The JTM1538 uses a fixed frequency, peak current mode boost

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 JTM1538 is a constant frequency, 5-pin TSOT23 current mode step-up converter intended for small,low power applications. The JTM1538 switches at 1.2MHz and allows the use of tiny, low cost capacitors and i nductors 2mm or less in height.Internal soft-start results in small inrush current and extends battery life. The JTM1538 operates from an input voltage as low as 2.5V and can generate 28V at up to 100mA from a 5V supply.
     The JTM1538 features automatic shifting to pulse frequency modulation mode at light loads. The JTM1538 includes under-voltage lockout, current limiting, and thermal overload protection to prevent damage in the event of an output overload. The JTM1538 is available in a small 5-pin TSOT-23 package.

二.产品特点(Features)
Integrated 0.5Ω Power MOSFET
· 40μA Quiescent Current
· 2.5V to 5.5V Input Voltage
· 1.2MHz Fixed Switching Frequency
· Internal 1.5A Switch Current Limit
· Adjustable Output Voltage
· Internal Compensation
· Up to 28V Output Voltage
· Automatic Pulse Frequency Modulation
   Mode at Light Loads
· Over 85% Efficiency
· Available in a 5-Pin TSOT23-5 Package

三,应用范围 (Applications)
OLED Biasing
· LCD Bias Supply
· White LED Driver
· PDAs
· Digital Still Cameras

四,产品封装图 (Package)

五,电路原理图

PIN	NAME	FUNCTION
1	SW	Power Switch Output. SW is the drain of the internal MOSFET switch. Connect the power inductor and output rectifier to SW. SW can swing between GND and 28V.
2	GND	Ground Pin
3	FB	Feedback Input. The FB voltage is 1.25V. Connect a resistor divider to FB.
4	EN	Regulator On/Off Control Input. A high input at EN turns on the converter, and a low input turns it off. When not used, connect EN to the input supply for automatic startup.
5	IN	Input Supply Pin. Must be locally bypassed.

(责任编辑：oumao18)