The JTM3349 is a step-up DC/DC converter with a constant cur

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

一,产品概述(General Description)
        The JTM3349 is a step-up DC/DC converter with a constant current to drive white LEDs or similar.
       The device can drive up to eight LEDs in seriesfrom a Li-Ion cell. The LED current is set by theexternal resistor (RSET) and is directly regulated by the feedback (FB) voltage (typ: 200 mV) across the external resistor RSET.To ensure maximum safety during operation, the
output has integrated overvoltage protection thatprevents damage to the device in case of some fault conditions. The OVP voltage can be programmed by two external resistors.
      The JTM3349 is available in a tiny DFN3*3-8L package.

二.产品特点(Features)
Input voltage range: 2.2 to 6V
Programmable LED Current
Drives LEDs Up to 27V
Switching Frequency：up to 800KHz
Programmable Overvoltage Protection
Tiny DFN3*3-8L Package

三,应用范围 (Applications)
PDA
Cellular Phones
Handheld Devices
MP3 Players
GPS Receivers

四,产品封装图 (Package)

PIN	NAME	DESCRIPTION
1	OVP	Overvoltage protection Pin
2	VIN	Input Supply Pin
3,4,9	SW	Switch Output Pin
5,6	GND	Ground
7	FB	Feedback Pin
8	EN	ON/OFF Control （High Enable）

五,电路原理图

六.产品PDF文档

JTM3349

七,功能概述
Operation
The JTM3349 operates in a constant frequency, current mode like a standard boost converter but regulates the voltage across the external resistor (RSET) instead of the output voltage. This gives an accurate regulated LED current independent of the input voltage and number of LEDs connected. With integrated overvoltage protection (OVP), the JTM3349 is configured as a current source with overvoltage protection ideally suited to drive LEDs. The device can drive up to eight serial LEDs with the internal switch.

LED Current Control

The LED current is controlled by the feedback resistor (RSET). The feedback reference is 200mV. TheLED current is 200mV/ RSET. In order to have accurate LED current, precision resistors are preferred(1% is recommended).

Dimming Control

With the PWM signal applied to the FB pin, the JTM3349 is turned on or off by the PWM signal. The LEDs operate at either zero or full current. The average LED current increases proportionally with the duty cycle of the PWM signal. A 0% duty cycle will turn off the JTM3349 and corresponds to zero LED current. A 100% duty cycle corresponds to full current. The typical frequency range of the PWM signal is

八,相关产品

LED台灯驱动IC
LED台灯驱动IC
型号	输入电压	驱动电流	工作效率	关机电流	采样阀值	调光功能	保护功能	封装	替代型号
JTM9921	20V-400V	20mA		0.35mA				SOT-89	HV9921
JTM9922	20V-400V	50mA		0.35mA				SOT-89	HV9922
JTM9923	20V-400V	30mA		0.35mA				SOT-89	HV9923
JTM9927	6V-500V	20-50mA			0.6V			TO-252	BJ1218
JTM225	2.0V-5.5V			3uA		LED台灯		SOP8
						带无级调光/
						分段调光

LED路灯驱动IC
LED路灯驱动IC
型号	输入电压	驱动电流	工作效率	关机电流	采样阀值	调光功能	保护功能	封装	替代型号
JTM5305	3.6V-100V	扩流最大2A	95%	1mA	0.25V	PWM调光	欠压/过温/	SOP8	TAC5305
JTM5305	3.6V-100V	扩流最大2A	95%	1mA	0.25V	PWM调光	过流/短路保护	SOP8	TAC5305

我司的JTM9910有以下优点：

1.宽电压工作（8V-600V）
2.低功耗（600mW）高效率（90%以上）
3.高耐压（600V）
4.宽驱动能力（几ma-1A）
5.欠压、过温、过流、短路保护
6.关断时间自动调整
7.支持线性调光和pwm脉宽调光
8.调节CS电阻可以调节输出电流，调小电阻值可以调大输出电流。
9.调节RT电阻可以调节输出功率，调小电阻值可以调大输出功率。
10.工业级工作温度:-40°C---+85°C
11.可以提供非隔离方式LED日光灯/球泡灯驱动的整套方案。


