Relay driver - ULN2003?

K

kmaryan@gmail.com

Guest
I've gotten into the habbit of using the ULN 200x and 280x darlington
low side drivers for controlling relay boards. I've just noticed that
Allegro is phasing them out. I'm not sure if TI has plans for the same,
but I thought I'd take this moment to ask this group if this is the
prefered way for driving small 5V, 12V and 24V relays?

Is this the right kind of driver? Is something else more commonly used
in industry for relay boards? Should I be looking at MOS switches
maybe?

thanks,

Chris Maryan
 
On 19 Jul 2005 06:09:47 -0700, the renowned "kmaryan@gmail.com"
<kmaryan@gmail.com> wrote:

I've gotten into the habbit of using the ULN 200x and 280x darlington
low side drivers for controlling relay boards. I've just noticed that
Allegro is phasing them out. I'm not sure if TI has plans for the same,
but I thought I'd take this moment to ask this group if this is the
prefered way for driving small 5V, 12V and 24V relays?
Click to expand...
The voltage drop of a darlington is a bit much at 5V, but for 12 and
24, sure. These are still very popular parts, I wouldn't (don't) worry
about it. Allegro probably just wants to make more $1.50 parts rather
than 15-cent parts.

Is this the right kind of driver? Is something else more commonly used
in industry for relay boards? Should I be looking at MOS switches
maybe?

thanks,

Chris Maryan
Click to expand...

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
In article <1121777377.894865.75590@g44g2000cwa.googlegroups.com>,
kmaryan@gmail.com says...
I've gotten into the habbit of using the ULN 200x and 280x darlington
low side drivers for controlling relay boards. I've just noticed that
Allegro is phasing them out. I'm not sure if TI has plans for the same,
but I thought I'd take this moment to ask this group if this is the
prefered way for driving small 5V, 12V and 24V relays?

Is this the right kind of driver? Is something else more commonly used
in industry for relay boards? Should I be looking at MOS switches
maybe?

thanks,

Chris Maryan


ST still makes 'em, never even seen the Allegro version.
Click to expand...
I use them quite often for relay drivers and so on.
Perfect fit for an 8 bit port to open collector lamp or relay drive.
I don't see any reason to not use them in on future projects.

Jim
 
Is something else more commonly used
in industry for relay boards?
Click to expand...
There are a lot of "smart" low-side and a number of high-side logic
drivers which can handle a respectable amount of current, enough to
replace not only the ULN2003 but the logic driving it. For example the
TPIC6C596 which I love as an "output expander".

Sprague (oops, I mean Allegro) also sells "smart" driver chips.

I doubt that the other makers of ULN2003's (off the top of my head, TI,
Toshiba, and STMicro) will stop soon.

But I could be wrong. Nobody makes CA3046's anymore, for example...

Tim.
 
James Beck wrote...
Chris Maryan says...

I've gotten into the habbit of using the ULN 200x and 280x darlington
low side drivers for controlling relay boards. I've just noticed that
Allegro is phasing them out. I'm not sure if TI has plans for the same,
but I thought I'd take this moment to ask this group if this is the
prefered way for driving small 5V, 12V and 24V relays?

Is this the right kind of driver? Is something else more commonly used
in industry for relay boards? Should I be looking at MOS switches
maybe?

ST still makes 'em, never even seen the Allegro version.
I use them quite often for relay drivers and so on.
Perfect fit for an 8 bit port to open collector lamp or relay drive.
I don't see any reason to not use them in on future projects.

Jim
Click to expand...
What's a good octal relay driver with integral shift register
and latch? For 3.3V ("TTL-level" from 3.3V cmos) logic. My
relays draw 33mA, but that's too much for HC, etc., to drive.


--
Thanks,
- Win
 
On 19 Jul 2005 12:18:17 -0700, Winfield Hill
<Winfield_member@newsguy.com> wrote:

James Beck wrote...

Chris Maryan says...

I've gotten into the habbit of using the ULN 200x and 280x darlington
low side drivers for controlling relay boards. I've just noticed that
Allegro is phasing them out. I'm not sure if TI has plans for the same,
but I thought I'd take this moment to ask this group if this is the
prefered way for driving small 5V, 12V and 24V relays?

Is this the right kind of driver? Is something else more commonly used
in industry for relay boards? Should I be looking at MOS switches
maybe?

ST still makes 'em, never even seen the Allegro version.
I use them quite often for relay drivers and so on.
Perfect fit for an 8 bit port to open collector lamp or relay drive.
I don't see any reason to not use them in on future projects.

