Hi all,
I need to drive with a PWM signal some led circuits (strip). The signal is generated by a microcontroller with a 20 mA maximum output current at 5 V power supply. Every led strip has a 15 Mohm input and output impedence and I observed a current lost of about 7 mA on every strip . So I want to design a little circuit for making an decoupling stage between two consecutive led strips. I thought to a voltage follower made by an op amp (e.g. MCP601 or TLV2371 or similar) for pumping to the output about 30 mA with an impedence adaption.
I have a doubt, because if I use a single power supply the maximum output voltage of the op amp stage in less than 5 V and also with a rail-to-rail behaviour I will lost gradually an amount of voltage on the PWM signal. Is it correct? And how can I solve the issue?
Thanks.
Marco
I need to drive with a PWM signal some led circuits (strip). The signal is generated by a microcontroller with a 20 mA maximum output current at 5 V power supply. Every led strip has a 15 Mohm input and output impedence and I observed a current lost of about 7 mA on every strip . So I want to design a little circuit for making an decoupling stage between two consecutive led strips. I thought to a voltage follower made by an op amp (e.g. MCP601 or TLV2371 or similar) for pumping to the output about 30 mA with an impedence adaption.
I have a doubt, because if I use a single power supply the maximum output voltage of the op amp stage in less than 5 V and also with a rail-to-rail behaviour I will lost gradually an amount of voltage on the PWM signal. Is it correct? And how can I solve the issue?
Thanks.
Marco