I found one similar to EmonTH project ULPNode Project Update – Charles's Blog
It’s also low power monitoring node. Especially I was very interested in how they provide power from batteries. They are using MCP1640 as Step-up voltage regulator.
So I’ve made small comparison table with LTC3525. I must say that MCP1640 can be a good alternative. With almost the same performance characteristic MCP1640 in 4 times cheaper.
Model Output Current Start-up VOUT Price Efficiency (1.2 V, 10mA) Package Shutdown current
LTC3525 400mA 0.85V 3V, 3.3V or 5V 4.16$ 88% SC70 0.1uA
MCP1640 350mA 0.65V 2.0V to 5.5V 0.57$ 82% SOT-23-6 0.7uA
NCP1400A 100mA 0.8V 1.9V to 5.0V 0.7$-0.3$ 80% SOT-23-5 0.15uA
MAX1674 420mA 0.9V 1.9V to 5.0V 2.5$-3$ 90% 8 µMAX 0.1uA
BL8530 200mA 0.8V 2.5V～6.0V 0.07$-0.2$ 80% SOT-89-3 7uA
Can some one comment? May be I don’t see something obvious except historical reasons.