ULN2003A internal register

hisakichi kobayashi

Other Parts Discussed in Thread: ULN2003A

Hi all,

Although the data-sheet of ULN2003A was read and it was worrisome,
Would you teach the individual variation of internal resistance,
and temperature characteristics?
Example:
R1:2.7komega±30% (300 ppm)
R2:7.2komega±30% (300 ppm)
R3:3.0komega±30% (300 ppm)

Best Rerds,
Hisa Kobayashi.

over 12 years ago

0 Ron Michallick over 12 years ago

TI__Guru**** 170716 points

Hisakichi-san,

The resistors are expected to be +/-15% and +1500ppm/C.
The variances affect all three resistors the same.
For example; If one resistor is +5% then all three will be +5%.

I can check to see if ULN2003A meet your needs.
What is application's input VIL and VIH?
What is application's maximum output current?
How many channels turned on at same time?
What is value of load power supply voltage?

0 hisakichi kobayashi over 12 years ago in reply to Ron Michallick

Intellectual 950 points

Hi Ronald-san,

The input of application is 3.75V.
The maximum output current of application is 400 mA.
The number of channels of application is two.
A temperature span is set to -20C ~ 70C.

Regerds
Hisa kobayashi

0 hisakichi kobayashi over 12 years ago in reply to hisakichi kobayashi

Intellectual 950 points

Hi Ronaid-san,

It is additional information.
As for load power service voltage, 14V is the maximum voltage.
The load minimum is 33.7ohms.

Best Regerds,
Hisa Kobayashi.

0 Ron Michallick over 12 years ago in reply to hisakichi kobayashi

TI__Guru**** 170716 points

Hisakichi-san,

3.75V input is more than enough drive to ensure a saturated driver. No problems here.
The only concern to check is internal die heating.

I suggest using three channels for one load and three or four channels for the second load.
At 14V and 33.7 ohms, max current per channel is (14V-1V)/33.7 ohms / 3 = 129mA

Using "D" SOIC package TJA = 73C/W, TA=70C, TJ[max] = 125C and typical 125C performance, gives a maximum current per channel (6 channels active) of 159mA.

Using "PW" TSSOP package TJA = 108C/W, TA=70C, TJ[max] = 125C and typical 125C performance, gives a maximum current per channel (6 channels active) of 118mA.

Therefore, I recommend the "D" package ("NS" and "N" are also acceptable)
The "PW" will typically run above 125C at worst load and highest TA.

The ULN2003 can run up to Tj=150C, but will have better long term reliability when 125C or less.

0 hisakichi kobayashi over 12 years ago in reply to Ron Michallick

Intellectual 950 points

Hi Ron.

Thank you for the best reply.
For the time being, It proposes making three channels into one.

Regards,
Hisa Kobayashi.

Interface

Interface forum

ULN2003A internal register