General Description
The MAX9930–MAX9933 low-cost, low-power logarith-
mic amplifiers are designed to control RF power ampli-
fiers (PA) and transimpedance amplifiers (TIA), and to
detect RF power levels. These devices are designed to
operate in the 2MHz to 1.6GHz frequency range. A typi-
cal dynamic range of 45dB makes this family of logarith-
mic amplifiers useful in a variety of wireless and GPON
fiber video applications such as transmitter power mea-
surement, and RSSI for terminal devices. Logarithmic
amplifiers provide much wider measurement range and
superior accuracy to controllers based on diode detec-
tors. Excellent temperature stability is achieved over the
full operating range of -40°C to +85°C.
The choice of three different input voltage ranges elimi-
nates the need for external attenuators, thus simplifying
PA control-loop design. The logarithmic amplifier is a
voltage-measuring device with a typical signal range of
-58dBV to -13dBV for the MAX9930/MAX9933, -48dBV
to -3dBV for the MAX9931, and -43dBV to +2dBV for
the MAX9932.
The MAX9930–MAX9933 require an external coupling
capacitor in series with the RF input port. These devices
feature a power-on delay when coming out of shutdown,
holding OUT low for approximately 2.5µs to ensure
glitch-free controller output.
The MAX9930–MAX9933 family is available in an 8-pin
µMAX®package. These devices consume 7mA with a
5V supply, and when powered down, the typical shut-
down current is 13µA.
Applications
RSSI for Fiber Modules, GPON-CATV Triplexors
Low-Frequency RF OOK and ASK Applications
Transmitter Power Measurement and Control
TSI for Wireless Terminal Devices
Cellular Handsets (TDMA, CDMA, GPRS, GSM)
Features
♦Complete RF-Detecting PA Controllers
(MAX9930/MAX9931/MAX9932)
♦Complete RF Detector (MAX9933)
♦Variety of Input Ranges
MAX9930/MAX9933: -58dBV to -13dBV
(-45dBm to 0dBm for 50ΩTermination)
MAX9931: -48dBV to -3dBV
(-35dBm to +10dBm for 50ΩTermination)
MAX9932: -43dBV to +2dBV
(-30dBm to +15dBm for 50ΩTermination)
♦2MHz to 1.6GHz Frequency Range
♦Temperature Stable Linear-in-dB Response
♦Fast Response: 70ns 10dB Step
♦10mA Output Sourcing Capability
♦Low Power: 17mW at 3V (typ)
♦13µA (typ) Shutdown Current
♦Available in a Small 8-Pin µMAX Package
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
________________________________________________________________
Maxim Integrated Products
1
MAX9930
MAX9931
MAX9932
+
1
2
3
4
VCC
OUT
N.C.
GND
TOP VIEW
RFIN
SHDN
SET
CLPF
8
7
6
5
µMAX
MAX9933
+
1
2
3
4
VCC
OUT
N.C.
GND
RFIN
SHDN
GND
CLPF
8
7
6
5
µMAX
Pin Configurations
19-0859; Rev 1; 3/09
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
Block Diagram appears at end of data sheet.
Ordering Information
+
Denotes a lead-free package.
T = Tape and reel.
PART TEMP RANGE PIN-PACKAGE
MAX9930EUA+T -40oC to +85oC 8 µMAX-8
MAX9931EUA+T -40oC to +85oC 8 µMAX-8
MAX9932EUA+T -40oC to +85oC 8 µMAX-8
MAX9933EUA+T -40oC to +85oC 8 µMAX-8
µMAX is a registered trademark of Maxim Integrated Products, Inc.
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(VCC = 3V, SHDN = 1.8V, TA= -40oC to +85oC, CCLPF = 100nF, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
(Voltages referenced to GND.)
