参数资料
| 型号： | LT3481HMSE#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 10/24页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 2A 10MSOP |
| 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： | 1.27 V ~ 20 V |
| 输入电压： | 3.6 V ~ 34 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 300kHz ~ 2.8MHz |
| 电流 - 输出： | 2A |
| 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： | 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 |
LT3481
APPLICATIONS INFORMATION
? V OUT + V D ? ? V OUT + V D ?
? ? ?
V IN ( MAX ) ? ?
L = ? ? 1– ?
? f Δ I L
frequency will be necessary to achieve safe operation at
high input voltages.
If the output is in regulation and no short-circuit or start-up
events are expected, then input voltage transients of up to
36V are acceptable regardless of the switching frequency.
In this mode, the LT3481 may enter pulse-skipping opera-
tion where some switching pulses are skipped to maintain
output regulation. In this mode the output voltage ripple
and inductor current ripple will be higher than in normal
operation.
The minimum input voltage is determined by either the
LT3481’s minimum operating voltage of ~3.6V or by its
maximum duty cycle (see equation in previous section).
The minimum input voltage due to duty cycle is:
at least 3.5A at low duty cycles and decreases linearly to
2.5A at DC = 0.8. The maximum output current is a func-
tion of the inductor ripple current:
I OUT(MAX) = I LIM – Δ I L /2
Be sure to pick an inductor ripple current that provides
suf?cient maximum output current (I OUT(MAX) ).
The largest inductor ripple current occurs at the highest
V IN . To guarantee that the ripple current stays below the
speci?ed maximum, the inductor value should be chosen
according to the following equation:
?
V IN ( MIN ) =
V OUT + V D
1– f SW t OFF ( MIN )
– V D + V SW
where V D is the voltage drop of the catch diode (~0.4V),
V IN(MAX) is the maximum input voltage, V OUT is the output
voltage, f SW is the switching frequency (set by RT), and
where V IN(MIN) is the minimum input voltage, and t OFF(MIN)
is the minimum switch off-time (150ns). Note that higher
switching frequency will increase the minimum input
voltage. If a lower dropout voltage is desired, a lower
switching frequency should be used.
Inductor Selection
For a given input and output voltage, the inductor value
and switching frequency will determine the ripple current.
The ripple current Δ I L increases with higher V IN or V OUT
L is in the inductor value.
The inductor’s RMS current rating must be greater than the
maximum load current and its saturation current should be
about 30% higher. For robust operation in fault conditions
(start-up or short circuit) and high input voltage (>30V),
the saturation current should be above 3.5A. To keep the
ef?ciency high, the series resistance (DCR) should be less
than 0.1 Ω , and the core material should be intended for
high frequency applications. Table 1 lists several vendors
and suitable types.
and decreases with higher inductance and faster switch-
ing frequency. A reasonable starting point for selecting
the ripple current is:
Table 1. Inductor Vendors
VENDOR URL
Murata www.murata.com
PART SERIES
LQH55D
TYPE
Open
Δ I L = 0.4( ( I OUT(MAX) )
where I OUT(MAX) is the maximum output load current. To
guarantee suf?cient output current, peak inductor current
must be lower than the LT3481’s switch current limit (I LIM ).
The peak inductor current is:
I L(PEAK) = I OUT(MAX) + Δ I L /2
where I L(PEAK) is the peak inductor current, I OUT(MAX) is
the maximum output load current, and Δ I L is the inductor
ripple current. The LT3481’s switch current limit (I LIM ) is
TDK
Toko
Sumida
www.componenttdk.com
www.toko.com
www.sumida.com
SLF7045
SLF10145
D62CB
D63CB
D75C
D75F
CR54
CDRH74
CDRH6D38
CR75
Shielded
Shielded
Shielded
Shielded
Shielded
Open
Open
Shielded
Shielded
Open
3481fc
10
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相关代理商/技术参数 |
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|---|---|
| LT3481IDD | 制造商:Linear Technology 功能描述:Conv DC-DC Single Step Down 3.6V to 36V 10-Pin DFN EP |
| LT3481IDD#PBF | 功能描述:IC REG BUCK ADJ 2A 10DFN 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 |
| LT3481IDD#PBF | 制造商:Linear Technology 功能描述:DC-DC CONVERTER BUCK 2.8MHZ 制造商:Linear Technology 功能描述:DC-DC CONVERTER, BUCK, 2.8MHZ, DFN-10 |
| LT3481IDD#TRPBF | 功能描述:IC REG BUCK ADJ 2A 10DFN 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 |
| LT3481IDD-PBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:36V, 2A, 2.8MHz Step-Down Switching Regulator with 50μA Quiescent Current |
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