Difference between the ICs LM3915 and LM3916?

[loetmann]

Hello,

I've got a question  related to the ICs LM3915 and LM3916. These ICs are used for driving Dot/Bar Displays.
Inside are amoong others 10 resistors connected in series, which divide the reference voltage into 10 smaller voltages.
When I calculate the ratiosof these resistors in the LM3915 it is mostly about 1.41. But with the LM3916 this ratio varies from 0.6 to 1.26.

Can someone explain to me, why the ratios in the LM391 are selecte this way?

[Alex Eisenhut]

IIRC they are selected for logarithmic response, ie for music.

[Kjelt]

What I remember:
LM3914 linear
LM3915 logaritmic
LM3916 floating driver for fluorescent displays.
But download the datasheets and compare, should be in there.

[dannyf]

Difference between the ICs LM3915 and LM3916?

LM3916 - LM3915 = 1.

Very scientific.

[Kartika]

[Ian.M]

TLDR: The LM391x are all the same chip except for the resistors in the reference divider chain.  LM3914 has a linear divider chain, LM3915 had a 3dB/step logarithmic divider chain, and LM3916 had a logarithmic divider chain optimized for VU meters.

As all except LM3914 are discontinued, if you *MUST* use a LM391x dot/bar chip, and need a logarithmic response, and cant find an affordable and trustworthy N.O.S. supplier for LM3915 or '3916, you'll need to put a logarithmic converter (e.g. an OPAMP with a diode in its feedback loop) in front of a LM3914.

[drussell]

What I remember:
LM3914 linear
LM3915 logaritmic
LM3916 floating driver for fluorescent displays.

the '14 is linear and the '15 is logarithmic, yes, but the LM3916 is the VU meter version.

It has steps optimized in dB increments that are appropriate for an audio VU meter, -20, -10, -7, -5, -3, -1, 0, +1, +2, +3 dB.

[Kartika]

Corporation

[Kartika]

TLDR: The LM391x are all the same chip except for the resistors in the reference divider chain.  LM3914 has a linear divider chain, LM3915 had a 3dB/step logarithmic divider chain, and LM3916 had a logarithmic divider chain optimized for VU meters.

As all except LM3914 are discontinued, if you *MUST* use a LM391x dot/bar chip, and need a logarithmic response, and cant find an affordable and trustworthy N.O.S. supplier for LM3915 or '3916, you'll need to put a logarithmic converter (e.g. an OPAMP with a diode in its feedback loop) in front of a LM3914.

[Ian.M]

@Kartika: So who are you going to get your LM3915 from, and what are you going to do if it turns out to actually be a remarked LM3914?

[Jwillis]

LM3914  replaced by LM3914VX/NOPB 20PLCC . The NTE 1508 is also discontinued .
lm3915  has NTE equivalent NTE1509
Could not find an equivalent for LM3916