DESCRIPTION
MAS9142 is designed for use in both the GSM900 and DCS1800 systems and particularly with Hitachi PF08103B power amplifier module. Other PA modules can be used with the MAS9142, but external compensation elements may be required to maintain the stability of the PA control loop. MAS9142 incorporates the power detector biasing components, RC-filtering for power ramping signal, operational amplifier with AC feedback and a low dropout (LDO) voltage regulator. The regulator has the output voltage of 2.8 V and the maximum load current of 50 mA for generating supply voltage for VCO/Modulator in the radio channel of a mobile phone. The regulator’s output is short-circuit protected. Both the PA control loop and LDO voltage regulator have common thermal (over-temperature) protection with 10 °C hysteresis.

FEATURES
• Two functional blocks: Power Amplifier Controller and LDO Voltage Regulator
• Low current consumption
• Temperature compensated biasing for external RF power detection Schottky diodes
• Both PAC loop and LDO voltage regulator have temperature-controlled power-down feature
• LDO voltage regulator with short circuit current protection
• Excellent ripple rejection in regulator
• Various operating modes provide greater flexibility

APPLICATION
• Dual- and Triple-Band Cellular Phones
• PCMCIA GSM/DCS data communications
• GSM based controller for vehicles
• Other RF power controlling applications