参数资料
| 型号： | LT3509HMSE#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 18/24页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 0.7A DL 16MSOP |
| 标准包装： | 37 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 2 |
| 输出电压： | 0.8 V ~ 35.3 V |
| 输入电压： | 3.6 V ~ 36 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 260kHz ~ 2.15MHz |
| 电流 - 输出： | 700mA |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 150°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-TFSOP（0.118"，3.00mm 宽）裸露焊盘 |
| 包装： | 管件 |
| 供应商设备封装： | 16-MSOP，裸露焊盘 |
LT3509
APPLICATIONS INFORMATION
I D ( AVG ) = I OUT IN OUT IN
Diode Selection
The catch diode (D1 from Figure 1) conducts current only
during switch off time. Average forward current in normal
operation can be calculated from:
( V – V )/ V
The only reason to consider a diode with a larger current
rating than necessary for nominal operation is for the
worst-case condition of shorted output. The diode current
will then increase to the typical peak switch current limit.
If transient input voltages exceed 40V, use a Schottky
diode with a reverse voltage rating of 45V or higher. If
the maximum transient input voltage is under 40V, use a
Schottky diode with a reverse voltage rating greater than
the maximum input voltage. Table 3 lists several Schottky
diodes and their manufacturers:
Table 3. Schottky Diodes
providing the boost supply to the BD pin. In this case the
voltage drop of the other switch will increase and lower
the ef?ciency. This could eventually cause the part to reach
the thermal shutdown limit. One other important feature
of the part that needs to be considered is that there is a
parasitic diode in parallel with the power switch. In normal
operation this is reverse biased but it could conduct if the
load can be powered from an alternate source when the
LT3509 has no input. This may occur in battery charging
applications or in battery backup systems where a bat-
tery or some other supply is diode ORed with one of the
LT3509 regulated outputs. If the SW pin is at more than
about 4V the V IN pin can attain suf?cient voltage for LT3509
control circuitry to power-up to the quiescent bias level
and up to 2mA could be drawn from the backup supply.
This can be minimized if some discrete FETs or open-drain
buffers are used to pull down the RUN/SS pins. Of course
the gates need to be driven from the standby or battery
MANUFACTURER/
PART NUMBER
V R
(V)
I AVE
(A)
V F at 1A
(mV)
backed supply. If there is the possibility of a short circuit
at the input or just other parallel circuits connected to V IN
On Semiconductor
it would be best to add a protection diode in series with
MBRM140
40
1
550
V IN . This will also protect against a reversed input polarity.
MicroSemi
These concepts are illustrated in Figure 12.
UPS140
40
1
450
Diodes Inc.
V IN
D2
V IN
BD
DFLS140L
1N5819HW
40
40
1
1
550
450
C IN
BOOST
LT3509
C BOOST
L1
Short and Reverse Protection
RUN/SS1
SW
D1
C OUT
V OUT
Provided the inductors are chosen to not go deep into
their saturation region at the maximum I LIMIT current the
LT3509 will tolerate a short circuit on one or both outputs.
RUN/SS2
GND
DA
The excess current in the inductor will be detected by the
DA comparator and the frequency will reduced until the
valley current is below the limit. This shouldn’t affect the
SLEEP
Figure 12. Reverse Bias Protection
3509 F12
other channel unless the channel that is shorted is also
3509fc
18
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3509IDE#PBF | 功能描述:IC REG BUCK ADJ 0.7A DL 14DFN 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 |
| LT3509IDE#PBF | 制造商:Linear Technology 功能描述:DC-DC CONVERTER BUCK 2.2MHZ 制造商:Linear Technology 功能描述:DC-DC CONVERTER, BUCK, 2.2MHZ, DFN-14 |
| LT3509IDE#TRPBF | 功能描述:IC REG BUCK ADJ 0.7A DL 14DFN 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:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LT3509IDE-PBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual 36V, 700mA Step-Down Regulator |
| LT3509IDE-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual 36V, 700mA Step-Down Regulator |
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