数据搜索系统,热门电子元器件搜索 |
|
LTM8049 数据表(PDF) 13 Page - Linear Technology |
|
LTM8049 数据表(HTML) 13 Page - Linear Technology |
13 / 20 page LTM8049 13 8049fa For more information www.linear.com/LTM8049 APPLICATIONS INFORMATION Frequency Foldback The frequency foldback function reduces the switching frequency for that channel when the output is about 15% below the target regulation point. This feature lowers the operatingfrequency,thuscontrollingthemaximumoutput current during start-up. When the FBX voltage is pulled above the above mentioned range in a positive output volt- age application, the switching frequency for that channel runs that the rate set by the RT resistor value. Note that the maximum output current at start-up is a function of many variables including load profile, output capacitance, target VOUT, VIN, switching frequency, so the user must evaluate the performance of the LTM8049 to ensure that it properly powers up its load. Thermal Shutdown If the part is too hot, the LTM8049 engages its thermal shutdown and terminates switching and discharges the soft-startcapacitor.Whentheparthascooled,thepartauto- maticallyrestarts.Thisthermalshutdownissettoengageat temperaturesabovethe125°Cabsolutemaximuminternal operating rating to ensure that it does not interfere with functionality in the specified operating range. This means that internal temperatures will exceed the 125°C absolute maximum rating when the overtemperature protection is active, possibly impairing the device’s reliability. PCB Layout Most of the headaches associated with PCB layout have been alleviated or even eliminated by the high level of integration of the LTM8049. The LTM8049 is neverthe- less a switching power supply, and care must be taken to minimize EMI and ensure proper operation. Even with the high level of integration, you may fail to achieve specified operation with a haphazard or poor layout. See Figure 2 for a suggested layout. Ensure that the grounding and heat-sinking are acceptable. A few rules to keep in mind are: 1. Place the RFBX and RT resistors as close as possible to their respective pins. 2. Place the CIN capacitor as close as possible to the VIN and GND connection of the LTM8049. 3. Place the COUT capacitor as close as possible to the VOUT and GND connection of the LTM8049. Figure 2. Layout Showing Suggested External Components, GND Plane and Thermal Vias 8049 F02 THERMAL/GND VIAS VIN2 VIN1 VOUT1 (POSITIVE OUTPUT) VOUT2 (NEGATIVE OUTPUT) GND GND GND GND SHARE2 SHARE1 SS1 SS2 RUN2 RUN1 SYNC1 SYNC2 RT1 RT2 PG2 PG1 FBX1 FBX2 CLKOUT1 CLKOUT2 GND CIN1 CIN2 COUT1 COUT2 |
类似零件编号 - LTM8049 |
|
类似说明 - LTM8049 |
|
|
链接网址 |
隐私政策 |
ALLDATASHEETCN.COM |
ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |