The JTM9284 is a step-up converter designed for driving up t

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)
The JTM9284 is a step-up converter designed for driving up to 7 series
white LEDs from a single cell Lithium lon battery . The JTM9284 uses current
mode， fixed frequency architecture to regulate an LED current. which is measured through an external current sense resistor.The JTM9284 includes
unde voltage lockout，current limiting and thermal overload protection
preventing damage in the event of an output overload.Optimized operation frequency can meet the requirement of small LC filters value and low
operation current with high efficiency. Internal soft start function can reduce the inrush current. Tiny package type provide the best solution for PCB
space saving and total BOM cost.

二.产品特点(Features)
High Efficiency: Up to 90%
1.2MHz Constant Frequency Operation
Integrated internal Power MOSFET
Drives up to 7 Series WLEDs Range
UVLO, Thermal Shutdown
Internal Current limit
Over Voltage Protection
Small LC Filter
Minimize the External Component
<1µA Shutdown Current
SOT23-6 Package

三,应用范围 (Applications)
Camera Flash White LED
Mobile Phone, Smart Phone LED Backlight
PDA LED Backlight
Digital Still Cameras
Camcorder

四.下载产品资料PDF文档

JTM9284

五,产品封装图 (Package)

Pin Name	Pin Number	Description
SW	1	Inductor Connection. Connect to the switched side of the external inductor as well as the anode of the external diode. SW is high impedance during shutdown.
GND	2	Ground Pin.
FB	3	Current-Sense Feedback Input. Connect a resistor from FB to GND to set the LED current.
EN	4	Enable and LED Brightness Control Input. Pull high to turn on IC.Drive EN with a 20kHz to 1MHz unfiltered PWM dimming signal for DC LED current that is proportional to the signal’s duty cycle.
OV	5	Over Voltage Input.The JTM9284 turn off the N-channel MOSFET when VOUT exceeds 28V .Connect OV to the output at the top of the LED string.
VIN	6	Power Supply Input. Must be closely decoupled to GND with a 1µF or greater ceramic capacitor.

六.电路原理图

七,功能概述

PARAMETER	CONDITIONS	MIN	TYP	MAX	UNIT
Operating Input Voltage		2.5		5.5	V
Under Voltage Lockout			2.2	2.45	V
Under Voltage Lockout Hysteresis			100		mV
Current (Shutdown)	V EN<0.4V		0.1	1	µA
Quiescent Current	V FB=0.15V，No switching		200	300	µA
Supply Current	V FB=0V，switching		0.6	1	mA
Regulated Feedback Voltage	JTM9284-28J	94	104	114	mV
	JTM9284AS6	94	104	114	mV
	JTM9284BS6	238	250	262	mV
	JTM9284CS6	285	300	315	mV
Switching Frequency			1.2		MHz
ON Resistance of NMOS			0.5		Ω
Peak Current Limit	V IN= 4.2V,Duty cycle=50%		1.5		A
EN Shutdown Voltage				0.4	V
EN Enable Voltage		1.5			V
EN Leakage Current			±0.01	±1.0	µA
OVP Threshold	Open LED,V OUT Rising		28		V

