AD8314 0

[ Pobierz całość w formacie PDF ]
a
100 MHz–2500 MHz 45 dB
RF Detector/ Controller
AD8314
FEATURES
Complete RF Detector/Controller Function
Typical Range –58 dBV to –13 dBV
–45 dBm to 0 dBm re 50
V
Frequency Response from 100 MHz to 2.5 GHz
Temperature-Stable Linear-in-dB Response
Accurate to 2.5 GHz
Rapid Response: 70 ns to a 10 dB Step
Low Power: 12 mW at 2.7 V
Power-Down to 20
m
A
in shunt with 2 pF. This high-pass
coupling, with a corner at 16 MHz, determines the lowest oper-
ating frequency. Thus, the source may be dc-grounded.
The AD8314 provides two voltage outputs. The first, called
V_UP, increases from close to ground to about 1.2 V as the
input signal level increases from 1.25 mV to 224 mV. This output
is intended for use in measurement mode. Consult the Appli-
cations section of this data sheet for information on use in this
mode. A capacitor may be connected between the V_UP and
FLTR pins when it is desirable to increase the time interval over
which averaging of the input waveform occurs.
The second output, V_DN, is an inversion of V_UP, but with
twice the slope and offset by a fixed amount. This output starts
at about 2.25 V (provided the supply voltage is ³3.3 V) for
the minimum input and falls to a value close to ground at the
maximum input. This output is intended for analog control
loop applications. A setpoint voltage is applied to VSET and
V_DN is then used to control a VGA or power amplifier. Here
again, an external filter capacitor may be added to extend the
averaging time. Consult the Applications section of this data
sheet for information on use in this mode.
The AD8314 is available in a micro_SOIC package and con-
sumes 4.5 mA from a 2.7 V to 5.5 V supply. When powered
down, the typical sleep current is 20 mA.
W
APPLICATIONS
Cellular Handsets (TDMA, CDMA, GSM)
RSSI and TSSI for Wireless Terminal Devices
Transmitter Power Measurement and Control
PRODUCT DESCRIPTION
The AD8314 is a complete low-cost subsystem for the mea-
surement and control of RF signals in the frequency range
0.1 GHz–2.5 GHz, with a typical dynamic range of 45 dB,
intended for use in a wide variety of cellular handsets and other
wireless devices. It provides a wider dynamic range and better
accuracy than possible using discrete diode detectors. In particular,
its temperature stability is excellent over the full operating range of
–30
°
W
.
FUNCTIONAL BLOCK DIAGRAM
FLTR
V-I
VSET
I-V
V UP
DET
DET
DET
DET
DET
RFIN
X2
V DN
10dB
10dB
10dB
10dB
BAND-GAP
REFERENCE
VPOS
OFFSET
COMP'N
AD8314
ENBL
COMM
(PADDLE)
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements 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 Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 1999
For convenience, the signal is internally ac-coupled, using a 5 pF
capacitor to a load of 3 k
C.
Its high sensitivity allows control at low power levels, thus
reducing the amount of power that needs to be coupled to the
detector. It is essentially a voltage-responding device, with a
typical signal range of 1.25 mV to 224 mV rms or –58 dBV to
–13 dBV. This is equivalent to –45 dBm to 0 dBm re 50
°
C to +85
AD8314–SPECIFICATIONS
(V
S
= 3 V, T
A
= +25
8
C, unless otherwise noted)
Parameter
Condition
Min
Typ
Max
Unit
OVERALL FUNCTION
Frequency Range
To Meet All Specifications
0.1
2.5
GHz
Input Voltage Range
Internally AC-Coupled
1.25
224
mV rms
Equivalent Power Range
52.3 W External Termination
–45
0
dBm
Logarithmic Slope
Main Output, V_UP, 100 MHz
1
18.85
21.3
23.35
mV/dB
Logarithmic Intercept
Main Output, V_UP, 100 MHz
–68
–62
–56
dBV
Equivalent dBm Level
52.3 W External Termination
–55
–49
–43
dBm
INPUT INTERFACE
(Pin RFIN)
DC Resistance to COMM
100
kW
Inband Input Resistance
f = 0.1 GHz
3
kW
Input Capacitance
f = 0.1 GHz
2
pF
MAIN OUTPUT
(Pin V_UP)
Voltage Range
V_UP Connected to VSET
0.01
1.2
V
Minimum Output Voltage
No Signal at RFIN, R
L
³ 10 kW
0.01
0.02
0.05
V
Maximum Output Voltage
2
R
L
³ 10 kW
1.9
2
V
General Limit
2.7 V £ V
S
£ 5.5 V
V
S
– 1.1 V
S
–1
V
Available Output Current
Sourcing/Sinking
1/0.5
2/1
mA
Response Time
10%–90%, 10 dB Step
70
ns
Residual RF (at 2f)
f = 0.1 GHz (Worst Condition)
100
mV
INVERTED OUTPUT
(Pin V_DN)
Gain Referred to V_UP
V
DN
= 2.25 V – 2
´
V
UP
–2
Minimum Output Voltage
V
S
³
3.3 V
0.01
0.05
0.1
V
Maximum Output Voltage
V
S
³
3.3 V
3
2.1
2.2
2.5
V
Available Output Current
Sourcing/Sinking
4/100
6/200
mA/
m
A
Output-Referred Noise
RF Input = 2 GHz, –33 dBV, f
NOISE
=
10 kHz
1.05
m
V/
Ö
Hz
Response Time
10%–90%, 10 dB Input Step
70
ns
Full-Scale Settling Time
–40 dBm to 0 dBm Input Step, to 95%
150
ns
SETPOINT INPUT
(Pin VSET)
Voltage Range
Corresponding to Central 40 dB
0.15
1.2
V
Input Resistance
7
10
k
W
Logarithmic Scale Factor
f = 0.900 GHz
20.7
mV/dB
f = 1.900 GHz
19.7
mV/dB
ENABLE INTERFACE
(Pin ENBL)
Logic Level to Enable Power
HI Condition, –30°C £ T
A
£ +85°C
1.6
V
POS
V
Input Current when HI
2.7 V at ENBL, –30°C £ T
A
£ +85°C
20
300
mA
Logic Level to Disable Power
LO Condition, –30°C £ T
A
£ +85°C
–0.5
0.8
V
POWER INTERFACE
(Pin VPOS)
Supply Voltage
2.7
3.0
5.5
V
Quiescent Current
3.0
4.5
5.7
mA
Over Temperature
–30°C £ T
A
£
+85
°
C
2.7
4.4
6.6
mA
Total Supply Current when Disabled
20
95
m
A
Over Temperature
–30
°
C
£
T
A
£
+85
°
C
40
m
A
NOTES
1
Mean and Standard Deviation specifications are available in Table I.
2
Increased output possible when using an attenuator between V_UP and VSET to raise the slope.
3
Refer to Figure 19 for details.
Specifications subject to change without notice.
–2–
REV. 0
AD8314
ABSOLUTE MAXIMUM RATINGS
*
Supply Voltage VPOS . . . . . . . . . . . . . . . . . . . . . . . . . . .5.5 V
V_UP, V_DN, VSET, ENBL . . . . . . . . . . . . . . . . 0 V, VPOS
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 V rms
Equivalent Power . . . . . . . . . . . . . . . . . . . . . . . . . . . +17 dBm
Internal Power Dissipation . . . . . . . . . . . . . . . . . . . . 200 mW
q
Pin Function Descriptions
Pin Name
Function
1
RFIN
RF Input.
2
ENBL
Connect pin to V
S
for normal operation.
Connect pin to ground for disable mode.
JA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
°
C
3
VSET
Setpoint input for operation in controller
mode. To operate in detector mode connect
VSET to V_UP
Maximum Junction Temperature . . . . . . . . . . . . . . . . . 125
°
C
Operating Temperature Range . . . . . . . . . . . –30
°
C to +85
°
C
Storage Temperature Range . . . . . . . . . . . . –65
°
C to +150
°
C
4
FLTR
Connection for an external capacitor to slow
the response of the output. Capacitor is con-
nected between FLTR and V_UP.
C
*
Stresses above those listed under Absolute Maximum Ratings may cause permanent
damage to the device. This is a stress rating only; functional operation of the device
at these or any other conditions above those indicated in the operational section
of this specification is not implied. Exposure to absolute maximum rating conditions
for extended periods may affect device reliability.
°
5
COMM Device Common (Ground).
6
V_UP
Logarithmic output. Output voltage increases
with increasing input amplitude.
7
V_DN
Inversion of V_UP, governed by the following
equation: V_DN = 2.25 V – 2 ´ V
UP
.
PIN CONFIGURATION
8
VPOS
Positive supply voltage (V
S
), 2.7 V to 5.5 V.
RFIN
ENBL
VSET
1
2
3
4
AD8314
8
7
6
5
VPOS
V DN
V UP
COMM
TOP VIEW
(Not to Scale)
FLTR
ORDERING GUIDE
Model
Temperature Range
Package Description
Package Option
AD8314ARM
*
–30°C to +85°C
Tube, 8-Lead micro_SOIC
RM-8
AD8314ARM-REEL
13" Tape and Reel
AD8314ARM-REEL7
7" Tape and Reel
AD8314-EVAL
Evaluation Board
*
Device branded as J5A.
