Analog Devices Inc. LTC6903HMS8#TRPBF

Overview

LTC6903HMS8#TRPBF from Analog Devices (formerly Linear Technology) is a precision serial-port programmable oscillator IC delivering digitally set square-wave output from 1.039 kHz to 68 MHz. It features SPI-compatible interface, 0.5% typical initial frequency accuracy, 10 ppm/°C drift, and operates from 2.7V to 5.5V over –40°C to 125°C. Used as a microcontroller clock source or DDS reference in industrial timing systems.

For engineers reviewing the LTC6903HMS8#TRPBF datasheet, LTC6903HMS8#TRPBF pinout, LTC6903HMS8#TRPBF application, or LTC6903HMS8#TRPBF equivalent, this page provides verified specifications, validated MS8 package mapping, confirmed SPI timing parameters, real-world jitter and accuracy behavior across temperature, and two field-validated alternative parts for design flexibility.

Technical Context

The LTC6903HMS8#TRPBF integrates a 34–68 MHz master VCO with a proprietary feedback loop that linearizes DAC- and OCT-controlled division, enabling monotonic 10-bit + 4-bit frequency programming. Its internal architecture uses resistor-based DAC tuning and binary power-of-two dividers to achieve precise digital frequency synthesis without external components.

It implements an asynchronous output enable (OE) pin for fast clock gating, supports dual complementary CLK/CLK outputs with configurable enable states via serial register bits CNF[1:0], and guarantees monotonicity across octave boundaries-ensuring no frequency reversal when transitioning between OCT settings.

Key Specifications

Pinout & Package

Package: 8-lead plastic MSOP (MS8), 3.0 mm × 3.0 mm × 0.86 mm, exposed pad not electrically connected, RoHS-compliant, tape-and-reel packaging (TRPBF).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digitally programmable oscillator applications.

Compared with LTC6903HMS8#TRPBF, LTC6904HMS8#TRPBF offers identical performance with I²C convenience but adds bus contention risk, while LTC6900CMS8#TRPBF trades frequency headroom and temperature range for lower power and cost-making it viable only in non-industrial contexts.

Availability

LTC6903HMS8#TRPBF is available at Aetrix Electronics and suitable for industrial automation controllers, automotive ECU timing modules, and high-reliability power management systems requiring stable component supply across extended temperature ranges.

Supply support for LTC6903HMS8#TRPBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices acquired Linear Technology in 2017 and maintains full product support, documentation, and manufacturing continuity for all Linear-branded precision analog and mixed-signal ICs.

The LTC6903 belongs to Linear's precision programmable oscillator family, designed specifically for replacing crystals, VCOs, and DAC+filter clock solutions in space-constrained, thermally demanding embedded systems.

FAQ

What is the operating temperature range for the LTC6903HMS8#TRPBF?

The LTC6903HMS8#TRPBF is fully specified and tested over –40°C to 125°C ambient temperature. This H-grade variant meets industrial and extended automotive requirements, unlike C-grade (0°C to 70°C) or I-grade (–40°C to 85°C) versions. The device remains functional beyond these limits, but parametric guarantees apply only within the –40°C to 125°C range per datasheet Note 4.

Does the LTC6903HMS8#TRPBF require external passive components to operate?

No, the LTC6903HMS8#TRPBF requires only a single 0.1 µF ceramic bypass capacitor between V+ and GND, placed within 2 mm of the pins. Unlike crystal oscillators or PLL-based solutions, it needs no load capacitors, loop filter components, or trimming resistors-reducing BOM count, layout area, and calibration effort. Additional 1 µF bulk capacitance is recommended for high-frequency stability.

How does the LTC6903HMS8#TRPBF achieve 0.1% frequency resolution?

The LTC6903HMS8#TRPBF achieves 0.1% resolution using a 10-bit DAC (1024 steps) combined with a 4-bit OCT divider (16 octaves), yielding 16,384 discrete frequency points across its 1.039 kHz–68 MHz range. The proprietary feedback loop ensures monotonicity and linearity, so each DAC/OCT combination produces a predictable, repeatable output without interpolation or calibration.

Can both CLK and CLK outputs of the LTC6903HMS8#TRPBF be used simultaneously?

Yes, both CLK (Pin 6) and CLK (Pin 5) outputs can be enabled simultaneously via the CNF[1:0] register bits (00 = both active, 180° out of phase). When both are active, they share the same programmed frequency but provide complementary edges-useful for differential clocking, push-pull driver stages, or glitch-free clock domain crossing. Unused outputs should be disabled to preserve accuracy and reduce current draw.

What is the maximum SPI clock frequency supported by the LTC6903HMS8#TRPBF?

The LTC6903HMS8#TRPBF supports SPI clock (SCK) frequencies up to 20 MHz across its full operating temperature range. Minimum timing requirements include tCKHI ≥ 25 ns and tCKLO ≥ 25 ns, enabling robust communication even at 20 MHz. The SEN pin must remain low for the full 16-clock cycle to complete a write; partial writes (e.g., 8-bit updates) are permitted but affect only the upper/lower byte.