DATA SHEET
SKY77318 iPAC™ PAM for Quad-Band GSM / GPRS
Applications
•
Quad-Band cellular
handsets encompassing
-
Class 4 GSM850/900
-
Class 1 DCS1800/
PCS1900
-
Class 12 GPRS multi-slot
operation
Description
The SKY77318 Power Amplifier Module (PAM) is designed in a low profile (1.2 mm), compact form
factor for quad-band cellular handsets comprising GSM850/900, DCS1800, and PCS1900 operation.
The PAM also supports Class 12 General Packet Radio Service (GPRS) multi-slot operation.
The module consists of separate GSM PA and DCS1800/PCS1900 PA blocks, impedance-matching
circuitry for 50
Ω
input and output impedances and a Power Amplifier Control (PAC) block with an
internal current-sense resistor. The custom BiCMOS integrated circuit provides the internal PAC
function and interface circuitry. Fabricated onto a single Gallium Arsenide (GaAs) die, one
Heterojunction Bipolar Transistor (HBT) PA block supports the GSM bands and the other supports the
DCS1800 and PCS1900 bands. Both PA blocks share common power supply pads to distribute
current. The GaAs die, the Silicon (Si) die, and the passive components are mounted on a multi-layer
laminate substrate. The assembly is encapsulated with plastic overmold.
RF input and output ports of the SKY77318 are internally matched to a 50
Ω
load to reduce the
number of external components for a quad-band design. Extremely low leakage current (2.5
μA,
typical) of the dual PA module maximizes handset standby time. The SKY77318 also contains band-
select switching circuitry to select GSM (logic 0) or DCS/PCS (logic 1) as determined from the Band
Select (BS) signal. In
Figure 1
below, the BS pad selects the PA output (DCS/PCS_OUT or GSM_OUT)
and the Analog Power Control (VAPC) controls the level of output power.
The VBATT pad connects to an internal current-sense resistor and interfaces to an integrated power
amplifier control (iPAC™) function, which is insensitive to variations in temperature, power supply,
process, and input power. The ENABLE input allows initial turn-on of PAM circuitry to minimize battery
drain.
Features
•
Low input power range
-
0 to 6 dBm
•
High efficiency
-
CELL 58%
-
GSM 56%
-
DCS 56%
-
PCS 56%
•
BiCMOS PA controller and
interface IC
-
Low power control slope
-
Fast response time
-
Improved control
accuracy
•
Integrated closed loop
power amplifier control
•
Internal I
CC
sense resistor
for PAC
•
Input/Output matching
50
Ω
internal (with DC
blocking)
•
20-pad package
•
Small outline: 6 x 6 mm
•
Low profile: 1.2 mm
•
MSL3/260 °C
VCC1
GSM_IN
Match
HBT
MODULE
VBATT
POWER CONTROL VAPC
ENABLE
BAND SELECT
DCS/PCS_IN
GND
BiCMOS
Integrated
Power
Amplifier
Controller
PA
Match
GSM_OUT
PA
Match
Match
DCS/PCS_OUT
200242_001
Figure 1. Functional Block Diagram
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
200424B • Skyworks Proprietary and Confidential Information • Products and product information are subject to change without notice. • December 17, 2007
1
SKYWORKS [ SKYWORKS SOLUTIONS INC. ]
