Integrated TEC controller for precision thermal management
It accepts a supply from 3V to 5.5V, covering common 3.3V and 5V rails found in optical transceivers, laser diode modules, and industrial temperature chambers.
With a supply range of 3V to 5.5V, the MAX1978ETM+T can run directly off a 3.3V or 5V rail without a separate regulator. At the low end, 3V leaves about 0.3V headroom above the minimum for a 3.3V rail with typical tolerance, so a well-regulated supply is needed. The upper end at 5.5V gives margin for a 5V rail that might rise during light load. This flexibility simplifies BOM consolidation when the same TEC controller is used across multiple board variants with different system voltages.
The 48-WFQFN exposed pad (7x7 mm) is the primary thermal path for the TEC drive current. Without adequate via stitching, the junction temperature can exceed the 85°C operating limit even at moderate output currents. The 48-TQFN footprint is standard for this package family, so layout guides from Maxim's application notes for the MAX1978 family apply directly.