CX77301 Datasheet, PDF (1/14 Pages) Skyworks Solutions Inc. – PA Module Dual-band EGSM900 DCS1800 / GPRS

DATA SHEET
CX77301: PA Module Dual-band EGSM900 DCS1800 / GPRS
APPLICATIONS
• Dual-band cellular handsets
encompassing
- Class 4 EGSM900,
- Class 1 DCS1800
- up to Class 10 GPRS multi-slot
operation.
FEATURES
• High efficiency
- EGSM 55%
- DCS 50%
• Input/output matching
- 50 Ω internal
• Small outline 9.1 mm x 11.6 mm
• Low profile 1.5 mm maximum
• Low APC current 10 µA typical
The CX77301 is a dual-band Power Amplifier Module (PAM) designed in a compact 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 (GaAs) 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 common 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 GaAs die, the Silicon (Si) die, and
passive components 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 components 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.
DCS IN
Power Control
Band Select
EGSM IN
Match
CMOS
Bias
Controller
Match
Match
HBT
Match
Figure 1. Functional Block Diagram
DCS OUT
EGSM OUT
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100956E
Skyworks Solutions, Inc. Proprietary Information
[781] 376-7000 • FAX [781] 376-3100 • [e-mail] • WWW.SKYWORKSINC.COM
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SEPTEMBER 19, 2003