Adafruit Precision LM4040 Voltage Reference Breakout - 2.048V and 4.096V

Breakout board with two shunt-type LM4040 voltage references: 2.048 V (suited to 3.3 V systems) and 4.096 V (suited to 5 V systems), each 0.1% accuracy with 750 Ω bias resistors. Use for calibrating ADCs, multimeters, or microcontroller analog inputs.

VIN1
Input supply for the LM4040 voltage-reference breakout. Adafruit says to power the board with about 5V-12V, or 3V when only the 2.048V reference is needed; the official Eagle schematic connects JP1 pin 1 to the VIN net.
Type · powerVoltage · about 5V-12V input; 3V supports only the 2.048V reference, per Adafruit product page
GND2
Ground reference. The official Eagle schematic connects JP1 pin 2 to the GND net.
Type · groundVoltage · 0V reference
2.048V3
Precision 2.048V reference output for measurement/reference use, not a regulator output for powering loads. The official Eagle schematic connects JP1 pin 3 to the 2.048V net.
Type · outputVoltage · 2.048V reference output, 0.1% accuracy per Adafruit product page
4.096V4
Precision 4.096V reference output for measurement/reference use, not a regulator output for powering loads. The official Eagle schematic connects JP1 pin 4 to the 4.096V net.
Type · outputVoltage · 4.096V reference output, 0.1% accuracy per Adafruit product page

Pin	Position	Type	Function	Voltage
VIN	1	power	Input supply for the LM4040 voltage-reference breakout. Adafruit says to power the board with about 5V-12V, or 3V when only the 2.048V reference is needed; the official Eagle schematic connects JP1 pin 1 to the VIN net.	about 5V-12V input; 3V supports only the 2.048V reference, per Adafruit product page
GND	2	ground	Ground reference. The official Eagle schematic connects JP1 pin 2 to the GND net.	0V reference
2.048V	3	output	Precision 2.048V reference output for measurement/reference use, not a regulator output for powering loads. The official Eagle schematic connects JP1 pin 3 to the 2.048V net.	2.048V reference output, 0.1% accuracy per Adafruit product page
4.096V	4	output	Precision 4.096V reference output for measurement/reference use, not a regulator output for powering loads. The official Eagle schematic connects JP1 pin 4 to the 4.096V net.	4.096V reference output, 0.1% accuracy per Adafruit product page

Test gear

120 other options

Over 120 parts spanning pocket oscilloscopes, logic analyzers, RF and semiconductor analyzers, multimeters, soldering tips and consumables. DSO Quad and Miniware's 4-channel scope cover waveforms; Kingst LA5016 and ScanaQuad handle logic capture.

View all 120

Related groups

4 groups

3D printing

DFRobot 1.75 mm PLA in 1 kg spools makes up the bulk of the group, in over 15 colors. Specialty options include PVA in both diameters, NinjaFlex flexible filament, Proto-Pasta conductive PLA, and wood-fill. OverLord printer spares and OverLord printers round out the hardware side.

Tools & prototyping · 3D printing · 53 parts

Breadboards

Solderless options run from 830- and 400-point boards to 4.5×3.5 cm minis and self-adhesive translucent boards. Adafruit Perma-Proto PCBs copy breadboard rail layout onto solderable copper, so a working layout transfers directly. SMT adapters bridge QFN, TQFP and SSOP parts to 2.54 mm.

Tools & prototyping · Breadboards & prototyping · 33 parts

Enclosures

Over 200 enclosures span board-specific aluminum Pi cases, generic ABS project boxes, DIN-rail housings and outdoor waterproof enclosures. Argon NEO, Argon ONE V2 and ARGON ONE V5 double as heatsinks; the V5 adds dual M.2 NVMe PCIe slots for the Raspberry Pi 5.

Tools & prototyping · Enclosures & cases · 206 parts

Mounting

M3 and M2 screw-and-nut sets, nylon and metal standoffs, LED holders in 5–10 mm, and DIN-rail PCB holders. Adafruit's M3 nylon stand-off set and Pimoroni's Pi standoffs handle the most common Raspberry Pi stacking heights.

Tools & prototyping · Hardware & mounting · 89 parts