CXLE8854B宽输入电压高效率的CC和CV降压DC/DC变换器在CV（恒定输出电压）模式或CC（恒定输出电流）模式低纹波功率高效率和良好的暂态特性PWM控制电路能使占空比线性化为0～90%

CXLE8854B是一种宽输入电压、高效率的CC和CV降压DC/DC变换器，工作在CV（恒定输出电压）模式或CC（恒定输出电流）模式下。
CXLE8854B具有低纹波功率、高效率和良好的暂态特性，PWM控制电路能使占空比线性化为0～90%。过电流保护和短路保护功能是建立在外部，它可以设置一个电阻。外部补偿很容易使系统稳定；可以使用低ESR输出电容。通过添加内部N通道功率MOS、线圈、电容器和外部连接的二极管，这些ic可以用作降压开关稳压器。
当与SOP-8L和SOP-8L-EP封装结合使用时，它们是便携式设备的理想电源单元，具有低电流消耗等突出特点。由于这种转换器可以容纳高达40V的输入电压，因此也适合通过交流适配器进行操作
输入电压：7V至40V
高CC精度±5%
高CV精度±2%
占空比：0%到90%的脉宽调制控制
振荡频率：
120K赫兹
B为250kHz
热关机功能。
短路保护（SCP）。
内置SW N通道MOS。
电流型非同步PWM变换器
循环限流
外部电流限制设置。
欠压锁定。
过电压保护。

目录

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

一,产品概述(General Description)         

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    CXLE8854B is a wide input voltage, high efficiency CC and CV step-down DC/DC converter that operates in either CV (Constant Output Voltage) mode or CC (Constant Output Current) mode.
   CXLE8854B provides low-ripple power, high efficiency, and excellent transient characteristics.The PWM control circuit is able to the duty ratio linearly forms 0 up to 90%. An over current protection and short circuit protection functions are built outside that it can set by a resistance. An external compensation is easily to system stable;the low ESR output capacitor can be used.With the addition of an internal N-channel Power MOS, a coil, capacitors, and a diode connected externally, these ICs can function as step-down switching regulators.

    They serve as ideal power supply units for portable devices when coupled with the SOP-8L and SOP-8L-EP packages, providing such outstanding features as low current consumption. Since this converter can accommodate an input oltage up to 40V, it isalso suitable for the operation via an AC adapter
二.产品特点(Features)

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 Perfect Solution for Car Charger
Input Voltage：7V to 40V
High CC accuracy ±5%
High CV accuracy ±2%
Duty ratio：0% to 90% PWM control
Oscillation frequency：
120K Hz for  A
250K Hz for       B
Thermal Shutdown function.
Short Circuit Protect (SCP).
Built-in internal SW N-channel MOS.
Current mode non-synchronous PWM converter
Cycle to cycle Current Limiting
External current limit setting.
Under Voltage Lockout.
Over Voltage Protection.
三,应用范围 (Applications)

四.下载产品资料PDF文档

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 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！

 

 五,产品封装图 (Package)

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PIN	NAME	DISCRIPTION
1	BOOT	Power to the internal high-side MOSFET gate driver. Connect a 10~100nF capacitor from BS pin to SW pin
2	SW	Power Switching Output to External Inductor
3	ISEN	Current Sense Input
4	VOUT	Output of DC/DC Converter, Connect To The Anodes Of Output Capacitor
5	VFB	The Feedback Of Output Voltage, Connect To The Divider Resistor
6	COMP	Error Amplifier Output. This pin is used to compensate the Converter.
7	VIN	Power Supply Input. Bypass this pin with a 10μF ceramic capacitor to GND, placed as close to the IC as possible.
8	GND	Ground

六.电路原理图

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七,功能概述

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As seen in Functional Block Diagram, the CXLE8854B is a peak current mode pulse width modulation
(PWM) converter with CC and CV control. The converter operates as follows:
A switching cycle starts when the rising edge of the Oscillator clock output causes the

