LMH13000: Application Brief SLOA360

marcel Groccia

Part Number: LMH13000

Dear TI Engineers,

I would like to use the LMH13000 for a future project, and I am currently reviewing TI documentation.

In Application Brief SLOA360, you reference the PLT5 518FB Osram laser diode. In the Application Brief, the laser supply voltage is specified as 5 V, and the diode operating current is 85 mA. In Fig. 4 (page 4), the VLD volatage is shown as 4.83 V ( 5V- 85 mA x2 Ohms.
However, according to the PLT5 518FB datasheet Figure “VF = f(IF)” (page 8) indicates that at 85 mA, the forward voltage (VF) is at least 5.6 V.

Could you please clarify how this circuit operates under these conditions?
Is there something I might be misunderstanding?

Best regards,
Marcel

PLT5 518FB_P_EN.pdf

5 months ago

0 Shreenidhi Patil 5 months ago

TI__Expert 5516 points

Hello Marcel , i remember this laser showing very small forward drop voltage when we pulse it vs the voltage drop shown in the datasheet ( which maybe continuous current condition).

That being said LMH13000 itself supports upto 18V and if required it would be definitely okay to increase VLD to higher voltage to accommodate the forward voltage drop,

If you have a laser in your lab can you confirm the forward drop in 10ns or so pulse width vs ms/sec type of pulse width ..

0 marcel Groccia 5 months ago

Prodigy 20 points

Hello Shreenidhi,
thank you for you answer,. I will do some test with the LMH1300 EVkit.

0 Shreenidhi Patil 5 months ago in reply to marcel Groccia

TI__Expert 5516 points

Hello Marcel , were you able to get more clarity on this. i am curious to understand if there has been any miss from our end as well which i will need to rectify .

Amplifiers

Amplifiers forum

LMH13000: Application Brief SLOA360