I followed the Ti web design and created LM43601PWPR as follows, I built 2 pcb those can get -2.7V output only. My -15V load is about 0.3A.
Here is my original bom:
Bill Of Materials May 6,2019 17:32:43
Item Quantity Value Pcb Footprint ManufPN Manuf DgkPN Description Price_1K Reference
1 2 4.7uF_50V C0805 C2012X5R1H475K125AB TDK Co. 445-5980-1-ND Cap MLCC 0805 4.7uF 10% 50V X5R 0.2346 C38,C40
2 1 2.2uF_16V C0603 EMK107BB7225KA-T Taiyo Yuden 587-5835-1-ND Cap Cer 2.2uF 16V X7R 0603 0.08898 C39
3 1 .47uF_50V C0603 UMK107B7474KA-TR Taiyo Yuden 587-3170-1-ND Cap Ceramic 0603 0.47uF 10% 50V X7R 0.04413 C41
4 1 220pF_50V C0805 C0805C221J5GACTU KEMET 399-1127-1-ND Cap 220pF/50V0805 C0G 5% Ceramic 0.02718 C42
5 2 22uF_25V C1206 CL31A226KAHNNNE Samsung EM 1276-3047-1-ND CAP CER 22uF 25V 10% X5R 1206 0.19685 C43,C45
6 1 100uF_50V CD83X105 EEE-FP1H101AP Panasonic EC P19726TR-ND Cap Aluminum Electrolytic 100uF 20% 50V SMD 180MOhm 0.27968 C44
7 1 47uH_1.8A DO3316P DO3316P-473MLD Coilcraft |MPN_994-DO3316P-473MLB DO3316P SMT Pwr Ind 47uH 20 % 1.8 A 0.914 L5
8 1 0603_1.00M R0603 RT0603FRE071ML Yageo YAG5944CT-ND Res 1.00M 0603 1% 1/10W 0.0122 R41
9 1 73.2K R0805 CR0805-8W-7322FT Panasonic EC ERJ-6ENF7322V Res 0805 73.2K Thick Chip 1% 1/8W 150V 0.01367 R42
10 1 0603_105K R0603 RC0603FR-07105KL Yageo 311-105KHRCT-ND Res 0603 105K 1/10W 1% 0.00476 R43
11 1 LM43601PWPR HTSSOP16 LM43601PWPR Ti 296-40221-1-ND IC REG BUCK ADJ 1A SYNC 16SSOP 2.03034 U12
According to the chip AN SNVA722B, After I changed the C26 to 0.1uF, R24 to 140K, R26 to 10K, tried grounding the pin6. I found the LM43601 convertor works after apply external -15V to the LM43601 output (use Cn1). Once it start working, if I remove the external -15V, it keeps working. But it stop working if I only apply the +15V to my board (use J3) from beginning.(Note: the CN1 trick doesn’t work for the PCB without above changes)
My board needs designed use 15V as input J3. Before LM43601PWPR works, I have to use CN1 with +/-15V for the power input.