Series AD25 Drive Absolute Encoders


Acuro Series AD25 Absolute Encoder

 AD25 Absolute Encoders
  Dynapar Brand Logo

Quick Specs...

  • For high performance BLDC Motors
  • Up to 22 Bit Single-turn Resolution
  • 4096 Revolutions of Multi-turn Resolution
  • Safety through self-diagnostics
  • Data storage on the encoder
  • Tapered Shaft
  • -15° C to +120° C Operating temperature

Buy Online

Printer-friendly Version

Dimensional Diagrams



Overview Industry/Application Specifications Related Info  

Overview / Design Principle:

The Acuro AD25 is an optical absolute encoder with an optical multi-turn gearbox (non magnetic). Double ball bearing design with flexible spring tether as a torque support. Designed for integration into BLDC servomotors for demanding applications such as CNC, precision positioning and high quality printing. Low current consumption of 85 mA contributes to lowering the drive cost.

The AD25 features new, fully digital technology … Conventional top of the range absolute encoders for motor feedback still provide analog sinusoidal signals to feedback the speed and position of the motor. This information is transmitted over a bidirectional synchronous interface with a variable clock rate up to 10 MHz, resulting in over 4 million measuring steps.

BiSS Interface

BiSS is a new, fully-digital and bi-directional sensor interface. It defines communication between one master and several slaves (sensors) in industrial control systems. BiSS manifests a new standard in technology and is available license-free. Due to its high performance, it constitutes an efficient alternative to the standard combination of data interface and analog sine/cosine incremental output.

BiSS needs only 6 wires, does not require any hardware for analog signals (cables and drive interpolation electronics) - and therefore, helps to reduce system costs.

Self-configuration capabilities allow "plug + play" and keep the system in an operable condition even after a power failure. For more detailed information on BiSS and implementation support please visit

Features and Benefits:

  • Compact design to save valuable space
  • Low power consumption
  • Fast delivery of any model variant
  • High Speed digital interface BiSS
  • Downward compatible (SSI + sincos)
  • PCB connector

The Dynapar Advantage:

  • Innovative, high quality leading edge technology encoder products
  • Broad commercial - industrial grade product line
  • Customized built to order solutions available
  • Global Manufacturing & Service Support
  • Fast-Friendly Customer Service & Technical Support with Multi-Lingual Capabilities
  • Global Network of Authorized Resellers
  • Competitive Product Warranty:  2 Years  


Fully digital position information with up to 22 Bit Single-turn + 12 Bit Multi-turn resolution for speed and position applications.

Standard Operating Characteristics
Supply Voltage: 5 VDC, +10% / -5%
Current Consumption (w/o output current): Single-turn: 45 mA (at 5V)
Multi-turn: 85 mA (at 5V)
Absolute Accuracy: ± 0.01° mechanical (36 arc-sec.)
Repeatability: ± 0.002° mechanical (7.2 arc-sec.)
Connection: 1 ft. Cable (30 cm)
Incremental Signals (SSI models only)
Resolution: 2048
Format: A, B Quadrature, 1 Vpp Sine wave
SSI Interface
Single-turn Resolution: 13 Bits
Multi-turn Resolution: 12 Bits
Number of lines: 4 unidirectional (2 for clock; 2 for data)
Electrical Interface: RS 422
Transmission speed: 70 kHz to 2 MHz per SSI definition
BiSS Interface
Single-turn Resolution: 22 Bits
Multi-turn Resolution: 12 Bits
Signals: Clock unidirectional (from master to encoder); Data unidirectional (from encoder to master)
Electrical Interface: RS 422
Number of lines: 4 unidirectional (2 for clock and 2 for data)
Transmission speed: 70 kHz - 10 MHz
Transmission security: 1 start bit, 1 stop bit, 4 Bit CRC
Diagnostic functions: possible failure modes are constantly checked with the following functions
LED current sensing: Pollution, condensation, over-temperature
Single-step check: Disk pollution or damage, condensation, mechanical overload
Temperature monitoring: Warning message if the user-defined limits have been reached/exceeded
For further information on the BiSS interface please consult:

Shaft Size: Tapered solid shaft: 10 mm diameter; Cone 1:10
Tapered hub shaft: 10 mm diameter; Cone 1:10
Shaft loading: 5 lb axial, 20 lb radial
Shaft speed: 12,000 RPM (continuous), 15,000 RPM (peak-ST only)
Starting torque: < 1.4 in-oz
Weight: 6.2 oz.
Diameter: 2.28"
Length: 1.85"

Operating Temperature: -15 to +120° C
Storage Temperature: -25 to +85° C (due to packaging)
Enclosure Rating: IP40
Shock: 100 g's for 6 msec duration
Vibration: 10 g's (10 to 2,000 Hz)

Available Specifications:

Related Products & Resources: