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Simple NPN Switch

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http://forum.allaboutcircuits.com – I'd like to use an NPN to switch a small load, either saturated or off. In the attached circuit, +VBAT varies between 3V and 4.2V and the base logic operates at 2.8V. I'm planning to use a BC817-40 (datasheet here). My calculations are: Ic = 4.2 / 10000 = 0.42mA Ib = 2.8 / 4700 = 0.50 mA I know it's not usual to have Ib>Ic, but with Hfe of approx 400, it'll be saturated! If I'm reading the datasheet correctly, this condition should give: Vce(sat) of 0.01v Vbe(sat) of 0.5v Does that all seem correct? Anything to watch out for with this circuit? (Embedded)