参数资料
| 型号： | SC196AMLTRT |
| 厂商： | Semtech |
| 文件页数： | 7/17页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC 1.5A 10MLP |
| 标准包装： | 1 |
| 类型： | 降压（降压） |
| 输出类型： | 固定 |
| 输出数： | 1 |
| 输出电压： | 1V，1.05V，1.2V，1.8V |
| 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： | 1.5A |
| 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） |
| 其它名称： | SC196AMLDKR |
SC196A
POWER MANAGEMENT
Applications Information
SC196A Detailed Description
The SC196A is a synchronous step-down, Pulse Width
Modulated (PWM), DC-DC converter utilizing a 1MHz
? xed-frequency current mode architecture. The device
is designed to operate in a ? xed-frequency PWM mode
across the full load range and can enter Power Save Mode
(PSAVE), utilizing Pulse Frequency Modulation (PFM) at
light loads to maximize ef ? ciency.
Operation
During normal operation, the PMOS is activated on each
rising edge of the internal oscillator. Current feedback
for the switching regulator uses the PMOS current path,
and it is ampli ? ed and summed with the internal slope
compensation network. The voltage feedback loop uses
an internal feedback divider. The on-time is determined by
comparing 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/
PRELIMINARY
? Over-voltage protection
? Soft-start
Thermal Shutdown
The device has a thermal shutdown feature to protect
the SC196A if the junction temperature exceeds 145°C.
In thermal shutdown, the on-chip power devices are
disabled, tri-stating the LX output. Switching will resume
when the temperature drops by 10°C. During this time,
if the output voltage decreases by more than 60% of its
programmed value, a soft-start will be invoked.
Current Limit
The PMOS and NMOS power devices of the buck switcher
are protected by current limit functions. In the case of a
short to ground on the output, the part enters frequency
foldback mode, which causes the switching frequency to
divide by a factor determined by the output voltage. This
prevents the inductor current from "stair-casing".
PWM pin.
Over-Voltage Protection
The SC196A has an internal synchronous NMOS recti ? er
and does not require a Schottky diode on the LX pin.
Programmable Output Voltage
The SC196A has four pre-determined output voltage
values which can be individually selected by the correct
programming of the VID0 and VID1 pins (see Programmable
Output Voltage table on Page 4). This eliminates the need
for external programming resistors, saving PCB area and
inventory. The VID pins can be statically tied to GND or
VIN for ? xed output con ? gurations, or they may be driven
by a microprocessor, enabling the possibility of dynamic
voltage adjustment for host equipment "sleep" states.
Continuous Conduction & Oscillator Synchronization
The SC196A is designed to operate in continuous
conduction, ? xed-frequency mode. When the SYNC/PWM
pin is tied high, the part runs in PWM mode using 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.
When the output voltage exceeds the regulation voltage
by approximately 15% while operating in PWM mode, the
PWM drive is disabled and the LX pin is tri-stated. Once
the output voltage drops below the OVP voltage, the
device will resume PWM mode control. In PSAVE mode,
the PSAVE burst drive is disabled when the output voltage
exceeds the regulation voltage by approximately 1.5%
and the LX pin is tri-stated. The device will resume PSAVE
burst switching when the output voltage has fallen below
the regulation voltage by approximately 2%.
Soft-Start
The soft-start mode is enabled after every shutdown cycle
to limit in-rush current. In conjunction with the frequency
foldback, this controls the maximum current during start-
up. The PMOS current limit is stepped up through seven
soft-start levels to the full value by a timer driven from
the internal oscillator. During soft-start, the switching
frequency is stepped by 1/8, 1/4, and 1/2 of the internal
oscillator frequency up to the full value, under control of
three output voltage thresholds. As soon as the output
voltage is within 2% of the regulation voltage, soft-start
mode is disabled.
Protection Features
The SC196A provides the following protection features:
? Thermal shutdown
? Current limit
? 2008 Semtech Corp.
7
www.semtech.com
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相关代理商/技术参数 |
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| SC196EVB | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:1.5A Synchronous Buck Converter with Integrated Power Devices |
| SC196UL.TRT | 制造商:SEMTECH 功能描述:I.C. |
| SC196ULTRT | 功能描述:IC REG BUCK SYNC ADJ 1.5A 10MLPD 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 |
| SC197 | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:3.5MHz, 500mA Synchronous Dual Step-Down DC-DC Regulator |
| SC1972 | 制造商:MITSUBISHI 制造商全称:Mitsubishi Electric Semiconductor 功能描述:NPN EPITAXIAL PLANAR TYPE(for RF power amplifiers on VHF band Mobile radio applications) |
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