參數(shù)資料
型號(hào): LTC3525LESC6-3#PBF
廠商: LINEAR TECHNOLOGY CORP
元件分類(lèi): 穩(wěn)壓器
英文描述: 0.45 A SWITCHING REGULATOR, PDSO6
封裝: LEAD FREE, PLASTIC, EIAJ, MO-203AB, SC-70, 6 PIN
文件頁(yè)數(shù): 10/12頁(yè)
文件大小: 487K
代理商: LTC3525LESC6-3#PBF
LTC3525L-3
7
3525lfa
During start-up, the synchronous rectifier is not enabled,
and the internal P-channel synchronous rectifier acts
as a follower, causing the peak voltage on SW to reach
(VIN+1V)typical.Thislimitsinrushcurrentbymaintaining
control of the inductor current when VOUT is less than VIN.
ToreducepowerdissipationintheP-channelsynchronous
rectifier when the output is shorted, a foldback feature is
incorporated that reduces the peak inductor current when
VIN is more than 1.7V greater than VOUT.
Normal Operation
Once VOUT has increased more than 0.2V typical above
VIN, and either voltage is above 1.8V, normal operation
begins, with synchronous rectification enabled. In this
mode,theinternalN-channelMOSFETconnectedbetween
SW and GND stays on until the inductor current reaches a
maximum peak value, after which it is turned off and the
P-channel synchronous rectifier is turned on. It stays on,
delivering current to the output, until the inductor current
has dropped below a minimum value at which point it
turns off and the cycle repeats. When the output voltage
reaches its regulated value both switches are turned off
and the LTC3525L-3 goes to sleep, during which time the
output capacitor supplies current to the load. Once the
output voltage drops below the regulation value the IC
leaves sleep mode and switching is resumed.
The LTC3525L-3 has been designed for low output voltage
ripple. The output voltage ripple is typically only 20mV
peak-to-peak at light load and 60mV peak-to-peak at
full load using the minimum recommended 10F output
capacitor. An anti-ring circuit damps any oscillation at the
switch node when the inductor current falls to zero.
Power Adjust Feature
The LTC3525L-3 incorporates a feature that maximizes
efficiency at light load while providing increased power
capability at heavy load by adjusting the peak and valley
of the inductor current as a function of load. Lowering the
peak inductor current to 150mA at light load optimizes
efficiency by reducing conduction losses in the internal
MOSFETswitches.Astheloadincreases,thepeakinductor
currentisautomaticallyincreasedtoamaximumof400mA.
At intermediate loads, the peak inductor current may vary
from 150mA to 400mA. Figure 2 shows an example of
how the inductor current changes as the load increases.
Please note that output capacitor values greater than 47F
will result in higher peak currents than necessary at light
load. This will lower the light load efficiency.
The valley of the inductor current is automatically adjusted
as well, to maintain a relatively constant inductor ripple
current. This keeps the switching frequency relatively
constant.
Figure 2. Inductor Current Changing as a Function of Load
OPERATION
3525l F02
INDUCTOR
CURRENT
100mA/DIV
LOAD
CURRENT
50mA/DIV
10s/DIV
相關(guān)PDF資料
PDF描述
LTC3526LEDC SWITCHING CONTROLLER, 1250 kHz SWITCHING FREQ-MAX, PDSO6
LTC3531ES6-3.3#PBF 0.46 A SWITCHING REGULATOR, PDSO6
LTC3538EDCB#TRM 0.8 A SWITCHING REGULATOR, 1200 kHz SWITCHING FREQ-MAX, PDSO8
LTC3542IS6#PBF SWITCHING REGULATOR, 2700 kHz SWITCHING FREQ-MAX, PDSO6
LTC3559EUD 1.05 A BATTERY CHARGE CONTROLLER, 2590 kHz SWITCHING FREQ-MAX, PQCC16
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC3526 制造商:LINER 制造商全稱(chēng):Linear Technology 功能描述:500mA 1MHz Synchronous Step-Up DC/DC Converters in 2mm × 2mm DFN
LTC3526-2 制造商:LINER 制造商全稱(chēng):Linear Technology 功能描述:500mA 2MHz Synchronous Step-Up DC/DC Converters in 2mm × 2mm DFN
LTC3526B 制造商:LINER 制造商全稱(chēng):Linear Technology 功能描述:500mA 1MHz Synchronous Step-Up DC/DC Converters in 2mm × 2mm DFN
LTC3526B-2 制造商:LINER 制造商全稱(chēng):Linear Technology 功能描述:500mA 2MHz Synchronous Step-Up DC/DC Converters in 2mm × 2mm DFN
LTC3526BEDC 制造商:LINER 制造商全稱(chēng):Linear Technology 功能描述:500mA 1MHz Synchronous Step-Up DC/DC Converters in 2mm X 2mm DFN