STMicroelectronics TS4061BICT-1.225

Overview

TS4061BICT-1.225 from STMicroelectronics is a precision micropower shunt voltage reference delivering a fixed 1.225 V output with ±0.2% initial accuracy at 25 °C, 10 µA operating current, 35 ppm/°C max temperature coefficient, and 10 µV_p-p low-frequency noise. It operates across –40 to +85 °C and is used in battery-powered instrumentation requiring stable, low-drift references.

For engineers reviewing the TS4061BICT-1.225 datasheet, TS4061BICT-1.225 pinout, TS4061BICT-1.225 application, or TS4061BICT-1.225 equivalent, key selection criteria include shunt reference topology, SOT323-3L package constraints, ultra-low current operation, thermal hysteresis (120 ppm), and capacitive-load stability-critical for portable data acquisition and precision analog front-ends.

Technical Context

The TS4061BICT-1.225 functions as a two-terminal shunt reference, sinking current to regulate voltage across its cathode-anode terminals. Its internal bandgap circuit achieves high initial accuracy without external trimming, and its low dynamic impedance (0.15–0.3 Ω) ensures minimal load regulation error over 10 µA–15 mA operating current range.

It exhibits stable behavior with capacitive loads up to 100 nF and features low thermal hysteresis (120 ppm) and wideband noise of 95 µV_RMS (10 Hz–10 kHz). The device's 35 ppm/°C max tempco and ±0.2% grade make it suitable for industrial-grade measurement systems where ambient drift must be tightly bounded.

Key Specifications

Pinout & Package

TS4061BICT-1.225 is housed in a SOT323-3L surface-mount package (1.8 × 1.35 × 0.8 mm), optimized for space-constrained PCBs in portable instrumentation. Pin 1 is Anode, Pin 2 is Cathode, and Pin 3 is NC (No Connect)-must remain unconnected or tied to Anode per datasheet guidance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431BIDBVR and REF3012AIDBZR, TS4061BICT-1.225 offers lowest operating current and true two-terminal simplicity for fixed-voltage shunt applications, but lacks adjustability and requires careful anode grounding-making it optimal for space- and power-constrained, fixed-reference instrumentation.

Availability

TS4061BICT-1.225 is available at Aetrix Electronics and suitable for portable data loggers, medical sensor interfaces, and industrial pressure transmitters requiring stable component supply with guaranteed long-term manufacturability.

Supply support for TS4061BICT-1.225 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

The TS4061 belongs to ST's precision analog reference product line, engineered specifically for ultra-low-power, high-accuracy voltage referencing in battery-operated and space-constrained measurement systems.

FAQ

What is the maximum capacitive load the TS4061BICT-1.225 can drive without oscillation?

The TS4061BICT-1.225 remains stable with capacitive loads up to 100 nF, as verified in Figure 9 of the official datasheet (DocID026252 Rev 2). This eliminates the need for series isolation resistors in most sensor interface and ADC reference applications, simplifying layout and improving noise immunity in compact PCBs.

Can Pin 3 (NC) be left floating or must it be connected?

Per ST's datasheet revision note (Rev 2, Feb 2018), Pin 3 is explicitly designated NC (No Connect) and must either be left unconnected or tied to the Anode (Pin 1). It has no internal connection; floating it poses no risk, but connecting to Anode improves mechanical reliability during reflow soldering in high-volume assembly.

How does the 10 µA operating current affect minimum load design?

The TS4061BICT-1.225 requires ≥10 µA sink current to maintain regulation. Designers must ensure total load current-including feedback paths, ADC reference inputs, and leakage-meets or exceeds this threshold. For example, pairing with a 1 MΩ pull-up yields only 1.225 µA, so auxiliary current paths (e.g., bias resistors or active loads) are necessary to guarantee regulation.

Is the 35 ppm/°C temperature coefficient guaranteed over the full –40 to +85 °C range?

Yes-the 35 ppm/°C maximum temperature coefficient is a guaranteed limit across the full industrial temperature range (–40 to +85 °C), as specified in Table 4 of the datasheet under "ΔVk/ΔT Average temperature coefficient." This value represents worst-case drift per degree, ensuring predictable performance in uncontrolled ambient environments.