- 您現在的位置：買賣IC網 > PDF目錄98283 > TPS54519RTER (TEXAS INSTRUMENTS INC) 8 A SWITCHING REGULATOR, 2000 kHz SWITCHING FREQ-MAX, PQCC16 PDF資料下載
參數資料
| 型號： | TPS54519RTER |
| 廠商： | TEXAS INSTRUMENTS INC |
| 元件分類： | 穩壓器 |
| 英文描述： | 8 A SWITCHING REGULATOR, 2000 kHz SWITCHING FREQ-MAX, PQCC16 |
| 封裝： | 3 X 3 MM, GREEN, PLASTIC, WQFN-16 |
| 文件頁數： | 11/33頁 |
| 文件大小： | 1269K |
| 代理商： | TPS54519RTER |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁當前第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁
-
Vinmax
Vout
L1 =
Io
Kind
Vinmax
sw
-
Vinmax
Vout
Iripple =
L1
Vinmax
sw
-
÷
è
2
1
Vo
(Vinmax
Vo)
ILrms =
Io
+
12
Vinmax
L1
sw
Iripple
ILpeak = Iout +
2
Iout
Co >
sw
Vout
D
D
1
Co >
Voripple
8
sw
Iripple
SLVSAT3
– SEPTEMBER 2011
For this design, the RMS inductor current is 5.009 A and the peak inductor current is 5.525 A. The chosen
inductor is a Coilcraft XAL5030-122ME. It has a saturation current rating of 11.8 A (20% inductance loss) and an
RMS current rating of 8.7 A ( 20
C temperature rise). The series resistance is 6,78 mΩ typical.
The current flowing through the inductor is the inductor ripple current plus the output current. During power up,
faults or transient load conditions, the inductor current can increase above the calculated peak inductor current
level calculated above. In transient conditions, the inductor current can increase up to the switch current limit of
the device. For this reason, the most conservative approach is to specify an inductor with a saturation current
rating equal to or greater than the switch current limit rather than the peak inductor current.
(22)
(23)
(24)
(25)
OUTPUT CAPACITOR
There are three primary considerations for selecting the value of the output capacitor. The output capacitor
determines the modulator pole, the output voltage ripple, and how the regulator responds to a large change in
load current. The output capacitance needs to be selected based on the more stringent of these three criteria.
The desired response to a large change in the load current is the first criteria. The output capacitor needs to
supply the load with current when the regulator can not. This situation would occur if there are desired hold-up
times for the regulator where the output capacitor must hold the output voltage above a certain level for a
specified amount of time after the input power is removed. The regulator is temporarily not able to supply
sufficient output current if there is a large, fast increase in the current needs of the load such as transitioning
from no load to a full load. The regulator usually needs two or more clock cycles for the control loop to see the
change in load current and output voltage and adjust the duty cycle to react to the change. The output capacitor
must be sized to supply the extra current to the load until the control loop responds to the load change. The
output capacitance must be large enough to supply the difference in current for 2 clock cycles while only allowing
a tolerable amount of droop in the output voltage. Equation 26 shows the minimum output capacitance necessary
to accomplish this.
For this example, the transient load response is specified as a 4% change in Vout for a load step from 1.25 A
(25% load) to 3.75 A (75%). For this example,
ΔIout = 3.75 - 1.25 = 2.5 A and ΔVout= 0.04 × 1.8 = 0.072 V.
Using these numbers gives a minimum capacitance of 69.4
μF. This value does not take the ESR of the output
capacitor into account in the output voltage change. For ceramic capacitors, the ESR is usually small enough to
ignore in this calculation.
Equation 27 calculates the minimum output capacitance needed to meet the output voltage ripple specification.
Where fsw is the switching frequency, Vripple is the maximum allowable output voltage ripple, and Iripple is the
inductor ripple current. In this case, the maximum output voltage ripple is 30 mV. Under this requirement,
Equation 27 yields 4.38uF.
(26)
Where
ΔIout is the change in output current, Fsw is the regulators switching frequency and ΔVout is the
allowable change in the output voltage.
(27)
Copyright
2011, Texas Instruments Incorporated
19
Product Folder Link(s): TPS54519
相關PDF資料 |
PDF描述 |
|---|---|
| TPS54612MPWPREP | 12 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO28 |
| TPS54615MPWPREP | 12 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO28 |
| TPS54622RHLT | 15 A SWITCHING REGULATOR, 1760 kHz SWITCHING FREQ-MAX, PQCC14 |
| TPS54623RHLT | 15 A SWITCHING REGULATOR, 1760 kHz SWITCHING FREQ-MAX, PQCC14 |
| TPS54672PWPG4 | 12 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO28 |
相關代理商/技術參數 |
參數描述 |
|---|---|
| TPS54519RTET | 功能描述:直流/直流開關調節器 2.95-6VIN,5A SYNC STEP-DOWN CONVERTER RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數量: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
| TPS54521 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:4.5V to 17V Input, 5A Synchronous Step Down SWIFT? Converter |
| TPS54521_1 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:4.5V to 17V Input, 5A Synchronous Step Down SWIFT? Converter |
| TPS54521EVM-607 | 功能描述:電源管理IC開發工具 TPS54521 Eval Mod RoHS:否 制造商:Maxim Integrated 產品:Evaluation Kits 類型:Battery Management 工具用于評估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
| TPS54521RHL | 制造商:TI 制造商全稱:Texas Instruments 功能描述:4.5V to 17V Input, 5A Synchronous Step Down SWIFT? Converter |
發布緊急采購，3分鐘左右您將得到回復。