VCC .......................................................................... -0.3V to +6V
OUT, SET, SHDN, CLPF ............................ -0.3V to (VCC + 0.3V)
RFIN
MAX9930/MAX9933 .....................................................+6dBm
MAX9931 ....................................................................+16dBm
MAX9932 ....................................................................+19dBm
Equivalent Voltage
MAX9930/MAX9933................................................. 0.45VRMS
MAX9931 ....................................................................1.4VRMS
MAX9932 ....................................................................2.0VRMS
OUT Short Circuit to GND ........................................ Continuous
Continuous Power Dissipation (TA= +70°C)
8-Pin µMAX (derate 4.5mW/°C above +70°C) .............362mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range ............................-65°C to +150°C
Lead Temperature (soldering, 10s) ................................ +300°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage VCC 2.70 5.25 V
Supply Current ICC VCC = 5.25V 7 12 mA
Shutdown Supply Current ICC SHDN = 0.8V, VCC = 5V 13 µA
Shutdown Output Voltage VOUT SHDN = 0.8V 1 mV
Logic-High Threshold Voltage VH1.8 V
Logic-Low Threshold Voltage VL0.8 V
SHDN = 3V 5 30
SHDN Input Current ISHDN SHDN = 0V -1 -0.01 µA
MAIN OUTPUT (MAX9930/MAX9931/MAX9932)
High, ISOURCE = 10mA 2.65 2.75
Voltage Range VOUT Low, ISINK = 350µA 0.15 V
Output-Referred Noise From CLPF 8 nV/√Hz
Small-Signal Bandwidth BW From CLPF 20 MHz
Slew Rate VOUT = 0.2V to 2.6V from CLPF 8 V/µs
SET INPUT (MAX9930/MAX9931/MAX9932)
Voltage Range (Note 2) VSET Corresponding to central 40dB span 0.35 1.45 V
Input Resistance RIN 30 MΩ
Slew Rate (Note 3) 16 V/µs
DETECTOR OUTPUT (MAX9933)
RFIN = 0dBm 1.45
Voltage Range VOUT RFIN = -45dBm 0.36 V
Small-Signal Bandwidth BW CCLPF = 150pF 4.5 MHz
Slew Rate VOUT = 0.36V to 1.45V, CCLPF = 150pF 5 V/µs
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
_______________________________________________________________________________________ 3
Note 1: All devices are 100% production tested at TA= +25°C and are guaranteed by design for TA = -40°C to +85°C as specified.
Note 2: Typical value only, set-point input voltage range determined by logarithmic slope and logarithmic intercept.
Note 3: Set-point slew rate is the rate at which the reference level voltage, applied to the inverting input of the gmstage, responds to
a voltage step at the SET pin (see Figure 1).
Note 4: Typical min/max range for detector.
Note 5: Pin capacitance to ground.
AC ELECTRICAL CHARACTERISTICS
(VCC = 3V, SHDN = 1.8V, fRF = 2MHz to 1.6GHz, TA= -40°C to +85°C, CCLPF = 100nF, unless otherwise noted. Typical values are at
TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
RF Input Frequency Range fRF 2 1600 MHz
MAX9930/MAX9933 -58 -13
MAX9931 -48 -3
RF Input Voltage Range
(Note 4) VRF
MAX9932 -43 +2
dBV
MAX9930/MAX9933 -45 0
MAX9931 -35 +10
Equivalent Power Range
(50Ω Termination) (Note 4) PRF
MAX9932 -30 +15
dBm
fRF = 2MHz, TA = +25°C 25 27 29
fRF = 2MHz 24 27 30
fRF = 900MHz, TA = +25°C 23.5 25.5 27.5
fRF = 900MHz 22.5 25.5 28.5
Logarithmic Slope VS
fRF = 1600MHz 27
mV/dB
MAX9930/MAX9933 -61 -56 -52
MAX9931 -51 -46 -42
fRF = 2MHz,
TA = +25°C
MAX9932 -46 -41 -37
MAX9930/MAX9933 -63 -56 -50
MAX9931 -53 -46 -40fRF = 2MHz
MAX9932 -48 -41 -35
MAX9930/MAX9933 -62 -59 -53
MAX9931 -53 -50 -44
fRF = 900MHz,
TA = +25°C
MAX9932 -49 -45 -40
MAX9930/MAX9933 -64 -59 -51
MAX9931 -55 -50 -42fRF = 900MHz
MAX9932 -51 -45 -38
MAX9930/MAX9933 -62
MAX9931 -52
Logarithmic Intercept PX
fRF = 1600MHz
MAX9932 -47
dBm
RF INPUT INTERFACE
DC Resistance RDC Connected to VCC 2kΩ
Inband Capacitance CIB Internally DC-coupled (Note 5) 0.5 pF
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VCC = 3V, SHDN = VCC, TA= +25°C, all log conformance plots are normalized to their respective temperatures, TA= +25°C, unless
otherwise noted.)
