Texas Instruments REF1004C-2.5/2K5

Overview

REF1004C-2.5/2K5 from Texas Instruments is a two-terminal micropower bandgap voltage reference diode delivering 2.500 V ±20 mV initial accuracy at 100 µA, with 20 ppm/°C temperature coefficient, 0.6 Ω dynamic impedance, and operation down to 20 µA minimum current - used in precision A/D and D/A converters requiring stable low-power biasing.

For engineers reviewing the REF1004C-2.5/2K5 datasheet, REF1004C-2.5/2K5 pinout, REF1004C-2.5/2K5 application, or REF1004C-2.5/2K5 equivalent, key selection criteria include its 2.5 V output tolerance, SOIC-8 package compatibility, long-term stability (20 ppm/kHr), ultra-low noise (120 µV RMS, 10 Hz–10 kHz), and suitability for battery-powered medical and portable instrumentation where supply current must stay below 20 µA.

Technical Context

The REF1004C-2.5/2K5 operates as a shunt-mode voltage reference, sinking current through its cathode terminal to maintain a precise 2.5 V across its terminals. It uses a bandgap core with curvature compensation to achieve 20 ppm/°C drift over 0°C to +70°C and supports load currents up to 20 mA while maintaining regulation.

Its reverse dynamic impedance remains ≤0.6 Ω at 100 µA, enabling fast transient response in feedback loops, and its wide-band noise is specified at 120 µV RMS (10 Hz–10 kHz), making it suitable for high-resolution data acquisition systems where reference noise directly impacts ADC ENOB.

Key Specifications

Pinout & Package

REF1004C-2.5/2K5 is housed in an 8-lead SOIC (D) package per JEDEC MS-012, with pins 1–4 and 5–8 arranged linearly on opposing sides. Pin 1 is cathode; pins 2–4 and 6–8 are no-connect (NC); pin 5 is anode. The device operates in shunt mode: anode connects to ground, cathode to regulated node.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt voltage reference applications.

Compared with LT1004CZ-2.5 and LM385B-2.5/NOPB, REF1004C-2.5/2K5 delivers tighter initial accuracy, lower tempco, lower noise, and half the minimum operating current - making it the preferred choice for new designs targeting 16-bit performance and multi-year battery operation without sacrificing SOIC-8 compatibility.

Availability

REF1004C-2.5/2K5 is available at Aetrix Electronics and suitable for portable medical instrumentation, battery-powered test equipment, and industrial A/D converter modules requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for REF1004C-2.5/2K5 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

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, specializing in analog and embedded processing technologies with leadership in precision analog ICs and power management solutions.

The REF1004 series was designed specifically for micropower, high-accuracy voltage referencing in portable and battery-operated systems - addressing the need for stable 1.2 V and 2.5 V references with sub-20 µA operation and ppm-level stability.

FAQ

What is the operating temperature range for REF1004C-2.5/2K5?

The REF1004C-2.5/2K5 is characterized for operation from 0°C to +70°C. This commercial-grade temperature range is validated per TI's datasheet specifications and applies to all electrical parameters including reference voltage, tempco, and dynamic impedance. The "C" suffix explicitly denotes this grade, distinguishing it from the extended-range REF1004I-2.5 variant rated for –40°C to +85°C. REF1004C-2.5/2K5 maintains 2.500 V ±20 mV accuracy across this full range.

Does REF1004C-2.5/2K5 require an external series resistor in typical shunt configurations?

Yes, REF1004C-2.5/2K5 requires an external series resistor to set the operating current between its 20 µA minimum and 20 mA maximum. For example, with a 5 V supply and target 100 µA bias, a 24.9 kΩ resistor yields 100.4 µA - ensuring stable regulation while staying within safe dissipation limits. The resistor value must be selected to guarantee current remains above 20 µA under worst-case supply and load conditions. REF1004C-2.5/2K5 does not integrate this resistor.

Is REF1004C-2.5/2K5 pin-compatible with the LT1004 series?

Yes, REF1004C-2.5/2K5 is a drop-in replacement for LT1004CZ-2.5 and LT1004CN-2.5 in 8-lead SOIC packages. Pin 1 (cathode) and Pin 5 (anode) match exactly, and all NC pins align. No PCB changes are required when upgrading from LT1004 to REF1004C-2.5/2K5, though design validation should confirm improved tempco and noise performance meet system requirements.

What is the maximum power dissipation for REF1004C-2.5/2K5 in SOIC-8 package?

The absolute maximum power dissipation for REF1004C-2.5/2K5 is determined by its SOIC-8 thermal resistance (θ_JA ≈ 160°C/W) and maximum junction temperature of +150°C. At +70°C ambient, maximum continuous power is ~500 mW - but practical operation is limited by current: at 20 mA and 2.5 V, power is 50 mW, well within safe margins. Derating is recommended above +70°C ambient per TI's thermal guidelines.

Can REF1004C-2.5/2K5 be used in series with other references or in stacked configurations?

No, REF1004C-2.5/2K5 is a two-terminal shunt reference and cannot be stacked or wired in series to generate higher voltages. Its anode must connect directly to ground (or common reference node), and cathode supplies the regulated voltage. Attempting series connection violates its internal bandgap topology and will result in improper regulation or device damage. For higher reference voltages, use dedicated series-mode references or resistor-divider scaling with buffering.