Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: newInRobotics on November 06, 2011, 11:48:21 AM
-
Hi everyone,
I'm a bit confused on how to drive H-bridge consisting of pMOSFETS and nMOSFETS (http://www.falstad.com/circuit/#%24+1+5.0E-6+10.20027730826997+50+5.0+50%0Af+224+96+272+96+1+1.5%0Af+448+96+400+96+1+1.5%0Af+224+224+272+224+0+1.5%0Af+448+224+400+224+0+1.5%0Aw+400+80+336+80+0%0Aw+336+80+272+80+0%0Aw+400+112+400+160+0%0Aw+400+160+400+208+0%0Aw+272+112+272+160+0%0Aw+272+160+272+208+0%0Ar+288+160+384+160+0+1000.0%0Aw+384+160+400+160+0%0Aw+288+160+272+160+0%0Ax+315+185+359+190+1+20+Load%0Ad+400+112+400+80+1+0.805904783%0Ad+400+240+400+208+1+0.805904783%0Ad+272+240+272+208+1+0.805904783%0Ad+272+112+272+80+1+0.805904783%0Ar+224+96+224+48+0+10000.0%0Aw+224+48+272+48+0%0Aw+272+48+272+80+0%0Ar+448+96+448+48+0+10000.0%0Aw+448+48+400+48+0%0Aw+400+48+400+80+0%0Ar+448+224+448+272+0+10000.0%0Ar+224+224+224+272+0+10000.0%0Aw+224+272+272+272+0%0Aw+272+272+272+240+0%0Aw+448+272+400+272+0%0Aw+400+272+400+240+0%0Aw+224+96+192+96+0%0Aw+448+224+480+224+0%0Aw+400+272+336+272+0%0Aw+336+272+272+272+0%0Ag+336+272+336+288+0%0AR+336+80+336+48+0+0+40.0+12.0+0.0+0.0+0.5%0Aw+224+224+192+224+0%0Aw+448+96+480+96+0%0As+144+96+64+96+0+1+false%0AR+64+96+32+96+0+0+40.0+5.0+0.0+0.0+0.5%0Aw+480+224+480+320+0%0Aw+192+96+144+96+0%0Aw+144+96+144+304+0%0Aw+480+320+144+320+0%0Aw+144+304+144+320+0%0Ax+209+39+288+44+0+20+pMOS_1%0Ax+391+294+469+299+0+20+nMOS_2%0A) with single signal pin.
When swith breaks the circuit, pull-up resistor of pMOS_1 turns pMOS OFF, however, nMOS_2 stays ON because of voltage created by pMOS and nMOS resistors voltage divider. What should I use in order to drive such half bridge?
-
Just have another question related to MOSFET H-bridge.
If I use H-bridge like this one (http://www.falstad.com/circuit/#%24+1+5.0E-6+10.20027730826997+50+5.0+50%0Af+288+160+336+160+1+1.5%0Af+512+160+464+160+1+1.5%0Af+288+288+336+288+0+1.5%0Af+512+288+464+288+0+1.5%0Aw+464+144+400+144+0%0Aw+400+144+336+144+0%0Aw+464+176+464+224+0%0Aw+464+224+464+272+0%0Aw+336+176+336+224+0%0Aw+336+224+336+272+0%0Ar+352+224+448+224+0+1000.0%0Aw+448+224+464+224+0%0Aw+352+224+336+224+0%0Ad+464+176+464+144+1+0.805904783%0Ad+464+304+464+272+1+0.805904783%0Ad+336+304+336+272+1+0.805904783%0Ad+336+176+336+144+1+0.805904783%0Ar+288+160+288+112+0+10000.0%0Aw+288+112+336+112+0%0Aw+336+112+336+144+0%0Ar+512+160+512+112+0+10000.0%0Aw+512+112+464+112+0%0Aw+464+112+464+144+0%0Ar+512+288+512+336+0+10000.0%0Ar+288+288+288+336+0+10000.0%0Aw+288+336+336+336+0%0Aw+336+336+336+304+0%0Aw+512+336+464+336+0%0Aw+464+336+464+304+0%0Aw+512+288+544+288+0%0Aw+464+336+400+336+0%0Aw+400+336+336+336+0%0Ag+400+336+400+352+0%0AR+400+144+400+112+0+0+40.0+12.0+0.0+0.0+0.5%0Aw+288+288+256+288+0%0AR+128+176+96+176+0+0+40.0+5.0+0.0+0.0+0.5%0Aw+544+288+544+384+0%0Aw+544+384+208+384+0%0Af+560+176+512+176+0+1.5%0Af+240+176+288+176+0+1.5%0Ag+512+224+512+240+0%0Ag+288+224+288+240+0%0Aw+240+176+208+176+0%0Aw+208+176+208+384+0%0As+128+176+208+176+0+1+true%0As+128+128+208+128+0+1+true%0Aw+128+176+128+128+0%0Aw+240+288+256+288+0%0Aw+560+176+560+80+0%0Aw+560+80+240+80+0%0Aw+240+288+224+288+0%0Aw+224+288+224+128+0%0Aw+224+128+208+128+0%0Aw+224+128+224+80+0%0Aw+224+80+240+80+0%0Ar+240+176+240+224+0+10000.0%0Aw+288+192+288+224+0%0Aw+288+224+240+224+0%0Ar+560+176+560+224+0+10000.0%0Aw+560+224+512+224+0%0Aw+512+224+512+192+0%0A), would switching speed be affected by having pMOS and nMOS at the top side and nMOS only on the lower side?
-
Hi,
Any chance you could post the schematics (or whatever it is) as pics, so they're visible?
-
Hi,
Any chance you could post the schematics (or whatever it is) as pics, so they're visible?
Done. It's in previous post. Also, link in previous post should point to the circuit as well ;D
-
Hi,
Drive the P-channel MOSFETs gates to ground with NPN transistors (whose bases are driven from the same source as their respective N-channel MOSFET (with a base resistor of course and a base pull down if it's not driven actively low).