Current Mirror Led Driver
Current Mirror Led Driver. Simplified diagram of max1916 led current mirrors. Also if any led fails short circuit, then the currents are still equally balanced.
I out is given by: A plurality of semiconductor circuits configured to generate an output current based on a reference current; Your 24v supply is only 1.2a, 6 of the led at 3.7v each is 22.2v, it won't work even if you don't use a current mirror.
The Current Mirror Comprises Q 4 Through Q 7 With Connected Bases And Emitters, And The Collector Current Of Q 3 Is The Control Output (Figure 1).
The current mirror will take up more voltage. As noted, the ideal current source in spice will output 0.75a no matter what, unlike a real current source. Whether for lighting up lcds in pdas, cell phones or remote controls, the luminescence of the wled makes the lcd displays bright and pleasant to the human eye.
Currently, I Have One Meanwell Led Driver Of 27V, 2300Ma On Hand And Will Be Running 2 Strings Of 6 Leds In Parallel.
A current mirror also helps protect against led failures. I had a pm asking how to adapt this current mirror to run 2 led strings in parallel from one of the 1.3a max output meanwell drivers. My understanding is if you give 24v input, it can only provide up to 21v of output.
Current Mismatch Between Outputs In The Max1916 Is 5% Maximum And The Mirror Constant Is 230A/A ±10%.
The voltage drops across r1 and r2 are equal, halving the led driver current. Also if any led fails short circuit, then the currents are still equally balanced. Where gm and ro are the transconductance and output resistance ofthe transistor, respectively [8].
You Might Still Be Able To Use My Circuit.
Posted wednesday, february 22, 2012. In tests using recom’s 700ma led driver and two strings of 350ma osram leds, the currents flowing through the two strings were matched to an accuracy of about 87% over the entire input voltage range of the driver from 16vdc to 36vdc. And a control module configured to alternately and continuously.
However, If Any Led Fails Open Circuit In The Second String, Then The.
Cascode current mirror, the output headroom requirement is 2vds sat and the output impedance is gmr; If any led in the first string fails open circuit, then the second string is protected (the reference current is zero, so the current in the other strings falls also to zero). The cm driver has been recommended to be
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