ZHCSLU2C December 2021 – August 2024 LM63440-Q1 , LM63460-Q1
PRODUCTION DATA
The following table shows the intended input, output, and performance parameters for this application example. The converter operates in dropout during cold crank when the input voltage decreases to 5V, with the output voltage slightly below the 5V setpoint.
DESIGN PARAMETER | VALUE |
---|---|
Input voltage range (for constant fSW) | 6V to 18V |
Minimum transient input voltage, cold crank | 5V |
Maximum transient input voltage, load dump | 36V |
Output voltage and full-load current | 5V, 4A |
Switching frequency | 2.1MHz |
Output voltage regulation | ±1% |
IC input current, no-load | < 10µA |
IC shutdown current | < 1µA |
The following table gives the selected buck converter power-stage components with availability from multiple vendors. This design uses a low-DCR inductor and all-ceramic output capacitor implementation.
REF DES | QTY | SPECIFICATION | VENDOR (1) | PART NUMBER | |
---|---|---|---|---|---|
CIN | 2 | 10µF, 50V, X7R, 1206, ceramic, AEC-Q200 | Samsung | CL31Y106KBKVPNE | |
TDK | CGA5L1X7R1H106K | ||||
10µF, 50V, X7S, 1210, ceramic, AEC-Q200 | Murata | GCM32EC71H106KA03 | |||
TDK | CGA6P3X7S1H106M | ||||
COUT | 1 | 47µF, 10V, X7S, 1210, ceramic, AEC-Q200 | Murata | GCM32EC71A476KE02 | |
TDK | CGA6P1X7S1A476M | ||||
2 | 22µF, 16V, X7S, 1206, ceramic, AEC-Q200 | Murata | GCM31CC71C226ME36 | ||
LO | 1 | 1.2µH, 8.7mΩ, 8.2A, 4.0mm × 4.0mm × 2.5mm, AEC-Q200 | Coilcraft | XGL4025-122MEC | |
1.5µH, 13.4mΩ, 6.2A, 4.2mm × 4.0mm × 2.1mm, AEC-Q200 | Cyntec | VCHA042A-1R5MS62M | |||
1.5µH, 14.1mΩ, 12.7A, 5.3mm × 5.1mm × 3.0mm, AEC-Q200 | TDK | SPM5030VT-1R5M-D | |||
1.2µH, 13.4mΩ, 11.6A, 4.1mm × 4.1mm × 3.1mm, AEC-Q200 | Würth Electronik | 74438357012 | |||
U1 | 1 | LM63440-Q1 synchronous buck converter, AEC-Q100 | Texas Instruments | LM63440AASQRYFRQ1 |
More generally, the LM63440-Q1 converter is designed to operate with a wide range of external components and system parameters. However, the integrated loop compensation is optimized for a certain range of buck inductance and output capacitance. As a starting point, the following table provides typical component values for several common application configurations.
fSW (kHz) | VOUT (V) | LO (µH) | COUT-EFF(min) (µF) | TYPICAL COUT COMPONENTS (1210) |
RFBT (kΩ) | RFBB (kΩ) | CFF (pF) | RFF (kΩ) |
---|---|---|---|---|---|---|---|---|
2100 | 3.3 | 0.68 | 30 | 2 × 22µF, 10V (X7R) or 1 × 47µF, 10V (X7S) |
100 | 43.2 | 10 | 1 |
2100 | 5 | 0.82 | 20 | 1 × 47µF, 10V (X7S) | 100 | 24.9 | 10 | 1 |
400 | 1.8 | 3.3 | 150 | 4 × 100µF, 4V (X7R) | 80.6 | 100 | 47 | 1 |
400 | 3.3 | 4.7 | 75 | 2 × 47µF, 10V (X7S) or 4 × 22µF, 10V (X7R) |
100 | 43.2 | 33 | 1 |
400 | 5 | 6.8 | 40 | 2 × 47µF, 10V (X7S) or 3 × 22µF, 16V (X7S) |
100 | 24.9 | 22 | 1 |
400 | 12 | 8.2 | 20 | 2 × 22µF, 25V (X7S) | 100 | 9.09 | 15 | 1 |
Note that the minimum output capacitances listed in Table 8-6 represents effective values for ceramic capacitors derated for DC bias voltage and temperature.