LM2907 - Frequency to Voltage Converter

LM2907

Frequency to Voltage Converter

Overview

Diagrams

Parametrics

Documents

Order

Packaging

Tools

Reliability

Obsolete Versions

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

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.

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

MY BRIEFCASE

Click any "Briefcase" icon to add an item

Typical Application click for larger image

Connection Diagram *click for larger image

LM2907 8-Pin Package

*click for larger image

LM2907N 14-Pin Package

Typical Performance click for larger image

Parameters Values

Temperature Min -40 deg C

Temperature Max 85 deg C

Function Frequency to Voltage

Datasheets
Title Size Date Other
Language

LM2907/LM2917 Frequency to Voltage Converter 542
Kbytes 9-Dec-08

More Application Notes
Title Size Date Other
Language

AN-97: Application Note 97 Versatile Timer Operates from Microseconds to Hours 457
Kbytes 24-Feb-99

AN-162: AN-162 LM2907 Tachometer/Speed Switch Building Block Applications 309
Kbytes 1-May-04

AN-607: Pulse Width Modulation A/D Conversion Techniques with COP800 Family Microcontrollers 148
Kbytes 5-Aug-95

AN-1237: Application Note 1237 RSDS™ Flat Panel Display Design Guidelines Part 2 141
Kbytes 14-May-03

Part Number(s)
(NSID)

Top View

Availability

Current Reported Stock

Budgetary Pricing

Standard Pack Size

LM2907M/NOPB
LM2907M

RoHS Status

SOIC NARROW

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	530
AVNET-EM	Worldwide	175
DIGIKEY	Worldwide	0
FUTURE	Worldwide	17
NEWARK	Americas	825

$0.70 each at 1K+ pcs

rail
of
55

LM2907M-8/NOPB
LM2907M-8

RoHS Status

SOIC NARROW

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	492
AVNET-EM	Worldwide	431
DIGIKEY	Worldwide	1329
FUTURE	Worldwide	530
RS COMPONENTS	Worldwide	60

$0.70 each at 1K+ pcs

rail
of
95

LM2907MX/NOPB
LM2907MX

RoHS Status

SOIC NARROW

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGIKEY		Worldwide	0
FUTURE		Worldwide	1100

$0.70 each at 1K+ pcs

reel
of
2500

LM2907MX-8/NOPB
LM2907MX-8

RoHS Status

SOIC NARROW

Full production
Lead Time: 12 weeks

Distributor	Region	Qty
AECO TECH	Asia Pacific	1000
AVNET-EM	Worldwide	2500
DIGIKEY	Worldwide	0

$0.70 each at 1K+ pcs

reel
of
2500

LM2907N/NOPB
LM2907N

RoHS Status

MDIP

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	642
AVNET-EM	Worldwide	841
DIGIKEY	Worldwide	898
FARNELL	Europe and Asia	704
FUTURE	Worldwide	1100
KEIKONG	Asia Pacific	4000
NEWARK	Americas	579
RS COMPONENTS	Worldwide	125
TAYLOR	Americas	5996

$0.76 each at 1K+ pcs

rail
of
25

LM2907N-8/NOPB
LM2907N-8

RoHS Status

MDIP

Full production
Lead Time: 12 weeks

Distributor	Region	Qty
ARROW	Worldwide	452
AVNET-EM	Worldwide	502
BRITESTONE	South Korea	16
DIGIKEY	Worldwide	1275
FUTURE	Worldwide	186
NEWARK	Americas	1197
RS COMPONENTS	Worldwide	230
TAYLOR	Americas	1

$0.70 each at 1K+ pcs

rail
of
40

Obsolete Versions

Obsolete Part Alternate Part or Supplier Source Last Time Buy Date

LM2907MX-8EP
NONE
NATIONAL SEMICONDUCTOR
16 Nov 2008

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

National's certificate of product compliance is located at RoHS Status.

Part Number(s) (NSID)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM2907M/NOPB LM2907M	SOIC NARROW	14	1 1	260 235	Detail	N/A	N/A	NSUZXYTTE# LM2907M
LM2907M-8/NOPB LM2907M-8	SOIC NARROW	8	1 1	260 235	Detail	N/A	N/A	NSZXTT LM29 07M-8
LM2907MX/NOPB LM2907MX	SOIC NARROW	14	1 1	260 235	Detail	N/A	N/A	NSUZXYTTE# LM2907M
LM2907MX-8/NOPB LM2907MX-8	SOIC NARROW	8	1 1	260 235	Detail	N/A	N/A	NSZXTT LM29 07M-8
LM2907N/NOPB LM2907N	MDIP	14	1 1	NA NA	Detail	N/A	N/A	NSUZXYYTTE# LM2907N
LM2907N-8/NOPB LM2907N-8	MDIP	8	1 1	NA NA	Detail	N/A	N/A	NSUZXYTTE# LM 2907N-8

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

National's certificate of product compliance is located at RoHS Status.

CAD Symbols and Models
N/A

Models
N/A

Reliability Metrics

Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)

LM2907M SLM 0 44046 0 0 3532500 1 1002356520

LM2907M-8 SLM 0 44046 0 0 3532500 1 1002356520

LM2907MX SLM 0 44046 0 0 3532500 1 1002356520

LM2907MX-8 SLM 0 44046 0 0 3532500 1 1002356520

LM2907N SLM 0 44046 0 0 3532500 1 1002356520

LM2907N-8 SLM 0 44046 0 0 3532500 1 1002356520

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.

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

National's certificate of product compliance is located at RoHS Status.

Obsolete Versions

Obsolete Part Alternate Part or Supplier Source Last Time Buy Date

LM2907MX-8EP
NONE
NATIONAL SEMICONDUCTOR
16 Nov 2008

[Information as of 9-Feb-2010]