Analog Devices Inc. LTC6906HS6#TRMPBF

Product summary LTC6906HS6#TRMPBF oscillator by Analog Devices Inc.

The LTC6906HS6#TRMPBF from Analog Devices Inc. is a silicon-based programmable oscillator IC designed for engineers requiring precise, low-power clock generation over a wide frequency range. Housed in a compact TSOT-23-6 package, the device supports frequency outputs from 10kHz to 1MHz, with configuration achieved via a single external resistor. It is optimized for minimal supply current—only 12μA at 100kHz on a 3.3V supply—making the LTC6906HS6#TRMPBF suited for applications demanding both accuracy and extended battery life. Its robust, simple design positions it as an ideal alternative to crystal and ceramic oscillator solutions, especially where resilience to shock and vibration is essential.

Main characteristics and performance indicators of LTC6906HS6#TRMPBF

The LTC6906HS6#TRMPBF brings a blend of precision and versatility. Noteworthy features include sub-0.65% frequency accuracy from 0°C to 70°C, a 10:1 programmable frequency range via an external resistor, and further flexibility with internal dividers (divide by 1, 3, or 10) to cover a full 100:1 output frequency span (10kHz–1MHz). Operating from a single supply voltage ranging from 2.25V to 5.5V, the device’s typical startup time is less than 200μs at 1MHz. Its low current consumption makes it attractive for battery-powered and portable designs. The LTC6906HS6#TRMPBF’s CMOS output is capable of driving moderate capacitive loads and retains signal integrity even in electrically noisy environments. Importantly, for most applications, no external power supply decoupling capacitor is required due to internal decoupling.

Pinout and packaging details of LTC6906HS6#TRMPBF

In its 6-lead TSOT-23 (ThinSOT™) package, the LTC6906HS6#TRMPBF maintains a low-profile footprint of just 1mm, allowing integration into dense PCB layouts. The pinout is as follows:

OUT (Pin 1): Oscillator output, designed for driving logic inputs or circuit loads.

GND (Pin 2): Ground reference.

DIV (Pin 3): Divider input for selecting N (1, 3, or 10) in frequency division.

SET (Pin 4): Connects to the precision resistor defining oscillator frequency.

GRD (Pin 5): Guard signal, used to reduce PCB leakage currents influencing frequency accuracy.

V+ (Pin 6): Supply voltage input (internally decoupled).

The GRD pin, in particular, is a unique feature tailored to help engineers minimize PC board leakage currents—a frequent challenge in high-resistance, low-current circuitry.

Operating principle How LTC6906HS6#TRMPBF produces clock signals

At the heart of the LTC6906HS6#TRMPBF is a precision resistor-programmable oscillator, utilizing an internal 10pF capacitor and a current-monitoring feedback loop to maintain frequency accuracy. The device generates a square wave where the period—and thus frequency—is set directly by an external resistor (RSET) connected between the SET pin and ground. The frequency formula is:

fOUT = (1MHz / N) × (100kΩ / RSET), where N is the divider selected by the DIV pin.

N can be set to 1, 3, or 10, allowing designers to span several decades of frequency using a single precision resistor and digital selection. The current through RSET is mirrored internally to set the oscillator’s timing, which, combined with the high-stability internal capacitor, dictates the output frequency. Digital division further refines the output as required by the target logic or timing scheme.

Primary use cases for LTC6906HS6#TRMPBF

Engineers will find the LTC6906HS6#TRMPBF particularly valuable in scenarios such as:

Precision clock generation for microcontrollers or logic circuits in portable and battery-powered devices.

Replacement for traditional crystal or ceramic oscillators in systems subject to shock, vibration, or harsh environmental conditions.

Low-power timers, clocks, or refresh circuits in PDAs, cellular phones, and miniaturized systems where PCB space and current budget are tightly limited.

Cost-sensitive applications requiring programmable or easily adjustable timing without the risks and complexity of mechanical resonator-based solutions.

Design factors for applications Precision, energy consumption, and PCB design

Frequency accuracy of the LTC6906HS6#TRMPBF is primarily governed by the precision of RSET and PCB cleanliness around the SET pin. Utilizing a metal or thin-film resistor with 0.5% tolerance (or better) is recommended for high-precision applications, while thick-film resistors suffice for less critical designs. PC board leakage currents can cause measurable errors when high-value resistors are used; thus, careful cleaning and the use of guard traces tied to the GRD pin are essential for maintaining accuracy.

For ultra-low-power operation, engineers should maximize RSET (lowering the oscillator current) and minimize capacitive loads on the OUT pin. The internal decoupling obviates the need for external capacitors in most cases, but larger capacitive loads may necessitate closer evaluation of waveform quality, especially at higher frequencies. Avoiding routing the OUT and DIV signals in parallel and using ample separation lowers susceptibility to signal coupling and false division state changes.

System interfacing and power supply options with LTC6906HS6#TRMPBF

The supply voltage range of 2.25V to 5.5V for the LTC6906HS6#TRMPBF supports direct operation from common logic or battery rails. When used above 3.6V, an external RC filter (e.g., 100Ω resistor and 1μF capacitor, placed close to the device) is recommended to prevent high-frequency resonance that may affect oscillator stability.

Thanks to internal supply decoupling, the LTC6906HS6#TRMPBF can tolerate substantial supply resistance and modest power supply noise. This permits powering the oscillator directly from logic device pins—enabling clock gating and further power savings—without compromising output integrity. The sub-200μs startup time ensures rapid resume of timing after power cycling or logic enablement.

Alternative or substitute models for LTC6906HS6#TRMPBF

Engineers considering alternatives or second-source strategies for the LTC6906HS6#TRMPBF should evaluate other members of the LTC6906 series for different temperature grades or packages (e.g., LTC6906C for 0°C to +70°C, LTC6906I for –40°C to +85°C), depending on the application's environmental demands. In system-level substitutions, programmable silicon oscillators with similar form factors and programming schemes from other suppliers could be evaluated, but careful comparison of frequency accuracy, supply current, and start-up behavior is critical to avoid compromises in performance.

Conclusion

The LTC6906HS6#TRMPBF from Analog Devices Inc. brings together precision, flexibility, and robust low-power operation in a compact programmable oscillator solution. Through careful engineering—including resistor selection, PCB layout around the SET and GRD pins, and supply conditioning—designers can leverage LTC6906HS6#TRMPBF’s features for applications ranging from portable electronics to rugged industrial systems. Its versatility as a silicon oscillator paves the way for innovative timing designs, offering a strong blend of accuracy and efficiency as either a primary clock source or a cost-effective replacement for traditional oscillator technologies.