Difference between revisions of "Meka"
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| − | *[https://ec.irf.com/v6/en/US/adirect/ir?cmd=eneNavigation&N=0+4294841672+4294873522+4294873544+4294873644+4294873516+4294873478+4294872810+4294873479+4294872808+4294873408+4294873418+4294873397+4294873562+4294873521+4294872805+4294873558+4294873486+4294873425+4294873543+4294873471+4294873489+4294872942+4294872794+4294873213+4294872978+4294873411+4294873216+4294873413+4294872662+4294872856+4294873054+4294873354+4294873584+4294873051+4294873225+4294873549+4294873020+4294873357+4294850280&Ns=rds_on__max_10v__mohms__5%7C0 IRF FETs >=75V, low Rds ON, dpak] | + | ==For larger but thermally safer design== |
| − | * [https://ec.irf.com/v6/en/US/adirect/ir?cmd=catSearchFrame&domSendTo=byID&domProductQueryName=IRLR3110ZPBF IRLR3110ZPBF top IRF choice. Available from IRF <$2/each] [http://www.irf.com/product-info/datasheets/data/irlr3110zpbf.pdf DS] | + | |
| + | *[https://ec.irf.com/v6/en/US/adirect/ir?cmd=eneNavigation&N=0+4294841672+4294873522+4294873544+4294873644+4294873516+4294873478+4294872810+4294873479+4294872808+4294873408+4294873418+4294873397+4294873562+4294873521+4294872805+4294873558+4294873486+4294873425+4294873543+4294873471+4294873489+4294872942+4294872794+4294873213+4294872978+4294873411+4294873216+4294873413+4294872662+4294872856+4294873054+4294873354+4294873584+4294873051+4294873225+4294873549+4294873020+4294873357+4294850280&Ns=rds_on__max_10v__mohms__5%7C0 IRF FETs >=75V, low Rds ON, dpak ] | ||
| + | * [https://ec.irf.com/v6/en/US/adirect/ir?cmd=catSearchFrame&domSendTo=byID&domProductQueryName=IRLR3110ZPBF IRLR3110ZPBF top IRF choice. 100V, 14mohm, 34nC, 1.05C/watt : Available from IRF <$2/each] [http://www.irf.com/product-info/datasheets/data/irlr3110zpbf.pdf DS] | ||
| + | |||
| + | |||
| + | ==For smallest design - Renesas LFPAK devices== | ||
| + | [http://america.renesas.com/ (Renesas) Enter part in search box for details] | ||
| + | |||
| + | * HAT2174H, 100V, 27mOhm, 33nC-2280 pF, 6.25C/W | ||
| + | * HAT2175H, 100V, 42mOhm, 21nC-1445 pF, 8.34C/W | ||
| + | |||
| + | *Estimated power dissipation for HAT2175H | ||
| + | Fsw (switching freq) 100kKz | ||
| + | Td (dead time) = 100nS | ||
| + | Ts (switching time) = 50nS | ||
| + | I (current) 6amps | ||
| + | Vd (diode drop) = 1.1V | ||
| + | Vsup (supply voltage) = 60V | ||
| + | R (turn on resistance) = 42mohm | ||
| + | |||
| + | Pr = I^2 * R = 1.5W | ||
| + | Pd = I * Vd * Td * f = 0.066W | ||
| + | Ps = I * Vsup/2 *Ts * f = 0.9W | ||
| + | |||
| + | Ploss = Pr + Pd + Ps = 2.5W | ||
| + | |||
| + | Temperature of junction overcase = 2.5 * 8.4 = 21C | ||
| + | |||
| + | Gate drive current : I = Q*f/t = 21nC * 100e3 = 2.1mA, 4.2mA for 2 fets (50mW) | ||
| + | |||
| + | |||
| + | *For HAT2174H | ||
| + | Ts (switching time) = 55nS | ||
| + | R (turn on resistance) = 21mohm | ||
| + | Ploss = 0.75 + 0.06 + 1.1 = 1.9W | ||
| + | |||
| + | Temperature of junction overcase = 1.9 * 6.3 = 12C | ||
| + | |||
| + | Gate drive current : I = Q*f/t = 33nC * 100e3 = 3.3mA, 6.6mA for 2 fets (80mW) | ||
| + | |||
| + | |||
| + | ==Ripple Voltage== | ||
| + | * dV = I dT / C | ||
| + | * dT = 9.5uS max at 100 KHz | ||
| + | * I = 6 amps max | ||
| + | * for C=25uF, dV = 2.3V | ||
Latest revision as of 01:32, 12 October 2007
For larger but thermally safer design
- IRF FETs >=75V, low Rds ON, dpak
- IRLR3110ZPBF top IRF choice. 100V, 14mohm, 34nC, 1.05C/watt : Available from IRF <$2/each DS
For smallest design - Renesas LFPAK devices
(Renesas) Enter part in search box for details
- HAT2174H, 100V, 27mOhm, 33nC-2280 pF, 6.25C/W
- HAT2175H, 100V, 42mOhm, 21nC-1445 pF, 8.34C/W
- Estimated power dissipation for HAT2175H
Fsw (switching freq) 100kKz Td (dead time) = 100nS Ts (switching time) = 50nS I (current) 6amps Vd (diode drop) = 1.1V Vsup (supply voltage) = 60V R (turn on resistance) = 42mohm
Pr = I^2 * R = 1.5W Pd = I * Vd * Td * f = 0.066W Ps = I * Vsup/2 *Ts * f = 0.9W
Ploss = Pr + Pd + Ps = 2.5W
Temperature of junction overcase = 2.5 * 8.4 = 21C
Gate drive current : I = Q*f/t = 21nC * 100e3 = 2.1mA, 4.2mA for 2 fets (50mW)
- For HAT2174H
Ts (switching time) = 55nS R (turn on resistance) = 21mohm Ploss = 0.75 + 0.06 + 1.1 = 1.9W
Temperature of junction overcase = 1.9 * 6.3 = 12C
Gate drive current : I = Q*f/t = 33nC * 100e3 = 3.3mA, 6.6mA for 2 fets (80mW)
Ripple Voltage
- dV = I dT / C
- dT = 9.5uS max at 100 KHz
- I = 6 amps max
- for C=25uF, dV = 2.3V
