STMICROELECTRONICS STPAC01F1

STPAC01F1
®
RF DETECTOR FOR
POWER AMPLIFIER CONTROL
IPADTM
MAIN PRODUCT CHARACTERISTICS
The STPAC01F1 has two outputs, one for the
signal detection and another one for the
temperature compensation:
VDCout = 0.88 V at 0.85 GHz at 10 dBm
VDCout = 1.07 V at 1.85 GHz at 10 dBm
Vsupply = 5 V max.
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■
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DESCRIPTION
The STPAC01 is an integrated RF detector for the
power control stage. It converts RF signal coming
from the coupler into a DC signal usable by the
digital stage. It is based on the use of two similar
diodes, one providing the signal detection while
the second one is used to provide a temperature
information to thermal compensation stage. A
biasing stage suppresses the detection diode drop
voltage effect.
Target applications are cellular phones and PDA
using GSM, DCS, PCS, AMPS, TDMA , CDMA
and 800MHz to 1900MHz frequency ranges
Flip-Chip package
PIN CONFIGURATION (ball side)
BENEFITS
■
The use of IPAD technology allows the RF
front-end designer to save PCB area and to
drastically suppress parasitic inductances.
3
2
1
DC
out
V
Temp
Gnd1
Gnd1
Gnd2
B
RFin
Gnd1
Bias
C
A
FUNCTIONAL DIAGRAM
Coupler
VBIAS
RF input
RF detector
Low pass
filter
Thermal
compensation
VDCOut
Vtemp
STPAC01F1
GND1
GND2
TM : IPAD is a trademark of STMicroelectronics.
January 2003 - Ed: 1
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STPAC01F1
ABSOLUTE RATINGS (Tamb = 25°C)
Symbol
Value
Unit
Bias voltage
5
V
PRF
RF power at the RF input
20
dBm
FOP
Operating frequency range
0.8 to 2
GHz
VPP
ESD level as per MIL-STD 883E method 3015.7 notice 8 (HBM)
100
V
TOP
Operating temperature range
-30 to +85
°C
TSTG
Storage temperature range
-55 to 150
°C
VBIAS
Parameter and test conditions
ELECTRICAL CHARACTERISTICS (Tamb = 25°C)
PARAMETERS RELATED TO BIAS VOLTAGE
Symbol
Parameter
VBIAS
Operating bias voltage
IBIAS
Bias current
Test conditions
Min.
Typ.
2.2
VBIAS = 3.2 V
Max.
Unit
3.2
V
0.5
mA
PARAMETERS RELATED TO DETECTION FUNCTION (VBIAS = 2.7 V, DC output load = 100 kΩ)
Symbol
VDCout
∆VDCout
Parameter
DC output voltage
(see fig. 1, IDC = 50µA)
Test conditions
Min.
Typ.
Max.
Unit
F = 1.85 GHz, PRF = 10 dBm
0.97
1.07
1.17
V
F = 1.85 GHz, PRF = -20 dBm
1.83
1.93
2.03
F = 0.85 GHz, PRF = 10 dBm
0.78
0.88
0.98
F = 0.85 GHz, PRF = -20 dBm
1.83
1.93
2.03
DC output voltage variation 0 < Tamb < 70°C,
(see fig. 5, IDC = 50µA)
F = 1.85 GHz, PRF = 10 dBm
0.09
2.2 < VBIAS < 3.2 V,
F = 1.85 GHz, PRF = 10 dBm
0.44
V
PARAMETERS RELATED TO TEMPERATURE FUNCTION
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
1.83
1.93
2.03
V
VTemp
Temperature output
voltage (see fig. 6)
IDC = 50µA
∆VTemp
Temperature output
voltage variation
(see fig. 6)
IDC = 50µA, 0 < Tamb < 70 °C
0.09
IDC = 50µA, 2.2 < VBIAS < 3.2 V
0.44
2/6
V
STPAC01F1
APPLICATION DIAGRAM
Coupler
VBIAS
IDC = 50µA
RF input
Low pass
filter
RF detector
Thermal
compensation
VDCOut
-
Vtemp
Out
+
STPAC01F1
IDC = 50µA
GND1
GND2
The STPAC01 is the first part of the power amplifier stage and provides both RF power and die
temperature measurements. The above figure gives the basic circuit of RF detector.
