I am using TPS61026, BQ24070 and BQ27501 to build my Battery management circuit. My AC-DC is 5V 2A, the battery is 3.7V Lithium Ion Battery 2250mAH. The input of TPS61026 is 4.4V and output is 5V. My load is an ARM CPU board (around 240mA) and a 3.5 inch LCD touch screen (around 350-400mA). My problem is I can boot up CPU board but can’t boot up CPU board and LCD at same time. The input of TPS61026 is 4.4V but VOUT is only 1.8V when boot up with LCD. If I power up PM circuit first and put resister as a load, I can get 800mA to 1000mA constantly from TPS61026 VOUT with AC-DC or battery. In my circuit FB pin is NC.
Thank you
John