CJ78L12

CJ78L12 is the SOT-89 ordering code for the CJ (Jiangsu Changjing) CJ78L12 three-terminal positive regulator, carried in the maker’s own CJ78L12 document for this exact code (the SOT-89-3L datasheet, Rev. C, Apr 2012). One version point belongs on the record: the figures here follow the maker’s historical Rev. C (Apr 2012) sheet for this code, while Changjing’s current official document for the same plain code (Rev. 2.3) specifies a reference output range of 11.64 V to 12.36 V - the plain code itself now carries a ±3 %-class range, so the offered lot’s document version must be reconciled before a production order; the current CJ78L00C series catalogue separately orders the 12 V member under the C-suffixed code CJ78L12C-P3T-ARG. The parameters here follow this code’s own document: an output of 11.5 V minimum, 12.0 V typical and 12.5 V maximum at reference conditions (19 V input, 40 mA load, 25 °C), widening to 11.40 V to 12.60 V across the full input, load and temperature range, a quiescent current of 4.3 mA typical and 6.5 mA maximum, a dropout voltage of 1.7 V typical (the sheet’s single 25 °C figure, printed in its typical column with no maximum specified), line regulation of 55 mV typical and 250 mV maximum, load regulation of 22 mV typical and 100 mV maximum, ripple rejection of 37 dB minimum and 42 dB typical, and a 100 mA output class. The selection point is a low-cost 12 V auxiliary rail for relays, fans and analogue stages in appliances and industrial controls, in the SOT-89 body that solders its tab as the heatsink. Selection advice: budget the dropout honestly - this 78L-class part needs roughly 2 V of headroom at working load, so it regulates from a 15 V-class bus, not from a nominal 12 V rail. Parameters verified against the Changjing CJ78L12 datasheet (Rev. C, Apr 2012, SOT-89-3L electrical characteristics) for this exact code; the maker’s current Rev. 2.3 document for this code (linked below) and the CJ78L00C series document (Rev. 1.7) were read for the version comparison; note the linked Rev. 2.3 document carries the newer output range, not the historical figures above.