X9470

Voltage on V+ (referenced to AGND)....................... 7V
Voltage on VCC (reference to VSS)......................... 7V
Voltage on all RH, RW, RL pins
(reference to AGND): ...........................................7V
Voltage on Vsense+ or
Vsense- (reference to AGRND)......................... 30V
Voltage on SDA, CS, SCL, SHDN
(reference to AGND) ............... -0.3V to (Vcc + 0.3V)
Current into Output Pin: ...................................±5mA
Continuous Power Dissipation:........................500mW
Operating Temperature range: ........-40°C to +85°C
Junction Temperature:......................................150°C
Storage Temperature.................... -65°C to +150°C
Lead Temperature (Soldering, 10 seconds): ....300°C


Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and the functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

The Xicor X9470 RF PA Bias Controller contains all of the necessary analog components to sense the PA drain current through an external sense resistor and automatically control the gate bias voltage of an LDMOS PA. The external sense resistor voltage is amplified by an instrumentation amplifier and the out-put of the amplifier along with an external reference voltage is fed to the inputs of a comparator. The comparator output indicates which direction the LDMOS gate bias voltage will move in the next calibration cycle. System calibration is accomplished by enabling the X9470 and providing a clock to the SCL pin. The LDMOS drain current can be maintained constant over temperature and aging changes by periodic calibration. The VOUT pin can be used to monitor the average power by tracking the drain current. Up to eight X9470 or additional Xicor Digital Potentiometers can be controlled via a two-wire serial bus.