数据搜索系统,热门电子元器件搜索 |
|
IRF7807A 数据表(PDF) 3 Page - International Rectifier |
|
IRF7807A 数据表(HTML) 3 Page - International Rectifier |
3 / 8 page www.irf.com 3 IRF7807/IRF7807A Control FET Special attention has been given to the power losses in the switching elements of the circuit - Q1 and Q2. Power losses in the high side switch Q1, also called the Control FET, are impacted by the R ds(on) of the MOSFET, but these conduction losses are only about one half of the total losses. Power losses in the control switch Q1 are given by; P loss = Pconduction+ Pswitching+ Pdrive+ Poutput This can be expanded and approximated by; P loss = I rms 2 × R ds(on ) () + I × Q gd i g × V in × f + I × Q gs2 i g × V in × f + Q g × Vg × f () + Q oss 2 ×V in × f This simplified loss equation includes the terms Q gs2 and Q oss which are new to Power MOSFET data sheets. Q gs2 is a sub element of traditional gate-source charge that is included in all MOSFET data sheets. The impor- tance of splitting this gate-source charge into two sub elements, Q gs1 and Qgs2, can be seen from Fig 1. Q gs2 indicates the charge that must be supplied by the gate driver between the time that the threshold volt- age has been reached (t1) and the time the drain cur- rent rises to I dmax (t2) at which time the drain voltage begins to change. Minimizing Q gs2 is a critical factor in reducing switching losses in Q1. Q oss is the charge that must be supplied to the output capacitance of the MOSFET during every switching cycle. Figure 2 shows how Q oss is formed by the paral- lel combination of the voltage dependant (non-linear) capacitance’s C ds and Cdg when multiplied by the power supply input buss voltage. Figure 1: Typical MOSFET switching waveform Synchronous FET The power loss equation for Q2 is approximated by; P loss = Pconduction + Pdrive + Poutput * P loss = I rms 2 × R ds(on) () + Q g × Vg × f () + Q oss 2 ×V in × f + Q rr × Vin × f ( ) *dissipated primarily in Q1. Power MOSFET Selection for DC/DC Converters 4 1 2 Drain Current Gate Voltage Drain Voltage t3 t2 t1 V GTH t0 |
类似零件编号 - IRF7807A |
|
类似说明 - IRF7807A |
|
|
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 |