参数资料
| 型号： | SC190CIMLTRT |
| 厂商： | Semtech |
| 文件页数： | 7/18页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 0.3A 10MLP |
| 标准包装： | 1 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 可调 |
| 输入电压： | 2.7 V ~ 5.5 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 1MHz |
| 电流 - 输出： | 300mA |
| 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： | 10-VFDFN 裸露焊盘 |
| 包装： | 标准包装 |
| 供应商设备封装： | 10-MLP（3x3） |
| 产品目录页面： | 1357 (CN2011-ZH PDF) |
| 其它名称： | SC190CIMLDKR |
SC190
POWER MANAGEMENT
Applications Information
SC190 Detailed Description
The SC190 is a step-down, pulse-width-modulated (PWM)
DC-DC converter with a low dropout (LDO) pre-regulator
and a low current LDO regulator for operation in low power
modes.
The device has an internal synchronous recti?er and does
not require a Schottky diode on the LX pin. The device is
designed to operate as a buck converter in PWM mode
with a ?xed frequency of 1MHz, but at loads below 5mA,
the part can be operated as an ultra-low current LDO
regulator to minimize supply current.
Programmable Output Voltage
The SC190 has four device variants (SC190A, SC190B,
SC190C, SC190D) each with a distinct range of output
voltages. The output voltage of each variant has four
predetermined values which can be individually selected
by the correct programming of the VID0 and VID1 pins.
(See “Programmable Output Voltage” table on page 5).
Note that the SC190C has much higher output voltage
settings than the other three variants. This device was
intended for use with higher input voltages, so some
performance over the entire input voltage range cannot
be guaranteed.
Switcher Mode with less than 1mV supply ripple
This is a ?xed frequency current mode architecture with
the input supply for the switching regulator pre-regulated
by a front-end LDO regulator. This technique reduces the
supply voltage ripple from 20mV, typically seen from a
switching converter, to approximately 1mV for the SC190.
The supply to the switcher is regulated to the supply
voltage minus approximately 300mV.
Current feedback for the switching regulator is through
the PMOS current path and it is ampli?ed and summed
with the internal slope compensation network and level
shift. The voltage feedback loop is through an internal
feedback divider. The ON time is determined by compar-
ing the summed current feedback and the output of the
error ampli?er. The period is set by the onboard oscillator
or by an external clock attached to the SYNC/PWM pin.
Continuous Conduction & Oscillator Synchronization
The SC190 is designed to operate in continuous conduction
mode thereby maintaining a ?xed frequency. When the
SYNC/PWM pin is tied high the part runs under control
of the internal oscillator. The part can be synchronized to
an external clock by driving a clock signal into the SYNC/
PWM pin. The part synchronizes to the rising edge of the
clock.
Back End LDO Mode
The SC190 ultra-low current linear regulator regulates
the same output as the switching regulator. The linear
regulator minimizes the supply current drawn at light
loads consuming only 10μA when supporting a 100μA
load. The SC190 can swap between switching regulator
and linear regulator mode under control of the MODE
pin (see “handover” section). In this way the part either
operates at a ?xed frequency or DC output, thereby never
generating load dependant frequencies that are typically
seen with lightly loaded switching regulators.
Handover (Switcher Mode to LDO Regulator Mode, LDO
Regulator Mode to Switcher Mode)
The device can be switched between Switcher mode and
Linear regulator mode and back to Switcher mode without
having to disable and re-enable the part. The output
maintains regulation during the switch over.
Linear Regulator Mode to Switching Mode
Transition
Switching Converter I OUT Specification
Applies
200ì μs
V MODE (Pin 5)
Wait Time
I OUT (Pin 3) < 5mA < 300mA
Time
Switching Mode to Linear Regulator Mode
Transition
Linear Regulator I OUT Specification
Applies
Ef?ciency at moderate to high loads can be improved by
shorting the VIN to BP pins at the expense of higher input
voltage ripple.
V MODE (Pin 5)
100ì μs s
Wait Time
I OUT (Pin 3)
< 300mA
Time
< 5mA
? 2005 Semtech Corp.
7
www.semtech.com
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SC190DEVB | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Synchronous Buck Converter with Programmable Output |
| SC190DIMLTRT | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Synchronous Buck Converter with Programmable Output |
| SC191 | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Low Supply Ripple Synchronous Buck Conversion Regulator |
| SC19-1 | 制造商:Thomas & Betts 功能描述:U CABLE CLIP - 6 MM 制造商:Belden Inc 功能描述: |
| SC191AEVB | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Low Supply Ripple Synchronous Buck Conversion Regulator |
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