- 您現在的位置：買賣IC網 > PDF目錄44985 > LT3509IDE#PBF (LINEAR TECHNOLOGY CORP) 1.2 A DUAL SWITCHING CONTROLLER, 2500 kHz SWITCHING FREQ-MAX, PDSO14 PDF資料下載
參數資料
| 型號： | LT3509IDE#PBF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 1.2 A DUAL SWITCHING CONTROLLER, 2500 kHz SWITCHING FREQ-MAX, PDSO14 |
| 封裝： | 4 X 3 MM, LEAD FREE, PLASTIC, MO-229WGED-3, DFN-14 |
| 文件頁數： | 8/24頁 |
| 文件大小： | 271K |
| 代理商： | LT3509IDE#PBF |
LT3509
16
3509fc
You can estimate output ripple with the following
equations.
For ceramic capacitors where low capacitance value is
more signicant than ESR:
V
RIPPLE = ΔIL /(8 fSW COUT )
For electrolytic capacitors where ESR is high relative to
capacitive reactance:
V
RIPPLE = ΔIL ESR
where ΔIL is the peak-to-peak ripple current in the inductor.
The RMS content of this ripple is very low so the RMS
current rating of the output capacitor is usually not of
concern. It can be estimated with the formula:
I
C(RMS) = ΔIL /12
Another constraint on the output capacitor is that it must
have greater energy storage than the inductor; if the stored
energy in the inductor transfers to the output, the resulting
voltage step should be small compared to the regulation
voltage. For a 5% overshoot, this requirement indicates:
CL I
V
OUT
LIM
OUT
> 10
2
(
/
)
The low ESR and small size of ceramic capacitors make
them the preferred type for LT3509 applications. Not all
ceramic capacitors are the same, however. Many of the
higher value capacitors use poor dielectrics with high
temperature and voltage coefcients. In particular, Y5V
APPLICATIONS INFORMATION
75k
RC
COMP-
NODE
R1
R2
1.73M
95pF
VIN
VREF = 0.8V
CPL
260μS
LT3509
1.1S
VOUT
3509 F10
+
–
COUT
Figure 10. Small-Signal Equivalent Circuit
or from RC. This model works well as long as the inductor
current ripple is not too low (ΔIRIPPLE > 5% IOUT) and the
loop crossover frequency is less than fSW/5. An optional
phase lead capacitor (CPL) across the feedback divider
may improve the transient response.
Output Capacitor Selection
The output capacitor lters the inductor current to generate
an output with low voltage ripple. It also stores energy in
order to satisfy transient loads and stabilize the LT3509’s
control loop. Because the LT3509 operates at a high
frequency, minimal output capacitance is necessary. In
addition, the control loop operates well with or without
the presence of output capacitor series resistance (ESR).
Ceramic capacitors, which achieve very low output ripple
and small circuit size, are therefore an option.
相關PDF資料 |
PDF描述 |
|---|---|
| LT3509EDE#PBF | 1.2 A DUAL SWITCHING CONTROLLER, 2500 kHz SWITCHING FREQ-MAX, PDSO14 |
| LT3509EDE#TRPBF | 1.2 A DUAL SWITCHING CONTROLLER, 2500 kHz SWITCHING FREQ-MAX, PDSO14 |
| LT3570EFE#TRPBF | 3.1 A SWITCHING REGULATOR, 2750 kHz SWITCHING FREQ-MAX, PDSO20 |
| LT3570IUF#PBF | 3.1 A SWITCHING REGULATOR, 2750 kHz SWITCHING FREQ-MAX, PQCC24 |
| LT3570EFE#PBF | 3.1 A SWITCHING REGULATOR, 2750 kHz SWITCHING FREQ-MAX, PDSO20 |
相關代理商/技術參數 |
參數描述 |
|---|---|
| LT3509IDE-TRPBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Dual 36V, 700mA Step-Down Regulator |
| LT3509IMSE#PBF | 功能描述:IC REG BUCK ADJ 0.7A DL 16MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關穩(wěn)壓器 系列:- 標準包裝:2,500 系列:- 類型:降壓（降壓） 輸出類型:固定 輸出數:1 輸出電壓:1.2V，1.5V，1.8V，2.5V 輸入電壓:2.7 V ~ 20 V PWM 型:- 頻率 - 開關:- 電流 - 輸出:50mA 同步整流器:是 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:10-TFSOP，10-MSOP（0.118"，3.00mm 寬）裸露焊盤 包裝:帶卷 (TR) 供應商設備封裝:10-MSOP 裸露焊盤 |
| LT3509IMSE#PBF | 制造商:Linear Technology 功能描述:DC-DC CONVERTER BUCK 2.2MHZ 制造商:Linear Technology 功能描述:DC-DC CONVERTER, BUCK, 2.2MHZ, MSOP-16 |
| LT3509IMSE#TRPBF | 功能描述:IC REG BUCK ADJ 0.7A DL 16MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關穩(wěn)壓器 系列:- 設計資源:Design Support Tool 標準包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數:1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開關:- 電流 - 輸出:100mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細型，TSOT-23-5 包裝:剪切帶 (CT) 供應商設備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT |
| LT3509IMSE-PBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Dual 36V, 700mA Step-Down Regulator |
發(fā)布緊急采購，3分鐘左右您將得到回復。