Sipex SP7651 Manual Download Page 4

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Figure 7. Output Load Short Circuit Figure 8. Output Load Short Circuit (Zoom-in)

Figure 9. Output Ripple: No Load Figure 10. Output Ripple:3A Load

Ichoke (2A/div)

Vout ripple = 10mV

Ichoke (1A/div)

Vout ripple = 10mV

SoftStart

Vout

Ichoke
25A/div

SoftStart

Vout

Ichoke
25A/div

Vi=12V
Vo=3.3V

Summary of Contents for SP7651

Page 1: ...0 to 3A Output Synchronous Buck Converter Built in Low RDS ON Power FETs UVLO Detects Both Vcc and VIN Highly Integrated Design Minimal Components High Efficiency 88 Feature Rich UVIN Programmable Sof...

Page 2: ...nation to meet the exact output voltage setting by restricting R1 resistance range such that 50K R1 100K for overall system loop stability Note that since the SP7651 Evaluation Board design was optimi...

Page 3: ...0 5 1 0 1 5 2 0 2 5 3 0 Load current A Output Voltage V Figure 1 Efficiency vs Load Figure 2 Load Regulation Figure 3 Load Step Response 1 5 3A Figure 4 Load Step Response 0 3A Figure 5 Start Up Respo...

Page 4: ...Circuit Figure 8 Output Load Short Circuit Zoom in Figure 9 Output Ripple No Load Figure 10 Output Ripple 3A Load Ichoke 2A div Vout ripple 10mV Ichoke 1A div Vout ripple 10mV SoftStart Vout Ichoke 2...

Page 5: ...5 to 1 10 of the switching frequency fs to insure proper operation Since the SP7651EB is designed with Ceramic Type output capacitors a Type III compensation circuit is required to give a phase boost...

Page 6: ...t filter pole frequency Cz2 1 Rz2 fp_LC h Calculate Cp1 by placing the first pole at ESR zero frequency Cp1 1 2 Rz2 fz_ESR i Calculate Rz3 by setting the second pole at of the switching frequency and...

Page 7: ...Corporation Page 7 of 8 PCB LAYOUT DRAWINGS Figure 12 SP7651EB Layout Top Side Component Placement Figure 13 SP7651EB PC Layout Bottom Side Component Placement Figure 14 SP7651EB PC Layout Inner Layer...

Page 8: ...OHM MCH185CN153KK 0603 Capacitor Ceramic 15nF 50V X7R 10 CP1 1 AVX CORPORATION 06035A100JAT2A 0603 Capacitor Ceramic 10pF 50V C0G 5 CZ2 1 AVX CORPORATION 06035A391JAT2A 0603 Capacitor Ceramic 390pF 50...