low-power switching regulator - for battery-operated equipment

for battery-operated equipment The low-power switching regulator type 4193, which is housed in an 8-pin miniature DIL package, is designed specifically for battery operated equipment. A regulated power supply can be constructed for such equipment with just eleven components: five resistors, two capacitors, one diode, a choke, a 4193, and a 2.4...9.0 V battery. The output of this supply will remain .near-constant at 9 V until the battery has decayed to a terminal voltage of 2.4 V. A practical circuit is shown in figure 1. LI D1 level, Ud, is programmed by means of resistors R2 and R5. The value of R2 is given by R2 = [103(Ud — 1.3)/51 kg The integral regulation loop turns off the chip when the feedback voltage drops below 1.3 V. Capacitor C1 is the frequency deter- mining component for the internal sawtooth oscillator in the regulation loop. The output voltage, Uo, is given by U0 = 11.3(R3 + R4)/R41 volts and is plotted (figure 2) against the output current, lo, for various value...