1、 FR8205AS6CTR（Vin:4.5V-18V,Vout:Adjustable Output Voltage Down to 0.6V，3A Output Current） Description
The FR8205 is a synchronous step-down DC/DC
converter that provides 4.5V to 18V input voltage
range and 3A continuous load current capability. At
light load condition, the FR8205 can operate at PSM
mode to support high efficiency and reduce power
loss.
The FR8205 fault protection includes cycle-by-cycle
current limit, UVLO, hiccup short circuit protection
and thermal shutdown. The internal 1ms soft-start
function prevents inrush current at turn-on. This
device uses current mode control scheme which
provides fast transient response. Internal
compensation function reduces external
compensatory components and simplifies the design
process. In shutdown mode, the supply current is
about 1μA.
The FR8205 is offered in SOT-23-6 package, which
provides good thermal conductance. Features
 Low RDS(ON) Integrated Power MOSFET
(90mΩ/50mΩ)
 Internal Compensation Function
 Wide Input Voltage Range: 4.5V to 18V
 Adjustable Output Voltage Down to 0.6V
 3A Output Current
 500kHz Switching Frequency
 Internal 1ms Soft-Start
 Cycle-by-Cycle Current Limit
 Over Temperature Protection with Auto Recovery
 Under Voltage Lockout
 Hiccup Short Circuit Protection
 SOT-23-6 Package
Applications
 STB (Set-Top-Box)
 LCD Display, TV
 Distributed Power System
 Networking, XDSL Modem 2、uP9601TSW8（输出电压5V，输出电流额定3A，输入电压8-29V，耐压极限36V） 3、RT8259GE（Vin:4.5V-24V,Vout:0.8V-15V,Output Current：1.2A,High Efficiency up to 92%）  4、RT6214A/B
General Description
The RT6214A/B is a simple, easy-to-use, 3A synchronous step-down DC-DC converter with an input supply voltage range of 4.5V to 18V. The device integrates low RDS(ON) power MOSFETs to achieve high efficiency in a SOT-23 package and build-in
accurate reference voltage (0.765V or 0.8V by product options).The RT6214A/B adopts Advanced Constant On-Time (ACOTTM) control architecture to provide an ultrafast transient response with few external components and to operate in nearly constant switching frequency over the line, load, and output voltage range. The RT6214A operates in automatic PSM that maintains high efficiency during light load operation. RT6214B operates in Forced PWM that helps meet tight voltage regulation accuracy requirements. The RT6214A/B senses both FETs current for a robust over-current protection. The device features
cycle-by-cycle current limit protection and prevent the device from the catastrophic damage in output short circuit, over current or inductor saturation. The RT6214A/B SOT-23-6 series built-in soft-start function prevents inrush current during start-up and the SOT-23-8 series offers programmable start-up by connecting a capacitor at external SS pin. The device also includes input under-voltage lockout, output under-voltage protection, and over-temperature protection (thermal shutdown) to provide safe and
smooth operation in all operating conditions. The RT6214A/B are offered in TSOT-23-6 (FC) and TSOT-23-8 (FC) package.
Features
 Input Supply Voltage Range : 4.5V to 18V
 3A Converter With Built-in 100mΩ/50mΩ Low RDS(ON) Power FETs
 Advanced Constant On-Time (ACOTTM) Control for Ultrafast Transient Response
 Fixed Switching Frequency : 500kHz (SOT23-6)or 650kHz (SOT23-8)
 Optional for Operation Modes :
 Automatically Power Saving Mode (PSM) (RT6214A)
 Forced PWM Mode (RT6214B)
 Optimized for Low-ESR Ceramic Output Capacitors
 1.5% High-Accuracy Feedback Reference Voltage
 Output Voltage Range : up to 6.5V
 Internal fixed Soft-Start (typ. 1ms) for SOT-23-6
 Externally Adjustable Soft-Start for SOT-23-8
 Monotonic Start-Up for Pre-biased Outputs
 Both HS/LS FETs Protection for Robust Over Current Protection
 Input Under-Voltage Lockout (UVLO)
 Output Under-Voltage Protection (UVP) with Hiccup Mode
 Over-Temperature Protection (OTP) (Thermal Shutdown)
 Enable Control
 Power Good Indication for SOT-23-8
 RoHS Compliant and Halogen Free
 Available in TSOT-23-6 or TSOT-23-8 Package 5、LM53603-Q1 (3A)、 LM53602-Q1 (2A)   6、TPS204xB/TPS205xB等八系列