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Greetings,
I am developing a minimal component count and board size power board, (that needs to be mounted by hand soldering
)
The board receives 12 Volts 2 A as input; this power feeds +/- 10 Volts analog circuitry and +5 Volts and +3,3 Volts digital ones.
As requirement the circuit needs to avoid usage of inductors or large switching converters; due to this the transition to +10 Volts is performed via a 7810 (around 600 - 700 mA are expected); the 10 Volts line feeds a 7805 (250 mA aprox.) and the 7805 feeds another 1117-33 (around 150 - 200 mA aprox.)
The -10 Volts are provided by LT1054, working as a voltage inverter, providing -12 Volts to a 7910 regulator. But a LT1054 is a 100 mA output only component, and probably 130 to 150 mA would be needed. If your pulls out 100 mA from a LT1054, the LT1054 output voltage drops near the 7910 input threshold (11.5 Volts, experimentally detected value).
I tested a simple parallel fashion for the LT1054, such the parallel connection if you are using a more common 7660; but if I place two of these LT1054 in a parallel way (equal to the parallel way of a 7660) one of the LT1054 blowns out. I am using the LT1054 due to I found these at a very low price (less than 0.1$ per DIP8 unit), and it can deal with a Vin of +12 Volts.
How these LT1054 needs to be connected in a parallel fashion?
Are there another cheap inverter charge pumps capable of deal with +12 Volts input thath provide 100+ mA as output?
Thanks for your attention,
I am developing a minimal component count and board size power board, (that needs to be mounted by hand soldering
)The board receives 12 Volts 2 A as input; this power feeds +/- 10 Volts analog circuitry and +5 Volts and +3,3 Volts digital ones.
As requirement the circuit needs to avoid usage of inductors or large switching converters; due to this the transition to +10 Volts is performed via a 7810 (around 600 - 700 mA are expected); the 10 Volts line feeds a 7805 (250 mA aprox.) and the 7805 feeds another 1117-33 (around 150 - 200 mA aprox.)
The -10 Volts are provided by LT1054, working as a voltage inverter, providing -12 Volts to a 7910 regulator. But a LT1054 is a 100 mA output only component, and probably 130 to 150 mA would be needed. If your pulls out 100 mA from a LT1054, the LT1054 output voltage drops near the 7910 input threshold (11.5 Volts, experimentally detected value).
I tested a simple parallel fashion for the LT1054, such the parallel connection if you are using a more common 7660; but if I place two of these LT1054 in a parallel way (equal to the parallel way of a 7660) one of the LT1054 blowns out. I am using the LT1054 due to I found these at a very low price (less than 0.1$ per DIP8 unit), and it can deal with a Vin of +12 Volts.
How these LT1054 needs to be connected in a parallel fashion?
Are there another cheap inverter charge pumps capable of deal with +12 Volts input thath provide 100+ mA as output?
Thanks for your attention,
