- 您现在的位置：买卖IC网 > PDF目录13980 > LTC3612EUDC#TRPBF (Linear Technology)IC REG BUCK SYNC ADJ 3A 20QFN PDF资料下载
参数资料
| 型号： | LTC3612EUDC#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 23/30页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 3A 20QFN |
| 标准包装： | 2,500 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.6 V ~ 5.5 V |
| 输入电压： | 2.25 V ~ 5.5 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 300kHz ~ 4MHz |
| 电流 - 输出： | 3A |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 20-WFQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 20-QFN（3x4） |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页当前第23页第24页第25页第26页第27页第28页第29页第30页
LTC3612
APPLICATIONS INFORMATION
R T =
3.82 ?10 11 Hz
? – 16k ? = 130k ?
L = ?
? = 0.466μH
? ? ? ? ? 1–
? I L = ?
? ? ? ? ? 1– 5.5V ? ? = 0.99A
TheR DS(ON) forboththetopandbottomMOSFETscan
be obtained from the Typical Performance Character-
istics curves. To obtain I 2 R losses, simply add R SW to
R L and multiply the result by the square of the average
output current.
Other losses including C IN and C OUT ESR dissipative
losses and inductor core losses generally account for
less than 2% of the total loss.
Thermal Considerations
In most applications, the LTC3612 does not dissipate much
heat due to its high efficiency.
However, in applications where the LTC3612 is running at
high ambient temperature with low supply voltage and high
duty cycles, such as in dropout, the heat dissipated may
exceed the maximum junction temperature of the part. If
the junction temperature reaches approximately 160°C,
both power switches will be turned off and the SW node
will become high impedance.
To prevent the LTC3612 from exceeding the maximum
junction temperature, some thermal analysis is required.
The temperature rise is given by:
T RISE = (P D )( θ JA )
where P D is the power dissipated by the regulator and θ JA
is the thermal resistance from the junction of the die to
the ambient temperature. The junction temperature, T J ,
is given by:
T J = T A + T RISE
where T A is the ambient temperature.
As an example, consider the case when the LTC3612 is in
dropout at an input voltage of 3.3V with a load current of
3A at an ambient temperature of 70°C. From the Typical
Performance Characteristics graph of Switch Resistance,
the R DS(ON) resistance of the P-channel switch is 0.075Ω.
Therefore, power dissipated by the part is:
P D = (I OUT ) 2 ? R DS(ON) = 675mW
Therefore, the junction temperature of the regulator op-
erating at 70°C ambient temperature is approximately:
T J = 0.675W ? 43°C/W + 70°C = 99°C
We can safely assume that the actual junction temperature
will not exceed the absolute maximum junction tempera-
ture of 125°C.
Note that for very low input voltage, the junction tempera-
ture will be higher due to increased switch resistance,
R DS(ON) . It is not recommended to use full load current
for high ambient temperature and low input voltage.
To maximize the thermal performance of the LTC3612 the
Exposed Pad should be soldered to a ground plane. See
the PCB Layout Board Checklist.
Design Example
As a design example, consider using the LTC3612 in an
application with the following specifications:
V IN = 2.25V to 5.5V, V OUT = 1.8V, I OUT(MAX) = 3A, I OUT(MIN)
= 100mA, f = 2.6MHz.
Efficiency is important at both high and low load current,
so Burst Mode operation will be utilized.
First, calculate the timing resistor:
2.6MHz
Next, calculate the inductor value for about 30% ripple
current at maximum V IN :
? 1.8V ? ? 1.8V ?
? 2.6MHz ?1A 5.5V ?
Using a standard value of 0.47μH inductor results in a
maximum ripple current of:
? 1.8V ? ? 1.8V ?
? 2.6MHz ? 0.47μH
For the QFN package, the θ JA is 43°C/W.
3612fb
For more information www.linear.com/LTC3612
23
相关PDF资料 |
PDF描述 |
|---|---|
| HM73-101R0LLFTR13 | INDUCTOR 1.0UH LOW PRO SHLD SMD |
| TO3316-100M | INDUCTOR 10UH 3.9A 3316 +-20% |
| HM77-60002LFTR | LOW PROFILE INDUCTORS |
| MAX6319LHUK31A+T | IC SUPERVISOR 3.080V SOT23-5 |
| LTC3569EUD#TRPBF | IC REG BUCK SYNC ADJ TRPL 20QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3612IFE#PBF | 功能描述:IC REG BUCK SYNC ADJ 3A 20TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON（1.45x1） 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2 |
| LTC3612IFE#TRPBF | 功能描述:IC REG BUCK SYNC ADJ 3A 20TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
| LTC3612IUDC#PBF | 功能描述:IC REG BUCK SYNC ADJ 3A 20QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
| LTC3612IUDC#TRPBF | 功能描述:IC REG BUCK SYNC ADJ 3A 20QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
| LTC3613EWKH#PBF | 功能描述:IC REG BUCK SYNC ADJ 15A 56-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
发布紧急采购，3分钟左右您将得到回复。