Current mode stand alone battery charger controller

A portable electrical device comprising:

• a DC to DC converter configured to accept an input DC voltage from an adapter and provide an output DC voltage and charging current to a rechargeable battery, said DC to DC converter comprising an inductor;
• a current mode battery charger controller to control said DC to DC converter, said current mode battery charger controller comprising:
• a first error amplifier having an output coupled to a common node, said first error amplifier configured to compare a first signal representative of a charging current provided to said rechargeable battery with a maximum charging current and provide a current control signal in response to said comparison;
• an internal compensation network coupled to said common node;
• and
• a comparator configured to compare an inductor current signal representative of an inductor current through said inductor with a compensation signal, said compensation signal representative of a voltage level at said common node, and wherein said compensation signal is reduced by said current control signal if said charging current is greater than said maximum charging current, wherein a reduction in said compensation signal results in a control signal provided by said current mode battery charger controller to reduce said charging current from said DC to DC controller.