1.产品概述                       2.产品特点Rj1嘉泰姆
3.应用范围                       4.下载产品资料PDF文档 Rj1嘉泰姆
5.产品封装图                     6.电路原理图                   Rj1嘉泰姆
7.功能概述                        8.相关产品Rj1嘉泰姆

一,产品概述(General Description)     Rj1嘉泰姆

VCC and VIN Power-On-Reset (POR)Rj1嘉泰姆
     The CXSD62154 keeps monitoring the voltage on VIN and VCC pins to preventRj1嘉泰姆
wrong logic operations which may occur when VIN or VCC voltage is not high enoughRj1嘉泰姆
for internal control circuitry to operate. The VCC POR rising threshold is 2.7V (typical)Rj1嘉泰姆
with 0.2V hysteresis and VIN POR rising threshold is 2.3V with 0.05V hysteresis.Rj1嘉泰姆
During startup, the VCC and VIN voltage must exceed the POR threshold. Then the IC starts a starts-up process and ramps up the output voltage to the voltage target. Rj1嘉泰姆
Output Under-Voltage Protection (UVP)Rj1嘉泰姆
In the operational process, if a short-circuit occurs, the output voltage will drop quickly. Before the current-limit circuit responds, the output voltage will fall out of the re-Rj1嘉泰姆
quired regulation range. The under-voltage continually monitors the FB voltage afterRj1嘉泰姆
soft-start is completed. If a load step is strong enough to pull the output voltage lowerRj1嘉泰姆
than the under-voltage threshold, the IC shuts down converter’s output.The under-voltage threshold is 50% of the nominal output voltage. The under-voltage comparator has aRj1嘉泰姆
built-in 3μs noise filter to prevent the chips from wrong UVP shutdown being caused by noise. The CXSD62154 will be latched after under-voltage protection.Rj1嘉泰姆
Over-Voltage Protection (OVP)Rj1嘉泰姆
The over-voltage function monitors the output voltage by FB pin. When the FB voltage increases over 125% of the reference voltage due to the high-side MOSFET failure orRj1嘉泰姆
for other reasons, the over-voltage protection comparator will force the low-side MOSFET gate driver high. This action actively pulls down the output voltage and eventuallyRj1嘉泰姆
attempts to blow the internal bonding wires. As soon as the output voltage is within regulation, the OVP comparator is disengaged. The chip will restore its normal operation Rj1嘉泰姆
Over-Temperature Protection (OTP)Rj1嘉泰姆
The over-temperature circuit limits the junction temperature of the CXSD62154. When the junction temperature exceeds TJ = 160 oC, a thermal sensor turns off the both power MOSFETs, allowing the devices to cool.The thermal sensor allows the converters toRj1嘉泰姆
start a startup process and to regulate the output voltage again after the junction temperature cools by 50oC. The OTP is designed with a 50 oC hysteresis to lower the average TJduring continuous thermal overload conditions, increasing lifetime of the CXSD62154. Rj1嘉泰姆
Current-Limit Protection Rj1嘉泰姆
The CXSD62154 monitors the output current, flows through the high-side and low-sideRj1嘉泰姆
power MOSFETs, and limits the current peak at current-limit level to prevent the ICRj1嘉泰姆
from damaging during overload, short-circuit and overvoltage conditions. Typical highRj1嘉泰姆
side power MOSFET current limit is 6A, and low side MOSFET current limit is 1.9A.Rj1嘉泰姆
Soft-StartRj1嘉泰姆
The CXSD62154 has a built-in soft-start to control the rise rate of the output voltage andRj1嘉泰姆
limit the input current surge during start-up. During soft-start, an internal voltage rampRj1嘉泰姆
connected to one of the positive inputs of the error amplifier, rises up from 0V to 0.95V to replace the reference voltage (0.8V) until the voltage ramp reaches the reference voltage. During soft-start without output overvoltage, the CXSD62154 converter’s sinking capability is disabled until the output voltage reaches the voltage target.Rj1嘉泰姆
Soft-StopRj1嘉泰姆
At the moment of shutdown controlled by EN signal, under-voltage event or overtemperature protection, the CXSD62154 initiates a soft-stop process to discharge the output voltage in the output capacitors. Certainly, the load current also discharges the output voltage. During soft-Rj1嘉泰姆
stop, the internal voltage ramp (VRAMP) falls down from 0.95V to 0V to replace the eference voltage. Therefore, the output voltage falls down slowly at the light load. After theRj1嘉泰姆
soft-stop interval elapses, the soft-stop process ends and the IC turns on the low-side power MOSFET.Rj1嘉泰姆
Enable and ShutdownRj1嘉泰姆
Driving EN to ground places the CXSD62154 in shutdown.In shutdown mode, the internal power MOSFETs turns off, all internal circuitry shuts down and the quiescent supply current reduces to less than 20μA.Rj1嘉泰姆
Power Good IndicatorRj1嘉泰姆
POK is actively held low in shutdown and soft-start status.In the soft-start process, the POK is an open-drain. Whenthe soft-start is finished, the POK is released. In normaloperation, the POK window is from 87.5% to 112.5% of the converter reference voltage. When the output voltage has to stay within this window, POK signal will become high after 0.5ms internal delay. When the output voltage outruns 82.55% or 117.5% of the target voltage, POK sig-Rj1嘉泰姆
nal will be pulled low immediately. In order to prevent false POK drop, capacitors need to parallel at the output to confine the voltage deviation with severe load step transient.Rj1嘉泰姆
二.产品特点(Features)Rj1嘉泰姆

