SNVA940 November   2021 LM5157 , LM5157-Q1 , LM51571-Q1 , LM5158 , LM5158-Q1 , LM51581 , LM51581-Q1

 

  1.   Trademarks
  2. 1LM5157 Boost Design Example
  3. 2Calculations and Component Selection
    1. 2.1  Switching Frequency
    2. 2.2  Inductor Calculation
    3. 2.3  Slope Compensation Check
    4. 2.4  Inductor Selection
    5. 2.5  Diode Selection
    6. 2.6  Output Capacitor Selection
    7. 2.7  Input Capacitor Selection
    8. 2.8  UVLO Resistor Selection
    9. 2.9  Soft-Start Capacitor Selection
    10. 2.10 Feedback Resistor Selection
    11. 2.11 Control Loop Compensation
      1. 2.11.1 Crossover Frequency (fcross) Selection
      2. 2.11.2 RCOMP Selection
      3. 2.11.3 CCOMP Selection
      4. 2.11.4 CHF Selection
    12. 2.12 Power Loss and Efficiency Estimation
  4. 3Implementation Results
  5. 4Small Signal Frequency Analysis
    1. 4.1 Boost Regulator Modulator Modeling
    2. 4.2 Compensation Modeling
    3. 4.3 Open Loop Modeling

3 Implementation Results

Please see the LM5157EVM-BST User's Guide for more testing results.

GUID-20201005-CA0I-5NKX-FWKW-25NH9V2JNXCX-low.gif Figure 3-1 Application Circuit
GUID-B50F1B70-5BFE-4215-8AEE-9E4F461B4F08-low.pngFigure 3-2 Efficiency vs. IOUT
Figure 3-4 Load Step: ILOAD 0.8A to 1.6A, VSUPPLY =6V
Figure 3-3 Control Loop Response VSUPPLY = 6V ILOAD = 1.6A
Figure 3-5 Thermal Image: VSUPPLY = 6V, ILOAD =1.6A
GUID-20210726-CA0I-2C1N-98HX-HV7MJVJ6WRM6-low.gif Figure 3-6 LM5157EVM-BST Schematic
Table 3-1 List of Materials
REFERENCE DESIGNATOR QTY. SPECIFICATION MANUFACTURER PART NUMBER
RT 1 RES, 9.53 k, 1%, 0.1 W, AEC-Q200 Grade 0, 0603 Vishay-Dale CRCW06039K53FKEA
RFBT 1 RES, 49.9 k, 1%, 0.1 W, 0603 Yageo America RC0603FR-0749K9L
RFBB 1 RES, 4.53 k, 1%, 0.1 W, AEC-Q200 Grade 0, 0603 Vishay-Dale CRCW06034K53FKEA
LM 1 Inductor, Shielded, Composite, 1.5 μH, 14 A, 0.01052 Ω, AEC-Q200 Grade 1, SMD Coilcraft XEL6030-152MEB
COUT1 6 CAP, CERM, 4.7 µF, 50 V, ±10%, X7R, 1210 TDK C3225X7R1H475K250AB
COUT2 (Bulk) 2 CAP, Aluminum Polymer, 100 µF, 50 V, ±20%, 0.025 Ω, AEC-Q200 Grade 2, D10xL10mm SMD Chemi-Con HHXB500ARA101MJA0G
CIN1 4 CAP, CERM, 10 µF, 50 V, ±10%, X7R, 1210 MuRata GRM32ER71H106KA12L
CIN2 (Bulk) 1 CAP, AL, 22 uF, 100 V, ±20%, 1.3 Ω, AEC-Q200 Grade 2, SMD Panasonic EEE-FK2A220P
D1 1 Diode, Schottky, 45 V, 10 A, AEC-Q101, CFP15 Nexperia PMEG045V100EPDAZ
RCOMP 1 RES, 2.61 k, 1%, 0.1 W, 0603 Yageo America RC0603FR-072K61L
CCOMP 1 CAP, CERM, 0.01 μF, 50 V, ±10%, X7R, 0603 Kemet C0603X103K5RACTU
CHF 1 CAP, CERM, 100 pF, 50 V, ±5%, C0G/NP0, AEC-Q200 Grade 0, 0603 TDK CGA3E2NP01H101J080AA
RUVLOT 1 RES, 61.9 k, 1%, 0.1 W, AEC-Q200 Grade 0, 0603 Vishay-Dale CRCW060361K9FKEA
RUVLOB 1 RES, 71.5 k, 1%, 0.1 W, AEC-Q200 Grade 0, 0603 Vishay-Dale CRCW060371K5FKEA
RUVLOS 1 RES, 0, 5%, 0.1 W, 0603 Yageo America RC0603JR-070RL
CSS 1 CAP, CERM, 0.022 μF, 50 V, ±10%, X7R, 0603 Kemet C0603X223K5RACTU
RBIAS 1 RES, 0, 5%, 0.1 W, 0603 Yageo America RC0603JR-070RL
CBIAS 1 CAP, CERM, 0.1 μF, 100 V, ±10%, X7R, AEC-Q200 Grade 1, 0603 MuRata GCJ188R72A104KA01D
CVCC 1 CAP, CERM, 1 µF, 16 V, ±10%, X7R, AEC-Q200 Grade 1, 0603 TDK CGA3E1X7R1C105K080AC
RVCC 1 RES, 5.1, 5%, 0.1 W, 0603 Yageo America RC0603JR-075R1L
RPG 1 RES, 100 k, 1%, 0.1 W, AEC-Q200 Grade 0, 0603 Vishay-Dale CRCW0603100KFKEA
RMODE 1 RES, 0, 5%, 0.1 W, 0603 Yageo America RC0603JR-070RL