Analog Devices Inc. LTC6990CDCB#TRPBF

Overview

LTC6990CDCB#TRPBF from Analog Devices is a precision voltage-controlled silicon oscillator (VCO) in the TimerBlox® family, delivering programmable output frequencies from 488 Hz to 2 MHz via RSET resistor and DIV pin configuration. It features CMOS logic output (±20 mA drive), 50% duty cycle square wave, and synchronized enable/disable with glitch-free operation. Used in timing-critical embedded systems requiring stable, low-power clock generation without crystals.

For engineers reviewing the LTC6990CDCB#TRPBF datasheet, LTC6990CDCB#TRPBF pinout, LTC6990CDCB#TRPBF application, or LTC6990CDCB#TRPBF equivalent, key selection criteria include its 2.25V–5.5V supply range, 72 µA typical current at 100 kHz, 500 µs start-up time, ±0.8% frequency accuracy over recommended RSET range, and DFN-6 package compatibility with high-vibration environments.

Technical Context

The LTC6990CDCB#TRPBF implements a master oscillator (1 MHz max) controlled by SET-pin current (ISET = VSET/RSET), where VSET is internally regulated to 1.00 V ±30 mV. Frequency division is performed by an internal 4-bit A/D converter reading DIV pin voltage to select NDIV = 1, 2, 4, 8, 16, 32, 64, or 128.

Its enable function uses hysteresis on the OE pin (VIH ≈ 0.7·V+, VIL ≈ 0.3·V+) and synchronizes transitions to the master clock to eliminate pulse slivers. Output disable behavior (Hi-Z or forced-low) is determined by the MSB of DIVCODE, configurable via resistor divider on the DIV pin.

Key Specifications

Pinout & Package

Package: 6-lead (2 mm × 3 mm) plastic DFN (DCB), exposed pad connected to GND. Low-profile (1 mm height), RoHS-compliant, suitable for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6804CSA+ and SiT1533AI-JE-33E-32.768E, the LTC6990CDCB#TRPBF uniquely combines wide-range programmability (488 Hz–2 MHz), true linear VCO operation, and selectable Hi-Z disable-making it the sole option among these three for adaptive timing, spread-spectrum clocking, or multi-ratio clock generation in a single chip.

Availability

LTC6990CDCB#TRPBF is available at Aetrix Electronics and suitable for motor control timing, industrial sensor interfaces, portable medical device clocking, and automotive body control modules requiring stable component supply across commercial temperature ranges.

Supply support for LTC6990CDCB#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, communications, automotive, and healthcare markets.

The LTC6990CDCB#TRPBF belongs to the TimerBlox® family-designed specifically for replacing crystals, ceramic resonators, and discrete timing circuits with highly integrated, programmable silicon oscillators for space- and power-constrained applications.

FAQ

What is the operating temperature range for the LTC6990CDCB#TRPBF?

The LTC6990CDCB#TRPBF is specified for 0°C to 70°C operation (Commercial grade). While characterized from –40°C to 85°C, full parametric performance-including ±0.8% frequency accuracy and 72 µA supply current-is guaranteed only within the 0°C to 70°C range per the datasheet's "LTC6990C" grade definition. This makes LTC6990CDCB#TRPBF ideal for indoor consumer and industrial equipment where ambient thermal stress is moderate.

How do I configure the LTC6990CDCB#TRPBF for fixed-frequency operation?

To configure the LTC6990CDCB#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. For example, to generate 20 kHz with minimal current: choose NDIV = 4 (from Table 1), then calculate RSET = (1 MHz × 50 kΩ) / (NDIV × fOUT) = 625 kΩ; use a 619 kΩ ±0.5% resistor. The LTC6990CDCB#TRPBF will then deliver stable 20 kHz with ±0.8% accuracy.

Does the LTC6990CDCB#TRPBF support high-impedance output disable?

Yes, the LTC6990CDCB#TRPBF supports high-impedance output disable via the Hi-Z bit in DIVCODE. When the MSB of DIVCODE is set to 1 (e.g., DIVCODE = 8–15), pulling OE low places OUT in Hi-Z state instead of forcing it low. This is configured by setting VDIV/V+ ≥ 0.53125 (e.g., R1 = 887 kΩ, R2 = 1 MΩ). The LTC6990CDCB#TRPBF thus enables wired-OR timing buses and prevents contention in multi-driver systems.

What is the maximum output drive capability of the LTC6990CDCB#TRPBF?

The LTC6990CDCB#TRPBF provides CMOS-compatible output drive: ±20 mA sink/source capability at V+ = 5.5 V (VOH ≥ 4.84 V at –16 mA; VOL ≤ 0.26 V at 16 mA). Its typical output resistance is ~30 Ω, allowing direct driving of 50 Ω transmission lines or LEDs with series current limiting. For loads demanding sustained >10 mA, thermal limits (θJA = 64°C/W) and layout grounding must be verified-confirming that LTC6990CDCB#TRPBF remains within 150°C junction temperature under worst-case conditions.

Can the LTC6990CDCB#TRPBF replace a crystal oscillator in my design?

Yes, the LTC6990CDCB#TRPBF is explicitly positioned as a crystal and ceramic oscillator replacement. It delivers 488 Hz–2 MHz programmability, ±0.8% accuracy, and 0.022% peak-to-peak jitter at NDIV = 128-surpassing typical ±20–50 ppm crystal stability over temperature. Unlike crystals, LTC6990CDCB#TRPBF requires no load capacitors, is immune to mechanical shock/vibration, and integrates enable and divider functions. It is widely adopted in portable, automotive, and industrial systems where reliability and board space matter.