Analog Devices Inc. LTC6990HS6#TRPBF

Overview

LTC6990HS6#TRPBF from Analog Devices is a precision voltage-controlled silicon oscillator in SOT-23-6 package, delivering programmable output frequencies from 488 Hz to 2 MHz with ±1.5% max frequency accuracy over –40°C to +125°C. It operates from a single 2.25 V to 5.5 V supply, draws as low as 56 µA at 2.25 V, and provides CMOS-compatible 20 mA drive capability with 50% duty cycle square wave output. It serves as a drop-in replacement for fixed crystal oscillators in automotive timing and sensor biasing circuits.

For engineers reviewing the LTC6990HS6#TRPBF datasheet, LTC6990HS6#TRPBF pinout, LTC6990HS6#TRPBF application, or LTC6990HS6#TRPBF equivalent, key selection criteria include its guaranteed operation up to +125°C, AEC-Q100 qualification, programmable divider (NDIV = 1–128), synchronized enable function, and resistor-based frequency programming without external capacitors.

Technical Context

The LTC6990HS6#TRPBF implements a master oscillator architecture with internal 1 MHz reference scaling, where output frequency is determined by ISET current sourced through RSET and divided by NDIV (1–128). Its SET pin regulates VSET to 1.00 V ±30 mV, decoupling frequency accuracy from supply drift when using a single RSET resistor.

Frequency modulation is achieved via a second resistor network on the SET pin, enabling linear VCO operation with >300 kHz bandwidth at 1 MHz output. The DIV pin hosts a V+-referenced 4-bit ADC that sets both NDIV and Hi-Z mode (high-impedance vs. forced-low disable state), with ±1.5% VDIV/V+ tolerance required for reliable code detection.

Key Specifications

Pinout & Package

Package: 6-lead TSOT-23 (S6), 1 mm profile, RoHS-compliant, lead-free finish. Exposed pad not present in S6 variant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage-controlled oscillator applications.

Compared with MAX974ACSA+ and SiT1533AI-JE-33E-32.768E, the LTC6990HS6#TRPBF uniquely combines AEC-Q100 qualification, resistor-programmable frequency (488 Hz–2 MHz), and configurable Hi-Z disable in a space-constrained SOT-23 package-making it optimal for automotive and industrial timing where reliability, flexibility, and footprint matter.

Availability

LTC6990HS6#TRPBF is available at Aetrix Electronics and suitable for automotive engine control units, industrial sensor interfaces, and portable medical devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC6990HS6#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. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC6990HS6#TRPBF belongs to the TimerBlox® family of silicon timing devices, designed specifically to replace quartz oscillators and RC timers in harsh-environment applications demanding precision, programmability, and reliability.

FAQ

What is the maximum operating temperature for the LTC6990HS6#TRPBF?

The LTC6990HS6#TRPBF is rated for continuous operation from –40°C to +125°C and is AEC-Q100 qualified for Grade H automotive applications. This specification is guaranteed across the full temperature range, unlike commercial-grade variants (e.g., LTC6990CS6#TRPBF), making it suitable for under-hood and powertrain systems where ambient temperatures exceed 105°C.

How do I configure the LTC6990HS6#TRPBF for fixed-frequency operation?

To configure the LTC6990HS6#TRPBF for fixed-frequency operation, connect a precision resistor (RSET) between the SET pin and GND, and set the DIV pin voltage using a resistor divider to select NDIV. Use RSET = (1 MHz × 50 kΩ) / (NDIV × fOUT) and refer to Table 1 in the datasheet for recommended DIV resistor pairs. No external capacitors are required.

Does the LTC6990HS6#TRPBF support voltage-controlled oscillator (VCO) functionality?

Yes, the LTC6990HS6#TRPBF supports linear VCO operation by adding a second resistor between the SET pin and a control voltage (VCTRL). This creates a current-summing node that modulates ISET, enabling frequency tuning with >300 kHz bandwidth at 1 MHz output. The VCO transfer function is fOUT = (1 MHz × 50 kΩ) / (NDIV × RSET) − (VCTRL × MHz/V), as shown in Figure TA01b.

What is the purpose of the DIV pin on the LTC6990HS6#TRPBF?

The DIV pin on the LTC6990HS6#TRPBF connects to an internal V+-referenced 4-bit ADC that determines two settings: the programmable frequency divider ratio (NDIV = 1–128) and the output behavior when disabled (Hi-Z or forced-low). The voltage applied to DIV must be accurate to ±1.5% of V+ to ensure correct DIVCODE detection and stable operation.

Can the LTC6990HS6#TRPBF replace a crystal oscillator in my design?

Yes, the LTC6990HS6#TRPBF is explicitly designed as a replacement for fixed crystal and ceramic oscillators. It delivers comparable frequency stability (±1.5% max), lower start-up time (sub-millisecond), immunity to mechanical shock/vibration, and eliminates board-level crystal layout constraints-all while occupying less than half the area of a typical 3.2 mm × 2.5 mm crystal package.