八,相关产品

内置MOS DC-DC 升压IC

型号	工作模式	工作	输出电压	输出电	输出电	内置MOS	效率	静态	工作频率	封装	直接替代型号
		电压范围		压形式	压精度	最大输		电流
						出电流
JTMXX1C	PFM	0.8V-Vout	2.2/2.7/2.8	固定输出	±2%	500mA	85%	4uA	350KHz	SOT-89	XC6382/XC6371/
			3.0/3.3/							SOT23-3L	RT9261B/HT77XX/
			3.6/4.0/5.0V							TO-92	BL8530/AIC1642/
											S8351
JTM1538	PWM	2.5V-6.0V	最大28V	可调输出	±2%	1.5A	90%	1uA	1.2MHz	SOT-25	AT1308/LTC1615/AP3012
	PFM										AIC1896/LM2703/ACT6311/APW7137/
											LM2731/TPS61040/MP1540/1/RT9284A/
											G5103/G5125/XC9119/AP1522/EUP2571/
JTM1548	PWM	2.5V-6.0V	最大12V	可调输出	±2%	3.5A	95%	1uA	1.2MHz	SOT-26	SY7208/SY7152/
	PFM										LTC3426/TPS6107X
JTM1548B	PWM	2.0V-24V	最大28V	可调输出	±2%	4A	97%	0.1uA	1.2MHz	SOT-26	SY7208/SY7152/
	PFM										LTC3426/TPS6107X
JTM1558	PWM	2.5V-6.5V	最大8V	可调输出	±2%	5A	93%	100uA	1.2MHz	SOT-26	SY7208/SY7152/
											LTC3426/TPS6107X
JTM1547	PWM	2.3-6V	最大14V	可调输出	±2%	4A/带限	96%	0.1uA	1.2MHz	SOT-26	FP6291
						流保护
JTM6291	PWM	2.5V-6.0V	最大12V	可调输出	±2%	2A/带限	90%	200uA	1.2MHz	SOT-26	FP6291
						流保护
JTM1534	PWM	0.9V-6.0V	1.5V-12V	可调输出	±2%	4A	90%	0.5uA	1MHz	SOT-25
	PFM
JTM1615	PWM	1.2V-15V	最大34V	可调输出	±2%	350mA	80%	1uA	1MHz	SOT-25	LTC1615/AIC1896/AP5727
											LM2703/5/AT1308/G5125/LM2731/
											TPS61040/1/G5103/MP1540/1/RT9284A
											XC9119/MP1522/AP1522/EUP2571/
JTM9266	PWM	1.0V-10V	最大12V	可调输出	±2%	2.5A	92%	70uA	450KHz	SOT-26	RT9266/PT1301/
											AX1301
JTM6293	PWM	2.6V-6.0V	最大12V	可调输出	±2%	3.5A	90%	170uA	1MHz	ESOP-8	FP6293
JTM6293B	PWM	2.5V-6.0V	最大9V	可调输出	±2%	4.5A	95%	0.1uA	1MHz	ESOP-8	FP6298/FP6293
	PFM
JTM9225	PWM	2.5V-6.5V	最大8V	可调输出	±2%	5.5A	93%	100uA	1.2MHz	ESOP-8
JTM6297	PWM	3.6V-26V	最大60V	可调输出	±2%	2A	90%	70uA	400KHz	SOP-8
JTM6298	PWM	3.6V-36V	最大60V	可调输出	±2%	3A	92%	70uA	400KHz	TO252-5L
JTM6299	PWM	5V-45V	最大60V	可调输出	±2%	5A	94%	70uA	220KHz	TO263-5L

外置MOS/扩流输出 DC-DC 升压IC

型号	工作模式	工作	输出电压	输出电	输出电	外置MOS	效率	静态	工作频率	封装	直接替代型号
		电压范围		压形式	压精度	最大输		电流
						出电流
JTM1533	PWM/PFM	0.9V-6.0V	1.5V-20V	可调输出	±2%	扩流达3A	90%	0.5uA	1MHz	SOT-25	XC9104/5/S8355/6/APW7077
											/EUP2573/SP6355
JTM1532	PWM/PFM	1.8V-6.0V	最大12V	可调输出	±2%	扩流达2A	92%	70uA	1.2MHz	SOT-25	XC9104/5/S8355/6/APW7077
											/EUP2573/SP6355
JTM9266	PWM	1V-10V	最大12V	可调输出	±2%	扩流达1.5A	92%	70uA	450KHz	SOT-26	RT9266/PT1301/AX1301
JTM5306	PWM	2.5V-100V	最大100V	可调输出	±2%	扩流0.5A	90%	220uA	1MHz	SOP-8	TAC2305
JTM3800S/T	PWM	1.8-15V		可调输出	±4%	扩流最大3A		1uA	1MHz	SOP8	MB3800/AT1380
										TSSOP8	APW7078

我司的JTMXX1CP/M SOT-89/SOT-23有以下优点：
1.输出电流最大可达500mA.
2.最低可达0.8V启动，启动电压低.
3.静态电流小，只有4uA(典型值)
4.工作频率可达350Khz(典型值)，纹波小，噪声低，对外界干扰小.
5.封装采用金线，全测产品，一致性好，品质稳定.