1764A Series

      The 1764A Series has features including Optimized for Fast Transient Response;Output Current: 3A;Dropout Voltage: 340mV at 3A;Low Noise: 40VRMS (10Hz to 100kHz);1mA Quiescent Current;Wide Input Voltage Range: 2.7V to 20V;No Protection Diodes Needed;Controlled Quiescent Current in Dropout.
      The 1764A Series is a low dropout regulator optimized for fast transient response. The device is capable of supplying 3A of output current with a dropout voltage of 340mV. Operating quiescent current is 1mA, dropping to <1A in shutdown. Quiescent current is well controlled; the 1764A Series does not rise in dropout as it does with many other regulators. In addition to fast transient response, the 1764A Series has very low output voltage noise which makes the device ideal for sensitive RF supply applications.Output voltage range is from 1.21V to 20V. The 1764A Series regulators are stable with output capacitors as low as 10F.Internal protection circuitry includes reverse battery protection, current limiting, thermal limiting and reverse current protection. The device is available in fixed output voltages of 1.5V, 1.8V, 2.5V, 3.3V and as an adjustable device with a 1.21V reference voltage. The 1764A Series regulators are available in 5-lead TO-220 and DD packages, and 16-lead FE packages.
      For fixed voltage versions of the 1764A Series (LT1764A-1.5/LT1764A-1.8/ LT1764A-2.5/LT1764A-3.3), the SENSE pin is the input to the error amplifier. Optimum regulation will be obtained at the point where the SENSE pin is connected to the OUT pin of the regulator. In critical applications, small voltage drops are caused by the resistance (RP) of PC traces between the regulator and the load. These may be eliminated by connecting the SENSE pin to the output at the load as shown in Figure 1 (Kelvin Sense Connection).Note that the voltage drop across the external PC traces will add to the dropout voltage of the regulator. The SENSE pin bias current is 600A at the nominal rated output voltage. The SENSE pin can be pulled below ground (as in a dual supply system where the regulator load is returned to a negative supply) and still allow the device to start and operate.
      The 1764A Series regulators incorporate several protection features which make them ideal for use in battery-powered circuits. In addition to the normal protection features associated with monolithic regulators, such as current limiting and thermal limiting, the 1764A Series are protected against reverse input voltages, reverse output voltages and reverse voltages from output to input.