max1044a

[Jeff B.]

Just a few random observations about charge pumps.

The LT1054 is a great replacement for for the 1044, it accepts up to 15V for the input voltage and has a current capability of 100mA.
7660 have a maximum input voltage of 12V I think.
7661 and 7662 chips will accept up to around 20-22V at their input.

When you double the voltage you halve the current.  For example using the LT1054 as a voltage doubler reduces it's available current to 50mA.  This is important because if you're using a charge pump with a low maximum output current (MAX1044) at 18V in a circuit with a high current draw you may run into problems.

Charge pumps can be paralleled for increased current capabilities.  Using 2 LT1054 chips would give you 200mA at 9V and 100mA at 18V.  I plan to try this when I box up my Warhead Vibe build to see if it makes any difference over a single charge pump version when dialing it in.

[gtr2]

Just a few random observations about charge pumps.

The LT1054 is a great replacement for for the 1044, it accepts up to 15V for the input voltage and has a current capability of 100mA.
7660 have a maximum input voltage of 12V I think.
7661 and 7662 chips will accept up to around 20-22V at their input.

When you double the voltage you halve the current.  For example using the LT1054 as a voltage doubler reduces it's available current to 50mA.  This is important because if you're using a charge pump with a low maximum output current (MAX1044) at 18V in a circuit with a high current draw you may run into problems.

Charge pumps can be paralleled for increased current capabilities.  Using 2 LT1054 chips would give you 200mA at 9V and 100mA at 18V.  I plan to try this when I box up my Warhead Vibe build to see if it makes any difference over a single charge pump version when dialing it in.

Hmm, I neglected to see this until you mentioned it.  It makes complete sense.  At the cost of doubling V you halve the mA.  Nothing comes without a price 

Josh

[stecykmi]

Just a few random observations about charge pumps.

The LT1054 is a great replacement for for the 1044, it accepts up to 15V for the input voltage and has a current capability of 100mA.
7660 have a maximum input voltage of 12V I think.
7661 and 7662 chips will accept up to around 20-22V at their input.

When you double the voltage you halve the current.  For example using the LT1054 as a voltage doubler reduces it's available current to 50mA.  This is important because if you're using a charge pump with a low maximum output current (MAX1044) at 18V in a circuit with a high current draw you may run into problems.

Charge pumps can be paralleled for increased current capabilities.  Using 2 LT1054 chips would give you 200mA at 9V and 100mA at 18V.  I plan to try this when I box up my Warhead Vibe build to see if it makes any difference over a single charge pump version when dialing it in.

Hmm, I neglected to see this until you mentioned it.  It makes complete sense.  At the cost of doubling V you halve the mA.  Nothing comes without a price 

Josh

Actually, this is one of the few cases where you almost get something for free.

these switched capacitor charge pumps operate at very high efficiency, usually in the 90% range, greater than 95% for some operating points (but dropping to ~80% for some "worst case" scenarios). this means you're getting almost as much power out as you are putting in (easily proved with the formula for power, P(in) = IV ~= P(out) = (I/2)(2V)(n) where n is efficiency), and this is quiet rare for most energy conversion methods.

Can you imagine if your car was anywhere close to 90% efficient?

[rps-10]

I have a pedal with a suspected blown MAX1044 (Snarling Dogs Mold Spore) ...So reading this thread could I simply just drop in one of the ICs mentioned as a replacement, or would I need to check the pinouts etc?

[jkokura]

Or use a max1044. Smallbear has them.

Jacob

[shawnee]

I have a pedal with a suspected blown MAX1044 (Snarling Dogs Mold Spore) ...So reading this thread could I simply just drop in one of the ICs mentioned as a replacement, or would I need to check the pinouts etc?

You can use a TC1044 with no changes. A TC1044 may be a good choice because it can take a few more volts on the input than the MAX1044 can take. The LT1054 may require you to remove pin 1 if they have 1 and 8 shorted on the pc board (and they cost 3 times as much) so I wouldn't use one unless you needed it for a higher current draw pedal.

[rps-10]

Or use a max1044. Smallbear has them.

Jacob

Could do, but as shawnee's post below your's suggests. My thinking is why replace a fragile part with the same if I am going to take that beast apart. So I may as well go for a more reliable part of the same design to save doing it again in the future.
(I'll solder in a DIL socket too while I'm at it)