Voltage reference that puts out two related voltages: a precise 3.3 V VREF and a VBIAS pin that tracks at exactly half of it. That midscale bias is what a bidirectional current-sense or bipolar ADC signal path needs for its zero point, and because VBIAS tracks VREF over temperature the two stay matched without a divider. It holds low initial error and low drift, and drives both outputs from a small SOT-23-5. A one-chip reference-plus-midscale for level-shifted and bidirectional measurement.

Pinout

Pin	Name	Type	Function
1	VBIAS	output	Bias voltage output equal to VREF/2 (1.65 V for REF2033). Can source and sink up to ±20 mA and tracks VREF over temperature.
2	GND	power_in	Device ground return.
3	EN	input	Active-high enable. Device is enabled when EN >= VIN - 0.7 V; shutdown when EN <= 0.7 V. Shutdown supply current is typically 3.3 uA.
4	VIN	power_in	Input supply voltage, VREF + 0.02 V to 5.5 V (absolute max 6 V). Quiescent current typ 360 uA in active mode.
5	VREF	output	Primary reference voltage output (3.3 V for REF2033). Sources/sinks up to ±20 mA with 10 mV typical dropout; stable with 0-10 uF output capacitance.

Key specifications

Parameter	Value
Type	Dual-output voltage reference
VREF	3.3 V
VBIAS	VREF/2 (tracking)
Initial accuracy	+/-0.05% to 0.1%
Temp drift	8 ppm/C (max)
Supply	VREF + 0.2 V to 5.5 V
Package	SOT-23-5

Ordering variants

Same part, different packaging or reel option.

REF2033AIDDFR (SOT-23-5)
REF2030AIDDFR (3.0 V variant)
REF2025AIDDFR (2.5 V variant)

CAD (KiCad official)

Symbol: Reference_Voltage:REF2033 (KiCad official)
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Texas Instruments datasheet (37 pp, sha256 b79fc315c8fa1a6c, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF