The MAX712 and MAX713 are nickel cadmium (Ni-Cd) battery fast charge controllers which will fast charge batteries from a DC source at least 1V higher than the maximum battery voltage. 1 to 16 series cells can be charged at rates up to 4C. A voltage-slope detecting analogue-to-digital converter, timer, and temperature window comparator determine charge completion. The MAX712 or 713 are powered by the DC source via an on-clip +5V shunt regulator, and draw a maximum of 5uA from the battery when not charging. A low-side current-sense resistor allows the battery charge current to be regulated while still supplying the power to the battery's load.
The MAX712 terminates fast charge by detecting zero voltage slope, while the MAX713 uses a negative voltage-slope detection scheme. Both devices are identically packaged as 16-pin DIL and share the same pin numbering and basic functions. An external power