A dual-mode transimpedance amplifier (TIA) is realised in a 0.18 μm CMOS technology for the applications of 1 Gbit/s laser detection and ranging (LADAR) systems. The proposed dual-mode CMOS feedforward TIA consists of a voltage-mode inverter input stage with a feedback resistor, followed by a current-mode common-gate amplifier with a feed-forward technique applied at the gate so as to achieve low noise, low power consumption, high gain and wide bandwidth characteristics simultaneously. The measured results demonstrate 76 dBΩ transimpedance gain, 720 MHz bandwidth for 0.5 pF photodiode capacitance, −26.3 dBm sensitivity for 10 −12 bit error rate and 20.7 mW power dissipation from a single 1.8 V supply.