LM2907 - Frequency to Voltage Converter

Datasheet	Packaging	Samples & Pricing	Reliability	Application Notes	Knowledge Base

Features

•	Ground referenced tachometer input interfaces directly with variable reluctance magnetic pickups
•	Op amp/comparator has floating transistor output
•	50 mA sink or source to operate relays, solenoids, meters, or LEDs
•	Frequency doubling for low ripple
•	Tachometer has built-in hysteresis with either differential input or ground referenced input
•	Built-in zener on LM2917
•	±0.3% linearity typical
•	Ground referenced tachometer is fully protected from damage due to swings above V_CC and below ground

General Description

Applications

•	Over/under speed sensing
•	Frequency to voltage conversion (tachometer)
•	Speedometers
•	Breaker point dwell meters
•	Hand-held tachometer
•	Speed governors
•	Cruise control
•	Automotive door lock control
•	Clutch control
•	Horn control
•	Touch or sound switches

Typical Application

click for larger image

Parametric Table expand

Parametric Table collapse

Function Frequency to Voltage

Temperature Min -40 deg C

Temperature Max 85 deg C

Function Frequency to Voltage

View Using Catalog

Typical Performance

click for larger image

Additional Resources

Application Notes (see below)

Connection Diagram

*click for larger image

LM2907 8-Pin Package

*click for larger image

LM2907N 14-Pin Package

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM2907/LM2917 Frequency to Voltage Converter	542 Kbytes	9-Dec-08	Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.

Package Availability, Models, Samples & Pricing

Part Number

Package

Factory Lead Time

Models

Samples &
Electronic
Orders

Budgetary Pricing

Std
Pack
Size

Package
Marking
Format

Type

Pins

Spec.

MSL
Rating

Peak
Reflow

RoHS
Report

CAD
Symbols

Weeks

Qty

$US each

LM2907M-8

SOIC NARROW

STD

NOPB

235

260

RoHS

N/A

Full production

N/A

1K+

$0.70

rail
of
95

NSZXTT
LM29
07M-8

6 weeks

1000

LM2907MX-8

SOIC NARROW

NOPB

260

RoHS

N/A

Full production

N/A

1K+

$0.70

reel
of
2500

NSZXTT
LM29
07M-8

8 weeks

5000

LM2907M

SOIC NARROW

STD

NOPB

235

260

RoHS

N/A

Full production

N/A

1K+

$0.70

rail
of
55

NSUZXYTT
LM2907M

6 weeks

2000

LM2907MX

SOIC NARROW

STD

NOPB

235

260

RoHS

N/A

Full production

N/A

1K+

$0.70

reel
of
2500

NSUZXYTT
LM2907M

6 weeks

10000

LM2907N-8

MDIP

STD

NOPB

RoHS

N/A

Full production

N/A

1K+

$0.70

rail
of
40

NSUZXYTT
LM
2907N-8

6 weeks

2000

LM2907N

MDIP

STD

NOPB

RoHS

N/A

Full production

N/A

1K+

$0.76

rail
of
25

NSUZXYYTTE#
LM2907N

6 weeks

2000

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2907MX-8EP	NONE	NATIONAL SEMICONDUCTOR	16 Nov 2008

General Description

The LM2907, LM2917 series are monolithic frequency to voltage converters with a high gain op amp/comparator designed to operate a relay, lamp, or other load when the input frequency reaches or exceeds a selected rate. The tachometer uses a charge pump technique and offers frequency doubling for low ripple, full input protection in two versions (LM2907-8, LM2917-8) and its output swings to ground for a zero frequency input.

The op amp/comparator is fully compatible with the tachometer and has a floating transistor as its output. This feature allows either a ground or supply referred load of up to 50 mA. The collector may be taken above V_CC up to a maximum V_CE of 28V.

The two basic configurations offered include an 8-pin device with a ground referenced tachometer input and an internal connection between the tachometer output and the op amp non-inverting input. This version is well suited for single speed or frequency switching or fully buffered frequency to voltage conversion applications.

The more versatile configurations provide differential tachometer input and uncommitted op amp inputs. With this version the tachometer input may be floated and the op amp becomes suitable for active filter conditioning of the tachometer output.

Both of these configurations are available with an active shunt regulator connected across the power leads. The regulator clamps the supply such that stable frequency to voltage and frequency to current operations are possible with any supply voltage and a suitable resistor.

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2907M	SLM	0	42786	0	0	3352500	2	951281028
LM2907M-8	SLM	0	42786	0	0	3352500	2	951281028
LM2907MX	SLM	0	42786	0	0	3352500	2	951281028
LM2907MX-8	SLM	0	42786	0	0	3352500	2	951281028
LM2907N	SLM	0	42786	0	0	3352500	2	951281028
LM2907N-8	SLM	0	42786	0	0	3352500	2	951281028

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

More Application Notes

Title	Size in Kbytes	Date
AN-97: Application Note 97 Versatile Timer Operates from Microseconds to Hours	457 Kbytes	24-Feb-99	Download
AN-162: AN-162 LM2907 Tachometer/Speed Switch Building Block Applications	309 Kbytes	1-May-04	Download
AN-607: Pulse Width Modulation A/D Conversion Techniques with COP800 Family Microcontrollers	148 Kbytes	5-Aug-95	Download
AN-1237: Application Note 1237 RSDS™ Flat Panel Display Design Guidelines Part 2	141 Kbytes	14-May-03	Download

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[Information as of 3-Jul-2009]