See all 'Engineer In Wonderland' postsHave you ever had the feeling that you are the first person ever to want a certain building block?
There are a lot of different half-bridge mosfet drivers in the world, but almost all are designed to drive two n-mosfets.
This means that the top mosfet's gate drive comes from a bootstrap circuit, which in turn means the half-bridge can never operate at 100% duty cycle.
I want 0-100% to build a bit of test gear, and so have been hunting for a half-bridge driver that will drive a p-channel mosfet at the top, and an n-channel below - at voltages from 4 to 20V, from a logic input.
The answer doesn't even have to be combined p and n drivers as I have a microcontroller that can separately time the n and p control signals.
Note:
Anyone know any chips, or a discrete circuit, that hits the spot?
'Alice'
Please respond below, or email alice@electronicsweekly.com
Note:
- The Linear Tech LTC1693 (pictured) nearly perfect, but only works up to 13.2V.
- The Nat Semi LM5111-4 is close, but tops out at 14V.
- The Zetex ZXGD3002 works up to 20V, but needs an input signal up to Vcc.
Anyone know any chips, or a discrete circuit, that hits the spot?
'Alice'
Please respond below, or email alice@electronicsweekly.com
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Comments (1)
I have the same problem, but it is worse for me as my requirement is a high side driver on a 28V automotive system and I need something that will stand at least 62V.
Currently looking at the TLE6282G, it is a dual half bridge driver, but at least all the sections can be used independently. This chip uses bootstrap when switching and a charge pump for DC.
Most bootstrap circuits can be made to work up to 99% DC.
Regards, Jeremy
Posted by Jeremy | December 3, 2008 3:38 PM
Posted on December 3, 2008 15:38