Electronic Components Datasheet Search |
|
TPS54311 Datasheet(PDF) 8 Page - Texas Instruments |
|
|
TPS54311 Datasheet(HTML) 8 Page - Texas Instruments |
8 / 10 page TPS54311, TPS54312 TPS54313, TPS54314 TPS54315, TPS54316 SLVS416A – FEBRUARY 2002 – JULY 2003 www.ti.com 8 APPLICATION INFORMATION Figure 10 shows the schematic diagram for a typical TPS54314 application. The TPS54314 (U1) can provide up to 3 A of output current at a nominal output voltage of 1.8 V. For proper thermal performance, the PowerPAD underneath the TPS54314 integrated circuit needs to be soldered to the printed circuit board. C2 RT SS/ENA VBIAS PWRGD VSENSE 1 2 3 4 5 6 7 9 VIN PH BOOT PGND PGND PGND PwrPAD U1 TPS54314PWP 1 2 VO GND J3 C7 0.047 µF R1 10 k Ω C11 1000 pF 1 J1 2 1 VI GND + 1 Optional 71.5 k Ω L1 5.2 µH R7 8 10 11 12 13 14 15 16 17 18 19 20 AGND NC PH PH PH PH FSEL VIN VIN C8 10 µF C3 0.1 µF + C9 470 µF 4 V PWRGD Figure 10. TPS54314 Schematic INPUT VOLTAGE The input to the circuit is a nominal 5 VDC, applied at J1. The optional input filter (C2) is a 220- µF POSCAP capacitor, with a maximum allowable ripple current of 3 A. C8 is the decoupling capacitor for the TPS54314 and must be located as close to the device as possible. FEEDBACK CIRCUIT The output voltage of the converter is fed directly into the VSENSE pin of the TPS54314. The TPS54314 is internally compensated to provide stability of the output under varying line and load conditions. OPERATING FREQUENCY In the application circuit, a 700 kHz operating frequency is selected by leaving FSEL open and connecting a 71.5 k Ω resistor between the RT pin and AGND. Different operating frequencies may be selected by varying the value of R3 using equation 1: R + 500 kHz Switching Frequency 100 k W Alternately, preset operating frequencies of 350 kHz or 550 kHz my be selected by leaving RT open and connecting the FSEL pin to AGND or VIN respectively. OUTPUT FILTER The output filter is composed of a 5.2- µH inductor and 470- µF capacitor. The inductor is a low dc resistance (16-m Ω) type, Sumida CDRH104R–5R2. The capacitor used is a 4-V POSCAP with a maximum ESR of 40 m Ω. The output filter components work with the internal compensation network to provide a stable closed loop response for the converter. GROUNDING AND PowerPAD LAYOUT The TPS54311–16 have two internal grounds (analog and power). Inside the TPS54311–16, the analog ground ties to all of the noise sensitive signals, while the power ground ties to the noisier power signals. The PowerPAD must be connected directly to AGND. Noise injected between the two grounds can degrade the performance of the TPS54311–16, particularly at higher output currents. However, ground noise on an analog ground plane can also cause problems with some of the control and bias signals. For these reasons, separate analog and power ground planes are recommended. These two planes should tie together directly at the IC to reduce noise between the two grounds. The only components that should tie directly to the power ground plane are the input capacitor, the output capacitor, the input voltage decoupling capacitor, and the PGND pins of the TPS54311–16. The layout of the TPS54314 evaluation module is representative of a recommended layout for a 4-layer board. Documentation for the TPS54314 evaluation module can be found on the Texas Instruments web site under the TPS54314 product folder and in the application note, TI literature number SLVA111. LAYOUT CONSIDERATIONS FOR THERMAL PERFORMANCE For operation at full rated load current, the analog ground plane must provide adequate heat dissipating area. A 3 inch by 3 inch plane of 1 ounce copper is recommended, (1) |
Similar Part No. - TPS54311 |
|
Similar Description - TPS54311 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |