SNVSCC1 May 2022 LM5143A-Q1
PRODUCTION DATA
Table 10-2 shows the intended input, output, and performance parameters for this automotive design example.
Design Parameter | Value |
---|---|
Input voltage range (steady state) | 8 V to 18 V |
Min transient input voltage (cold crank) | 3.5 V |
Max transient input voltage (load dump) | 36 V |
Output voltages | 3.3 V, 5 V |
Output currents | 7 A |
Switching frequency | 2.1 MHz |
Output voltage regulation | ±1% |
Standby current, output 1 enabled, no load | < 50 µA |
Shutdown current | 4 µA |
The switching frequency is set at 2.1 MHz by resistor RRT. In terms of control loop performance, the target loop crossover frequency is 60 kHz with a phase margin greater than 50°. The output voltage soft-start times are set at 2 ms by 68-nF soft-start capacitors.
The selected buck regulator powertrain components are cited in Table 10-3, 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 Section 10.1.1.4. This design uses a low-DCR, metal-powder composite inductor, and ceramic output capacitor implementation.
Ref Des | Qty | Specification | Manufacturer(1) | Part Number |
---|---|---|---|---|
CIN | 4 | 10 µF, 50 V, X7R, 1210, ceramic, AEC-Q200 | Taiyo Yuden | UMJ325KB7106KMHT |
10 µF, 50 V, X7S, 1210, ceramic, AEC-Q200 | Murata | GCM32EC71H106KA03 | ||
TDK | CGA6P3X7S1H106M | |||
CO | 8 | 47 µF, 6.3 V, X7R, 1210, ceramic, AEC-Q200 | Murata | GCM32ER70J476KE19L |
Taiyo Yuden | JMK325B7476KMHTR | |||
47 µF, 6.3 V, X7S, 1210, ceramic, AEC-Q200 | TDK | CGA6P1X7S0J476M | ||
LO1, LO2 | 2 | 0.68 µH, 4.8 mΩ, 25 A, 7.3 × 6.6 × 2.8 mm, AEC-Q200 | Würth Elektronik | 744373460068 |
0.68 µH, 4.5 mΩ, 22 A, 6.95 × 6.6 × 2.8 mm, AEC-Q200 | Cyntec | VCMV063T-R68MN2T | ||
0.68 µH, 3.1 mΩ, 20 A, 7 × 6.9 × 3.8 mm, AEC-Q200 | Würth Elektronik | 744311068 | ||
0.68 µH, 7.4 mΩ, 12.2 A, 5.4 × 5.0 × 3 mm, AEC-Q200 | TDK | SPM5030VT-R68-D | ||
0.68 µH, 2.9 mΩ, 15.3 A, 6.7 × 6.5 × 3.1 mm, AEC-Q200 | Coilcraft | XGL6030-681 | ||
Q1, Q2, Q3, Q4 | 4 | 40 V, 5.7 mΩ, 9 nC, SON 5 × 6, AEC-Q101 | Infineon | IPC50N04S5L-5R5 |
RS1, RS2 | 2 | Shunt, 7 mΩ, 0508, 1 W, AEC-Q200 | Susumu | KRL2012E-M-R007 |
U1 | 1 | LM5143A-Q1 65-V dual-channel, phase buck controller, AEC-Q100 | Texas Instruments | LM5143QRHARQ1 |