.97
    11.522 5.78 1.502 40 90.21
    Table5. Efficiency test of Parallel Multiphase

    Figure6. Comparision of Efficiency of Spec and Act of Multiphase

    Figure7. Comparison of Efficiency of Single Phase and Multiphase

    1.3.2 Output Voltage Ripple

    Figure8. VOUT at BNC Connector

    Figure9. VOUT at Different Output Capcitor

    1.3.3 Parallel Multiphase Transient Response

    Figure10. Trans Response on VOUT1 with 20A high and 0A low

    Figure11. Trans Respnose compared with Single phase and MultiPhase

    Figure12. Multiphase Trans Respnose LTSpice simulation result

    2. Test Environment

    Environment Details Others
    Room Temperature 26.5^\circC
    DC Power Supply GPS-2303C
    DC Load M9811 for VOUT2 test
    DC Load CD8610T for VOUT1 test
    Digital Multimeter DM3068
    Signal Source DG1602
    Oscilloscope MSO5354

    3. Other Problem

    3.1 Voltage Ripple Measurement Problem

    在纹波测量当中,我们遇到了一些之前没有见到的问题.
    对于传统的纹波测量方案来说,往往采用X1探头配合

    3.2 Transient Response Method

    3.3 Layout Problem under High Current

最后修改日期:2022年1月1日