LA-200/400/500 Series Linear Amplifiers

The LA Linear Servo Amplifier Series are the perfect choice for systems requiring low radiated noise and zero distortion. These high power linear amplifiers are well suited to drive loads such as brushless and brush servo motors or voice coils. Our designs incorporate class AB linear output stages for true linear output.

The design of these amplifiers includes an onboard high-speed DSP that monitors all key system functions in real time, and provides protection for the outputs by limiting output power to a “Safe Operating Area”. An intelligent user interface allows setup and storage of all system parameters via the serial interface. Non-volatile memory provides storage of the parameters during power off conditions.

Modes of Operation

Current Mode

In current mode the amplifier is commutated by an external controller. Our Linear Amplifier Series are designed to drive single & 3-phase loads by analog input commands.

These current mode linear amplifiers are available in the following standard configurations:

“T-Mode” – Three-phase current output. This configuration is used for driving three phase rotary or linear motors with a full-bridge output configuration. In this configuration the amplifier receives two sinusoidal current commands for phases A and B (ABSine). The phase C command is generated internally in the amplifier.

“S-Mode” – Single-phase H-Bridge type output. This configuration is used for driving single phase loads such as brush-type motors or voice coils. In this mode the amplifier can deliver the full rail-to-rail bipolar bus voltage to the load.

The following is an example of S-Mode operation. When operating in full-bridge configuration (Phase to Phase), the maximum bus voltage that can be applied to the voice coil is the full B+ to B- voltage. For example if you are using a +/-50VDC bus and a full-bridge connected voice coil, the maximum voltage that can be applied to the voice coil is +100V or -100V. This is illustrated in the following picture which shows positive current from PhaseB to PhaseC (+100V):

Linear Amplifier Sizing — S-Mode Operation

“D-Mode” – Dual independent Half-Bridge type outputs. This mode is used to drive two independent single phase loads, such as brush-type motors or voice coils, with one amplifier module. In this mode the amplifier can deliver half of the full rail-to-rail bipolar bus voltage to the load. The sum total wattage requirements of the two independent loads must be within the capabilities of the amplifier module.

The following is an example of D-Mode operation, (or one or two voice coil connected to a T-Mode amplifier). When operating in Half-Bridge configuration (Phase to Common), the maximum bus voltage that can be applied to the voice coil is 1/2 of the full +/-Bus supply. For example if you are using a +/-50VDC bus and a half-bridge connected voice coil, the maximum voltage that can be applied to the voice coil is +50V or -50V. This is illustrated in the following picture which shows positive current from phaseB to Common (+50V):

Internally Commutated Current Mode

Our optional VMC2* plug-in board can interface with the encoder to allow the amplifier full sinusoidal commutation.

Velocity Mode & Position Mode

Our optional VMC2* plug-in board can interface with your feedback device to provide velocity & position mode.

*Please contact Varedan for more information.

Request Application Assistance

Tell us about your application so we can help you select the right solution.

Please use this fillable PDF form to guide you through the information about your application that we need to properly size and select an amplifier for your application. Please also see out Amplifier Sizing & Tools page for sizing calculators, white papers and other tools.

Standard Models

Amplifier Series	Current Continuous/Peak	Power Continuous/Peak	±VDC Bus Voltage	Dimensions	Weight
LA-210	2.5/10 Amps	200/400 Watts	±12VDC - ±85 VDC	7.50” x 8.00” x 1.65”	2.6 pounds
LA-415	5/15 Amps	400/1800 Watts	±12VDC - ±85 VDC	7.50” x 8.00” x 2.26”	3.6 pounds
LA-525	10/25 Amps	500/1950 Watts	±12VDC - ±85 VDC	7.50” x 8.00” x 2.76”	4.6 pounds

Key Design Benefits

Linear Output Control for Quiet Operation
True Rail to Rail Output
Multiple Power Levels Share Common Interface
Single-Phase, Three-Phase and D-Mode
Safe Operating Area Protection of Power Devices
Zero Crossover Distortion
External Sinusoidal or Trapezoidal Commutation
Over Current Protection
Over Voltage Protection
Up to 10kHz Bandwidth

Non-Volatile Storage of All System Parameters
Serial User Interface for Programming/Monitoring
RS-232 Communication Interface
Configure Using Jumpers or Serial Interface
Dedicated Limit inputs (Trapezoidal Mode)
Exclusive Autobalance Feature Speeds Setup
7-Segment Display Shows Status in Real-Time
Optional Single-Axis Motion Controller
Factory Programmable Options

Factory or Customer Programmable Options:
- RMS Over-current Trip Level
- RMS Over-current Trip Time
- Absolute Over-current Trip Level
- Enable level
- Enable Source
- Fault level

Models & Specifications

LA-200/400/500 Series Amplifiers

	Datasheet	Manual
Amplifier Module - For high density or OEM applications. Available with or without covers.
Stand-Alone Amplifier Package - For "plug & play" applications. Available in a fully enclosed package with built in fan and power supply.
2 Axis Package with 500VA Power Supply (isolation transformer included) - Mounted on a baseplate with built in fan & power supply.	Contact Varedan	Contact Varedan
2 Axis Package with 1KVA Power Supply (isolation transformer included) - Mounted on a baseplate with built in fan & power supply.	Contact Varedan	Contact Varedan
2 Axis Package (needs external isolation transformer) - Mounted on a baseplate with built in fan.	Contact Varedan	Contact Varedan
4 Axis Package (needs external isolation transformer) - Mounted on a baseplate with built in fan.	Contact Varedan	Contact Varedan