Texas Instruments REF1112AIDBZTG4

Overview

REF1112AIDBZTG4 from Texas Instruments is a two-terminal shunt voltage reference IC delivering a precise 1.25V output with ±0.2% initial tolerance, 10ppm/°C typical temperature coefficient (0°C to +70°C), 25μV_PP low-frequency noise (0.1Hz–10Hz), and operation down to 1.2μA quiescent current. It serves as a high-accuracy, ultra-low-power voltage reference in space-constrained sensor signal chains and portable instrumentation.

For engineers reviewing the REF1112AIDBZTG4 datasheet, REF1112AIDBZTG4 pinout, REF1112AIDBZTG4 application, or REF1112AIDBZTG4 equivalent, this page delivers verified specifications, SOT-23-3 pin mapping, real-world implementation constraints, and validated alternative options for battery-powered, industrial, and medical measurement systems requiring stable sub-2μA biasing and <50ppm/°C drift over –40°C to +85°C.

Technical Context

The REF1112AIDBZTG4 operates as a precision bandgap shunt reference-functionally equivalent to a regulated Zener diode-requiring only an external bias resistor and optional load capacitor. Its internal feedback loop fixes the output at 1.25V without external adjustment, and regulation is maintained only when cathode current remains between 1.2μA and 5mA.

It achieves 50ppm/°C max drift over –40°C to +85°C via thin-film resistor trimming and exhibits 0.135Ω typical dynamic impedance across its operating current range, enabling stable performance under varying load conditions in high-impedance sensing nodes.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: 2.92mm × 1.3mm body, 1.12mm max height, JEDEC TO-236 compliant, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431ACDBVR and LM4040CIM3-ADJ/NOPB, REF1112AIDBZTG4 uniquely supports true micropower operation (<2μA), tighter initial tolerance (±0.2% vs. ±0.5%), and lower noise-making it the only viable option for battery life-critical, high-accuracy sensor nodes operating continuously for >5 years.

Availability

REF1112AIDBZTG4 is available at Aetrix Electronics and suitable for battery-powered instrumentation, building security sensors, and medical equipment requiring stable component supply with guaranteed long-term continuity.

Supply support for REF1112AIDBZTG4 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 leader specializing in analog, embedded processing, and digital signal technologies, with over 50 years of innovation in precision analog ICs.

The REF1112AIDBZTG4 belongs to TI's precision voltage reference product line, engineered specifically for ultra-low-power, space-constrained applications such as portable test equipment, wireless sensor nodes, and implantable medical devices where sub-2μA operation and <50ppm/°C drift are mandatory.

FAQ

What is the minimum operating current for REF1112AIDBZTG4?

The REF1112AIDBZTG4 requires a minimum operating current of 1.2μA to maintain regulation. Below this threshold, output voltage deviates from 1.25V and temperature stability degrades. This value is confirmed in Section 5.5 Electrical Characteristics of the SBOS283E datasheet, where IR_MIN is specified as 1.2μA under recommended operating conditions. Designers must size RBIAS to ensure this current is sustained across worst-case supply voltage and load variations.

Can REF1112AIDBZTG4 be used in a series configuration to generate 2.5V?

Yes, REF1112AIDBZTG4 can be stacked in series to produce 2.5V, as demonstrated in Figure 7-3 of the SBOS283E datasheet. Two REF1112AIDBZTG4 devices in series yield V_OUT = 2 × 1.25V = 2.5V while maintaining total cathode current at ~1μA. This configuration preserves micropower operation but requires matched units and careful thermal layout to minimize drift mismatch. The series topology is validated for 1μA operation and does not require additional bias components.

What is the maximum load current REF1112AIDBZTG4 can drive directly?

The REF1112AIDBZTG4 is a shunt reference and does not source current-it sinks current to maintain 1.25V at its VO terminal. Therefore, it does not "drive" load current in the conventional sense. Instead, the maximum current it can sink is 5mA (per Absolute Maximum Ratings), meaning the sum of reference current (I_REF) and load current (I_LOAD) must remain ≤5mA. For example, if I_REF = 1.2μA, then I_LOAD may approach 5mA-but practical designs limit I_REF to ≥10μA for improved stability, reducing usable I_LOAD accordingly.

Is pin 3 (NC) on REF1112AIDBZTG4 required to be grounded?

No, pin 3 (NC) on REF1112AIDBZTG4 must be left unconnected or connected to GND-both configurations are explicitly permitted per Table 4-1 and the Feature Description section of SBOS283E. TI states NC "indicates the pin must be left unconnected or connected to GND"; no internal connection exists. Grounding pin 3 may improve noise immunity in high-EMI environments, but floating is functionally identical and commonly used in space-optimized layouts.

Does REF1112AIDBZTG4 support operation at +125°C?

Yes, REF1112AIDBZTG4 is characterized for operation from –40°C to +125°C, though key specifications like temperature coefficient (50ppm/°C max) and output voltage tolerance (±0.2%) are guaranteed only from –40°C to +85°C. Section 6.1 Overview confirms "operation extending from –40°C to +125°C", and Absolute Maximum Ratings list +125°C as the max operating temperature. At +125°C, parameters such as dynamic impedance and noise remain functional but are outside guaranteed specs-designers should verify system-level accuracy requirements at extremes.