參數(shù)資料
型號(hào): SC418ULTRT
廠商: Semtech
文件頁數(shù): 16/30頁
文件大?。?/td> 691K
描述: IC REG DL BUCK/LINEAR 20MLPQ
產(chǎn)品培訓(xùn)模塊: Power Supplies 101
標(biāo)準(zhǔn)包裝: 1
系列: EcoSpeed®
拓?fù)洌?/td> 降壓(降壓)(1),線性(LDO)(1)
功能: 任何功能
輸出數(shù): 2
頻率 - 開關(guān): 1MHz
電壓/電流 - 輸出 1: 控制器
電壓/電流 - 輸出 2: 0.75 V ~ 5.25 V,200mA
帶 LED 驅(qū)動(dòng)器:
帶監(jiān)控器:
帶序列發(fā)生器:
電源電壓: 3 V ~ 28 V
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 20-MLPQ
供應(yīng)商設(shè)備封裝: 20-MLPQ(3x3)
包裝: 標(biāo)準(zhǔn)包裝
其它名稱: SC418ULTRTDKR
SC418
6
FB Ripple
Voltage (V
FB
)
FB threshold
(500mV)
Inductor
Current
DH
DL
(0A)
minimum frequency
After the programmable time-out, DL drives
high if V
FB
 has not reached the FB threshold.
DH On-time is triggered when
V
FB
 reaches the FB Threshold
On-time
(T
ON
)
programmable time-out
Figure 5  Ultrasonic Power-Save Operation
The equation for determining the R
PSV
 resistor value is
shown next. The desired minimum frequency is f
SWMIN
.
SWMIN
PSV
f
pF
350
1
R
Power-Save Mode Operation
The device provides power-save operation at light loads
with no minimum operating frequency, selected by float-
ing the PSV pin (no connection). In this mode of opera-
tion, the zero cross comparator monitors inductor current
via the voltage across the low-side MOSFET during the
off-time. If the inductor current falls to zero for 8 consecu-
tive switching cycles, the controller enters power-save
operation. It will then turn off the low-side MOSFET on
each subsequent cycle, provided that the current crosses
zero. After the low-side MOSFET is off, both high-side and
low-sides MOSFETs remain off until V
FB
 drops to the 500mV
threshold. While the MOSFETs are off the load is supplied
by the output capacitor. If the inductor current does not
reach zero on any switching cycle, the controller immedi-
ately exits power-save and returns to forced continuous
mode. Figure 6 shows power-save operation at light
loads.
FB Ripple
Voltage
(V
FB
)
FB threshold
DL
DH
Inductor
Current
Zero (0A)
DH On-time is triggered when
V
FB
 reaches the FB Threshold.
(500mV)
On-time (T
ON
)
DL drives high when on-time is completed.
DL remains high until inductor current reaches zero.
Dead time varies
according to load
Figure 6  Power-Save Operation
Smart Power-Save Protection
Active loads may leak current from a higher voltage into
the switcher output. Under light load conditions with
power-save enabled, this can force V
OUT
 to slowly rise and
reach the over-voltage threshold, resulting in a hard shut-
down. Smart power-save prevents this condition. When
the FB voltage exceeds 0% above nominal (exceeds
550mV), the device immediately disables power-save and
DL drives high to turn on the low-side MOSFET. This draws
current from V
OUT
 through the inductor and causes V
OUT
 to
fall. When V
FB
 drops back to the 500mV trip point, a normal
T
ON
 switching cycle begins. This method prevents a hard
OVP shutdown and cycles energy from V
OUT
 back to V
IN
. It
also minimizes operating power by avoiding forced con-
duction mode operation. Figure 7 shows typical wave-
forms for the Smart Power-save feature.
Applications Information (continued)
相關(guān)PDF資料
PDF描述
SC424MLTRT IC REG DL BUCK/LINEAR 28MLPQ
SC4250LISTRT IC HOT SWAP CTRLR 8-SOIC
SC427MLTRT IC REG DL BUCK/LINEAR 32MLPQ
SE95D,112 IC SENSOR TEMP 2.8-5.5V SOT96-1
SE97BTP,547 IC TEMP SENSOR DIMM 8HWSON
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SC419 制造商:SEMTECH 制造商全稱:Semtech Corporation 功能描述:EcoSpeedTM DC-DC Converter with Integrated Boost Diode
SC419970CGCR2 制造商:Motorola Inc 功能描述:
SC419EVB 制造商:SEMTECH 制造商全稱:Semtech Corporation 功能描述:EcoSpeedTM DC-DC Converter with Integrated Boost Diode
SC419ULTRT 功能描述:IC REG CTRLR BUCK PWM 20-MLPQ RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:EcoSpeed®, SmartDrive™ 特色產(chǎn)品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 標(biāo)準(zhǔn)包裝:1 系列:PowerWise® PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1MHz 占空比:81% 電源電壓:4.5 V ~ 18 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-5°C ~ 125°C 封裝/外殼:32-WFQFN 裸露焊盤 包裝:Digi-Reel® 產(chǎn)品目錄頁面:1303 (CN2011-ZH PDF) 其它名稱:LM3754SQDKR
SC41E6 制造商:INFINEON 制造商全稱:Infineon Technologies AG 功能描述:SIEMENS ANNOUNCES A SUB-MICTON GENERATION OF CHANNELLESS GATE-ARRAYS BASED ON THE PROVEN MEGALOGIC PROCESS