I need an H-bridge IC with these requirements
1) Shoot through current protection 2) supply > 15V 3) logic inputs Vih(min) = 2.6 or less 4) available in SM package 5) motor current > 500mA 6) Should not have external power FETs or bipolar. Thats the point of the whole searchI have been searching for a long time now and havent found anything to match my requirements.
I was looking for something similar (except I don't have requirements for the 2.6V Vih), and I was recommended the Allegro A3948 or 3949. I was primarily looking to migrate LMD1820x designs to all-SMD.
I chose the A3949, and it seems from a quick check of the datasheet that it will meet your needs. Allegro was VERY responsive, I asked for
5 samples and had them on my desk inside three days. I'm waiting for PCBs to arrive so I can test them... looks promising.The A3949 doesnt meet the Vih(min) spec for the sleep pin input. It is
2.7 V and I will control it using a Pic running on 3.3V. The PIC I/O pin can therfore go down to (Vcc-0.7) = 2.6V. Although both are worst case and it might work, I wont be comfortable with it. I might also choose not to use the Sleep feature at all, but I could find a better part, why not.And just as a side note, If some of you are looking for similar specs, I found other chips. Thes dont meet some spec or the other of mine, but might be helpful to someone else looking for H bridge ICs.
1)LMD 18200 by National 2)Si9988 by Vishay 3)TPIC0108B by Ti 4)L6201/2/3 by sgs thomson 5)TLE 5206-2 by infenion ( this one meets my specs, but its so damn hard to get hold of) 6)3953 by allergroGood point. The PIC can source around ~3 mA when high, but the 3949 take in only about 50uA. So I guess the PIC pin output will never fall as low as
2.6V and should reqmain relatively close to Vcc (3.3V). Please correct me if I am wrong.Kunal
(snip)
That voltage spec includes a specified load current. How does that specified current compare with the current needed by the A3949 for a logic high input?
-- John Popelish
I agree. The output voltage spec is a way if implying approximately the channel resistance of the pull up mosfet. A 2.6 volt output from a 3.3 volt supply while delivering 3 ma implies a channel resistance of about (3.3-2.6)/.003=233 ohms. That resistance would drop only about 12 millivolts with a 50 ua load, so you can expect a logic high of about 3.29 volts.
-- John Popelish
Hi, Could you tell where this chip is available? Its availability doesnt seem too good.
Thanks Kunal
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