JAJSV63A August 2024 – August 2024 LM5137-Q1
ADVANCE INFORMATION
Table 8-6 shows the intended input, output, and performance parameters for this automotive circuit example.
DESIGN PARAMETER | VALUE |
---|---|
Input voltage range (steady state) | 8V to 18V |
Minimum transient input voltage (cold crank) | 6V |
Maximum transient input voltage (load dump) | 36V |
Output voltage | 5V |
Output current | 20A |
Switching frequency | 2.1MHz |
Output voltage regulation | ±1% |
No-load sleep current with phase 2 disabled | < 20µA |
Shutdown current | 4µA |
Resistor RRT of 10.5kΩ sets the switching frequency at 2.1MHz. In terms of control loop performance, the target loop crossover frequency is 80kHz with a phase margin greater than 50°. Leaving the RSS pin open sets the output voltage soft-start time to 6.5ms.
Table 8-7 cites the selected buck regulator powertrain components, with many of the components available from multiple vendors. Similar to circuit example 1, this design uses 40V logic-level MOSFETs, shielded buck inductors, shunt resistors with wide aspect ratio for low ESL, and an all-ceramic input and output capacitor implementation.
REFERENCE DESIGNATOR | QTY | SPECIFICATION(1) | MANUFACTURER | PART NUMBER |
---|---|---|---|---|
CIN1, CIN2 | 4 | 10µF, 50V, X7R, 1210, ceramic, AEC-Q200 | TDK | CNA6P1X7R1H106K |
10µF, 50V, X7S, 1210, ceramic, AEC-Q200 | Murata | GCM32EC71H106KA03 | ||
TDK | CGA6P3X7S1H106M | |||
COUT1, COUT2 | 8 | 47µF, 6.3V, X7R, 1210, ceramic, AEC-Q200 | Murata | GCM32ER70J476KE19L |
Taiyo Yuden | JMK325B7476KMHTR | |||
47µF, 6.3V, X7S, 1210, ceramic, AEC-Q200 | TDK | CGA6P1X7S0J476M | ||
LO1, LO2 | 2 | 0.47µH, 2.2mΩ, 26.5A, 6.71 × 6.51 × 3.1mm, AEC-Q200 | Coilcraft | XGL6030-471MEC |
0.47µH, 3mΩ, 25A, 6.95 × 6.6 × 4.3mm, AEC-Q200 | Cyntec | VCUW064ER47MS5 | ||
0.47µH, 3.1mΩ, 20A, 7 × 6.9 × 3.8mm, AEC-Q200 | Würth Electronik | 744311047 | ||
0.56µH, 3mΩ, 29A, 6.6 × 6.4 × 2.8mm, AEC-Q200 | Bourns | SRP6030CA-R56M | ||
Q1, Q3 | 2 | 40V, 4.7mΩ, 7nC, SON 5 × 6, AEC-Q101 | Infineon | IAUC60N04S6L039ATMA |
Q2, Q4 | 2 | 40V, 3.6mΩ, 9nC, SON 5 × 6, AEC-Q101 | Infineon | IAUCN04S7L028ATMA |
RS1, RS2 | 2 | Shunt, 4mΩ ±1%, ±50ppm/°C, 0612, 1.5W, AEC-Q200 | Susumu | KRL3216E-C-R004-F |
U1 | 1 | LM5137-Q1 80V two-phase buck controller, AEC-Q100 | Texas Instruments | LM5137QRHARQ1 |