The JTM3108 is a 180 KHz fixed frequency PWM buck (step-down

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 JTM3108 is a 180 KHz fixed frequency PWM buck (step-down) DC/DC converter, capable of driving a 3.5A load with high efficiency, low ripple and excellent line and load regulation. Requiring a minimum number of external components, the regulator is simple to use and include internal frequency    compensation    and    a
fixed-frequency oscillator.
       The PWM control circuit is able to adjust the duty ratio linearly from 0 to 100%. An over current protection function is built inside.When short protection function happens, the operation frequency will be reduced from 180KHz to 48KHz. An internal compensation block is built in to minimize external component count
二.产品特点(Features)

Wide 8V to 36V Input Voltage Range
Output Adjustable from 1.25V to 32V
Maximum Duty Cycle 100%
Minimum Drop Out 0.3V
Fixed 180KHz Switching Frequency
Maximum 3.5A Switching Current
Internal Optimize Power MOSFET
High efficiency
Excellent line and load regulation
With output constant current loop
Built in thermal shutdown function
Built in current limit function
Built in output short protection function
SOP8-EP package
三,应用范围 (Applications)
Car Charger
Battery Charger
LCD Monitor and LCD TV
Portable instrument power supply
Telecom / Networking Equipment
四,产品封装图 (Package)

Pin Number	Pin Name	Description
1	NC	No Connected.
2	SW	Power Switch Output Pin (SW). SW is the switch node that supplies power to the output. (Note: Connected the back exposed PAD to SW.)
3	GND	Ground Pin. Care must be taken in layout. This pin should be placed outside of the Schottky Diode to output capacitor ground path to prevent switching current spikes from inducing voltage noise into JTM3108.
4	FB	Feedack Pin (FB). Through an external resistor divider network, FB senses the output voltage and regulates it. The feedback threshold voltage is 1.25V.
5	EN	Enable Pin. Drive EN pin low to turn off the device, drive it high to turn it on.
6	OCSET	Output Constant Current Set Pin.
7	VC	Internal Voltage Regulator Bypass Capacity. In typical system application, The VC pin connect a 1uf capacity to VIN.
8	VIN	Supply Voltage Input Pin. JTM3108 operates from a 8V to 36V DC voltage. Bypass Vin to GND with a suitably large capacitor to eliminate noise on the input.

(责任编辑：oumao18)