- 您现在的位置：买卖IC网 > PDF目录14465 > LT3505IMS8E#PBF (Linear Technology)IC REG BUCK ADJ 1.2A 8MSOP PDF资料下载
参数资料
| 型号： | LT3505IMS8E#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 10/24页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 1.2A 8MSOP |
| 标准包装： | 50 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.78 V ~ 33.8 V |
| 输入电压： | 3.6 V ~ 36 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 200kHz ~ 3.01MHz |
| 电流 - 输出： | 1.2A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-TSSOP，8-MSOP（0.118"，3.00mm 宽）裸露焊盘 |
| 包装： | 管件 |
| 供应商设备封装： | 8-MSOP-EP |
LT3505
APPLICATIONS INFORMATION
V SW
20V/DIV
I L
0.5A/DIV
V OUT
200mV/DIV
AC COUPLED
Now the required on time has decreased below the
minimum on time of 130ns. Instead of the switch pulse
width becoming narrower to accommodate the lower duty
cycle requirement, the switch pulse width remains ?xed
at 130ns. In Figure 2 the inductor current ramps up to a
value exceeding the load current and the output ripple
increases to ~200mV. The part then remains off until the
output voltage dips below 100% of the programmed value
before it begins switching again.
V SW
20V/DIV
I L
0.5A/DIV
V OUT
200mV/DIV
AC COUPLED
2 s/DIV
C OUT = 10 F I LOAD = 0.75A
V OUT = 3V L = 10 H
V IN = 30V R T = 75.0k
Figure 1
2 s/DIV
C OUT = 10 F I LOAD = 0.75A
V OUT = 3V L = 10 H
V IN = 35V R T = 75.0k
Figure 2
3505 F01
3505 F02
For switching frequencies above 750kHz, the input voltage
must not exceed V IN(PS) . See the “Input Voltage Frequency
Foldback” section of the datasheet for a circuit solution
that provides safe operation above V IN(PS) at switching
frequencies exceeding 750kHz. For switching frequencies
below 750kHz, operation above V IN(PS) is safe and will
not damage the part as long as the output voltage stays
in regulation and the inductor does not saturate. Figure
3 shows the switching waveforms of a 750kHz applica-
tion when the input voltage is increased to its absolute
maximum rating of 40V.
As the input voltage increases, the inductor current ramp
rate increases, the number of skipped pulses increases
and the output voltage ripple increases. The part is robust
enough to survive prolonged operation under these condi-
tions as long as the programmed switching frequency is
less than 750kHz and the peak inductor current does not
exceed 2.2A. Inductor current saturation may further limit
performance in this operating regime.
Frequency Selection
V SW
20V/DIV
I L
0.5A/DIV
V OUT
200mV/DIV
AC COUPLED
2 μ s/DIV
3505 F03
The maximum frequency that the LT3505 can be pro-
grammed to is 3MHz. The minimum frequency that the
LT3505 can be programmed to is 200kHz. The switching
frequency is programmed by tying a 1% resistor from the R T
pin to ground. Table 1 can be used to select the value of R T .
Minimum on-time and edge loss must be taken into consid-
eration when selecting the intended frequency of operation.
Higher switching frequency increases power dissipation
and lowers ef?ciency.
C OUT = 10 μ F
V OUT = 3V
V IN = 40V
I LOAD = 0.75A
L = 10 μ H
R T = 75.0k
Figure 3
3505fc
10
相关PDF资料 |
PDF描述 |
|---|---|
| LT1304CS8#PBF | IC REG BOOST ADJ 0.2A 8SOIC |
| RSM15DTMD-S189 | CONN EDGECARD 30POS R/A .156 SLD |
| LT1109CS8#PBF | IC REG BOOST ADJ 0.1A 8SOIC |
| HC2-R68TR-R | INDUCTOR PWR HI CURR 0.68UH SMD |
| VI-J5W-EX-B1 | CONVERTER MOD DC/DC 5.5V 75W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3505IMS8E-TR | 制造商:LINER 制造商全称:Linear Technology 功能描述:1.2A, Step-Down Switching Regulator in 3mm × 3mm DFN |
| LT3505IMS8E-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:1.2A, Step-Down Switching Regulator in 3mm × 3mm DFN |
| LT3506 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Monolithic Dual Tracking 3A Step-Down Switching |
| LT3506A | 制造商:LINER 制造商全称:Linear Technology 功能描述:Monolithic Dual Tracking 3A Step-Down Switching |
| LT3506AEDHD | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Monolithic 1.6A Step-Down Switching Regulator |
发布紧急采购，3分钟左右您将得到回复。