A method and apparatus to dynamically modify internal compensation of a
low dropout (LDO) voltage regulator is provided. The LDO voltage
regulator includes an output pass transistor, an error amplifier, a bias
transistor and a compensation network. The compensation network is
connected between a gate and a drain of the output pass transistor to
compensate for the feedback loop. The compensation network and the bias
transistor generate pole-zero pairs to perform a maximum 45 degrees phase
shift before reaching the crossover frequency in the LDO voltage
regulator. Therefore a minimum 45 degrees phase margin is provided for
the feedback loop in various load conditions. Furthermore, the pole-zero
pairs produced in the LDO voltage regulator are adaptively adjusted
according to load conditions, so that the bandwidth is optimized and
faster transient response is achieved.