CX77301 Datasheet | Conexant Systems

Preliminary Information m o .c U CX77301 4 t e e for Dual-band EGSM900 / DCS1800 / GPRS PA Module h S a Distinguishing Features t a D . w w w This document contains information on a new product. The parametric information, although not fully characterized, is the result of testing initial devices. The CX77301 is a dual-band Power Amplifier Module (PAM) designed in a pact form factor for Class 4 EGSM900 and Class 1 DCS1800 operation that also supports multi-slot transmission for Class 10 General Packet Radio Service (GPRS) operation. - The module consists of an EGSM900 PA block, a DCS1800 PA block, impedance matching circuitry for 50 Ω input and output impedances, and bias control circuitry. Two separate Heterojunction Bipolar Transistor (HBT) PA blocks are fabricated on a single Gallium Arsenide (Ga As) die. One PA block operates in the EGSM900 band and the other PA block supports the DCS1800 band. Optimized for lithium ion battery operation, both PA blocks share mon power supply pins to distribute current. A custom CMOS integrated circuit provides the internal interface circuitry, including a current amplifier that minimizes the required power control current (IAPC) to 10 µA, typical. The Ga As die, the Silicon (Si) die, and passive ponents are mounted on a multi-layer laminate substrate. The assembly is encapsulated with plastic overmold. The RF input and output ports are internally matched to 50 Ω to reduce the number of external ponents for a dual-band design. Extremely low leakage current (2 µA, typical) of the dual PA module maximizes handset standby time. The CX77301 also contains band-select switching circuitry to select EGSM (logic 0) or DCS (logic 1) as determined from the Band Select (BS) signal. In the Functional Block Diagram shown below, the BS pin selects the PA output (DCS OUT or EGSM OUT) while the Analog Power Control (APC) controls the level of output power. Functional Block Diagram DCS IN m o .c U 4 t e e h S a t a .D w w w - -...