The LTC6903/LTC6904 are low power self contained digital frequency sources providing a precision frequency from 1kHz to 68MHz, set through a serial port. The LTC6903/ LTC6904 require no external components other than a power supply bypass capacitor, and they operate over a single wide supply range of 2.7V to 5.5V.The LTC6903/LTC6904 feature a proprietary feedback loop that linearizes the relationship between digital control setting and frequency, resulting in a very simple frequency setting equation:where OCT is a 4-bit digital code and DAC is a 10-bit digital code.The LTC6903 is controlled by a convenient SPI compatible serial interface. The LTC6904 uses an industry standard I2C compatible interface.ApplicationsPrecision Digitally Controlled OscillatorPower ManagementDirect Digital Frequency Synthesis (DDS) ReplacementReplacement for DAC and VCOSwitched Capacitor Filter Clock

The LTC6905-X series of parts are precision, fixed frequency, silicon oscillators designed to minimize board space while maximizing accuracy and ease of use.Programmed at the factory to a fixed frequency, the LTC6905-X series of parts need no external trim components. An internal three-state divider allows for division of the master clock by 1, 2 or 4, providing 3 frequencies (for each device).The LTC6905-X series operate with a single 2.7V to 5.5V power supply and provide a rail-to-rail, 50% duty cycle, square wave output. The OE pin will disable the output when brought low and synchronously enable the output when brought high, avoiding pulse slivers.The four products of the LTC6905-X family are:LTC6905-133: fOSC= 133MHz, 66.7MHz, 33.3MHzLTC6905-100: fOSC= 100MHz, 50MHz, 25MHzLTC6905-96: fOSC= 96MHz, 48MHz, 24MHzLTC6905-80: fOSC= 80MHz, 40MHz, 20MHzThe LTC6905-X series of parts are designed with a factory trim option to modify the divider ratios from 1, 2, 4 to 8, 16, 32. A second trim option allows for additional master clock frequencies. For the alternate divider ratios and unlisted frequencies, contact LTC marketing.Protected by U.S. Patents, including 6614313, 6342817.ApplicationsData Clocks for High Reliability ApplicationsHigh Vibration, High Acceleration EnvironmentsReplacement for Fixed Crystal and Ceramic Oscillators

The LTC6906 is a precision programmable oscillator that is versatile, compact and easy-to-use. Micropower operation benefits portable and battery-powered equipment. At 100kHz, the LTC6906 consumes 12µA on a 3.3V supply.A single resistor programs the oscillator frequency over a 10:1 range with better than 0.5% initial accuracy. The output frequency can be divided by 1, 3 or 10 to span a 100:1 total frequency range, 10kHz to 1MHz.No decoupling capacitor is needed in most cases, yielding an extremely compact solution occupying less than 20mm2. Contact LTC Marketing for a version of the part with a shutdown feature or lower frequency operation.The LTC6906 is available in the 6-lead SOT-23 (ThinSOT) package.APPLICATIONSLow Cost Precision Programmable OscillatorRugged, Compact Micropower Replacement for Crystal and Ceramic OscillatorsHigh Shock and Vibration EnvironmentsPortable and Battery-Powered EquipmentPDAs and Cellular Phones

The LTC6907 is a precision programmable oscillator that is versatile, compact and easy to use. Micropower operation benefits portable and battery-powered equipment. At 400kHz, the LTC6907 consumes 36µA on a 3V supply.A single resistor programs the oscillator frequency over a 10:1 range with better than 0.5% initial accuracy. The output frequency can be divided by 1, 3 or 10 to span a 100:1 total frequency range, 40kHz to 4MHz.The LTC6907 is easily programmed according to this simple formula:fout = 4MHz / N * (50k/Rset) N = {10 DIV Pin = V+, 3 DIV Pin = Open, 1 DIV Pin = GND}The LTC6907 is available in the 6-lead SOT-23 (ThinSOT) package. Contact LTC Marketing for a version of the part with a shutdown feature or lower frequency operation.ApplicationsLow Cost Precision Programmable OscillatorRugged, Compact Micropower Replacement forCrystal and Ceramic OscillatorsHigh Shock and Vibration EnvironmentsPortable and Battery-Powered EquipmentPDAs and Cellular Phones

The LTC6908 is an easy-to-use precision oscillator that provides 2-outputs, shifted by either 180° or 90°. The oscillator frequency is programmed by a single external resistor (RSET) and spread spectrum frequency modulation (SSFM) can be activated for improved electromagnetic compatibility (EMC) performance.The LTC6908 operates with a single 2.7V to 5.5V supply and provides rail-to-rail, 50% duty cycle square wave outputs. A single resistor from 10k to 2M is used to select an oscillator frequency from 50kHz to 10MHz (5V supply). The oscillator can be easily programmed using the simple formula outlined below:fOUT=10MHz • 10k/RSETThe LTC6908’s SSFM capability modulates the output frequency by a pseudorandom noise (PRN) signal to decrease the peak electromagnetic radiation level and improve EMC performance. The amount of frequency spreading is fixed at ±10% of the center frequency. When SSFM is enabled, the rate of modulation is selected by the user. The three possible modulation rates are fOUT/16, fOUT/32 and fOUT/64.ApplicationsSwitching Power Supply Clock ReferencePortable and Battery-Powered EquipmentPrecision Programmable OscillatorCharge Pump Driver