High Efficiency up to 94%Rj1嘉泰姆
- Automatic Skip/PWM Mode OperationRj1嘉泰姆
Adjustable Output Voltage from 0.8V to V INRj1嘉泰姆
Operating from 2.9 to 6V SupplyRj1嘉泰姆
Integrated 85mΩ High Side / 75mΩ Low SideRj1嘉泰姆
MOSFETsRj1嘉泰姆
Low Dropout Operation: 100% Duty CycleRj1嘉泰姆
Stable with Low ESR Ceramic CapacitorsRj1嘉泰姆
Current up to 4ARj1嘉泰姆
Power-On-Reset Detection on VCC and VINRj1嘉泰姆
Integrate Soft-Start and Soft-StopRj1嘉泰姆
Over-Temperature ProtectionRj1嘉泰姆
Over-Voltage ProtectionRj1嘉泰姆
Under-Voltage ProtectionRj1嘉泰姆
High/ Low Side Current LimitRj1嘉泰姆
Power Good IndicationRj1嘉泰姆
Enable/Shutdown FunctionRj1嘉泰姆
Available in SOP-8P and TDFN3x3-10 PackagesRj1嘉泰姆
Lead Free and Green Devices AvailableRj1嘉泰姆
(RoHS Compliant)Rj1嘉泰姆
三,应用范围 (Applications)Rj1嘉泰姆

 Notebook Computer & UMPCRj1嘉泰姆
·  LCD Monitor/TVRj1嘉泰姆
·  Set-Top Box
DSL, Switch HUBrRj1嘉泰姆
Portable InstrumentRj1嘉泰姆
四.下载产品资料PDF文档 Rj1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！Rj1嘉泰姆

 Rj1嘉泰姆

五,产品封装图 (Package)Rj1嘉泰姆

Rj1嘉泰姆
六.电路原理图Rj1嘉泰姆

Rj1嘉泰姆
七,功能概述Rj1嘉泰姆

CXSD62154 is a synchronous buck converters with integrated 85m Ω high side and 75m Ω low side powerRj1嘉泰姆
MOSFETs. The CXSD62154 with a current-mode control scheme can convert wide input voltage of 2.9V to 6V toRj1嘉泰姆
the output voltage adjustable from 0.8V to 6V to provide excellent output voltage regulation.Rj1嘉泰姆
The CXSD62154 is equipped with an automatic Skip/PWM mode operation. At light load , the IC operates in the SkipRj1嘉泰姆
mode to reduce the switching losses. At heavy load, the IC works in PWM mode. The CXSD62154 is also equipped with Power-on-reset, soft start, soft-stop, and whole protections (under-voltage,over-voltage, over-temperature and current-limit) into a single package.This device, available in SOP-8P and TDFN3x3-10Rj1嘉泰姆
packages, provides a very compact system solution external components and PCB area.Rj1嘉泰姆
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