Analog Devices Inc. LT6660JCDC-3.3

Overview

LT6660JCDC-3.3 from Analog Devices (formerly Linear Technology) is a micropower series voltage reference IC delivering a precise 3.3V output with ±0.4% initial accuracy, 20ppm/°C max temperature coefficient, and guaranteed 20mA sourcing capability in a 3-lead 2mm × 2mm DFN package. It operates from VIN = VOUT + 0.9V (≥4.2V) up to 20V, requires no output capacitor, and features reverse-battery protection-making it ideal for battery-powered precision regulators and portable instrumentation.

For engineers reviewing the LT6660JCDC-3.3 datasheet, LT6660JCDC-3.3 pinout, LT6660JCDC-3.3 application, or LT6660JCDC-3.3 equivalent, key selection considerations include its 180µA typical supply current at 3.3V output, 1.3V dropout at 10mA load, 50ppm/V line regulation over full input range, and compatibility with zero-output-capacitance designs where fast settling and minimal board area are critical.

Technical Context

The LT6660JCDC-3.3 uses curvature-compensated bandgap architecture and laser-trimmed thin-film resistors to achieve low drift and high accuracy without external compensation. Its series topology eliminates the fixed idle current required by shunt references, enabling dynamic power savings in intermittent-load systems.

It integrates reverse-battery protection to block conduction below –15V, supports capacitive loads up to 1µF at 10mA (per Table 1), and maintains stability with 0µF output capacitance-enabling use in intrinsic safety and space-constrained applications where ESD-sensitive or ultra-low-noise performance is required.

Key Specifications

Pinout & Package

3-lead plastic DFN (2mm × 2mm × 0.75mm); exposed pad is GND and must be soldered to PCB thermal plane per JEDEC MO-229 variation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision series reference applications.

Compared with LT6660JCDC-3.3, LT6657IMS8-3.3 trades higher supply current and larger package for significantly lower drift, while REF3333AIDBVR offers better initial accuracy and drive strength at the cost of mandatory output capacitance and reduced micropower advantage.

Availability

LT6660JCDC-3.3 is available at Aetrix Electronics and suitable for handheld instruments, precision regulators, A/D and D/A converters, and power supplies requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for LT6660JCDC-3.3 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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LT6660 family was designed by Linear Technology (acquired by ADI in 2017) specifically for micropower, space-constrained precision reference applications-emphasizing low drift, no-output-capacitor operation, and robustness in battery-powered and portable instrumentation.

FAQ

What is the minimum input voltage required for stable operation of the LT6660JCDC-3.3?

The LT6660JCDC-3.3 requires a minimum input voltage of VOUT + 0.9V = 4.2V to maintain regulation. Dropout voltage increases with load: it is 0.9V at zero load and rises to 1.4V max at 20mA. Below 4.2V input, the LT6660JCDC-3.3 enters dropout and output voltage declines linearly with input. Operation below the specified minimum violates Absolute Maximum Ratings and may cause unpredictable behavior.

Does the LT6660JCDC-3.3 require an output capacitor for stability?

No, the LT6660JCDC-3.3 is explicitly designed to be stable with 0µF output capacitance-a key differentiator from most series references. This eliminates ESR-related oscillation risks and saves PCB area. However, if an output capacitor is used (e.g., for noise filtering), Table 1 in the datasheet specifies maximum values (e.g., 1µF at 10mA for 3.3V output) to avoid instability due to phase margin degradation.

What is the guaranteed output current capability of the LT6660JCDC-3.3?

The LT6660JCDC-3.3 guarantees continuous sourcing of up to 20mA across its full operating temperature range (0°C to 70°C). It can deliver short-duration peak currents beyond 20mA, but sustained operation above this level risks exceeding thermal limits (θJA = 102°C/W) and violating the 5-second short-circuit duration rating. The device does not sink current-it is a series reference only.

How does reverse-battery protection function in the LT6660JCDC-3.3?

The LT6660JCDC-3.3 incorporates internal reverse-polarity protection that blocks conduction when the IN pin is driven below GND by up to –15V. This prevents destructive current flow during incorrect battery installation or transient reverse-voltage events. The protection is inherent to the IC's internal structure and requires no external components-unlike discrete diode solutions, it adds no forward voltage drop or leakage in normal operation.

What is the long-term stability specification for the LT6660JCDC-3.3?

The LT6660JCDC-3.3 exhibits 100ppm/√kHr long-term stability of output voltage, measured over 1000+ hours on soldered PC boards at 30°C ambient. This translates to approximately ±100ppm (±330µV) drift after 1000 hours, with diminishing drift thereafter. Long-term stability is affected by mechanical stress from board assembly; the LT6660JCDC-3.3's low IR reflow-induced shift (0.02% typ) helps minimize initial post-soldering drift.