Answer:
As shown in the "Absolute Maximum Ratings" top of page 2:
Operating Temperature Range for MAX1870AETJ is -40°C to +85°C
Continuous Power Dissipation (TA = +70°C)
32-Pin Thin QFN 5mm x 5mm
(derate 21mW/°C above +70°C)......................................1.7W
Maximum junction temperature is +150°C.
Additional Thermal Resistance Data not included in product datasheet:
Single-Layer Board
Theta jA = 47°C/W
Theta jC = 1.70°C/W
Multi-Layer Board
Theta jA = 29°C/W
Theta jC = 1.70°C/W