Features and Benefits
- Fixed-Frequency or Voltage-Controlled Operation
- Fixed: Single Resistor Programs Frequency with <1.5% Max Error
- VCO: Two Resistors Set VCO Center Frequency and Tuning Range
- Frequency Range: 488Hz to 2MHz
- 2.25V to 5.5V Single Supply Operation
- 72μA Supply Current at 100kHz
- 500μs Start-Up Time
- VCO Bandwidth >300kHz at 1MHz
- CMOS Logic Output Sources/Sinks 20mA
- 50% Duty Cycle Square Wave Output
- Output Enable (Selectable Low or Hi-Z When Disabled)
- –55°C to 125°C Operating Temperature Range
- Available in Low Profile (1mm) SOT-23 (ThinSOT™) and 2mm × 3mm DFN Package
The LTC6990 is a precision silicon oscillator with a programmable 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 internal 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.
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 selection of the two resistors.
The LTC6990 includes an enable function that is synchronized 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, download the TimerBlox Designer tool at www.linear.com/timerblox.
- Low Cost Precision Programmable Oscillator
- Voltage-Controlled Oscillator
- High Vibration, High Acceleration Environments
- Replacement for Fixed Crystal and Ceramic Oscillators
- Portable and Battery-Powered Equipment
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (3)
DC2769A-A-KIT is a kit of the DC2771A-A transmitter board, featuring LTC6990, the DC2775A-A, featuring LTC4124, and the DC2774A application-sized receiver board featuring LTC4124. The DC2775A-A receiver can charge a single Li-Ion battery at up to 10mA with an air gap of 0.5mm between the transmit and receive coils.
DC2769A-B-KIT is a kit of the DC2771A-B transmitter board, featuring LTC6990 and the DC2775A-B, featuring LTC4124. The DC2775A-B receiver can charge a single Li-Ion battery at up to 25mA with an air gap of 2mm to 5mm between the transmit and receive coils.
Demonstration circuit 1562B is an engineering tool to design and evaluate the LTC699X-X family of TimerBlox® circuits. The center section of the board contains a preconfigured TimerBlox function. DC1562B comes in twelve timing function variations as outlined in Table 1.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
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Rarely Asked Questions (1)
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Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.