LM2907EP/LM2917EP

Enhanced Plastic Frequency to Voltage Converter

General Description

The LM2907EP, LP2917EP 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 fre-

quency doubling for low ripple, full input protection in two

versions (LM2907-8EP, LM2917-8EP) and its output swings

to ground for a zero frequency input.

The op amp/comparator is fully compatible with the tachom-

eter 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

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 ta-

chometer 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 tachom-

eter 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.

ENHANCED PLASTIC

•

Extended Temperature Performance of −40˚C to +85˚C

•

Baseline Control - Single Fab & Assembly Site

•

Process Change Notification (PCN)

•

Qualification & Reliability Data

•

Solder (PbSn) Lead Finish is standard

•

Enhanced Diminishing Manufacturing Sources (DMS)

Support

Features

n

Ground referenced tachometer input interfaces directly

with variable reluctance magnetic pickups

n

Op amp/comparator has floating transistor output

n

50 mA sink or source to operate relays, solenoids,

meters, or LEDs

n

Frequency doubling for low ripple

n

Tachometer has built-in hysteresis with either differential

input or ground referenced input

n

Built-in zener on LM2917EP

0.3% linearity typical

n

Ground referenced tachometer is fully protected from

damage due to swings above V

Advantages

n

Output swings to ground for zero frequency input

n

Easy to use; V

n

Only one RC network provides frequency doubling

n

Zener regulator on chip allows accurate and stable

frequency to voltage or current conversion (LM2917EP)

Applications

n

Selected Military Applications

n

Selected Avionics Applications

Ordering Information

PART NUMBER

VIN PART NUMBER

NS PACKAGE NUMBER (Note 3)

LM2907MX-8EP

V62/04635-01

M08A

LM2917MXEP

V62/04635-02

M14A

(Notes 1, 2)

TBD

TBD

Note 1: For the following (Enhanced Plastic) versions, check for availablility: LM2907M-8EP, LM2907MEP, LM2907MXEP, LM2907N-8EP, LM2907NEP

and LM2917M-8EP, LM2917MX-8EP, LM2917MEP, LM2917N-8EP, LM2917NEP. Parts listed with an "X" are provided in Tape & Reel and parts without

an "X" are in Rails.

Note 2: FOR ADDITIONAL ORDERING AND PRODUCT INFORMATION, PLEASE VISIT THE ENHANCED PLASTIC WEB SITE AT: www.national.com/

mil

Note 3: Refer to package details under Physical Dimensions

June 2004

© 2004 National Semiconductor Corporation

DS200906

www.national.com