MAX9930
SET vs. INPUT POWER
MAX9930 toc01
INPUT POWER (dBm)
SET (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
-60 10
1.6GHz
900MHz
2MHz
50MHz
MAX9930
LOG CONFORMANCE vs. INPUT POWER
MAX9930 toc02
INPUT POWER (dBm)
ERROR (dB)
0-10-50 -40 -30 -20
-3
-2
-1
0
1
2
3
4
-4
-60 10
1.6GHz
900MHz
2MHz
50MHz
MAX9930
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 2MHz
MAX9930 toc03
INPUT POWER (dBm)
SET (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-60 10
TA = -40°C
TA = +25°C
TA = +85°C
MAX9930
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 50MHz
MAX9930 toc04
INPUT POWER (dBm)
SET (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-60 10
TA = -40°C
TA = +25°C
TA = +85°C
MAX9930
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 900MHz
MAX9930 toc05
INPUT POWER (dBm)
SET (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-60 10
TA = -40°C
TA = +25°C
TA = +85°C
MAX9930
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 1.6GHz
MAX9930 toc06
INPUT POWER (dBm)
SET (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-60 10
TA = -40°C
TA = +25°C
TA = +85°C
MAX9930
LOG SLOPE vs. FREQUENCY
MAX9930 toc07
FREQUENCY (MHz)
LOG SLOPE (mV/dB)
15001200900600300
22
23
24
25
26
27
21
01800
TA = -40°CTA = +25°C
TA = +85°C
MAX9930
LOG INTERCEPT vs. FREQUENCY
MAX9930 toc09
FREQUENCY (MHz)
LOG INTERCEPT (dBm)
1200800400
-66
-64
-62
-60
-68
01600
TA = -40°C
TA = +25°C
TA = +85°C
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
_______________________________________________________________________________________
5
MAX9930
LOG INTERCEPT vs. VCC
MAX9930 toc10
VCC (V)
LOG INTERCEPT (dBm)
5.04.54.03.53.0
-69
-67
-65
-63
-61
-59
-57
-71
2.5 5.5
2MHz
50MHz
900MHz
1.6GHz
MAX9930
LOG CONFORMANCE vs. TEMPERATURE
MAX9930 toc11
TEMPERATURE (°C)
ERROR (dB)
7550250-25
-0.5
-0.4
-0.3
-0.2
-0.1
0
-0.6
-50 100
INPUT POWER = -22dBm
fRF = 50MHz
MAX9931
SET vs. INPUT POWER
MAX9930 toc12
INPUT POWER (dBm)
SET (V)
100-40 -30 -20 -10
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
-50 20
1.6GHz
900MHz 2MHz
50MHz
MAX9931
LOG CONFORMANCE vs. INPUT POWER
MAX9930 toc13
INPUT POWER (dBm)
ERROR (dB)
100-40 -30 -20 -10
-3
-2
-1
0
1
2
3
4
-4
-50 20
1.6GHz
900MHz
2MHz
50MHz
MAX9931
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 2MHz
MAX9930 toc14
INPUT POWER (dBm)
SET (V)
100-40 -30 -20 -10
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-50 20
TA = -40°C
TA = +25°C
TA = +85°C
MAX9931
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 50MHz
MAX9930 toc15
INPUT POWER (dBm)
SET (V)
100-40 -30 -20 -10
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-50 20
TA = -40°C
TA = +25°C
TA = +85°C
MAX9931
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 900MHz
MAX9930 toc16
INPUT POWER (dBm)
SET (V)
100-40 -30 -20 -10
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-50 20
TA = -40°C
TA = +25°C
TA = +85°C
MAX9931
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 1.6GHz
MAX9930 toc17
INPUT POWER (dBm)
SET (V)
100-40 -30 -20 -10
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-50 20
TA = -40°C
TA = +25°C
TA = +85°C
MAX9931
LOG SLOPE vs. FREQUENCY
MAX9930 toc18
FREQUENCY (MHz)
LOG SLOPE (mV/dB)
15001200900600300
24
25
26
27
28
29
23
0 1800
TA = -40°C
TA = +25°C
TA = +85°C
Typical Operating Characteristics (continued)
(VCC = 3V, SHDN = VCC, TA= +25°C, all log conformance plots are normalized to their respective temperatures, TA= +25°C, unless
otherwise noted.)
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VCC = 3V, SHDN = VCC, TA= +25°C, all log conformance plots are normalized to their respective temperatures, TA= +25°C, unless
otherwise noted.)
