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Hi,
Seeking LED driver with following requirements:
1. I2C control
2. Analog brightness control (that needs to be completly turn off at one end)
3. LED will be 2S2P Configuration ( There will be 4 LEDs, Out of that, 2 LEDs will parallel and that 2 set will be series. Hence this setup will be having single common anode and single common cathode)
4. Maximum Current consumption is around 20mA.
5. Forward Voltage is around 6V.
6. Medical grade component
It is highly appreciated, if you guys assist me for proper component identification.
Hello Ameenu
What is the input voltage requirement here?
From your 2S2P configuration, seems only one channel is needed?
Hi Mason,
input voltage can be up to 5V (1.8 or 3.3V or 5V)
Yes, one channel is enough.
Thanks and Regards,
Ameenu
hi ameenu
We have limited backlight devices supporting input voltage low to 1.8V, only TPS61042, TPS61043, but have no I2C control. For input voltage higher, Lm36922, lm36274 can be options.
Hi Mason,
Thank you for your valuable response.
It looks like LM36922 meets our requirement. But one more concern is whether it is pure current control or not. we need pure current control.
Thanks and Regards,
Ameenu
hi ameenu
This device is pure current control, which is also known as pure analog dimming.
Hi Mason,
The total string voltage is 6V. So boost voltage will be 6.23V as per the equation which is mentioned in page 29 I hope it can boost from 5V input supply to 6.23 and there is no minimum boost voltage for this LM36922. right?
Thanks and Regards,
Ameenu
hi ameenu
for 5V input and 6.23V output, the duty cycle is roughly around 20%. I think there is no problem using LM36922.