High-Side Power Switch to turn on. With the SW side of the inductor now connected to Sense1, the inductor current ramps up to store energy in the magnetic field. The inductor current level is measured by the Current Sense Amplifier and added to the Oscillator ramp signal. If the resulting summation is higherthan the COMP voltage, the output of the PWM Comparator goes high. When this happens or when Oscillator clock output goes low, the High-Side Power Switch turns off.
At this point, the SW side of the inductor swings to a diode voltage below ground, causing the
inductor current to decrease and magnetic energy to be transferred to output. This state continues untilthe cycle starts again. The High-Side Power Switch is driven by logic using BS as the positive rail. This pin is charged to VSW + 5V when the Low-Side Power Switch turns on. The COMP voltage is the integration of the error between FB input and the internal 1V reference. If FB is lower than the reference voltage, COMP tends to go higher to increase current to the output. Output current will increase until it reaches the CC limit set by the R1 resistor. At this point, the device will transition from regulating output voltage to regulating output current, and the output voltage will drop with increasing load.
The Oscillator normally switches at 200KHz. However, if FB voltage is less than 0.45V, then the
switching frequency decreases until it reaches a typical value of 30KHz at VFB = 0.15V
八,相关产品                 更多同类产品......

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降压型LED射灯驱动IC
型号	工作电压范围	输出电流	输出电 流精度	线性调 整率	效率	工作频率	调光功能	封装
CXLE8835ES	6V-40V	1.2A	3%	1.50%	98%	1MHz(max)	PWM调光	ESOP8
CXLE8835MR	6V-40V	1.2A	3%	1.50%	98%	1MHz(max)	PWM调光	SOT-26
CXLE8836	6V-60V	1.2A	2%		94%	1.1MHz	PWM/模拟 调光	SOT-89-5
CXLE8837	2V-6.5V	0.95A	10%	0.45%	92%	1.4 MHz	PWM调光	SOT-25
CXLE8838	2.5V-5.5V	0.7A	3%		93%	1.4MHz	PWM调光	SOT-25
CXLE8839	5.5V-36V	扩流2.5A	1%		96%	1MHz	PWM调光	SOT-26
CXLE8840	4V--28V	扩流25W	1%		96%	2MHz	PWM/模拟 调光	SOT-26
CXLE8841	2.5V-100V	扩流2.5A	1%		90%	1MHz	PWM调光	SOT-26
CXLE8842	5-100V	1.5A	1%		92%	1MHz	PWM/模拟 调光	ESOP8
CXLE8843	5-100V	2.5A	1%		92%	1MHz	PWM/模拟 调光	ESOP8
CXLE8844	6V-100V	扩流3A	3%		95%	200KHz	PWM调光	SOT-26
CXLE8845	8V-45V	3A	3%		95%	220KHz		ESOP8
CXLE8846	8V-40V	4A	3%		95%	220KHz	PWM调光	TO252-5L
CXLE8847	8V-40V	5A	3%		95%	220KHz		TO263-5L
CXLE8848	5V-36V	1.5A	2%		96%	380KHz	PWM调光	SOP-8
CXLE8849	4.5V-45V	2A	2%		83%	150KHz	PWM调光	ESOP8
CXLE8850	8V-45V	3A	2%		89%	150KHz		ESOP8
CXLE8851	8V-40V	3A	2%		89%	180KHz		SOP8
CXLE8852	8V-40V	3.5A	2%		87%	180KHz	PWM调光	ESOP8
CXLE8853	8V-40V	2A	2%		89%	110KHz		SOP8
CXLE8854B	7V-40V	2.5A	2%		89%	250KHz		ESOP8
CXLE8855	8V-40V	5A	2%		86%	150KHz		TO263-5L
CXLE8835	6V-40V	1.2A	3%	1.50%	98%	1MHz(max)	PWM调光	SOT89-5
CXLE8835B	6V-34V	1.0A	5%	1.50%	97%	1MHz(max)	PWM/模拟 调光	SOT89-5