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LM3914 的PDF资料 下载 ,347497K

LM3914 的货源和报价 LM3914 的相关技术信息

相关型号

LM386N LM3875 LM3886 LM3886TF LM393 LM393N LM393P LM399

LM3914 - Dot/Bar Display Driver

Features • Drives LEDs, LCDs or vacuum fluorescents • Bar or dot display mode externally selectable by user • Expandable to displays of 100 steps • Internal voltage reference from 1.2V to 12V • Operates with single supply of less than 3V • Inputs operate down to ground • Output current programmable from 2 mA to 30 mA • No multiplex switching or interaction between outputs • Input withstands ±35V without damage or false outputs • LED driver outputs are current regulated, open-collectors • Outputs can interface with TTL or CMOS logic • The internal 10-step divider is floating and can be referenced to a wide range of voltages General Description The LM3914 is a monolithic integrated circuit that senses analog voltage levels and drives 10 LEDs, providing a linear analog display. More...

Typical Application click for larger image Parametric Table     expand Parametric Table    collapse Segments 10 Temperature Min 0 deg C Temperature Max 70 deg C Segments 10 DisplayType LED View Using Catalog Typical Performance click for larger image

Also Recommended LP3944 LED controller for RGB/color/white LEDs, 12C interface Additional Resources Application Notes (see below) Block Diagram click for larger image

Package Availability, Models, Samples & Pricing

Part Number

Package

Factory Lead Time

Models

Budgetary Pricing

Std Pack Size

Package Marking Format

Type

Pins

Spec.

MSL Rating

Peak Reflow

RoHS Report

Weeks

Qty

Qty

$US each

LM3914N-1

MDIP

18

STD NOPB

1 1

NA NA

RoHS

Full production

N/A

1K+

$1.09

rail of 20

NSUZXYYTT LM3914N-1

6 weeks

2000

LM3914V

PLCC

20

STD NOPB

1 2A

220 250

RoHS

Full production

N/A

1K+

$1.63

rail of 40

NSUZXYTT LM3914V

8 weeks

2000

LM3914VX

PLCC

20

STD NOPB

1 2A

220 250

RoHS

Full production

N/A

1K+

$1.63

reel of 1000

NSUZXYTT LM3914V

8 weeks

3000

LM3914 MDC

Unpackaged Die

Full production

N/A

CALL

tray of N/A

-

General Description

The LM3914 is a monolithic integrated circuit that senses analog voltage levels and drives 10 LEDs, providing a linear analog display. A single pin changes the display from a moving dot to a bar graph. Current drive to the LEDs is regulated and programmable, eliminating the need for resistors. This feature is one that allows operation of the whole system from less than 3V.

The circuit contains its own adjustable reference and accurate 10-step voltage divider. The low-bias-current input buffer accepts signals down to ground, or V^-, yet needs no protection against inputs of 35V above or below ground. The buffer drives 10 individual comparators referenced to the precision divider. Indication non-linearity can thus be held typically to ½%, even over a wide temperature range.

Versatility was designed into the LM3914 so that controller, visual alarm, and expanded scale functions are easily added on to the display system. The circuit can drive LEDs of many colors, or low-current incandescent lamps. Many LM3914s can be "chained" to form displays of 20 to over 100 segments. Both ends of the voltage divider are externally available 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. The simplified block diagram illustrates this extremely simple external circuitry.

When in the dot mode, there is a small amount of overlap or "fade" (about 1 mV) between segments. This assures that at no time will all LEDs be "OFF", and thus any ambiguous display is avoided. Various novel displays are possible.

Much of the display flexibility derives from the fact that all outputs are individual, DC regulated currents. Various effects can be achieved by modulating these currents. The individual outputs can drive a transistor as well as a LED at the same time, so controller functions including "staging" control can be performed. The LM3914 can also act as a programmer, or sequencer.

The LM3914 is rated for operation from 0°C to +70°C. The LM3914N-1 is available in an 18-lead molded (N) package.

The following typical application illustrates adjusting of the reference to a desired value, and proper grounding for accurate operation, and avoiding oscillations.

Application Notes

Title	Size in Kbytes	Date
LB-48: Linear Brief 48 Simple Voltmeter Monitors TTL Supplies	71 Kbytes	2-Oct-02	View Online	Download	Receive via Email
AN-460: Application Note 460 LM34/LM35 Precision Monolithic Temperature Sensors	306 Kbytes	20-Sep-02	View Online	Download	Receive via Email
AN-460 (Japanese): Application Note 460 LM34/LM35 Precision Monolithic Temperature Sensors	322 Kbytes

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