MAX9931
LOG SLOPE vs. VCC
MAX9930 toc19
VCC (V)
LOG SLOPE (mV/dB)
5.04.54.03.53.0
23
24
25
26
27
28
29
22
2.5 5.5
2MHz
50MHz
900MHz
1.6GHz
MAX9931
LOG INTERCEPT vs. FREQUENCY
MAX9930 toc20
FREQUENCY (MHz)
LOG INTERCEPT (dBm)
1200800400
-52
-50
-48
-46
-54
0 1600
TA = -40°C
TA = +25°C
TA = +85°C
MAX9931
LOG INTERCEPT vs. VCC
MAX9930 toc21
VCC (V)
LOG INTERCEPT (mV/dB)
5.04.54.03.53.0
-60
-58
-56
-54
-52
-50
-48
-62
2.5 5.5
2MHz
50MHz
900MHz
1.6GHz
MAX9931
LOG CONFORMANCE vs. TEMPERATURE
MAX9930 toc22
TEMPERATURE (°C)
ERROR (dB)
7550250-25
-0.3
-0.2
-0.1
0
0.1
0.2
-0.4
-50 100
INPUT POWER = -12dBm
fRF = 50MHz
MAX9932
SET vs. INPUT POWER
MAX9930 toc23
INPUT POWER (dBm)
SET (V)
2010-30 -20 -10 0
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
-40
1.6GHz
2MHz
50MHz
900MHz
MAX9932
LOG CONFORMANCE vs. INPUT POWER
MAX9930 toc24
INPUT POWER (dBm)
ERROR (dB)
100-30 -20 -10
-3
-2
-1
0
1
2
3
4
-4
-40 20
1.6GHz
900MHz
2MHz
50MHz
MAX9932
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 2MHz
MAX9930 toc25
INPUT POWER (dBm)
SET (V)
2010-40 -30 -20 -10 0
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
TA = -40°C
TA = +25°C
TA = +85°C
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
MAX9932
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 50MHz
MAX9930 toc26
INPUT POWER (dBm)
SET (V)
2010-30 -20 -10 0
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-40
TA = -40°C
TA = +25°C
TA = +85°C
MAX9932
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 900MHz
MAX9930 toc27
INPUT POWER (dBm)
SET (V)
100-30 -20 -10
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
-40 20
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
TA = -40°C
TA = +25°C
TA = +85°C
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
_______________________________________________________________________________________
7
MAX9932
SET AND LOG CONFORMANCE
vs. INPUT POWER AT 1.6GHz
MAX9930 toc28
INPUT POWER (dBm)
SET (V)
100-30 -20 -10
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
-40 20
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
TA = -40°C
TA = +25°C
TA = +85°C
MAX9932
LOG SLOPE vs. FREQUENCY
MAX9930 toc29
FREQUENCY (MHz)
LOG SLOPE (mV/dB)
15001200900600300
24
25
26
27
28
29
23
0 1800
TA = -40°C
TA = +25°C
TA = +85°C
MAX9932
LOG SLOPE vs. VCC
MAX9930 toc30
VCC (V)
LOG SLOPE (mV/dB)
5.04.54.03.53.0
23
24
25
26
27
28
29
22
2.5 5.5
2MHz
50MHz
900MHz
1.6GHz
MAX9932
LOG INTERCEPT vs. FREQUENCY
MAX9930 toc31
FREQUENCY (MHz)
LOG INTERCEPT (dBm)
1200800400
-46
-44
-42
-40
-48
0 1600
TA = -40°C
TA = +25°C
TA = +85°C
MAX9932
LOG INTERCEPT vs. VCC
MAX9930 toc32
VCC (V)
LOG INTERCEPT (dBm)
5.04.54.03.53.0
-53
-51
-49
-47
-45
-43
-41
-55
2.5 5.5
2MHz
50MHz
900MHz
1.6GHz
MAX9932
LOG CONFORMANCE vs. TEMPERATURE
MAX9930 toc33
TEMPERATURE (°C)
ERROR (dB)
7550250-25
-0.4
-0.3
-0.2
-0.1
0
0.1
-0.5
-50 100
INPUT POWER = -10dBm
fRF = 50MHz
MAX9933
OUT vs. INPUT POWER
MAX9930 toc34
INPUT POWER (dBm)
OUT (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
-60 10
1.6GHz
900MHz
2MHz
50MHz
MAX9933
LOG CONFORMANCE vs. INPUT POWER
MAX9930 toc35
INPUT POWER (dBm)
ERROR (dB)
0-10-50 -40 -30 -20
-3
-2
-1
0
1
2
3
4
-4
-60 10
1.6GHz
900MHz
2MHz
50MHz
MAX9933
OUTPUT AND LOG CONFORMANCE
vs. INPUT POWER AT 2MHz
MAX9930 toc36
INPUT POWER (dBm)
OUT (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-60 10
TA = -40°C
TA = +25°C
TA = +85°C
Typical Operating Characteristics (continued)
(VCC = 3V, SHDN = VCC, TA= +25°C, all log conformance plots are normalized to their respective temperatures, TA= +25°C, unless
otherwise noted.)
_______________________________________________________________________________________
7
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
8 _______________________________________________________________________________________
MAX9933
OUTPUT AND LOG CONFORMANCE
vs. INPUT POWER AT 50MHz
MAX9930 toc37
INPUT POWER (dBm)
OUT (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-60 10
TA = -40°C
TA = +25°C
TA = +85°C
MAX9933
OUTPUT AND LOG CONFORMANCE
vs. INPUT POWER AT 900MHz
MAX9930 toc38
INPUT POWER (dBm)
OUT (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-60 10
TA = -40°C
TA = +25°C
TA = +85°C
MAX9933
OUTPUT AND LOG CONFORMANCE
vs. INPUT POWER AT 1.6GHz
MAX9930 toc39
INPUT POWER (dBm)
OUT (V)
0-10-50 -40 -30 -20
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0.2
ERROR (dB)
-3
-2
-1
0
1
2
3
4
-4
-60 10
TA = -40°C
TA = +25°C
TA = +85°C
MAX9933
LOG SLOPE vs. FREQUENCY
MAX9930 toc40
FREQUENCY (MHz)
LOG SLOPE (mV/dB)
15001200900600300
24
25
26
27
28
29
23
0 1800
TA = -40°C
TA = +25°C
TA = +85°C
MAX9933
LOG SLOPE vs. VCC
MAX9930 toc41
VCC (V)
LOG SLOPE (mV/dB)
5.04.54.03.53.0
23
24
25
26
27
28
29
22
2.5 5.5
2MHz
50MHz
900MHz
1.6GHz
MAX9933
LOG INTERCEPT vs. FREQUENCY
XMAX9930 toc42
FREQUENCY (MHz)
LOG INTERCEPT (dBm)
1200800400
-62
-60
-58
-56
-54
-52
-64
0 1600
TA = -40°C
TA = +25°C
TA = +85°C
MAX9933
LOG INTERCEPT vs. VCC
MAX9930 toc43
VCC (V)
LOG INTERCEPT (dBm)
5.04.54.03.53.0
-64
-62
-60
-58
-56
-54
-52
-66
2.5 5.5
2MHz
50MHz
900MHz
1.6GHz
MAX9933
LOG CONFORMANCE vs. TEMPERATURE
MAX9930 toc44
TEMPERATURE (°C)
ERROR (dB)
7550250-25
-0.1
0
0.1
0.2
0.3
0.4
-0.2
-50 100
INPUT POWER = -22dBm
fRF = 50MHz
SUPPLY CURRENT
vs. SHDN VOLTAGE
MAX9930 toc45
SHDN (V)
SUPPLY CURRENT (mA)
1.81.61.2 1.40.4 0.6 0.8 1.00.2
0
1
2
3
4
5
6
7
8
-1
02.0
VCC = 5.25V
Typical Operating Characteristics (continued)
(VCC = 3V, SHDN = VCC, TA= +25°C, all log conformance plots are normalized to their respective temperatures, TA= +25°C, unless
otherwise noted.)
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
_______________________________________________________________________________________
9
SHDN POWER-ON DELAY
RESPONSE TIME
MAX9930 toc47
2μs/div
OUT
1V/div
0V
0V
SHDN
500mV/div
CCLPF = 150pF
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX9930 toc46
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.04.54.03.53.0
6.8
6.6
6.4
6.2
7.0
7.2
7.4
7.6
7.8
8.0
6.0
2.5 5.5
SHDN RESPONSE TIME
MAX9930 toc48
2μs/div
OUT
500mV/div
0V
0V
SHDN
1V/div
CLPF = 150pF
MAIN OUTPUT NOISE-SPECTRAL DENSITY
MAX9930 toc49
FREQUENCY (Hz)
NOISE-SPECTRAL DENSITY (nV/√Hz)
1k 10k 100k 1M
1000
10,000
100
100 10M
MAX9933
CLPF = 220pF
MAXIMUM OUT VOLTAGE
vs. VCC BY LOAD CURRENT
MAX9930 toc50
VCC (V)
OUT (V)
5.04.54.03.53.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.0
2.5 5.5
0mA
5mA
10mA
LARGE-SIGNAL
PULSE RESPONSE
MAX9930 toc51
10μs/div
OUT
500mV/div
RFIN
250mV/div
≤ 900mV
CCLPF = 10,000pF
fRF = 50MHz
-2dBm
-42dBm
Typical Operating Characteristics (continued)
(VCC = 3V, SHDN = VCC, TA= +25°C, all log conformance plots are normalized to their respective temperatures, TA= +25°C, unless
otherwise noted.)
