JAJSKS0C December 2020 – February 2023 LM5149-Q1
PRODUCTION DATA
Table 9-9 shows the intended input, output, and performance parameters for this automotive design example.
DESIGN PARAMETER | VALUE |
---|---|
Input voltage range (steady-state) | 8 V to 72 V |
Min transient input voltage (cold crank) | 4 V |
Max transient input voltage (load dump) | 80 V |
Output voltage | 3.3 V |
Output current | 20 A |
Switching frequency | 400 kHz |
Output voltage regulation | ±1% |
Standby current, no-load | 44 µA |
Shutdown current | 4.6 µA |
Soft-start time | 3 ms |
The switching frequency is set at 400 kHz by resistors RRT1 and RRT2. The selected buck regulator powertrain components are cited in Table 9-10, and many of the components are available from multiple vendors. The MOSFETs in particular are chosen for both lowest conduction and switching power loss, as discussed in detail in Power MOSFETs.
REFERENCE DESIGNATOR | QTY | SPECIFICATION | MANUFACTURER | PART NUMBER |
---|---|---|---|---|
CIN | 4 | 4.7 μF, 100 V, X7S, 1210, ceramic, AEC-Q200 | TDK | CGA6M3X7S2A475K200 |
Murata | GCM32DC72A475KE02L | |||
CO | 8 | 47 µF, 6.3 V, X7R, 1210, ceramic, AEC-Q200 | Murata | GCM32ER70J476KE19L |
47 µF, 10 V, X7S, 1210, ceramic, AEC-Q200 | TDK | CGA6P1X7S1A476M250AC | ||
4 | 100 µF, 6.3 V, X7S, 1210, ceramic, AEC-Q200 | Murata | GRT32EC70J107ME13 | |
LO1, LO2 | 2 | 2.2 μH, 4.3 mΩ, 12.5 A, 6.7 × 6.5 × 6.1 mm, AEC-Q200 | Coilcraft | XGL6060-222MEC |
2.2 µH, 6.5 mΩ, 10 A, 10 × 11 × 3.8 mm, AEC-Q200 | Würth Electronik | 74437368022 | ||
Q1, Q2, Q3, Q4 | 4 | 80 V, 9.6 mΩ, 22 nC, SON 5 × 6, AEC-Q101 | Infineon | IAUC50N08S5L096 |
RS1, RS2 | 2 | Shunt, 4 mΩ, 0508, 1 W, AEC-Q200 | Susumu |
KRL2012E-M-R004-F-T5 |
U1, U2 | 2 | LM5149-Q1 80-V synchronous buck controller with AEF, AEC-Q100 | Texas Instruments | LM5149QRGYRQ1 |
LM5148-Q1 80-V synchronous buck controller, AEC-Q100 | Texas Instruments | LM5148QRGYRQ1 |