数据搜索系统,热门电子元器件搜索 |
|
LTM8055 数据表(PDF) 12 Page - Linear Technology |
|
LTM8055 数据表(HTML) 12 Page - Linear Technology |
12 / 26 page LTM8055 12 8055fb For more information www.linear.com/LTM8055 APPLICATIONS INFORMATION will source the same current to the load, assuming each LTM8055 output current sense resistor is the same value. ParalleledLTM8055sshouldnormallybeallowedtoswitch in discontinuous mode to prevent current from flowing from the output of one unit into another; that is, the MODE pin should be tied to LL. In some cases, operating the master in forced continuous (MODE open) and the slaves in discontinuous mode (MODE = LL) is desirable. If so, current from the output can flow into the master’s input. Please refer to Input Precaution in this section for a discussion of this behavior. Minimum Input Voltage and RUN The LTM8055 needs a minimum of 5V for proper opera- tion, but system parameters may dictate that the device operate only above some higher input voltage. For ex- ample, a LTM8055 may be used to produce 12VOUT, but the input power source may not be budgeted to provide enough current if the input supply voltage is below 8V. The RUN pin has a typical falling voltage threshold of 1.2V and a typical hysteresis of 25mV. In addition, the pin sinks 3µA below the RUN threshold. Based upon the above information and the circuit shown in Figure 2, the VIN rising (turn-on) threshold is: VIN = 3µA •R1 ( )+1.225V R1+R2 R2 and the VIN falling turn-off threshold is: VIN =1.2 R1+R2 R2 RUN LTM8055 VIN R1 R2 8055 F02 Figure 2. This Simple Resistor Network Sets the Minimum Operating Input Voltage Threshold with Hysteresis Figure 1. Two or More LTM8055s May Be Connected in a Master/Slave Configuration for Increased Output Current The design of a master-slave configuration is straight forward: 1. Apply the FB resistor network to the master, choosing the proper values for the desired output voltage. Sug- gested values for popular output voltages are provided in Table 1. 2. Apply a FB resistor network to the individual slaves so that the resulting output is higher than the desired output voltage. 3. Apply the appropriate output current sense resistors between VOUT and IOUT. If the same value is used for the master and slave units, they will share current equally. 4. Connect the master IOUTMON to the slaves’ CTL pin through a unity gain buffer. The unity gain buffer is requiredtoisolatetheoutputimpedanceoftheLTM8055 from the integrated pull-up on the CTL pins. 5. Tie the outputs together. Note that this configuration does not require the inputs to be tied together, making it simple to power a single heavy load from multiple input sources. Ensure that each input power source has sufficient voltage and current sourcing capability to provide the necessary power. Please refer to the Maximum Output Current vs VIN and Input Current vs Output Current curves in the Typical Performance Characteristics section for guidance. Minimum Input Voltage and SVIN The minimum input voltage of the LTM8055 is 5V, but this is only if VIN and SVIN are tied to the same voltage source. If SVIN is powered from a power source at or above 5VDC, VIN can be allowed to fall below 5V and the LTM8055 can MASTER VOUT IOUT OUTPUT CURRENT SENSE RESISTOR OUTPUT CURRENT SENSE RESISTOR UNITY GAIN BUFFER IOUTMON CTL VOUT IOUT SLAVE TO LOAD 8055 F01 |
类似零件编号 - LTM8055 |
|
类似说明 - LTM8055 |
|
|
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 |