sip for gsm/edge in cmos technology...evm for high- and low bands •prbs edge modulation with...
Post on 08-Apr-2020
22 Views
Preview:
TRANSCRIPT
Andreas Ishak Loza1
Giuseppe Li Puma1, Ernst Kristan1, Paolo De Nicola2, Cyril Vannier3,
Braam Greyling4, Salvatore Piccolella5
K
Duisburg, Germany1, Sophia-Antipolis, France2, Xi’an, China3 ,Villach, Austria4, Padova, Italy5
SiP for GSM/EDGE in CMOS Technology
Infineon Technologies AGU.R.S.I. – Kleinheubacher Tagung 2008
Outline
• Motivation
• System Overview
• RF-Integration Aspects
• Measurement Results
Motivation• Integration of RF+BB and PMU in CMOS • Benefits of SiP
– BOM reduction– Small Form Factor
• Customer ease– Fewer board spins– Less validation effort– Faster development
Advantages of SiP• Exploitation of mature existing solutions
• Reduces chip development time
• Lowers risk of crosstalks
• Offers possibility of stacked chipscaletechnology– Logic-Memory Stacking
System Overview
Micrograph• BB+RF SoC
– 0.13 µm CMOS– 6 Metal layers– MIM-capacitors– 20Ωcm substrate– bumps over
active area– w/o deep trench,
triple well
• PMU– 0.25 µm CMOS– thick top metal
layer– 5V capability
RXLNA+MixFilterADC
PLL+
VCO
TX
DCXO Digital
Block Diagram of RF-Part• RX
- Quad-band Zero-IF- 3rd order Channel-filter- 87dB 3rd CT-Σ∆ ADC- Noise Figure 2.4dB- AM Suppression 88dB
• TX- linear polar modulator- closed loop power control+6dBm output power
• Two 26MHz outputbuffers
• Digital Interface to BB
RF-Integration Challenges• Crosstalk
– PMU to RF coupling– BB to RF coupling
Technology Trend
- Number digital gates
- Clock frequency
- I/O-interface speeddigital noise increases
• Thermal effectsFrequency
Synthesizer
TX2
4
DCXO
Package• Increased
routing complexity– 2 distribution layers
• Packagecrosstalk effects– inter-package– package-to-chip RF MS
BB
PMU
TxM
ext.Device
RX-SAW
Crosstalk Analysis• Example:
Coupling into VCO Supply– spurious tone:
– AM/FM conversion– sensitivity factor:
– single sideband to carrier ratio:
– PLL transfer characteristic inherentlysuppresses spurs within loop bandwidth
• similar analysis applicable to LO-path and Driver– AM/AM and AM/PM conversion
VDDVCOFM VfK ∆∆=
)2()( 111 fAKfSSCR FM=
)2cos( 11 tfA π
1
1
2 fAKA FM
c
cA
Schematic of the VCO• Separate supply
voltage and ground
• Supply blocking
• Substrate shielding
• Reduce thermal stress
VbatVbg
Ctune
VDDLO
VDDVCO
Step Down Converter• High PSRR of RF-LDO needed to meet GSM
specification mask
0 5 10 15 20-150
-130
-110
-90
-70
-50
f [MHz]
Rip
ple
[dB
Vp]
Measured Phase Noise Spectrum
• Measured withrunning BB andPMU
• Sideband tone @ 925kHz due to DC/DC switchingfrequency
Temperature Distribution• Package • On-Chip
RFMS
BBPMUBB
RFMSPMU
• PMU is major heat source contributor• Reduced thermal stress of RF-part due to separation
-90
-85
-80
-75
-70
-65
-60
-55
-50
910 920 930 940 950 960 970 980 990Frequency [MHz]
TX p
ower
in R
X ba
nds
[dB
m] RX band E-GSM 900
RX band GSM 900
limit due to GSM specification
Measured TX Spectrum in GSM900 RX Bands at 914.8MHz Carrier Frequency
fTX+52MHz moves with carrier
26MHz harmonics
EDGE Modulation Mask @ ±400kHz
• PRBS EDGE modulation with running PMU and BB
• Measured output power @ ± 400kHz offset from carrier for GSM high- and low bands
• Sufficient margin to GSM specification limits
Spec. Limit Spec. Limit
-75
-70
-65
-60
-55
-50
1700 1730 1760 1790 1820 1850 1880 1910freq. [MHz]
spec
trum
[dB
c]-400kHz
+400kHz
Spec. Limit
GSM 1800 GSM 1900
Spec Limit Spec Limit
-75
-70
-65
-60
-55
-50
820 840 860 880 900 920freq. [MHz]
spec
trum
[dB
c]
-400kHz+400kHzSpec Limit
GSM 850 EGSM 900
EVM for High- and Low Bands• PRBS EDGE
modulation with running PMU and BB
• EVM for high- and low bands
• sufficient margin to GSM specification limits
820 840 860 880 900 9200
2
4
6
8
10
EV
M [
%]
1700 1750 1800 1850 19000
2
4
6
8
10
Frequency [MHz]
EV
M [
%]
EVM AvgEVM Hold
GSM800 GSM900
GSM1800 GSM1900
Limit Limit
LimitLimit
Receiver Sensitivity• Measured
sensitivity withrunning BB and PMU
• No degradationobservable duetointegration
• Achievedperformance iscomparable to stand-alonetransceivers
860 880 900 920 940 960-113
-112
-111
Ref
.Sen
s. [
dBm
]
Class 2 BER 2.4%
Frequency [MHz]
GSM 850GSM 900
1800 1850 1900 1950 2000-113
-112
-111
Frequency [MHz]
Ref
.Sen
s. [
dBm
]
GSM 1800GSM 1900
Conclusion• SiP with integrated highly efficient power
management-unit
• Fabricated in standard CMOS technologies
• RF-performance is comparable to stand-alone CMOS transceivers
• Careful floorplanning, package routing, supply and ground partitioning is mandatory
top related