SLVSHM4A December 2023 – June 2024 TPS62916E
PRODUCTION DATA
The external components have to fulfill the needs of the application, but also meet the stability criteria of the control loop of the device. The device is designed to work within a range of external components, and can be optimized for efficiency, output ripple, component count, or lowest 1/f noise.
Typical applications that have input voltages of ≤ 6 V use a 1 µH inductor with a 2.2 MHz switching frequency. Applications that have input voltages > 6 V can be optimized for efficiency using a 1 µH inductor with a 1 MHz or 1.4 MHz switching frequency depending on the output voltage. Optimization for powering clock and PLL circuits that need a 3.3 V output use a 1 µH inductor with 2.2 MHz switching frequency, minimizing output voltage ripple and low frequency noise.
For the application cases that are not found in Table 7-2, there are two methods to design the TPS62916E circuit. Section 7.2.2.1 uses WEBENCH to design the circuit automatically or the calculations in Section 7.2.2.2 can be used instead.
DESIGN GOAL | VIN | VOUT | FSW | INDUCTOR (2) | OUTPUT CAPACITORS (3) |
---|---|---|---|---|---|
Typical | 12 V(1) | ≤ 1.4 V(1) | 1 MHz | 1 µH | 6 × 22 µF, 10 V, 0805 |
Typical | 12 V | 1.4 V < VOUT ≤ 2.2 V | 1.4 MHz | 1 µH | 6 × 22 µF, 10 V, 0805 |
Typical | 12 V | > 2.2 V | 2.2 MHz | 1 µH | 8 × 22 µF, 10 V, 0805 |
Typical | 5 V | ≤ 3.3 V | 2.2 MHz | 1 µH | 6 × 22 µF, 10 V, 0805 |
Typical | 5 V | > 3.3V | 2.2 MHz | 1 µH | 8 × 22 µF, 10 V, 0805 |
The second stage L-C filter is optional, as the device can be used without this filter to achieve below 20 μVRMS noise typically. A second stage filter is added to provide additional attenuation of the output ripple voltage. The output voltage is sensed after the second L-C filter by connecting the FB resistors to the second stage L-C filter capacitor. This action provides remote sense, minimizing output voltage drop due to the ferrite bead. Refer to Table 7-3 for second stage L-C filter recommendations based on the output voltage.
VOUT (V) | FERRITE BEAD IMPEDANCE (AT 100 MHZ)(2) | OUTPUT CAPACITORS (1) |
---|---|---|
≤ 2.2 V | 8 to 20 Ω | 1 × 22 µF, 10 V, 0805 |
> 2.2 V | 8 to 20 Ω | 2 × 22 µF, 10 V, 0805 |