Texas Instruments REF35409YBHR

Overview

REF35409YBHR from Texas Instruments is a nanopower, high-precision series voltage reference delivering 4.096V output with ±0.05% initial accuracy, 10ppm/°C max temperature coefficient (−40°C to +85°C), and 650nA typical quiescent current in a 4-pin WCSP package. It serves as a stable reference for precision ADCs, DACs, and sensor signal chains in portable and industrial instrumentation.

For engineers reviewing the REF35409YBHR datasheet, REF35409YBHR pinout, REF35409YBHR application, or REF35409YBHR equivalent, key selection criteria include ultra-low power consumption, tight initial tolerance, low thermal drift over extended temperature range, noise reduction via NR pin, and enable-controlled shutdown mode.

Technical Context

The REF35409YBHR implements a bandgap-based series reference architecture with integrated noise-reduction (NR) and enable (EN) terminals. Its design targets applications requiring long-term stability (40ppm at 1k hour) and low thermal hysteresis (70ppm) without external trimming.

It operates across −55°C to +125°C functional range, with specified performance over −40°C to +85°C for the YBH (WCSP) package. Input voltage range is VREF + VDO to 6V, supporting source/sink load currents of +10mA/−5mA while maintaining 20ppm/mA load regulation.

Key Specifications

Pinout & Package

REF35409YBHR uses a 4-pin Wafer Chip Scale Package (WCSP), measuring 1.05mm × 0.84mm, optimized for space-constrained PCB layouts in wearable and IoT edge sensors.

Key Features

Applications

Equivalent & Alternatives

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

Compared with REF35409YBHR, REF3440QDBVR offers superior accuracy and drift at the cost of board area and feature set, while ADR3440ARMZ trades nanopower operation for ease of hand-soldering and broader distributor availability - making REF35409YBHR optimal for miniaturized, battery-critical designs demanding both precision and intelligence.

Availability

REF35409YBHR is available at Aetrix Electronics and suitable for flow transmitter calibration, blood glucose monitor production, and servo drive control module manufacturing requiring stable component supply and long-lifecycle support.

Supply support for REF35409YBHR 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 and embedded processing technologies, with decades of expertise in precision analog ICs.

The REF35 family was designed specifically for ultra-low-power, high-accuracy reference needs in portable instrumentation, medical diagnostics, and industrial process control-prioritizing nanopower operation without sacrificing stability or accuracy.

FAQ

What is the maximum operating temperature range for REF35409YBHR?

The REF35409YBHR is functional from −55°C to +125°C. Its guaranteed specifications-including ±0.05% initial accuracy and 10ppm/°C temperature coefficient-are validated over −40°C to +85°C for the YBH (WCSP) package. This makes REF35409YBHR suitable for under-hood automotive and industrial environments where extended thermal robustness is required beyond standard commercial ranges.

Does REF35409YBHR require an external capacitor on the NR pin?

No, the NR pin of REF35409YBHR may be left floating with no impact on basic functionality. However, connecting a capacitor (typically 1µF to 10µF) between NR and GND reduces 0.1Hz–10Hz output noise from 3.3ppm_P-P to as low as 1.8ppm_P-P, which is beneficial in high-resolution DC measurements. The REF35409YBHR datasheet confirms stable operation with NR open or bypassed.

Can REF35409YBHR drive a 10kΩ load directly?

Yes. With a 4.096V output and ±5mA sink/source capability, REF35409YBHR can drive a minimum resistive load of 409.6Ω (4.096V ÷ 10mA). A 10kΩ load draws only 409.6µA - well within its +10mA sourcing limit and introduces <20ppm load regulation error. No buffer amplifier is needed for typical ADC reference or op-amp biasing applications.

What is the dropout voltage specification for REF35409YBHR at 10mA load?

The dropout voltage for REF35409YBHR is 250mV maximum at 10mA load, per Section 6.6 of the SNAS809C datasheet. This means VIN must be ≥ 4.346V (4.096V + 0.25V) for full-spec operation at full load. At 5mA, dropout is 120mV, allowing operation from as low as 4.216V input - enabling use with single-cell Li-ion (3.0–4.2V) when paired with a low-dropout pre-regulator.

How does the enable (EN) pin behavior differ between active and shutdown states in REF35409YBHR?

In REF35409YBHR, the EN pin asserts active mode when voltage exceeds 0.7×VIN (or is left floating), enabling the reference output and drawing 0.65µA typical quiescent current. When EN is pulled below 0.3×VIN, the device enters shutdown, disabling VREF output and reducing supply current to 0.1µA typical. EN pin current remains ≤0.1µA in both states, minimizing control-line loading.