• "

Ordering

1.产品概述                       2.产品特点M8U嘉泰姆
3.应用范围                       4.下载产品资料PDF文档 M8U嘉泰姆
5.产品封装图                     6.电路原理图                   M8U嘉泰姆
7.功能概述                        8.相关产品M8U嘉泰姆

七,功能概述M8U嘉泰姆

VCC and VIN Power-On-Reset (POR)M8U嘉泰姆
TThe CXSD62152/A keeps monitoring the voltage on VIN and VCC pins to prevent wrong logic operations whichM8U嘉泰姆
may occur when VIN or VCC voltage is not high enough for internal control circuitry to operate. The VCC POR ris-M8U嘉泰姆
ing threshold is 2.7V (typical) with 0.2V hysteresis and VIN POR rising threshold is 2.3V with 0.05V hysteresis.M8U嘉泰姆
During startup, the VCC and VIN voltage must exceed the POR threshold. Then the IC starts a starts-up processM8U嘉泰姆
and ramps up the output voltage to the voltage target. M8U嘉泰姆
Output Under-Voltage Protection (UVP)M8U嘉泰姆
In the operational process, if a short-circuit occurs, the output voltage will drop quickly. Before the current-limitM8U嘉泰姆
circuit responds, the output voltage will fall out of the required regulation range. The under-voltage continuallyM8U嘉泰姆
monitors the FB voltage after soft-start is completed. If a load step is strong enough to pull the output voltage lowerM8U嘉泰姆
than the under-voltage threshold, the IC shuts down converter’s output.The under-voltage threshold is 50% of theM8U嘉泰姆
nominal out put voltage. The under-voltage comparator has a built-in 3μs noise filter to prevent the chips from wrongM8U嘉泰姆
UVP shut down being caused by noise. The CXSD62152/A will be latched after under-voltage protection.M8U嘉泰姆
Over-Voltage Protection (OVP)M8U嘉泰姆
The over-voltage function monitors the output voltage by FB pin. When the FB voltage increases over 125% of theM8U嘉泰姆
reference voltage due to the high-side MOSFET failure or for other reasons, the over-voltage protection comparatorM8U嘉泰姆
will force the low-side MOSFET gate driver high till the occurence of low-side current limit. This action activelyM8U嘉泰姆
pulls down the output voltage. As soon as the output voltage is less than 0.2V, the CXSD62152/A will be latched offM8U嘉泰姆
and needs a POR or enable to recover to normal operation.M8U嘉泰姆
Over-Temperature Protection (OTP)M8U嘉泰姆
The over-temperature circuit limits the junction tempera ture of the CXSD62152/A. When the junction temperatureM8U嘉泰姆
exceeds TJ = 160oC, a thermal sensor turns off the both power MOSFETs, allowing the devices to cool.M8U嘉泰姆
The thermal sensor allows the converters to start a start up process and to regulate the output voltage again afterM8U嘉泰姆
the junction temperature cools by 50oC. The OTP is designed with a 50oC hysteresis to lower the average TJM8U嘉泰姆
during continuous thermal overload conditions, increasing lifetime of the CXSD62152/A.M8U嘉泰姆
Current-Limit Protection M8U嘉泰姆
The CXSD62152/A monitors the output current, flows through the high-side and low-side power MOSFETs, and limitsM8U嘉泰姆
the current peak at current-limit level to prevent the IC from damaging during overload, short-circuit and over-M8U嘉泰姆
voltage conditions. Typical high side power MOSFET current limit is 3A, and low side MOSFET current limit is 1.9A.M8U嘉泰姆
 Soft-StartM8U嘉泰姆
The CXSD62152/A has a built-in soft-start to control the rise rate of the output voltage and limit the input current surgeM8U嘉泰姆
during start-up. During soft-start, an internal voltage ramp connected to one of the positive inputs of the errorM8U嘉泰姆
amplifier, rises up from 0V to 0.95V to replace the reference voltage (0.8V) until the voltage ramp reaches theM8U嘉泰姆
reference voltage. During soft-start without output overvoltage, the CXSD62152/A converter¡|s sinking capability isM8U嘉泰姆
disabled until the output voltage reaches the voltage target.M8U嘉泰姆
Soft-StopM8U嘉泰姆
At the moment of shutdown controlled by EN signal, under-voltage event or over-temperature protection, theCXSD62152/A initiates a soft-stop process to discharge the output voltage in the output capacitors. Certainly, the loadM8U嘉泰姆
current also discharges the output voltage. During softstop, the internal voltage ramp (VRAMP) falls down from 0.M8U嘉泰姆
95V to 0V to replace the reference voltage. Therefore, the output voltage falls down slowly at the light load. After theM8U嘉泰姆
soft-stop interval elapses, the soft-stop process ends and the IC turns on the low-side power MOSFET.M8U嘉泰姆
八,相关产品                更多同类产品.......M8U嘉泰姆

◀ Previous:24V 3A 500kHz synchronous Buck Converter CXSD62148 CXSD62149 CXSD62150 CXSD62151 is a 2.5A synchronous buck converter with integrated low Rds(on) power MOSFETs

Back to top

Next▶:3.2A 5V 1MHz Synchronous Buck Converter CXSD62153/A is a synchronous buck converters with integrated 85mW high side and 75mW low side power MOSFETs a current-mode control sche