Jim

What's a good octal relay driver with integral shift register
and latch? For 3.3V ("TTL-level" from 3.3V cmos) logic. My
relays draw 33mA, but that's too much for HC, etc., to drive.
Click to expand...

TPIC6C596 looks interesting, but I haven't used it. We were going to,
but then cut over to bipolar-drive latching relays to zap thermal
EMFs, so we had to do something else.

But it needs 5 volts and isn't (legally) 3.3v compatible on the logic
inputs. More danged level shift issues!

John
 
On 19 Jul 2005 10:33:22 -0700, in sci.electronics.design "Tim Shoppa"
<shoppa@trailing-edge.com> wrote:

Is something else more commonly used
in industry for relay boards?

There are a lot of "smart" low-side and a number of high-side logic
drivers which can handle a respectable amount of current, enough to
replace not only the ULN2003 but the logic driving it. For example the
TPIC6C596 which I love as an "output expander".

Sprague (oops, I mean Allegro) also sells "smart" driver chips.

I doubt that the other makers of ULN2003's (off the top of my head, TI,
Toshiba, and STMicro) will stop soon.

But I could be wrong. Nobody makes CA3046's anymore, for example...

Tim.
huh?
Click to expand...
http://uk.farnell.com/jsp/endecaSearch/searchPage2.jsp?x=14&Ntt=ca3046&Nty=1&N=401&Ntk=gensearch&y=7


martin
 
On 19 Jul 2005 12:18:17 -0700, the renowned Winfield Hill
<Winfield_member@newsguy.com> wrote:

James Beck wrote...

Chris Maryan says...

I've gotten into the habbit of using the ULN 200x and 280x darlington
low side drivers for controlling relay boards. I've just noticed that
Allegro is phasing them out. I'm not sure if TI has plans for the same,
but I thought I'd take this moment to ask this group if this is the
prefered way for driving small 5V, 12V and 24V relays?

Is this the right kind of driver? Is something else more commonly used
in industry for relay boards? Should I be looking at MOS switches
maybe?

ST still makes 'em, never even seen the Allegro version.
I use them quite often for relay drivers and so on.
Perfect fit for an 8 bit port to open collector lamp or relay drive.
I don't see any reason to not use them in on future projects.

Jim

What's a good octal relay driver with integral shift register
and latch? For 3.3V ("TTL-level" from 3.3V cmos) logic. My
relays draw 33mA, but that's too much for HC, etc., to drive.
Click to expand...
Why not use a HC595 and ULN2803? Two cheap parts instead of one part,
but you don't have to worry about that 250mA+ through the ground pin.

I've used the TPIC6595 and similar (single-sourced) TI parts in
products, but the voltage doesn't quite match, as John L points out,
and they can get grumpy about layout issues. They also force the DMOS
output transistors to absorb the inductive 'kick', rather than
steering it out of a pin where you can do as you will with it.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
On 19 Jul 2005 12:18:17 -0700, Winfield Hill
<Winfield_member@newsguy.com> wrote:


What's a good octal relay driver with integral shift register
and latch? For 3.3V ("TTL-level" from 3.3V cmos) logic. My
relays draw 33mA, but that's too much for HC, etc., to drive.
Click to expand...
---
If you can stand to do a level conversion on the serial data, the data
clock, and the latch clock inputs, ( to 5V from 3.3V ) an Allegro
A6275 would work for you.

--
John Fields
Professional Circuit Designer
 
"Winfield Hill" <Winfield_member@newsguy.com> schreef in bericht
news:dbjjlp0m86@drn.newsguy.com...
What's a good octal relay driver with integral shift register
and latch? For 3.3V ("TTL-level" from 3.3V cmos) logic. My
relays draw 33mA, but that's too much for HC, etc., to drive.
Click to expand...
ST's L9822N on 4.5V, perhaps. Nah...

--
Thanks, Frank.
(remove 'q' and 'invalid' when replying by email)
 
On 19 Jul 2005 06:09:47 -0700, "kmaryan@gmail.com" <kmaryan@gmail.com> wroth:

I've gotten into the habbit of using the ULN 200x and 280x darlington
low side drivers for controlling relay boards. I've just noticed that
Allegro is phasing them out. I'm not sure if TI has plans for the same,
but I thought I'd take this moment to ask this group if this is the
prefered way for driving small 5V, 12V and 24V relays?

Is this the right kind of driver? Is something else more commonly used
in industry for relay boards? Should I be looking at MOS switches
maybe?

thanks,

Chris Maryan
Click to expand...
I've recently used a MAX7301 driving a bunch of National's DS3668 chips.
An SPI port can give you up to 28 outputs or a mix of outputs and inputs. Works
fine at either 3.3 or 5.0 volts for the logic.

