NJ Roadmap
New Member
Hey, I'll try and keep this simple and hope that someone can help.
I'm using a PIC to drive a 12V 210mA valve (a solenoid irrigation valve if anyone's interested). The PIC is powered by a 5VDC 300mA regulated mains adaptor. Now I've planned and half-implemented a DC-DC converter for the valve, but am waiting on a 120uH inductor to complete the supporting circuit for the converter. The inductor has a 300mA rating so it should be able to drive the valve. Currently the DC-DC converter's input ends are connected to the 5V 300mA supply but ideally I'd like it to be connected to a pin on the PIC so it can be directly driven.
The DC-DC converter is a LT1173, and at the inductor and capacitor ratings for it's supporting circuit, it *should* supply 12V at 90mA minimum as quoted by the datasheet, the link to which is below:
https://www.electro-tech-online.com/custompdfs/2006/11/63348.pdf
(See page 11 for the configuration table and look under 5V to 12V at 90mA minimum output..I have used a 120uH L and 100uF C as stated in the table)
The thing I don't get is the 90mA minimum output current from the LT1173 in the 5V->12V configuration. What does that mean, and will it be able to drive a 210mA load in that configuration? Also how will a 5V 300mA supply limit the 12V output in terms of current?
And finally (yes I know this post wasn't short!) what other approach could be taken to drive a 12V 210mA load from a 5V logic supply?
Thanks in advance, I look forward to some informative replies!
I'm using a PIC to drive a 12V 210mA valve (a solenoid irrigation valve if anyone's interested). The PIC is powered by a 5VDC 300mA regulated mains adaptor. Now I've planned and half-implemented a DC-DC converter for the valve, but am waiting on a 120uH inductor to complete the supporting circuit for the converter. The inductor has a 300mA rating so it should be able to drive the valve. Currently the DC-DC converter's input ends are connected to the 5V 300mA supply but ideally I'd like it to be connected to a pin on the PIC so it can be directly driven.
The DC-DC converter is a LT1173, and at the inductor and capacitor ratings for it's supporting circuit, it *should* supply 12V at 90mA minimum as quoted by the datasheet, the link to which is below:
https://www.electro-tech-online.com/custompdfs/2006/11/63348.pdf
(See page 11 for the configuration table and look under 5V to 12V at 90mA minimum output..I have used a 120uH L and 100uF C as stated in the table)
The thing I don't get is the 90mA minimum output current from the LT1173 in the 5V->12V configuration. What does that mean, and will it be able to drive a 210mA load in that configuration? Also how will a 5V 300mA supply limit the 12V output in terms of current?
And finally (yes I know this post wasn't short!) what other approach could be taken to drive a 12V 210mA load from a 5V logic supply?
Thanks in advance, I look forward to some informative replies!