隆压型LED射灯驱动IC

型号	工作电压范围	输出电流	输出电	线性	效率	工作频率	调光功能	封装	替代型号
型号	工作电压范围	输出电流	流精度	调整率	效率	工作频率	调光功能	封装	替代型号
JTM4115	6.0V-40V	1.2A	3%	1.50%	98%	1MHz(max)	PWM调光	SOT89-5	PT4115/PAM2861/SN3350/CL6808
JTM4115ES	6.0V-40V	1.2A	3%	1.50%	98%	1MHz(max)	PWM调光	ESOP8	PT4115/PAM2861/2/PT4205
JTM4115MR	6.0V-40V	1.2A	3%	1.50%	98%	1MHz(max)	PWM调光	SOT-26	ZXLD1350/ZXLD1360/PT4211
JTM2806	2.0V-6.5V	800mA	10.00%	0.45%	92%	1.4 MHz	PWM调光	SOT-25	PAM2804
JTM1350	5.5V-36V	2.5A	1%		96%	1MHz	PWM调光	SOT-26
JTM9911	2.5V-100V	2.5A	1%		90%	1MHz	PWM调光	SOT-26	MH6206
JTM6103	6.0V-100V	3A	3%		95%	200KHz	PWM调光	SOT-26
JTM4101	8V-45V	3A	3%		95%	220KHz		ESOP8
JTM4103	8V-40V	4A	3%		95%	220KHz	PWM调光	TO252-5L
JTM4105	8V-40V	5A	3%		95%	220KHz		TO263-5L
JTM3106	5.0V-36V	1.5A	2%		96%	380KHz	PWM调光	SOP-8
JTM3101	4.5V-45V	2A	2%		83%	150KHz	PWM调光	ESOP8
JTM3102	8V-45V	3A	2%		89%	150KHz		ESOP8
JTM3109	8V-40V	3A	2%		89%	180KHz		SOP8
JTM3108	8V-40V	3.5A	2%		87%	180KHz	PWM调光	ESOP8
JTM3112	8V-40V	2A	2%		89%	110KHz		SOP8
JTM3113B	7V-40V	2.5A	2%		89%	250KHz		ESOP8
JTM3115	8V-40V	5A	2%		86%	150KHz		TO263-5L

升压型LED射灯驱动IC

型号	工作电压范围	输出电流	输出	线性	效率	工作频率	调光功能	封装	替代型号
型号	工作电压范围	输出电流	电流精度	调整率	效率	工作频率	调光功能	封装	替代型号
JTM2803	0.9V-6.0V	1A	-	-	90%	1.0 MHz	PWM调光	SOT-26	PAM2803
JTM5663	3V-24V	内置2A MOS	2%	-	90%	1.2MHz	PWM调光	SOT-26	SY7200/1
JTM9293C	2.5V-5.5V	内置2A MOS	2%	-	90%	1.2MHz	PWM调光	SOT-26
JTM6281	3.6V-26V	2A	2%		92%	400KHz	PWM调光	SOP-8
JTM6283	3.6V-26V	2A	2%		92%	400KHz	PWM调光	SOP-8
JTM6283B	5V-45V	2A	2%		93%	400KHz	PWM调光	SOP-8
JTM6285	3.6V-36V	4A	2%		94%	180KHz	PWM调光	TO252-5L
JTM6286	5.0V-36V	5A	2%		94%	180KHz	PWM调光	TO252-5L

升降压型LED射灯驱动IC

型号	工作电压范围	输出电流	输出	效率	工作频率	调光功能	封装	替代型号
型号	工作电压范围	输出电流	电流精度	效率	工作频率	调光功能	封装	替代型号
JTM3441	2.2V-5.0V	0.7A	3%	95%	1.15MKHz	PWM调光	MSOP-10	LTC3454
JTM6281	3.6V-26V	2A	2%	92%	400KHz	PWM调光	SOP-8
JTM6283	3.6V-26V	2A	2%	92%	400KHz	PWM调光	SOP-8
JTM6283B	5V-45V	2A	2%	93%	400KHz	PWM调光	SOP-8
JTM6285	3.6V-36V	4A	2%	94%	180KHz	PWM调光	TO-252-5L
JTM6286	5.0V-36V	5A	2%	94%	180KHz	PWM调光	TO-252-5L


型号	工作电压	恒流值	工作电流	压差	工作结温	封装	直接替换
JTM71XX	2.7-7V	260/280/300/320/350mA	90uA	130mV	-125	SOT-89	QX7135-XX
JTM7136	2.7-18V/输入端可接高压	10mA-扩流2.5A	80uA	50mV	-165	SOT-89-5	QX7136
JTM7137	2.7-5.5V/输入端可接400V高压	扩流100mA-3A	26uA	150mV	-105	SOT-25
JTM7138	3.0-6.0V/输入端可接400V高压	扩流20mA-3A	85uA	250mV	-20-85	SOT-25
JTM7139	2.8-6.5V	30mA--1.5A	175uA	350mV	45	SOP-8


型号	工作电压	输出电流	开关频率	启动电压	封装	替代型号
JTM6203B	0.9V-1.5V	60mA		0.9V	SOT-23	QX5231
JTM6004	1.8V-3.2V	280mA	900KHz	1.8V	SOT-23	兼容QX5237
JTM6205	1.0V-1.5V	130mA	600KHz	1.0V	SOT-89
JTM6002A	1.0V-3.3V	500mA	350KHz	1.0V	SOT-89	兼容QX5235
JTM5103	2.1V-6.0V	扩流3A		2.1V	SOT-25
JTM6105	2.1V-6.0V	2A		2.1V	SOP-8
JTM6106	2.8V-6.0V	1.5A可调		2.8V	SOP-8

型号	工作电压范围	输出电流	输出电流精度	效率	工作频率	封装
JTM9801	12V--80V	0.5A	2%	97%	80KHz	SOP-8
JTM9803	24V--80V	0.5A	2%	96%	80KHz	SOP-8
JTM9805	24V--100V	0.5A	2%	95%	127KHz	SOP-8
JTM9804	24V--80V	1A	2%	96%	70KHz	TO252-5L
JTM9802	12V--80V	1A	2%	98%	80KHz	TO263-5L

(责任编辑：oumao18)