The MAX881REUB+ is a low noise bias supply with power-OK for GaAsFET power amplifiers in 10 pin μMAX package. This inverting power supply is a charge pump inverter followed by a negative linear regulator. The input voltage range is 2.5V to 5.5V. The output is preset at -2V or can be set using two resistors to any voltage from -0.5V to (-VIN + 0.6V). It can deliver up to 4mA. The internal linear regulator also filters the output to 1mVp-p ripple and noise. The MAX881R includes power-OK (active-low POK) output that signals when negative voltage is within 7.5% of its set point. It protects GaAsFET by not allowing power to be applied to GaAsFET's drain until it is properly biased. The signal can be routed either to a microcontroller or directly to aswitch at the GaAsFET drain.
Oscillator frequency of 100KHz
Operating temperature range from -40°C to 85°C
Power-OK signal to control GaAsFET drain switch
0.05μA logic controlled shutdown current and 500μA supply current
1ms start-up and 1mVp-p output ripple
Operates with one 4.7μF and three 0.22μF capacitors (no inductors needed)
Output load regulation of 2mV/mA at VIN >= 2.7V, IOUT = 0 to 4mA
(EN)