The LTC6909 is an easy to use precision oscillator that can provide 1-, 2-, 3-, 4-, 5-, 6-, 7- or 8-phase synchronized outputs. The LTC6909 also offers spread spectrum frequency modulation (SSFM), which can be enabled to improve electromagnetic compatibility (EMC) performance.Eight separate outputs provide up to eight rail-to-rail, 50% duty cycle clock signals. Using three logic inputs, the outputs are configured for phase separation, ranging from 45° to 120° (three to eight phases). The clock outputs can also be held low or configured for Hi-Z. A single resistor, combined with the phase configuration, sets the output frequency, based on the following formula:The LTC6909 can be used in applications requiring only one or two output phases. Alternatively, the LTC6908 family of parts provides the same two output signals but in a smaller SOT-23 or 2mm × 3mm DFN package. The LTC6908-1 provides complimentary (180°) outputs while the LTC6908-2 provides quadrature (90°) outputs.ApplicationsSynchronizing Multiple Switching Power Supplies

The LTC690 family provides complete power supply monitoring and battery control functions for microprocessor reset, battery backup, CMOS RAM write protection, power failure warning and watchdog timing. A precise internal voltage reference and comparator circuit monitor the power supply line. When an out-of-tolerance condition occurs, the reset outputs are forced to active states and the chip enable output unconditionally write-protects external memory. In addition, theRESEToutput is guaranteed to remain logic low even with VCCas low as 1V.The LTC690 family powers the active CMOS RAMs with a charge pumped NMOS power switch to achieve low dropout and low supply current. When primary power is lost, auxiliary power, connected to the battery input pin, powers the RAMs in standby through an efficient PMOS switch.For an early warning of impending power failure, the LTC690 family provides an internal comparator with a user-defined threshold. An internal watchdog timer is also available, which forces the reset pins to active states when the watchdog input is not toggled prior to a preset timeout period.ApplicationsCritical μP Power MonitoringIntelligent InstrumentsBattery-Powered Computers and ControllersAutomotive Systems

The LTC6910 family are low noise digitally programmable gain amplifiers (PGAs) that are easy to use and occupy very little PC board space. The inverting gain is adjustable using a 3-bit digital input to select gains of 0, 1, 2, 5, 10, 20, 50 and 100V/V in the LTC6910-1; 0, 1, 2, 4, 8, 16, 32 and 64V/V in the LTC6910-2; and 0, 1, 2, 3, 4, 5,6 and 7V/V in the LTC6910-3.The LTC6910-Xs are inverting amplifiers with rail-to-rail output. When operated with unity gain, they will also process rail-to-rail input signals. A half-supply reference generated internally at the AGND pin supports single power supply applications. Operating from single or split supplies from 2.7V to 10.5V, the LTC6910-X family is offered in an 8-lead SOT-23 package.ApplicationsData Acquisition SystemsDynamic Gain ChangingAutomatic Ranging CircuitsAutomatic Gain Control

The LTC6911 is a family of low noise digitally programmable gain amplifiers (PGAs) that are easy to use and occupy very little PC board space. The matched gain of both channels is adjustable using a 3-bit parallel interface to select voltage gains of 0, 1, 2, 5, 10, 20, 50 and 100V/ V (LTC6911-1) and 0, 1, 2, 4, 8, 16, 32 and 64V/V (LTC6911-2). All gains are inverting.The LTC6911 family consists of two matched inverting amplifiers with rail-to-rail outputs. When operated with unity gain, they will also process rail-to-rail input signals. A half-supply reference generated internally at the AGND pin supports single power supply applications. Operating from single or split supplies from 2.7V to 10.5V, the LTC6911 family is offered in a 10-lead MSOP package.ApplicationsData Acquisition SystemsDynamic Gain ChangingAutomatic Ranging CircuitsAutomatic Gain Control

The LTC6912 is a family of dual channel, low noise, digitally programmable gain amplifiers (PGA) that are easy to use and occupy very little PC board space. The gains for both channels are independently programmable using a 3-wire SPI interface to select voltage gains of 0, 1, 2, 5, 10, 20, 50, and 100V/V (LTC6912-1 ); and 0, 1, 2, 4, 8, 16, 32, and 64V/V (LTC6912-2). All gains are inverting.The LTC6912 family consists of 2 matched amplifiers with rail-to-rail outputs. When operated with unity gain, they will also process rail-to-rail input signals. A half-supply reference generated internally at the AGND pin supports single power supply applications. Operating from single or split supplies from 2.7V to 10.5V total, the LTC6912-X family is offered in tiny SSOP and DFN-12 Packages.ApplicationsData Acquisition SystemsDynamic Gain ChangingAutomatic Ranging CircuitsAutomatic Gain Control