Low Noise Precision Resistors (UAR)

Direct's low noise precision resistors define accuracy.

The high precision (UAR) resistor represents a significant technical advancement in resistive technology, combining low temperature coefficients with high environmental stabilities, and high frequency performance.

Laser beam trimming gives tolerance accuracies from 0.02 % to 1 %.

The precision (UAR) range effectively bridges the gap that has hitherto existed between the high precision, high stability networks or wirewound technology and conventional film technology.

Full lines equate Vishay, IRC, Ohmite, Caddock, Panasonic precision resistors with fast delivery and more competitive price.

The metal film series is RoHS compliant with Pb-free terminations. Detailed specifications, both mechanical and electrical, please contact our sales representative for more information.

Mil-Std-202 Standard :
This standard establishes uniform methods for testing electronic and electrical component parts, including basic environmental tests to determine resistance to deleterious effects of natural elements and conditions surrounding military operations, and physical and electrical tests.

Download complete PDF Low Noise Precision Resistors (UAR).

Features :
  1. Very tight tolerances: down to A2(±0.02%).
  2. Exceptionally low noise; typically 0.05 μV/V.
  3. 0.125 W to 0.33 W at 85 °C, Electrical Insulation > 1000 MΩ.
  4. Very Low temperature coefficient: ±3, ±5, ±10 and ±15 ppm/°C.
  5. Excellent high frequency performance, industrial grades, RoHS Compliant.
Applications :
  1. All General Purpose Applications,
  2. Medical Electronics, Current Pulse Limiters,
  3. Precision Instruments, Telecom, Test and Measurement.
Dimensions & Technical Characteristics (UAR)
(UAR) Dimensions
(UAR) Dimensions
Type UAR1/4 UAR1/8 UAR1/10
Power Rating at 85°C (W) 0.33 0.25 0.125
Max. Working Voltage (V) 300 300 300
Resistance Range (Ω ) 500.0~1.0M 100.0~1.0M 100.0~1.0M
Dimensions (Unit: mm) L±0.3 14.8 10.0 6.8
D±0.3 5.2 3.7 2.5
A±0.05 0.60 0.60 0.60
Specification (UAR)
Tolerance: ±0.02, ±0.05, ±0.10, ±0.25, ±0.5, ±1.0%
Temp. Coefficient: ±3, ±5, ±10, ±15ppm/°C
Standard Temperature Characteristic: +25 to 85 °C
On Request: -10 to +85 °C
Noise: less than 0.05 μV/V
Voltage Coefficient: less than 0.02 ppm/V
Non Linearity (3. Harm): more than (-100)dB
Thermal Voltage to Copper: 1 ~ 3 μV/°C
Isolations Resistance: 1010Ω
Tests According MIL-STD-202 (UAR)
Temperature Cycling: 0.02%
Low Temp. Operation: 0.013%
Short Time Overload: 0.01%
Dielectric Strength: 0.01%
Load Life: 0.04%
Resistance to Soldering Heat: 0.012%
Moisture Test: 0.050%
Shock and Vibrations Test: 0.015%
Order Codes (UAR)
UAR1/8 210R B C6 P
Part Number
Resistance Value (Ω)
210R 210Ω
2K1 2.1KΩ
21K 21KΩ
Resistance Tolerance (%)
A2 ±0.02%
A5 ±0.05%
B ±0.10%
C ±0.25%
D ±0.5%
F ±1.0%
Temperature coefficient (PPM/°C)
C5 ±15ppm/°C
C6 ±10ppm/°C
C7 ±5ppm/°C
C9 ±3ppm/°C
P Bulk