Jim
 
John Larkin wrote...
Winfield Hill wrote:

What's a good octal relay driver with integral shift register
and latch? For 3.3V ("TTL-level" from 3.3V cmos) logic. My
relays draw 33mA, but that's too much for HC, etc., to drive.

TPIC6C596 looks interesting, but I haven't used it. We were going
to, but then cut over to bipolar-drive latching relays to zap thermal
EMFs, so we had to do something else.

But it needs 5 volts and isn't (legally) 3.3v compatible on the
logic inputs. More danged level shift issues!
Click to expand...
Right. Yes, but TI gives its 250mA-capability specs at 4.5V min,
yet shows curves for operation down to 3V. I'm only driving 35mA
relays, so the higher 1.8-ohm Ron isn't a problem. The $1.17 at
DigiKey doesn't look too bad either. As for Spehro's suggestion
of hc595 plus uln2803, yes the steering-diode pin has its appeal,
but at 35mA it's lessened. Plus a bad mark, the Darlington drop
puts me out of spec for the dinky struggling 5V relay.


--
Thanks,
- Win
 
Hello Martin,

But I could be wrong. Nobody makes CA3046's anymore, for example...

Tim.

huh?
http://uk.farnell.com/jsp/endecaSearch/searchPage2.jsp?x=14&Ntt=ca3046&Nty=1&N=401&Ntk=gensearch&y=7
Click to expand...
Intersil's site hung again but that didn't surprise much. Digikey says
that the last order bell had been clanging. The usual: Obsolete item.
Quantity available zilch. Call for a copy of the obituary...

Regards, Joerg

http://www.analogconsultants.com
 
Spehro Pefhany wrote:
On 19 Jul 2005 12:18:17 -0700, the renowned Winfield Hill
Winfield_member@newsguy.com> wrote:


James Beck wrote...

Chris Maryan says...

I've gotten into the habbit of using the ULN 200x and 280x darlington
low side drivers for controlling relay boards. I've just noticed that
Allegro is phasing them out. I'm not sure if TI has plans for the same,
but I thought I'd take this moment to ask this group if this is the
prefered way for driving small 5V, 12V and 24V relays?

Is this the right kind of driver? Is something else more commonly used
in industry for relay boards? Should I be looking at MOS switches
maybe?

ST still makes 'em, never even seen the Allegro version.
I use them quite often for relay drivers and so on.
Perfect fit for an 8 bit port to open collector lamp or relay drive.
I don't see any reason to not use them in on future projects.

Jim

What's a good octal relay driver with integral shift register
and latch? For 3.3V ("TTL-level" from 3.3V cmos) logic. My
relays draw 33mA, but that's too much for HC, etc., to drive.


Why not use a HC595 and ULN2803? Two cheap parts instead of one part,
but you don't have to worry about that 250mA+ through the ground pin.

I've used the TPIC6595 and similar (single-sourced) TI parts in
products, but the voltage doesn't quite match, as John L points out,
and they can get grumpy about layout issues. They also force the DMOS
output transistors to absorb the inductive 'kick', rather than
steering it out of a pin where you can do as you will with it.


Best regards,
Spehro Pefhany
Click to expand...
Hey, Spehro -

If you meant the TPIC6C595, there is also the STPIC6C595 by ST.

Just thought you'd like to know.

Cheers,
John
 
John - KD5YI wrote...
Spehro Pefhany wrote:
Winfield Hill wrote:
James Beck wrote...
Chris Maryan says...

I've gotten into the habbit of using the ULN 200x and 280x darlington
low side drivers for controlling relay boards. I've just noticed that
Allegro is phasing them out. I'm not sure if TI has plans for the same,
but I thought I'd take this moment to ask this group if this is the
prefered way for driving small 5V, 12V and 24V relays?

Is this the right kind of driver? Is something else more commonly used
in industry for relay boards? Should I be looking at MOS switches
maybe?

ST still makes 'em, never even seen the Allegro version.
I use them quite often for relay drivers and so on.
Perfect fit for an 8 bit port to open collector lamp or relay drive.
I don't see any reason to not use them in on future projects.

What's a good octal relay driver with integral shift register
and latch? For 3.3V ("TTL-level" from 3.3V cmos) logic. My
relays draw 33mA, but that's too much for HC, etc., to drive.

Why not use a HC595 and ULN2803? Two cheap parts instead of one part,
but you don't have to worry about that 250mA+ through the ground pin.

I've used the TPIC6595 and similar (single-sourced) TI parts in
products, but the voltage doesn't quite match, as John L points out,
and they can get grumpy about layout issues. They also force the DMOS
output transistors to absorb the inductive 'kick', rather than
steering it out of a pin where you can do as you will with it.

