參數(shù)資料
型號: LT3694IUFD#TRPBF
廠商: LINEAR TECHNOLOGY CORP
元件分類: 穩(wěn)壓器
英文描述: 2.6 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PQCC28
封裝: 4 X 5 MM, LEAD FREE, PLASTIC, MO-220, QFN-28
文件頁數(shù): 7/28頁
文件大小: 276K
代理商: LT3694IUFD#TRPBF
LT3694/LT3694-1
15
36941fa
The power section, consisting of the modulator, power
switch and inductor, is modeled as a transconductance
amplifier generating an output current proportional to
the voltage at the VC1 pin. Note that the output capacitor
integrates this current, and that the capacitor on the VC1
pin (CC) integrates the error amplifier output current,
resulting in two poles in the loop. In most cases a zero
is required and comes from either the output capacitor
ESR or from a resistor RC in series with CC. This simple
model works well as long as the value of the inductor is
not too high and the loop crossover frequency is much
lower than the switching frequency. A phase lead capaci-
tor (CPL) across the feedback divider may improve the
transient response.
Figure 3 shows the transient response when the load
current steps from 1A to 2.6A and back to 1A.
BST and BIAS Pin Considerations
Capacitor C3 and the internal boost Schottky diode (see the
Block Diagram in Figure 1) are used to generate a boost
voltage that is higher than the input voltage. In most cases
a 0.22μF capacitor will work well. Figure 4 shows three
ways to arrange the boost circuit. The BST pin must be
more than 2.3V above the SW pin for best efficiency. For
outputs of 3V and above, the standard circuit (Figure 4a)
is best. For outputs between 2.8V and 3V, use a 1μF boost
APPLICATIONS INFORMATION
Figure 3. Transient Load Response of the LT3694
Front Page Application as the Load Current Is
Stepped from 1A to 2.6A. VOUT = 3.3V
VIN
BST
SW
BIAS
VIN
VOUT
4.7μF
C3
GND
LT3694
VIN
BST
SW
BIAS
VIN
VOUT
4.7μF
C3
D2
GND
LT3694
VIN
BST
SW
BIAS
VIN
VOUT
4.7μF
C3
GND
LT3694
36941 FO4
(4a) For VOUT > 2.8V
(4b) For 2.5V < VOUT < 2.8V
(4c) For VOUT < 2.5V; VIN(MAX) = 7V
Figure 4. Three Circuits for Generating the Boost Voltage
36941 F03
IL
1A/DIV
VOUT
100mV/DIV
100μs/DIV
capacitor. A 2.5V output presents a special case because it
is marginally adequate to support the boosted drive stage
while using the internal boost diode. For reliable BST pin
operation with 2.5V outputs, use a good external Schottky
diode (such as the ON Semi MBR0540), and a 1μF boost
capacitor (see Figure 4b). For lower output voltages, the
BIAS pin can be tied to the input (Figure 4c), or to another
supply greater than 2.8V. Tying BIAS to VIN reduces the
maximum input voltage to 7V. The circuit in Figure 4a is
more efficient because the BST pin current and BIAS pin
quiescent current comes from a lower voltage source.
One must also ensure that the maximum voltage ratings
of the BST and BIAS pins are not exceeded. The minimum
相關(guān)PDF資料
PDF描述
LT3694IFE#PBF 2.6 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PDSO20
LT3694-1IUFD#PBF 2.6 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PQCC28
LT3694IUFD#PBF 2.6 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PQCC28
LT3694-1IFE#PBF 2.6 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PDSO20
LT3694-1EFE#PBF 2.6 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PDSO20
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LT3695 制造商:LINER 制造商全稱:Linear Technology 功能描述:1A Fault Tolerant Micropower Step-Down Regulator
LT3695EMSE#PBF 功能描述:IC REG BUCK ADJ 1A 16MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標準包裝:250 系列:- 類型:降壓(降壓) 輸出類型:固定 輸出數(shù):1 輸出電壓:1.2V 輸入電壓:2.05 V ~ 6 V PWM 型:電壓模式 頻率 - 開關(guān):2MHz 電流 - 輸出:500mA 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:6-UFDFN 包裝:帶卷 (TR) 供應商設(shè)備封裝:6-SON(1.45x1) 產(chǎn)品目錄頁面:1032 (CN2011-ZH PDF) 其它名稱:296-25628-2
LT3695EMSE#TRPBF 功能描述:IC REG BUCK ADJ 1A 16MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)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(shù):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(guān):- 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(shè)備封裝:10-MSOP 裸露焊盤
LT3695EMSE-3.3#PBF 功能描述:IC REG BUCK 3.3V 1A 16MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)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(shù):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(guān):- 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(shè)備封裝:10-MSOP 裸露焊盤
LT3695EMSE-3.3#PBF 制造商:Linear Technology 功能描述:IC STEP-DOWN REGULATOR MSOP-16