Analog Devices AD8314 a Datasheet

100 MHz–2.7 GHz 45 dB

a

FEATURES
Complete RF Detector/Controller Function
Typical Range –58 dBV to –13 dBV

–45 dBm to 0 dBm re 50 
Frequency Response from 100 MHz to 2.7 GHz
Temperature-Stable Linear-in-dB Response

Accurate to 2.7 GHz
Rapid Response: 70 ns to a 10 dB Step
Low Power: 12 mW at 2.7 V
Power-Down to 20 A

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 measure­ment and control of RF signals in the frequency range of 100 MHz
to 2.7 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°C to +85°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 Ω.

RF Detector/Controller

AD8314

For convenience, the signal is internally ac-coupled, using a 5 pF
capacitor to a load of 3 kΩ in shunt with 2 pF. This high-pass
coupling, with a corner at approximately 16 MHz, determines the
lowest operating 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 Appli­cations 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 ≥3.3 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 micro_SOIC and chip scale packages
and consumes 4.5 mA from a 2.7 V to 5.5 V supply. When pow­ered down, the typical sleep current is 20 µA.

*

FUNCTIONAL BLOCK DIAGRAM

RFIN

OFFSET

COMPENSATION

COMM

(PADDLE)

REV. A

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 that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.

FLTR

DETDETDETDETDET

10dB10dB 10dB

10dB

BAND-GAP

AD8314

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © Analog Devices, Inc., 2002

REFERENCE

V-I

I-V

X2

VPOS

ENBL

VSET

V

UP

V DN

AD8314–SPECIFICATIONS

(VS = 3 V, TA = 25C, unless otherwise noted)

Parameter Conditions Min Typ Max Unit

OVERALL FUNCTION

Frequency Range

1

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 Ω External Termination –45 0 dBm

Logarithmic Slope Main Output, V_UP, 100 MHz

2

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 Ω External Termination –55 –49 –43 dBm

INPUT INTERFACE (Pin RFIN)

DC Resistance to COMM 100 kΩ
Inband Input Resistance f = 0.1 GHz 3 kΩ
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
Maximum Output Voltage

General Limit 2.7 V ≤ V

3

RL ≥ 10 kΩ 1.9 2 V

≤ 5.5 V VS– 1.1 VS–1 V

S

≥ 10 kΩ 0.01 0.02 0.05 V

L

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 µV

INVERTED OUTPUT (Pin V_DN)

Gain Referred to V_UP VDN = 2.25 V – 2 × V
Minimum Output Voltage V
Maximum Output Voltage V

≥ 3.3 V 0.01 0.05 0.1 V

S

≥ 3.3 V

S

4

UP

2.1 2.2 2.5 V

–2

Available Output Current Sourcing/Sinking 4/100 6/200 mA/µA
Output-Referred Noise RF Input = 2 GHz, –33 dBV, f

= 10 kHz 1.05 µV/√Hz

NOISE

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 710 kΩ
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 ≤ TA ≤ +85°C 1.6 V

Input Current when HI 2.7 V at ENBL, –30°C ≤ T

≤ +85°C 20 300 µA

A

POS

V

Logic Level to Disable Power LO Condition, –30°C ≤ TA ≤ +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

≤ +85°C 2.7 4.4 6.6 mA

A

Total Supply Current when Disabled 20 95 µA

Over Temperature –30°C ≤ TA ≤ +85°C40µA

NOTES

1

For a discussion on operation at higher frequencies, see Applications section.

2

Mean and Standard Deviation specifications are available in Table I.

3

Increased output possible when using an attenuator between V_UP and VSET to raise the slope.

4

Refer to TPC 19 for details.

Specifications subject to change without notice.

–2–

REV. A

AD8314

WARNING!

ESD SENSITIVE DEVICE

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

θ

(µSO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200°C/W

JA

(CSP, Paddle Soldered) . . . . . . . . . . . . . . . . . . . . 80°C/W

θ

JA

θ

(CSP, Paddle not Soldered) . . . . . . . . . . . . . . . . 200°C/W

JA

Maximum Junction Temperature . . . . . . . . . . . . . . . . . 125°C

Operating Temperature Range . . . . . . . . . . . –30°C to +85°C

Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C

Lead Temperature Range (Soldering 60 sec)

µSO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300°C

CSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240°C

*Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent 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.

PIN CONFIGURATION

RFIN

ENBL

VSET

1

AD8314

2

TOP VIEW

3

(Not to Scale)

4

8

7

6

5

VPOS

DN

V

UP

V

COMMFLTR

Pin Function Descriptions

Pin Name Function

1 RFIN RF Input
2 ENBL Connect pin to V

for normal operation.

S

Connect pin to ground for disable mode.

3 VSET Setpoint input for operation in controller

mode. To operate in detector mode connect
VSET to V_UP.

4 FLTR Connection for an external capacitor to slow

the response of the output. Capacitor is con-

nected between FLTR and V_UP.
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

.

8 VPOS Positive supply voltage (VS), 2.7 V to 5.5 V.

ORDERING GUIDE

Temperature Package Package Branding

Model Range Description Option Information

AD8314ARM –30°C to +85°C Tube, 8-Lead micro_SOIC RM-8 J5A
AD8314ARM-REEL 13" Tape and Reel
AD8314ARM-REEL7 7" Tape and Reel
AD8314-EVAL Evaluation Board
AD8314ACP-REEL –30°C to +85°C 13" Tape and Reel CP-8 J5A

8-Lead Chip Scale Package
AD8314ACP-REEL7 7" Tape and Reel
AD8314ACP-EVAL Evaluation Board

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.