Hey, Spehro -

If you meant the TPIC6C595, there is also the STPIC6C595 by ST.
Just thought you'd like to know.
Click to expand...
Ok, I'll see your TI tpic6a595, 6b595 and 6c595, your ST 6c595,
your Allegro 6b595, your TI c6595, *ahem* <cough> and raise you
a SamHop smb6b595. Aha! Gotcha! You can fold now.


--
Thanks,
- Win
 
On Wed, 20 Jul 2005 02:06:31 GMT, the renowned John - KD5YI
<groups5munge@verizon.net> wrote:

Hey, Spehro -

If you meant the TPIC6C595, there is also the STPIC6C595 by ST.

Just thought you'd like to know.

Cheers,
John
Click to expand...
Yes, that's very interesting, thank you for the pointer, John. ST
seesm to be second-sourcing some of the TI CMOS op-amps too.

The part number I mentioned (without the C) has much lower Rds(on)
than the TPIC6C595 (and more pins-- 20 rather than 16) but that's
certainly not necessary for every application. One very nice feature
you get with the extra pins is separate power and logic grounds.

Here's an interesting application note:
http://focus.ti.com/lit/an/slpa004a/slpa004a.pdf

Definitely split the ground plane on this one. ;-)

data sheet:
http://focus.ti.com/lit/ds/symlink/tpic6595.pdf

Looks like typical Rds(on) at 3V/125°C is 3 ohms. If we can scale that
by 2:1 for worst case (??) that would only be 200mV drop at

TPIC6C595 data sheet:
http://focus.ti.com/lit/ds/symlink/tpic6c595.pdf33mA.





Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Winfield Hill <Winfield_member@newsguy.com> writes:

John - KD5YI wrote...
Spehro Pefhany wrote:
Winfield Hill wrote:
SNIP
What's a good octal relay driver with integral shift register
and latch? For 3.3V ("TTL-level" from 3.3V cmos) logic. My
relays draw 33mA, but that's too much for HC, etc., to drive.

Why not use a HC595 and ULN2803? Two cheap parts instead of one part,
but you don't have to worry about that 250mA+ through the ground pin.

I've used the TPIC6595 and similar (single-sourced) TI parts in
products, but the voltage doesn't quite match, as John L points out,
and they can get grumpy about layout issues. They also force the DMOS
output transistors to absorb the inductive 'kick', rather than
steering it out of a pin where you can do as you will with it.

Hey, Spehro -

If you meant the TPIC6C595, there is also the STPIC6C595 by ST.
Just thought you'd like to know.

Ok, I'll see your TI tpic6a595, 6b595 and 6c595, your ST 6c595,
your Allegro 6b595, your TI c6595, *ahem* <cough> and raise you
a SamHop smb6b595. Aha! Gotcha! You can fold now.
Click to expand...

Doesn't seem to have built-in diodes (to suppress the back-emf from
relay coils).

--

John Devereux
 
On 20 Jul 2005 09:41:58 +0100, the renowned John Devereux
<jdREMOVE@THISdevereux.me.uk> wrote:
Doesn't seem to have built-in diodes (to suppress the back-emf from
relay coils).
Click to expand...
They are avalanche-rated. This has advantages and disadvantages.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Spehro Pefhany wrote:
On Wed, 20 Jul 2005 02:06:31 GMT, the renowned John - KD5YI
groups5munge@verizon.net> wrote:


Hey, Spehro -

If you meant the TPIC6C595, there is also the STPIC6C595 by ST.

Just thought you'd like to know.

Cheers,
John


Yes, that's very interesting, thank you for the pointer, John. ST
seesm to be second-sourcing some of the TI CMOS op-amps too.

The part number I mentioned (without the C) has much lower Rds(on)
than the TPIC6C595 (and more pins-- 20 rather than 16) but that's
certainly not necessary for every application. One very nice feature
you get with the extra pins is separate power and logic grounds.

Here's an interesting application note:
http://focus.ti.com/lit/an/slpa004a/slpa004a.pdf

Definitely split the ground plane on this one. ;-)

data sheet:
http://focus.ti.com/lit/ds/symlink/tpic6595.pdf

Looks like typical Rds(on) at 3V/125°C is 3 ohms. If we can scale that
by 2:1 for worst case (??) that would only be 200mV drop at

TPIC6C595 data sheet:
http://focus.ti.com/lit/ds/symlink/tpic6c595.pdf33mA.





Best regards,
Spehro Pefhany
Click to expand...

Good points, Spehro. Thanks.

John
 
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