Analog Devices Inc. LTC6905HS5#TRPBF

Overview

LTC6905HS5#TRPBF from Analog Devices (formerly Linear Technology) is a precision programmable silicon oscillator IC designed for high-frequency clock generation in space-constrained systems. It delivers rail-to-rail CMOS square-wave output from 17.225MHz to 170MHz with ±0.5% typical frequency accuracy over 0°C to 70°C, ±20ppm/°C temperature stability, and 7.2ps RMS timing jitter at 170MHz - enabling use in high-speed data bus timing, FPGA clocking, and crystal oscillator replacement.

For engineers reviewing the LTC6905HS5#TRPBF datasheet, LTC6905HS5#TRPBF pinout, LTC6905HS5#TRPBF application, or LTC6905HS5#TRPBF equivalent, key selection criteria include its resistor-programmable frequency range, SOT-23-5 thin package, three-state divider control (÷1/÷2/÷4), fast 100μs start-up time, and operation from a single 2.7V–5.5V supply with 6mA typical current at 100MHz.

Technical Context

The LTC6905HS5#TRPBF integrates a master oscillator whose frequency is linearly controlled by the voltage across and current through an external R_SET resistor (10kΩ–25kΩ), eliminating lookup tables via proprietary feedback linearization. Its internal three-state DIV input selects division ratios of 1, 2, or 4 to extend usable output range while maintaining low jitter.

It features a regulated SET pin bias (V_SET ≈ V+ − 1V), rail-to-rail CMOS output driver capable of driving 500Ω loads at 3V, and robust supply rejection (0.5%/V drift). The device operates across –40°C to +125°C junction temperature, with guaranteed performance over –40°C to +125°C for the H-grade variant.

Key Specifications

Pinout & Package

Package: 5-lead TSOT-23 (S5), 1mm profile, JEDEC MO-193 compliant, footprint compatible with standard SOT-23-5 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC6905IS5#TRPBF and LTC6905CS5#TRPBF, the LTC6905HS5#TRPBF provides the widest guaranteed operating temperature range (–40°C to +125°C) and maintains ±0.5% frequency accuracy across the full 0°C to 70°C range - making it the only option qualified for under-hood automotive, motor drive control, and high-reliability industrial deployments.

Availability

LTC6905HS5#TRPBF is available at Aetrix Electronics and suitable for high-speed data bus clocking, FPGA reference timing, and crystal oscillator replacement requiring stable component supply across extended temperature ranges.

Supply support for LTC6905HS5#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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.

The LTC6905HS5#TRPBF belongs to Linear's precision silicon oscillator product line, engineered to replace quartz crystals and ceramic resonators in applications demanding small size, fast start-up, and programmable frequency without microcontroller intervention.

FAQ

What is the maximum operating temperature for the LTC6905HS5#TRPBF?

The LTC6905HS5#TRPBF is rated for operation from –40°C to +125°C junction temperature, with guaranteed electrical performance over this full range. This H-grade qualification makes it suitable for under-hood automotive, industrial motor controls, and other high-temperature environments where standard I-grade (–40°C to +85°C) or C-grade (0°C to +70°C) variants would fail.

How do I calculate the R_SET resistor value for a target output frequency with the LTC6905HS5#TRPBF?

Use the formula R_SET = (10kΩ × 168.5MHz) / (f_OSC × N – 1.5MHz), where f_OSC is your desired output frequency in MHz and N is the divider ratio (1, 2, or 4). For example, for 50MHz with N = 2: R_SET = (10k × 168.5) / (50 × 2 – 1.5) ≈ 17.0kΩ. The LTC6905HS5#TRPBF requires R_SET between 10kΩ and 25kΩ for valid operation.

Can the LTC6905HS5#TRPBF drive a 50Ω transmission line directly?

No - the LTC6905HS5#TRPBF CMOS output is designed for 5kΩ resistive or 5pF capacitive loads. Driving a 50Ω line requires an external buffer or series termination. At 170MHz, its typical output resistance is ~27Ω (at 3V), so direct 50Ω connection causes significant signal degradation and increased jitter. Use a dedicated clock buffer (e.g., ADCLK9xx) if 50Ω drive capability is required.

What is the start-up time specification for the LTC6905HS5#TRPBF?

The LTC6905HS5#TRPBF achieves frequency stability within 1% of final value in 100μs typical after power-on. This fast start-up is enabled by its all-silicon oscillator architecture and internal bias stabilization - significantly faster than quartz oscillators (typically 1–10ms) and essential for power-gated systems needing rapid clock restoration.

Does the LTC6905HS5#TRPBF require a decoupling capacitor?

Yes - a minimum 0.1μF ceramic capacitor must be placed directly between V+ (Pin 1) and GND (Pin 2), with no vias or traces between the capacitor pads and the LTC6905HS5#TRPBF pins. This decoupling is mandatory to suppress supply noise that can modulate frequency (via 0.5%/V supply sensitivity) and increase jitter; failure to implement it degrades both accuracy and timing performance.