參數(shù)資料
型號(hào)： LTC3604IMSE#TRPBF
廠商： LINEAR TECHNOLOGY CORP
元件分類： 穩(wěn)壓器
英文描述： SWITCHING REGULATOR, PDSO16
封裝： LEAD FREE, PLASTIC, MSOP-16
文件頁(yè)數(shù)： 8/24頁(yè)
文件大?。?/td> 277K
代理商： LTC3604IMSE#TRPBF
LTC3604
16
3604f
Each time a power MOSFET gate is switched from low
to high to low again, a packet of charge dQ moves
from VIN to ground. The resulting dQ/dt is a current
out of INTVCC that is typically much larger than the DC
control bias current. In continuous mode, IGATECHG
= f(QT + QB), where QT and QB are the gate charges
of the internal top and bottom power MOSFETs and f
is the switching frequency. For estimation purposes,
(QT + QB) on the LTC3604 is approximately 1nC.
To calculate the total power loss from the LDO load,
simply add the gate charge current and quiescent cur-
rent and multiply by VIN:
PLDO = (IGATECHG + IQ) VIN
3. Other “hidden” losses such as transition loss, cop-
per trace resistances, and internal load currents can
account for additional efciency degradations in the
overall power system. Transition loss arises from the
brief amount of time the top power MOSFET spends in
the saturated region during switch node transitions. The
LTC3604 internal power devices switch quickly enough
that these losses are not signicant compared to other
sources.
Other losses, including diode conduction losses during
dead time and inductor core losses, generally account
for less than 2% total additional loss.
Thermal Considerations
The LTC3604 requires the exposed package backplane
metal (PGND pin on the QFN, SGND pin on the MSOP
package) to be well soldered to the PC board to provide
good thermal contact. This gives the QFN and MSOP
packages exceptional thermal properties, compared to
other packages of similar size, making it difcult in normal
operation to exceed the maximum junction temperature
of the part. In many applications, the LTC3604 does not
dissipate much heat due to its high efciency and low
thermal resistance package backplane. However, in applica-
tions in which the LTC3604 is running at a high ambient
temperature, high input voltage, high switching frequency,
and maximum output current, the heat dissipated may
exceed the maximum junction temperature of the part. If
the junction temperature reaches approximately 150°C,
APPLICATIONS INFORMATION
both power switches will be turned off until temperature
decreases approximately 10°C.
Thermal analysis should always be performed by the user
to ensure the LTC3604 does not exceed the maximum
junction temperature.
The temperature rise is given by:
TRISE = PDθJA
where PD is the power dissipated by the regulator and θJA
is the thermal resistance from the junction of the die to
the ambient temperature.
Consider the example in which an LTC3604EUD is operat-
ing with IOUT = 2.5A, VIN = 12V, f = 1MHz, VOUT = 1.8V,
and an ambient temperature of 25°C. From the Typical
Performance Characteristics section the RDS(ON) of the top
switch is found to be nominally 130mΩ while that of the
bottom switch is nominally 100mΩ yielding an equivalent
power MOSFET resistance RSW of:
RDS(ON)TOP 1.8/12 + RDS(ON)BOT 10.2/12 = 105mΩ.
From the previous section, IGATECHG is ~1mA when f =
1MHz, and the spec table lists the maximum IQ to be 1mA.
Therefore, the total power dissipation due to resistive
losses and LDO losses is:
PD = IOUT2 RSW + VIN (IGATECHG + IQ)
PD = (2.5A)2 (0.105Ω) + 12V 2mA = 680mW
The QFN 3mm
×3mmpackagejunction-to-ambientthermal
resistance,
θJA, is around 45°C/W. Therefore, the junction
temperature of the regulator operating in a 25°C ambient
temperature is approximately:
TJ = 0.680W 45°C/W + 25°C = 56°C
Remembering that the above junction temperature is
obtained from an RDS(ON) at 25°C, we might recalculate the
junction temperature based on a higher RDS(ON) since it
increaseswithtemperature.Redoingthecalculationassum-
ing that RSW increased 15% at 56°C yields a new junction
temperature of 66°C. If the application calls for a signi-
cantly higher ambient temperature and/or higher switching
frequency, care should be taken to reduce the temperature
rise of the part by using a heat sink or air ow.
相關(guān)PDF資料
PDF描述
LTC3775EMSE#TRPBF SWITCHING CONTROLLER, 575 kHz SWITCHING FREQ-MAX, PDSO16
LTC3775IMSE#PBF SWITCHING CONTROLLER, 575 kHz SWITCHING FREQ-MAX, PDSO16
LTC3805MPMSE#PBF SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO10
LTC3805MPMSE#TR SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO10
LTC3829IFE#PBF SWITCHING REGULATOR, PDSO38
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC3604IUD#PBF 功能描述:IC REG BUCK SYNC 2.5A 16QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開(kāi)關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開(kāi)關(guān):- 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(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT
LTC3604IUD#TRPBF 功能描述:IC REG BUCK SYNC 2.5A 16QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開(kāi)關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開(kāi)關(guān):- 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(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT
LTC3605AEUF#PBF 功能描述:IC REG BUCK SYNC ADJ 5A 24QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開(kāi)關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開(kāi)關(guān):- 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(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT
LTC3605AEUF#TRPBF 功能描述:IC REG BUCK SYNC ADJ 5A 24QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開(kāi)關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開(kāi)關(guān):- 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(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT
LTC3605AIUF#PBF 功能描述:IC REG BUCK SYNC ADJ 5A 24QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開(kāi)關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開(kāi)關(guān):- 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(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*