MAX1969

 

Part Number	Replacement	Explanation

Description

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The MAX1968/MAX1969 are highly integrated and cost-effective, high-efficiency, switch-mode drivers for Peltier thermoelectric cooler (TEC) modules. Both devices utilize direct current control to eliminate current surges in the TEC. On-chip FETs minimize external components while providing high efficiency. A 500kHz/1MHz switching frequency and a unique ripple cancellation scheme reduce component size and noise.

The MAX1968 operates from a single supply and provides bipolar ±3A output by biasing the TEC between the outputs of two synchronous buck regulators. Bipolar operation allows for temperature control without "dead zones" or other nonlinearities at low load currents. This arrangement ensures that the control system does not hunt when the set point is very close to the natural operating point, requiring a small amount of heating or cooling. An analog control signal precisely sets the TEC current. The MAX1969 provides unipolar output up to 6A. Reliability is optimized with settable limits for both TEC voltage and current, with independently set limits for heating and cooling current. An analog output also monitors TEC current.

The MAX1968/MAX1969 are available in a low-profile 28-pin TSSOP-EP package and is specified over the -40°C to +85°C temperature range. The thermally-enhanced TSSOP-EP package with exposed metal pad minimizes operating junction temperature. An evaluation kit is available to speed designs.

MAX1968, MAX1969: Typical Operating Circuit Enlarge+

Key Features

• High Accuracy and Adjustability Improves System Performance by Optimizing TEC Operation
  • Direct Current Control Prevents TEC Current Surges
  • Ripple Cancellation for Low Noise
  • No Dead-Zone or Hunting at Low-Output Current
  • 1% Accurate Voltage Reference
  • Adjustable TEC Voltage Limit
  • Separately Adjustable Heating and Cooling Current Limits
  • ITEC Output Provides Proportional Voltage to TEC Current for Monitoring
• High-Efficiency Switch-Mode Design
  • On-Chip Power MOSFETs Improve Efficiency While Reducing External Components
  • 500kHz/1MHz Switching Frequency
• Choose from ±3A Output Current (MAX1968) or 6A Output Current (MAX1969)
• Thermally Enhanced TSSOP-EP Package Minimizes Operating Junction Temperature

Applications/Uses

• Automated Test Equipment (ATE)
• Biotech Lab Equipment
• EDFA Optical Amplifiers
• Fiber Optic Network Equipment
• Fiber-Optic Laser Modules
• Telecom Fiber Interfaces
• WDM, DWDM Laser Diode Temperature Control