LTC6990IDCB-TRMPBF View Datasheet(PDF) - Analog Devices

Part Name

Description

Manufacturer

LTC6990IDCB-TRMPBF

TimerBlox: Voltage Controlled Silicon Oscillator

Analog Devices 

LTC6990

TimerBlox: Voltage Controlled

Silicon Oscillator

FEATURES

n Fixed-Frequency or Voltage-Controlled Operation

n Fixed: Single Resistor Programs Frequency with

<1.5% Max Error

n VCO: Two Resistors Set VCO Center Frequency

and Tuning Range

n Frequency Range: 488Hz to 2MHz

n 2.25V to 5.5V Single Supply Operation

n 72µA Supply Current at 100kHz

n 500µs Start-Up Time

n VCO Bandwidth >300kHz at 1MHz

n CMOS Logic Output Sources/Sinks 20mA

n 50% Duty Cycle Square Wave Output

n Output Enable (Selectable Low or Hi-Z When Disabled)

n 55°C to 125°C Operating Temperature Range

n Available in Low Profile (1mm) SOT-23 (ThinSOT™)

and 2mm × 3mm DFN Package

n AEC-Q100 Qualified for Automotive Applications

APPLICATIONS

n Low Cost Precision Programmable Oscillator

n Voltage-Controlled Oscillator

n High Vibration, High Acceleration Environments

n Replacement for Fixed Crystal and Ceramic Oscillators

n Portable and Battery-Powered Equipment

All registered trademarks and trademarks are the property of their respective owners. Protected

by U.S. patents, including 6342817, 6614313.

DESCRIPTION

The LTC®6990 is a precision silicon oscillator with a pro-

grammable frequency range of 488Hz to 2MHz. It can be

used as a fixed-frequency or voltage-controlled oscillator

(VCO). The LTC6990 is part of the TimerBlox® family of

versatile silicon timing devices.

A single resistor, RSET, programs the LTC6990’s inter-

nal master oscillator frequency. The output frequency

is determined by this master oscillator and an internal

frequency divider, NDIV, programmable to eight settings

from 1 to 128.

fOUT

=

1MHz

NDIV

•

50kΩ

RSET

,

NDIV

=

1,

2,

4

…128

Optionally, a second resistor at the SET input provides

linear voltage control of the output frequency and can be

used for frequency modulation. A narrow or wide VCO

tuning range can be configured by the appropriate selec-

tion of the two resistors.

The LTC6990 includes an enable function that is synchro-

nized with the master oscillator to ensure clean, glitch-

free output pulses. The disabled output can be configured

to be high impedance or forced low.

For easy configuration of the LTC6990, use the TimerBlox

LTC6990: Voltage Controlled Oscillator Web-Based

Design Tool.

TYPICAL APPLICATION

Voltage Controlled Oscillator with 16:1 Frequency Range

VCTRL

V+

fOUT

=

2MHz

−

VCTRL

•

MHz

V

RVCO

100k

OE

OUT

LTC6990

GND

V+

SET

RSET

100k

DIV

6990 TA01a

V+

C1

0.1µF

VCO Transfer Function

1000

750

500

250

0

0

0.5

1

1.5

2

VCTRL (V)

6990 TA01b

Document Feedback

For more information www.analog.com

Rev. D

1

Share Link: