STMICROELECTRONICS STPAC01F2

STPAC01F2
®
IPAD™
RF DETECTOR FOR
POWER AMPLIFIER CONTROL
MAIN PRODUCT CHARACTERISTICS
The STPAC01F2 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
Lead free package
■
Flip-Chip
(8 Bumps)
DESCRIPTION
The STPAC01F2 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.
Table 1: Order Code
Part Number
STPAC01F2
Marking
RA
Figure 1: Pin Configuration (Ball side)
Target applications are cellular phones and PDA
using GSM, DCS, PCS, AMPS, TDMA, CDMA and
800 MHz to 1900 MHz frequency ranges.
3
2
1
DC
out
V
Temp
Gnd1
Gnd1
Gnd2
B
RFin
Gnd1
Bias
C
A
BENEFITS
■
The use of IPAD technology allows the RF
front-end designer to save PCB area and to
drastically suppress parasitic inductances.
Figure 2: Functional diagram
Coupler
VBIAS
RF input
RF detector
Low pass
filter
Thermal
compensation
VDCOut
Vtemp
STPAC01F2
GND1
October 2004
REV. 1
GND2
1/7
STPAC01F2
Table 2: Absolute Retings (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)
250
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)
Table 3: 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
Table 4: Parameters related detection function (VBIAS + 2.7 V, DC output load = 100kΩ)
Symbol
VDCout
∆VDCout
Parameter
DC output voltage
(see fig. 1, IDC = 50 µA)
DC output voltage variation (see fig. 8,
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
0 < Tamb < 70°C
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
Table 5: Parameters related to detection function
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
1.83
1.93
2.03
V
VTemp
Temperature output
voltage (see fig. 9)
IDC = 50µA
∆VTemp
Temperature output
voltage variation
(see fig. 9)
IDC = 50µA, 0 < Tamb < 70°C
0.09
IDC = 50µA, 2.2 < VBIAS < 3.2V
0.44
2/7
V
STPAC01F2
Figure 3: Application diagram
Coupler
VBIAS
IDC = 50µA
RF input
Low pass
filter
RF detector
Thermal
compensation
VDCOut
-
Vtemp
Out
+
STPAC01F2
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.
Figure 4: VDCout measurement circuit
Figure 5: VDCout versus RF input power
VDCout
RF generator
Power
supply
RF in
STPAC
test board
VDCOut
2
Multimeter
1.8
DC output
voltage
VBIAS
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
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STPAC01F2
Figure 6: Relative variation of VDCout versus
frequency (from 800 to 900 MHz)
Figure 7: 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
Figure 8: Temperature effect measurement
circuit on VDCout
RF in
STPAC
test board
Climatic
chamber
VDCOut
Power
supply
IDC
Current
generator
Current
generator
Figure 10: Vtemp output
ambient temperature
voltage
versus
Vtemp
1.98
Ibias = 50µA
1.96
1.94
1.92
1.9
1.88
0
10
20
30
40
Tamb (°C)
4/7
STPAC
test board
Multimeter
DC output
voltage
VBIAS
Power
supply
1900
Figure 9: Vtemp measurement circuit
Climatic
chamber
RF generator
1875
Frequency in MHz
50
60
70
Vtemp
Multimeter
Temp.
voltage
VBIAS
IDC
STPAC01F2
Figure 11: FLIP-CHIP Package Mechanical Data
500µm ± 50
650µm ± 65
1.57mm ± 50µm
500µm ± 50
315µm ± 50
1.57mm ± 50µm
Figure 12: Foot print recommendations
Copper pad Diameter :
250µm recommended , 300µm max
Solder stencil opening : 330µm
Solder mask opening recommendation :
340µm min for 300µm copper pad diameter
Figure 13: Marking
365
240
365
Dot, ST logo
xx = marking
z = packaging location
yww = datecode
(y = year
ww = week)
E
40
220
x x z
y ww
All dimensions in µm
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STPAC01F2
Figure 14: 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 E
xxz
yww
ST E
xxz
yww
ST E
xxz
yww
8 +/- 0.3
0.73 +/- 0.05
4 +/- 0.1
User direction of unreeling
All dimensions in mm
Table 6: Ordering Information
Ordering code
Marking
Package
Weight
Base qty
Delivery mode
STPAC01F2
RA
Flip-Chip
3.3 mg
5000
Tape & reel 7”
Note: More informations are available in the application notes:
AN1235: “Flip-Chip: Package description and recommendations for use”
AN1751: "EMI Filters: Recommendations and measurements"
Table 7: Revision History
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Date
Revision
21-Oct-2004
1
Description of Changes
First issue
STPAC01F2
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.
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All other names are the property of their respective owners
© 2004 STMicroelectronics - All rights reserved
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