A coupler located on the line between RF amplifier output and the antenna takes a part of the available
power and applies it to STPAC01 RF input.
The RF detector and the low pass filter provide a DC voltage depending on the input power. Thermal
compensation provides a DC voltage depending on the ambient temperature. As the detection system and
the thermal compensation are based on the same topology, VDCout will have the same temperature
variation as Vtemp. Connected to a differential amplifier, the output will be a voltage directly linked to the
RF input power. VDCout and Vtemp must be bias with 50µA DC current.
This topology offers the most accurate output value as it is 100% compensated.
Fig. 1: VDCout measurement circuit.
Fig. 2: VDCout versus RF input power.
VDCout
RF generator
Power
supply
RF in
STPAC
test board
VDCOut
2
Multimeter
DC output
voltage
VBIAS
1.8
1.6
1850MHz
Tamb = 25°C
Ibias = 50µA
Vbias = 2.7V
1.4
850MHz
1.2
Current
generator
IDC
1
0.8
-20
-15
-10
-5
Pin (dBm)
0
5
10
3/6
STPAC01F1
Fig. 3: Relative variation of VDCout versus
frequency (from 800 to 900 MHz).
Fig. 4: Relative variation of VDCout versus
frequency (from 1800 to 1900 MHz).
VDCout (Freq.) / VDCOut (850MHz)
VDCout (Freq.) / VDCOut (850MHz)
1.05
1.05
1
1
0.95
0.95
0.9
800
825
850
875
900
0.9
1800
Frequency in MHz
1825
1850
Fig. 5: Temperature effect measurement circuit on
VDCout.
RF in
Climatic
chamber
STPAC
test board
VDCOut
STPAC
test board
Multimeter
DC output
voltage
VBIAS
Power
supply
Power
supply
IDC
Current
generator
Current
generator
Fig. 7: Vtemp output voltage versus ambient
temperature.
Vtemp
1.98
Ibias = 50µA
1.96
1.94
1.92
1.9
1.88
0
10
20
30
40
Tamb (°C)
4/6
1900
Fig. 6: Vtemp measurement circuit.
Climatic
chamber
RF generator
1875
Frequency in MHz
50
60
70
Vtemp
Multimeter
Temp.
voltage
VBIAS
IDC
STPAC01F1
PACKAGE MECHANICAL DATA
500µm ± 50
650µm ± 65
1.57mm ± 50µm
500µm ± 50
315µm ± 50
1.57mm ± 50µm
FOOT PRINT RECOMMENDATIONS
MARKING
365
240
365
Dot, ST logo
xxx = marking
yww = datecode
(y = year
ww = week)
Copper pad Diameter :
250µm recommended , 300µm max
Solder stencil opening : 330µm
220
x x x
y ww
40
Solder mask opening recommendation :
340µm min for 300µm copper pad diameter
All dimensions in µm
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STPAC01F1
FLIP-CHIP TAPE AND REEL SPECIFICATION
Dot identifying Pin A1 location
1.75 +/- 0.1
Ø 1.5 +/- 0.1
4 +/- 0.1
3.5 +/- 0.1
ST
xxx
yww
ST
xxx
yww
ST
xxx
yww
8 +/- 0.3
0.73 +/- 0.05
4 +/- 0.1
User direction of unreeling
All dimensions in mm
OTHER INFORMATION
Ordering code
Marking
Package
Weight
Base qty
Delivery mode
STPAC01F1
RAT
Flip-Chip
3.3 mg
5000
Tape & reel
Note: More packing informations are available in the application note AN1235: ''Flip-Chip: Package description and
recommandations for use''
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of
use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by
implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to
change without notice. This publication supersedes and replaces all information previously supplied.
STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written
approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics
© 2003 STMicroelectronics - Printed in Italy - All rights reserved.
STMicroelectronics GROUP OF COMPANIES
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