参数资料
| 型号： | SC2440TETRT |
| 厂商： | Semtech |
| 文件页数： | 16/26页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK 2A DL 16TSSOP |
| 标准包装： | 1 |
| 类型： | 降压（降压） |
| 输出数： | 2 |
| 输入电压： | 2.8 V ~ 20 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 1.4MHz |
| 电流 - 输出： | 2A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-TSSOP（0.173"，4.40mm）裸露焊盘 |
| 包装： | 标准包装 |
| 供应商设备封装： | 16-TSSOP |
| 产品目录页面： | 1358 (CN2011-ZH PDF) |
| 其它名称： | SC2440TEDKR |
SC2440
POWER MANAGEMENT
Applications Information
the soft-start pins is pulled low, 105μA flows out of that
pin. Pulling both soft-start pins below 0.2V shuts off the
internal bias circuit of the SC2440. The total V IN current
decreases to 38μA. In shutdown either SS pin sources
only 2μA. A fast charging circuit (enabled by the internal
bias circuit), which charges the soft-start capacitor below
1V, causes the difference in the soft-start pin currents.
If either SS pin is released in shutdown, the internal
current source pulls up on the SS pin. When this SS
voltage reaches 0.3V, the SC2440 turns on and the V IN
quiescent current increases to 3.3mA. The current
flowing out of the other SS pin (which is still pulled low)
increases to 105μA. The fast charging circuit quickly pulls
the released soft-start capacitor to 1V (slightly below the
switching threshold). The fast charging circuit is then
2.4V
2V
disabled. A 1.8μA current source continues to charge
the soft-start capacitor (Figure 3). The soft-start voltage
ramp at the SS pin clamps the error amplifier output
(Figure 2). During regulator start-up, COMP voltage follows
the SS voltage. The converter starts to switch when its
COMP voltage exceeds 1.1V. The peak inductor current
gradually increases until the converter output comes into
regulation. Proper soft-start prevents output overshoot
during start-up. Current drawn from the input supply is
also well controlled. Notice that the inductor current, not
the converter output voltage, is ramped during soft-start.
Both soft-start capacitors are charged to a final voltage
of about 2.4V.
1V
VSS
Hiccup
Enabled
0.3V
0
Fast
Charge
VFB
1V
0.74V
Switc hing Starts
0
Output must be at
least 74% of its set
voltage in this
interval or the
regulator will
undergo shutdown
and restart
(hiccup).
Figure 10(a). Normal Soft-start.
2V
VSS
VCOMP
1V
0.3V
0
Switc hing
Not Switchi ng
Switc hing
Not Switchi ng
1V
0.74V
VFB
0
Figure 10(b). Start-up Fails due to (i) Short Soft-start Duration or (ii) Output Overload or (iii)
Output Short-circuited.
? 2005 Semtech Corp.
16
www.semtech.com
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SC2441 | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Very Low Input Voltage 2-Phase Synchronous Step-down Controllers with Step-up Converter |
| SC2441A | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:1.8V to 20V Input 2-Phase Synchronous Step-down Controllers with Step-up Converter |
| SC2441A_09 | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:1.8V to 20V Input 2-Phase Synchronous Step-down Controllers with Step-up Converter |
| SC2441AEVB | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:1.8V to 20V Input 2-Phase Synchronous Step-down Controllers with Step-up Converter |
| SC2441ATETRT | 制造商:Semtech Corporation 功能描述: |
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