lm3914-mdc National Semiconductor Corporation, lm3914-mdc Datasheet
lm3914-mdc
Related parts for lm3914-mdc
lm3914-mdc Summary of contents
Page 1
... Both ends of the voltage divider are externally avail- able so that 2 drivers can be made into a zero-center meter. The LM3914 is very easy to apply as an analog meter circuit. A 1.2V full-scale meter requires only 1 resistor and a single 3V to 15V supply in addition to the 10 display LEDs. If the 1 resistor is a pot, it becomes the LED brightness control ...
Page 2
Typical Applications Note: Grounding method is typical of all uses. The 2.2µF tantalum or 10 µF aluminum electrolytic capacitor is needed if leads to the LED supply are 6" or longer. www.national.com Bar Graph Meter 2 00797001 ...
Page 3
Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Power Dissipation (Note 6) Molded DIP (N) Supply Voltage Voltage on Output Drivers Input Signal Overvoltage (Note 4) Divider ...
Page 4
... Note 5: Bar mode results when pin 9 is within 20mV of V output current) is disabled if pin 9 is pulled 0.9V or more below V Note 6: The maximum junction temperature of the LM3914 is 100˚C. Devices must be derated for operation at elevated temperatures. Junction to ambient thermal resistance is 55˚C/W for the molded DIP (N package). ...
Page 5
Typical Performance Characteristics Supply Current vs Temperature Reference Voltage vs Temperature LED Current-Regulation Dropout Operating Input Bias Current vs Temperature 00797002 Reference Adjust Pin Current vs Temperature 00797021 LED Driver Saturation 00797023 5 00797020 00797022 Voltage 00797024 www.national.com ...
Page 6
Typical Performance Characteristics Input Current Beyond Signal Range (Pin 5) LED Driver Current Regulation Common-Mode Limits www.national.com (Continued) LED Current vs Reference Loading 00797025 Total Divider Resistance vs Temperature 00797027 Output Characteristics 00797029 6 00797026 00797028 00797030 ...
Page 7
Block Diagram (Showing Simplest Application) 7 00797003 www.national.com ...
Page 8
... Continue connecting pin 9 of lower input drivers to pin 1 of higher input drivers for 30, 40, or more LED displays. The last LM3914 driver in the chain will have pin 9 wired to pin 11. All previous drivers should have a 20k resistor in parallel with LED No. 9 (pin Mode Pin Functional Description This pin actually performs two functions ...
Page 9
... LM3914, LED No off. Pin 9 of LM3914 No. 1 thus sees effectively an open circuit so the chip is in dot mode. As soon as the input voltage reaches the thresh- old of LED No. 11, pin 9 of LM3914 No pulled an LED drop (1.5V or more) below V . This condition is sensed by ...
Page 10
Typical Applications www.national.com Zero-Center Meter, 20-Segment 10 00797007 ...
Page 11
Typical Applications (Continued) *This application illustrates that the LED supply needs practically no filtering Calibration: With a precision meter between pins 4 and 6 adjust R1 for voltage V The adjustments are non-interacting. Expanded Scale Meter, Dot or Bar of ...
Page 12
Typical Applications LEDs light up as illustrated with the upper lit LED indicating the actual input voltage. The display appears to increase resolution and provides an analog indication of overrange. Indicator and Alarm, Full-Scale Changes Display from Dot to Bar ...
Page 13
Typical Applications (Continued) Full-scale causes the full bar display to flash. If the junction of R1 and C1 is connected to a different LED cathode, the display will flash when that LED lights, and at any higher input signal. Adding ...
Page 14
... Operating with a High Voltage Supply (Dot Mode Only) The LED currents are approximately 10mA, and the LM3914 outputs operate in saturation for minimum dissipation. *This point is partially regulated and decreases in voltage with temperature. Voltage requirements of the LM3914 also decrease with temperature. www.national.com ...
Page 15
... Programs LEDs to 10mA Application Hints Three of the most commonly needed precautions for using the LM3914 are shown in the first typical application drawing showing a 0V–5V bar graph meter. The most difficult prob- lem occurs when large LED currents are being drawn, espe- cially in bar graph mode ...
Page 16
... To do this, adjust R2 first, so that the voltage across R5 is exactly 1V. Then the voltages across R3 and R4 can be independently adjusted by shunting each with selected resistors of 6kΩ or higher resistance. This is possible be- cause the reference of LM3914 No acting as a constant current source. www.national.com Non-Interacting Adjustments For Expanded Scale Meter (4 ...
Page 17
Application Hints (Continued) Non-Interacting Adjustments for Expanded Scale Meter (4.5V to 5V, Bar or Dot Mode) Adjusting Linearity of Several Stacked Dividers Other Applications • “Slow” — fade bar or dot display (doubles resolution) • 20-step meter with single pot ...
Page 18
... Connection Diagrams www.national.com Plastic Chip Carrier Package Top View Order Number LM3914V See NS Package Number V20A Dual-in-Line Package Top View Order Number LM3914N-1 See NS Package Number NA18A Order Number LM3914N * See NS Package Number N18A * Discontinued, Life Time Buy date 12/20/99 18 00797018 00797019 ...
Page 19
... LM3914 MDC MWC Dot/Bar Display Driver Die/Wafer Characteristics Fabrication Attributes Physical Die Identification Die Step Physical Attributes Wafer Diameter Dise Size (Drawn) Thickness Min Pitch Special Assembly Requirements: Note: Actual die size is rounded to the nearest micron. (Referenced to die center, coordinates in µ Connection, N.U. = Not Used ...
Page 20
Die/Wafer Characteristics LED NO.5 18 LED NO.4 19 LED NO.3 20 LED NO U.S.A Tel #: Fax: IN EUROPE Tel: Fax: IN ASIA PACIFIC Tel: IN JAPAN Tel: www.national.com (Continued) -320 1154 105 -526 1154 105 -1086 1086 ...
Page 21
... Standard Lead Finish: 200 microinches /5.08 micrometer minimum lead/tin 37/63 or 15/85 on alloy 42 or equivalent or copper 2. Reference JEDEC registration MS-001, Variation AC, dated May 1993. Dual-In-Line Package (N) Order Number LM3914N-1 NS Package Number NA18A Plastic Chip Carrier Package (V) Order Number LM3914V NS Package Number V20A 21 www.national.com ...
Page 22
... Deutsch Tel: +49 (0) 69 9508 6208 English www.national.com Français Tel: +33 ( 8790 Dual-In-Line Package (N) Order Number LM3914N * NS Package Number N18A * Discontinued, Life Time Buy date 12/20/ critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system affect its safety or effectiveness ...