This thesis presents a low power DC-DC converter suitable for harvesting energy from high impedance thermoelectric generators (TEGs) for the use in body powered electronics. The chip has been fabricated in a 130nm CMOS technology. To meet the power demands of body powered networks, a novel dual-path architecture capable of efficiently harvesting power at levels below 5 μW has been developed. To control the converter, a low power control loop has been developed. The control loop features a low-power clock and a pulse counting system that is capable of matching the converter impedance with high impedance TEGs. The system consumes less than 900nW of quiescent power and maintains an efficiency of 68% for a load of 5 μW.