REV. A

–3–

AD8314

–Typical Performance Characteristics

1.2

1.0

0.8

0.6

– Volts

UP

V

0.4

0.2

0

–75 –5–65

1.2

1.0

0.8

0.6

– Volts

UP

V

0.4

(–52dBm)

–55 –45 –35 –25 –15

INPUT AMPLITUDE – dBV

TPC 1. VUP vs. Input Amplitude

+25C

–30C

+85C

+25C

0.1GHz

2.5GHz

0.9GHz

1.9GHz

(–2dBm)

–30C

4

3

2

1

0

ERROR – dB

–1

–2

–3

–4

–70 0–60

(–47dBm) (+3dBm)

–50 –40 –30 –20 –10

INPUT AMPLITUDE – dBV

1.9GHz

2.5GHz

0.1GHz

0.9GHz

TPC 4. Log Conformance vs. Input Amplitude

3

2

1

0

ERROR – dB

–1

1.2

1.0

0.8

0.6

– Volts

UP

V

0.4

+85C

+25C

–30C

3

2

1

0

ERROR – dB

–1

0.2

0

–60

–70 0

(–47dBm)

SLOPE AND INTERCEPT
NORMALIZED AT +25C AND
APPLIED TO –30C AND +85C

–50 –40 –30 –20

INPUT AMPLITUDE – dBV

–10

(+3dBm)

TPC 2. VUP and Log Conformance vs. Input

°

Amplitude at 0.1 GHz; –30

1.2

1.0

0.8

0.6

– Volts

–30C

UP

V

0.4

0.2

0

–60

–70 0

(–47dBm)

+25C

+85C

SLOPE AND INTERCEPT
NORMALIZED AT +25C AND
APPLIED TO –30C AND +85C

–50 –40 –30 –20

INPUT AMPLITUDE – dBV

C, +25°C, and +85°C

–10

(+3dBm)

TPC 3. VUP and Log Conformance vs. Input

°

Amplitude at 0.9 GHz; –30

C, +25°C, and +85°C

–2

–3

0.2

0

–70 0

(–47dBm)

SLOPE AND INTERCEPT
NORMALIZED AT +25C AND
APPLIED TO –30C AND +85C

–60

–50 –40 –30 –20

INPUT AMPLITUDE – dBV

–10

(+3dBm)

–2

–3

TPC 5. VUP and Log Conformance vs. Input

°

Amplitude at 1.9 GHz; –30

3

2

1

0

ERROR – dB

–1

–2

–3

1.2

1.0

–60

(–47dBm)

+85C

+25C

–30C

SLOPE AND INTERCEPT
NORMALIZED AT +25C AND
APPLIED TO –30C AND +85C

–50 –40 –30 –20

INPUT AMPLITUDE – dBV

0.8

0.6

– Volts

UP

V

0.4

0.2

0

–70 0

C, +25°C, and +85°C

+85C

–10

(+3dBm)

3

2

1

0

ERROR – dB

–1

–2

–3

TPC 6. VUP and Log Conformance vs. Input

°

Amplitude at 2.5 GHz; –30

C, +25°C, and +85°C

–4–

REV. A

AD8314

V

ENBL

– Volts

–1

0.2

SUPPLY CURRENT – mA

INCREASING
V

ENBL

0

1

2

3

4

5

6

0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6

DECREASING

V

ENBL

23

22

21

20

SLOPE – mV/dB

19

18

+25C

0

0.5

–30C

1.0

FREQUENCY – GHz

+85C

1.5 2.0 2.5

TPC 7. Slope vs. Frequency; –30°C, +25°C, and +85°C

22

0.1GHz

21

0.9GHz

–55

–60

–65

INTERCEPT – dBV

UP

V

–70

–75

0 0.5 1.0

+85C

1.5 2.0 2.5

FREQUENCY – GHz

–30C

+25C

TPC 10. VUP Intercept vs. Frequency: –30°C, +25°C, and

°

C

+85

–61

–62

–63

–64

0.1GHz

2.5GHz

0.9GHz

SLOPE – mV/dB

UP

20

V

19

3.0 3.5 4.0 4.5 5.0 5.5

2.5
VS – Volts

1.9GHz

2.5GHz

TPC 8. VUP Slope vs. Supply Voltage

3500

3000

2500

2000

1500

RESISTANCE – 

1000

500

0

0

X

FREQUENCY (GHz)

0.1

0.9

1.9

2.5

R

0.5 1.0
FREQUENCY – GHz

R

|| - jX

3030

|| - j748

760

|| - j106

301

|| - j80

90

|| - j141

X

R

1.5 2.0 2.5

0

–200

–400

–600

–800

REACTANCE – 

–1000

–1200

–1400

TPC 9. Input Impedance

INTERCEPT – dBV

–65

UP

V

–66

1.9GHz

–67

3.0 3.5 4.0 4.5 5.0 5.5

2.5
VS – Volts

TPC 11. VUP Intercept vs. Supply Voltage

TPC 12. Supply Current vs. ENBL Voltage, VS = 3 V

REV. A

–5–