ZHCSPA9A november 2021 – may 2023 TPS62441 , TPS62442
PRODUCTION DATA
The TPS6244x is designed for a nominal 0.47-µH inductor with a switching frequency of typically 2.25 MHz. Larger values can be used to achieve a lower inductor current ripple but they can have a negative impact on efficiency and transient response. Smaller values than 0.47 µH cause a larger inductor current ripple, which causes larger negative inductor current in forced PWM mode at low or no output current. For a higher or lower nominal switching frequency, the inductance must be changed accordingly.
The inductor selection is affected by several effects like the following:
In addition, the inductor selected has to be rated for appropriate saturation current and DC resistance (DCR). THe following equation calculates the maximum inductor current.
where
| TYPE | INDUCTANCE [µH] | CURRENT [A](1) | FOR DEVICE | NOMINAL SWITCHING FREQUENCY | DIMENSIONS [L × B × H] mm | MANUFACTURER(2) |
|---|---|---|---|---|---|---|
| DFE201210U-R47M | 0.47 µH, ±20% | see data sheet | TPS62442 | 2.25 MHz | 2.0× 1.2 × 1.0 | Murata |
| DFE201210U-R68M | 0.68 µH, ±20% | see data sheet | TPS62441 | 2.25 MHz | 2.0 × 1.2 × 1.0 | Murata |
| DFE201610E-R47M# | 0.47 µH, ±20% | see data sheet | TPS62442 | 2.25 MHz | 2.0 × 1.6 × 1.0 | Murata |
| XEL3515-561ME | 0.56 µH, ±20% | 4.5 | TPS62442 | 2.25 MHz | 3.5 × 3.2 × 1.5 | Coilcraft |
| XFL4015-701ME | 0.70 µH, ±20% | 5.3 | TPS62442 | 2.25 MHz | 4.0 × 4.0 × 1.6 | Coilcraft |
| XFL4015-471ME | 0.47 µH, ±20% | 5.4 | TPS62442 | 2.25 MHz | 4.0 × 4.0 × 1.6 | Coilcraft |
| TFM201610ALM-R47MTAA | 0.47 µH, ±20% | 5.8 | TPS62442 | 2.25 MHz | 2.0 × 1.6 × 1.0 | TDK |
Calculating the maximum inductor current using the actual operating conditions gives the minimum saturation current of the inductor needed. TI recommends to add a margin of about 20%. A larger inductor value is also useful to get lower ripple current, but increases the transient response time and size as well.