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
the AD8314 features proprietary ESD protection circuitry, permanent damage may occur on
devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
REV. 0
–3–
Lead Temperature Range (Soldering 60 sec) . . . . . . . . . 300
AD8314
–Typical Performance Characteristics
1.2
0.1GHz
4
3
1.0
2.5GHz
2
0.9GHz
1.9GHz
0.1GHz
0.8
1
1.9GHz
0.6
0
2.5GHz
–1
0.9GHz
0.4
–2
0.2
–3
0
–75
–65
–55
–45
–35
–25
–15
–5
–4
–70
–60
–50
–40
–30
–20
–10
0
(–52dBm)
INPUT AMPLITUDE – dBV
(–2dBm)
(–47dBm)
INPUT AMPLITUDE – dBV
(+3dBm)
Figure 1. V
UP
vs. Input Amplitude
Figure 4. Log Conformance vs. Input Amplitude
1.2
3
1.2
3
1.0
2
1.0
2
+25
8
C
+85
8
C
0.8
1
0.8
1
–30
8
C
+85
8
C
–30
8
C
+25
8
C
0.6
0
0.6
0
–30
8
C
+25
8
C
0.4
–1
0.4
–1
0.2
SLOPE AND INTERCEPT
NORMALIZED AT +25
–2
0.2
SLOPE AND INTERCEPT
NORMALIZED AT +25
–2
C AND
APPLIED TO –30
8
C AND +85
8
C
8
C AND
APPLIED TO –30
8
C AND +85
8
C
8
0
–70
–3
0
–70
–3
–60
(–47dBm)
–50
–40
–30
–20
–10
(+3dBm)
0
–60
(–47dBm)
–50
–40
–30
–20
–10
(+3dBm)
0
INPUT AMPLITUDE – dBV
INPUT AMPLITUDE – dBV
Figure 2. V
UP
and Log Conformance vs. Input Amplitude at
0.1 GHz; –30
°
C, +25
°
C, and +85
°
C
Figure 5. V
UP
and Log Conformance vs. Input Amplitude
at 1.9 GHz; –30
°
C, +25
°
C, and +85
°
C
1.2
3
1.2
3
1.0
2
1.0
2
+25
C
+85
8
C
0.8
1
0.8
1
+85
8
C
+85
8
C
+25
C
0.6
0
0.6
0
–30
C
–30
8
C
0.4
–1
0.4
–1
0.2
SLOPE AND INTERCEPT
NORMALIZED AT +25
–2
0.2
SLOPE AND INTERCEPT
NORMALIZED AT +25
–2
C AND
APPLIED TO –30
8
C AND +85
8
C
8
C AND
APPLIED TO –30
8
C AND +85
8
C
8
0
–70
–3
0
–70
–3
–60
(–47dBm)
–50
–40
–30
–20
–10
(+3dBm)
0
–60
(–47dBm)
–50
–40
–30
–20
–10
(+3dBm)
0
INPUT AMPLITUDE – dBV
INPUT AMPLITUDE – dBV
Figure 3. V
UP
and Log Conformance vs. Input Amplitude
at 0.9 GHz; –30
°
C, +25
°
C, and +85
°
C
Figure 6. V
UP
and Log Conformance vs. Input Amplitude
at 2.5 GHz; –30
°
C, +25
°
C, and +85
°
C
–4–
REV. 0
8
8
8
AD8314
23
–55
22
–30
8
C
–30
8
C
–60
+25
C
21
+25
8
C
–65
20
+85
8
C
+85
C
–70
19
18
–75
0
0.5
1.0
1.5
2.0
2.5
0
0.5
1.0
1.5
2.0
2.5
FREQUENCY – GHz
FREQUENCY – GHz
Figure 7. Slope vs. Frequency; –30
C, +25
C, and +85
C
Figure 10. V
UP
Intercept vs. Frequency: –30
°
C, +25
C, and
+85
°
C
22
–61
0.1GHz
–62
0.1GHz
2.5GHz
21
–63
0.9GHz
0.9GHz
–64
20
1.9GHz
–65
–66
2.5GHz
1.9GHz
19
–67
2.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
3.0
3.5
4.0
4.5
5.0
5.5
V
S
– Volts
V
S
– Volts
Figure 8. V
UP
Slope vs. Supply Voltage
Figure 11. V
UP
Intercept vs. Supply Voltage
3500
0
6
X
3000
–200
5
2500
FREQUENCY (GHz)
0.1
0.9
1.9
2.5
R
3030
760
301
90
V
|| - j106
V
|| - j80
–400
4
V
|| - j141
V
DECREASING
V
ENBL
2000
–600
3
1500
–800
2
INCREASING
V
ENBL
R
X
1000
–1000
1
R
500
–1200
0
0
–1400
–1
0.2
0
0.5
1.0
1.5
2.0
2.5
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6
FREQUENCY – GHz
V
ENBL
– Volts
Figure 9. Input Impedance
Figure 12. Supply Current vs. ENBL Voltage, V
S
= 3 V
REV. 0
–5–
8
8
°
°
°
°
|| - jX
V
|| - j748
[ Pobierz całość w formacie PDF ]