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目录R8b嘉泰姆

1.产品概述                       2.产品特点R8b嘉泰姆
3.应用范围                       4.下载产品资料PDF文档 R8b嘉泰姆
5.产品封装图                     6.电路原理图                   R8b嘉泰姆
7.功能概述                        8.相关产品R8b嘉泰姆

一,产品概述(General Description)         R8b嘉泰姆

      The CXSU63139 is a synchronous rectifier, fixed switching frequency (1.2MHz typical), andR8b嘉泰姆
current-mode step-up regulator. The device allows use of small inductors and output capacitors for USB devices. The current-mode control scheme provides fast transient response and good output voltage accuracy.At light loads, the CXSU63139 will automatically enter in Pulse Frequency Modulation (PFM) operation to reduce the dominant switching losses. During PFM operation,the IC consumes very low quiescent current and maintains high efficiency over the complete load range.R8b嘉泰姆
      The CXSU63139 also includes current-limit and over-temperature shutdown to prevent damageR8b嘉泰姆
in the event of an output overload.R8b嘉泰姆
      The CXSU63139 is available in 4mmx4mm TQFN4x4-16 and DFN3x3-12 packages.R8b嘉泰姆
二.产品特点(Features)R8b嘉泰姆

1.)92% Effiicency Synchronous Boost Converter With 1000-mA Output Current FromR8b嘉泰姆
      1.8V InputR8b嘉泰姆
2.)Stable with Low ESR Output CapacitorsR8b嘉泰姆
3.)Fixed 1.2MHz Oscillator FrequencyR8b嘉泰姆
4.)Low EMI Converter (Integrated Anti-Ringing Function)R8b嘉泰姆
5.)Low Battery OutputR8b嘉泰姆
6.)Integrated Power Save Mode Operation to Improve Light Load EfficiencyR8b嘉泰姆
7.)Load Disconnected During ShutdownR8b嘉泰姆
8.)Output Current-Limit ProtectionR8b嘉泰姆
9.)Over Temperature ProtectionR8b嘉泰姆
10.)Under Voltage ProtectionR8b嘉泰姆
11.)Enable/Shutdown FunctionR8b嘉泰姆
12.)Available in TQFN4x4-16 and DFN3x3-12 PackagesR8b嘉泰姆
13.)Lead Free and Green Devices Available (RoHS Compliant)R8b嘉泰姆
三,应用范围 (Applications)R8b嘉泰姆

Power BankR8b嘉泰姆
TabletR8b嘉泰姆
Portable EquimentR8b嘉泰姆
四.下载产品资料PDF文档 R8b嘉泰姆

需要详细的PDF规格书请扫一扫微信联系我们，还可以获得免费样品以及技术支持！R8b嘉泰姆

 R8b嘉泰姆

五,产品封装图 (Package)R8b嘉泰姆

R8b嘉泰姆

六.电路原理图R8b嘉泰姆

R8b嘉泰姆

七,功能概述R8b嘉泰姆

Main Control LoopR8b嘉泰姆

The CXSU63139 is a constant frequency, synchronous rectifier, and current-mode switching regulator. R8b嘉泰姆

In normal operation, the internal N-channel power MOSFET is turned on each cycle when the oscillatorR8b嘉泰姆

 sets an internal RS latch and turned off when an internal comparator (ICMP) resets the latch. The peakR8b嘉泰姆

 inductor current which ICMP resets the RS latch is controlled by the voltage on the COMP node, which R8b嘉泰姆

is the output of the error amplifier (EAMP). An external resistive divider connected between VOUT and R8b嘉泰姆

ground allows the EAMP to receive an output feedback voltage VFB at FB pin. When the load current R8b嘉泰姆

increases, it causes a slightly decrease in VFB relative to the 0.5V reference, which in turn causes theR8b嘉泰姆

 COMP volt- age to increase until the average inductor current matches the new load current.R8b嘉泰姆
 Start-upR8b嘉泰姆
A start-up oscillator circuit is integrated in the CXSU63139.When the device enables, the circuit pumpsR8b嘉泰姆

 the output voltage high. Once the output voltage reaches 1.6V (typ),the main DC-DC circuitry turns onR8b嘉泰姆

 and boosts the output voltage to the final regulation voltage. R8b嘉泰姆
Automatic PFM/PWM mode SwitchR8b嘉泰姆
The CXSU63139 is a fixed frequency PWM peak current modulation control step-up converter. At lightR8b嘉泰姆

 loads, theCXSU63139 will automatically enter in pulse frequency modulation operation to reduce the R8b嘉泰姆

dominant switching losses. In PFM operation, the inductor current may reach zero or reverse on eachR8b嘉泰姆

 pulse. A zero current comparator turns off the P-channel synchronous MOSFET, forcing DCM(DiscontinuousR8b嘉泰姆

 Current Mode) operation at light load.These controls get very low quiescent current, help to maintain R8b嘉泰姆

high efficiency over the complete load range. R8b嘉泰姆
Synchronous RectificationR8b嘉泰姆
The internal synchronous rectifier eliminates the need for an external Schottky diode, thus reducing costR8b嘉泰姆

 and board space. During the cycle off-time, the P-FET turns on and shunts the FET body diode. As a R8b嘉泰姆

result, the syn-chronous rectifier significantly improves efficiency with-out the addition of an externalR8b嘉泰姆

 component. Conversion efficiency can be as high as 92%.R8b嘉泰姆
Load DisconnectR8b嘉泰姆
Driving EN to ground places the CXSU63139 in shutdown mode. When in shutdown, the internal powerR8b嘉泰姆

 MOSFET turns off, all internal circuitry shuts down and the quies-cent supply current reduces to 1μAR8b嘉泰姆

 maximum.A special circuit is applied to disconnect the load from the input during shutdown the R8b嘉泰姆

converter. In conventional syn-chronous rectifier circuits, the back-gate diode of the high-side P-FET R8b嘉泰姆

is forward biased in shutdown and allows current flowing from the battery to the output. However,thisR8b嘉泰姆

 device uses a special circuit, which takes the cath-ode of the back-gate diode of the high-side P-FETR8b嘉泰姆

 and disconnects it from the source when the regulator is shutdown. The benefit of this feature for R8b嘉泰姆

the system de-sign engineer is that the battery is not depleted during shutdown of the converter.  R8b嘉泰姆

No additional componentsmust be added to the design to make sure that the bat-tery is disconnectedR8b嘉泰姆

 from the output of the converter. R8b嘉泰姆
Current-Limit ProtectionR8b嘉泰姆
The CXSU63139 monitors the inductor current, flowing through the N-FET, and  limits the current R8b嘉泰姆

peak at current-limit level to prevent loads and the CXSU63139 from dam-ages during overloadR8b嘉泰姆

 conditions.R8b嘉泰姆
Over-Temperature Protection (OTP)R8b嘉泰姆
The over-temperature circuit limits the junction tempera-ture of the CXSU63139. When the junctionR8b嘉泰姆

 temperature ex-ceeds 150oC, a thermal sensor turns off the both N-FETand P-FET, allowing the R8b嘉泰姆

devices to cool. The thermal sensor allows the converters to start a soft-start process and regulateR8b嘉泰姆

 the output voltage again after the junction temperature cools by 30oC. The OTP is designed with R8b嘉泰姆

a 30oC hysteresis to lower the average Junction Tempera-ture (TJ) during continuous thermal overload conditions,increasing the lifetime of the device.R8b嘉泰姆

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