Are there any decent generic H bridge chips? - Page 1
Forum section: electronics / beginners

author: Infraviolet
author_rank: Super Contributor
timestamp: October 05, 2023, 09:36:46 pm
content: I've been looking in to H bridges to drive brushed DC motors.I've used various types before, TB6612 for example which worked well for the applications I used it for, but went looking today for cheap single motor options with minimal internal voltage drops, so most of the supply voltage makes it to the motor even at 5V supply voltages. Low drops in this regard being like in the TB6612 and not like in the L293.I haven't any spare TB6612s lying around, and for when driving only one motor is needed, but the peak current can be a bit higher than the TB6612 is rated for, wondered if there might well be a cheaper more easily available option (unless something has changed recently the TB6612 is a serious chip crisis case, none in stock anywhere and lead times of years).I saw some options, but wondered if there are any "generic" ones? Chips for this which aren't coming from just one manufacturer for which supply might run out at a moment's notice. I think the L293D is like that, several places make it, but it is a dreadful chip due to all those voltage drops.Failing that, any cross-compatible chips? That is to say where two manufacturers make an h-bridge chip with pretty similar performance specs and with the same arrangement of pin layout? So you could literally solder either in to the same spot on a PCB, so long as the application could work with both the option with slightly higher or slightly lower performance?I also wondered about a pair of half bridge chips to do this, whether there was a generic equivalent of the BTS7960? I note the chip is no longer in production, Infineon brand successors to it seel for about £5 each, and yet somehow there are loads of BTS7960 pre-made boards available for £2 for a board with two such chips. Have BTS7960 clones started being made? Those boards are seemingly pretty good value, but I'm interested here in buying the chips for soldering on to custom boards designed with a form factor in mind far smaller than those pre-made boards. Just to note, I know the BTS7960 is rated for well in excess of the currents I need, I'm looking more around 2 Amps maximum.P.S. I'm ideally after surface mountable types with sideways leads (no dependence on underside inaccessible pads, no QFN, LGA...), pitch preferably 1.27mm, but larger or smaller are fineThanks

author: cortex_m0
author_rank: Regular Contributor
timestamp: October 05, 2023, 11:43:04 pm
content: This is only incidental to your question, but Toshiba TB6612FNB is in ready stock at many distributors.Top of my head, I do not know of H-bridge drivers like this with second sources.

author: Nominal Animal
author_rank: Super Contributor
timestamp: October 06, 2023, 01:06:21 am
content: I don't know of any multiple source options either. There are some TI chips that might be interesting, though.TI DRV8838is designed to be used with brushed DC motors at 0-11 V, with just 0.28Ω on-resistance.TI DRV8835is similar with two motors. These are found in many Arduino brushed DC motor controllers, for example byPololu.WhileTI DRV8833is commonly used (2.7-10.8 V), as its dual outputs can be paralleled for high-current one brushed DC motor (up to 3A RMS for the DRV8833PWP with 0.2Ω on-resistance when paralleled), but it is/will be replaced with DRV8411. See e.g.Adafruit DRV8833 break-out board.TI DRV8411is quite new, but well stocked at Mouser and Digikey as of October 2023; DRV8411PWPR is HTSSOP-16 (0.65mm pitch, does have a thermal pad underneath). It is for 1.65-11V brushed DC motors (two brushed DC motors or one bipolar stepper per chip), with typical 0.4Ω on-resistance and up to 4A peak current (so motor current is limited by chip temperature and cooling), and current limiting set by an external resistor (per DC motor; 0.2 V sense voltage). For example, with 2Ω resistor, you can limit the stall current of a brushed DC motor to 1A. The outputs can be paralleled for higher sustained current (up to 3A, I guess) halving the on-resistance. With sufficient cooling, and paralleling the outputs (using one chip to drive one brushed DC motor), about 100%×(1-0.2Ω/R) of the power goes to the DC motor with coil resistanceR.

author: meshtron
author_rank: Regular Contributor
timestamp: October 06, 2023, 03:22:45 am
content: I am using the DRV814X series from TI and they are nice little chips.

author: tszaboo
author_rank: Super Contributor
timestamp: October 06, 2023, 07:41:40 am
content: Quote from: Nominal Animal on October 06, 2023, 01:06:21 amThese ones and the DRV8837 for example are easy to replace. All the SO8 package ones, with power pad. They are available from Allegro, sometimes ST and a lot of Chinese suppliers. They are footprint compatible and the internals look the same. For low voltage ones, the SOT23 packages are the choice.

author: Infraviolet
author_rank: Super Contributor
timestamp: October 06, 2023, 09:12:52 pm
content: Most of TI's DRV8*** drivers are pin compatible then? Not as good as multiple separate manufacturers, but if mutiple models from the same have the same pinout that's a good insurance against suddenly being unable to get any chip that fits.Anyone know more about half-bridge IC options though?

author: tszaboo
author_rank: Super Contributor
timestamp: October 06, 2023, 09:31:33 pm
content: Quote from: Infraviolet on October 06, 2023, 09:12:52 pmCompare the Allegro A4950 to the TI DRV8231 for example. Then search around on LCSC website. You will find a bunch of drivers that will have the exact same pinout and characteristics. Sometimes even the type number is almost the same.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: October 06, 2023, 10:53:26 pm
content: Don't be afraid of QFN. They might be easier than leaded packages. Make you pads a bit longer than they need to be so you can brush an iron over them. It's impossible for the leads to cross over two pads since they do not exist.