{"contentHash":"1e34b64f7ff16886aa2bd322f1ecd5fa9bae30f788c511dae15be463c0639822","protocol":"bitcoin","authorPubkey":"0f7479c277bb515baa29754d3f150d2f9f2e5e298c4671f65008b5764dfcf0d9","text":">Diodes pointing towards FB means you get the greater of the two feedback signals, diodes pointing away from FB (wth a pull-up resistors) means you get the lesser of the two feedbacks signals. i see this now (in ltspice.) thanks for saving me a frustratingly stupid board revision. >Even the small amount of ripple that gets through your low-pass filter will be hugely amplified by your error amplifiers, resulting in a bunch of output ripple. are PWM DACs more difficult than i'm perceiving? settling time doesn't really matter to me. 100 khz PWM through a 30K and 100nF RC filter should yield roughly 1.65 mv ripple peak to peak on a 3.3V input. that's close to 11 bits? afaik DACs don't have output ripple but shouldn't this ripple be functionally the same as the precision/accuracy of a 10-11 bit DAC? >Seems like Q1A is a bit superfluous Q1A exists to shut off the charging power path no matter what happens. i selected them to withstand VCC (20V from USB-C.) normal charge termination? shut off charging. buck converter fails and the output rail sees 20V? shut off charging. >If it’s tied to ground in a single-supply circuit, it will clip any negative voltages i don't want to charge a dead battery since it's unsafe. off-board comparators check for a minimum voltage, like 3.0V for an 18650. a reverse polarity cell would read 0V, as would an absent cell. a dead cell would read <3V. comparators trigger SD LATCH, no current flow can occur because Q1A/Q1B are held off.","topicHash":"f04b384c0125f2981b53e0738968aafe40ec78569cb0e5075ae829ab39f7527b","topicName":"do-it-yourself","parentHash":"6f8364908a06aa9bf4a4a6ecd18b0c6229191bb9a513c07ab190f99ddc8b14b8","costSunk":"0","biasSupport":0,"biasOppose":0,"biasVouch":0,"biasNull":0,"blockHeight":null,"confirmations":0,"timestamp":"2026-11-08T19:02:36.929Z","tripFp":"c840192c3fa2","viewCount":0,"powDifficulty":0,"relation":0,"ephemeral":true,"nonce":"1c76443e30678dc7","sig":"a3d1599a2e5eba8c5ceacfbd5956dbc9e7eff0f834b5f74f910df1ec5bc1122ffc2e00497bfca98310d45aba47cb058302bc5a11405d2ec7658af48fa0dc2a1f","ephStamp":{"blockHashHex":"00000000000000000000b130846bf2fdfadb5a05a89aa40c62276700e08ee489","nonceHex":"c01d000000000000"},"replyCount":0,"chainReplyCount":0,"vaporReplyCount":0,"clusterSize":1,"receiptHeight":975088,"expiryHeight":979408,"authorMarks":{"since":"2026-11-04T04:03:15.588Z","via":"sight","inscribed":0,"likes":0,"biases":0},"lang":"en","servedBy":{"host":"6af58b1822e0cabfe57d76540f745d059b438f489a796ec6a705c6540233845e","t":"2026-11-08T19:39:56.324Z","sig":"5416d6ad0087bae8f485d2df00799e958a877f51e902292eab9de97b6f32bf1695f965d732537db492bc27470ae40a56fbfa5d15ddff9d9883c9c074374b194f","h":"0000000000000000000149fda0f179108ae890d4c4e6c5c08289bcf8490e054f"}}