Selected language     English  ▼

LM334M Datasheet(PDF) 7 Page - Texas Instruments

Click here to check the latest version.
Part No. LM334M
Description  LM134/LM234/LM334 3-Terminal Adjustable Current Sources
Download  25 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  TI1 [Texas Instruments]

 7 page
background image
LM134, LM234, LM334
SNVS746C – MAY 2004 – REVISED MARCH 2005
Figure 14. Gain Adjustment
This property of the LM134 is illustrated in the accompanying graph. Line abc is the sensor current before
trimming. Line a
′b′c′ is the desired output. A gain trim done at T2 will move the output from b to b′ and will
simultaneously correct the slope so that the output at T1 and T3 will be correct. This gain trim can be done on
RSET or on the load resistor used to terminate the LM134. Slope error after trim will normally be less than ±1%.
To maintain this accuracy, however, a low temperature coefficient resistor must be used for RSET.
A 33 ppm/°C drift of RSET will give a 1% slope error because the resistor will normally see about the same
temperature variations as the LM134. Separating RSET from the LM134 requires 3 wires and has lead resistance
problems, so is not normally recommended. Metal film resistors with less than 20 ppm/°C drift are readily
available. Wire wound resistors may also be used where best stability is required.
Application as a Zero Temperature Coefficent Current Source
Adding a diode and a resistor to the standard LM134 configuration can cancel the temperature-dependent
characteristic of the LM134. The circuit shown in Figure 15 balances the positive tempco of the LM134 (about
+0.23 mV/°C) with the negative tempco of a forward-biased silicon diode (about
−2.5 mV/°C).
Figure 15. Zero Tempco Current Source
The set current (ISET) is the sum of I1 and I2, each contributing approximately 50% of the set current, and IBIAS.
IBIAS is usually included in the I1 term by increasing the VR value used for calculations by 5.9%. (See
Copyright © 2004–2005, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: LM134 LM234 LM334

Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25 

Datasheet Download

Link URL

Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Bookmark   |   Link Exchange   |   Manufacturer List
All Rights Reserved© 2003 - 2017    

Mirror Sites
English :  ,  |   Chinese :  |   German :  |   Japanese :  |   Russian :
Korean :   |   Spanish :  |   French :  |   Italian :  |   Portuguese :  |   Polish :