SMALL-SIGNAL
PULSE RESPONSE
MAX9930 toc52
1μs/div
OUT
75mV/div
RFIN
25mV/div
≤ 0V
CCLPF = 150pF
fRF = 50MHz
-24dBm
-18dBm
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
10 ______________________________________________________________________________________10 ______________________________________________________________________________________
OUTPUT-
ENABLED
DELAY
DET DET DET DET
10dB
REFERENCE
CURRENT
OFFSET
COMP
SHDN
OUT
*INVERTING VOLTAGE TO CURRENT CONVERTER
CLPF
SET
RFIN
GND
VCC
DET
10dB 10dB 10dB
X1
V-I*
OUTPUT-
ENABLED
DELAY
DET DET DET DET
10dB
REFERENCE
CURRENT
OFFSET
COMP
SHDN
OUT
CLPF
RFIN
GND
VCC
DET
10dB 10dB 10dB
X1
V-I*
MAX9933
MAX9930
MAX9931
MAX9932
gm
gm
Figure 1. Functional Diagram
Pin Description
PIN
MAX9930/
MAX9931/
MAX9932
MAX9933 NAME FUNCTION
1 1 RFIN RF Input
22SHDN Shutdown. Connect to VCC for normal operation.
3 — SET Set-Point Input
4 4 CLPF Lowpass Filter Connection. Connect external capacitor between CLPF and GND to set
control-loop bandwidth.
5 3, 5 GND Ground
6 6 N.C. No Connection. Not internally connected.
7 7 OUT PA Gain-Control Output
88V
CC Supply Voltage. Bypass to GND with a 0.1µF capacitor.
MAX9930–MAX9933
Detailed Description
The MAX9930–MAX9933 family of logarithmic ampli-
fiers (log amps) comprises four main amplifier/limiter
stages each with a small-signal gain of 10dB. The out-
put stage of each amplifier is applied to a full-wave rec-
tifier (detector). A detector stage also precedes the first
gain stage. In total, five detectors, each separated by
10dB, comprise the log amp strip. Figure 1 shows the
functional diagram of the log amps.
A portion of the PA output power is coupled to RFIN of
the logarithmic amplifier controller/detector, and is
applied to the logarithmic amplifier strip. Each detector
cell outputs a rectified current and all cell currents are
summed and form a logarithmic output. The detected
output is applied to a high-gain gmstage, which is
buffered and then applied to OUT. For the
MAX9930/MAX9931/MAX9932, OUT is applied to the
gain-control input of the PA to close the control loop.
The voltage applied to SET determines the output
power of the PA in the control loop. The voltage applied
to SET relates to an input power level determined by
the log amp detector characteristics. For the MAX9933,
OUT is applied to an ADC typically found in a base-
band IC which, in turn, controls the PA biasing with the
output (Figure 2).
Extrapolating a straight-line fit of the graph of SET vs.
RFIN provides the logarithmic intercept. Logarithmic
slope, the amount SET changes for each dB change of
RF input, is generally independent of waveform or termi-
nation impedance. The MAX9930/MAX9931/MAX9932
slope at low frequencies is about 25mV/dB.
Variance in temperature and supply voltage does not
alter the slope significantly as shown in the
Typical
Operating Characteristics
.
The MAX9930/MAX9931/MAX9932 are specifically
designed for use in PA control applications. In a control
loop, the output starts at approximately 2.9V (with supply
voltage of 3V) for the minimum input signal and falls to a
value close to ground at the maximum input. With a por-
tion of the PA output power coupled to RFIN, apply a volt-
age to SET (for the MAX9930/MAX9931/MAX9932) and
connect OUT to the gain-control pin of the PA to control
its output power. An external capacitor from CLPF to
ground sets the bandwidth of the PA control loop.
Transfer Function
Logarithmic slope and intercept determine the transfer
function of the MAX9930–MAX9933 family of log amps.
The change in SET voltage (OUT voltage for the
MAX9933) per dB change in RF input defines the loga-
rithmic slope. Therefore, a 10dB change in RF input
results in a 250mV change at SET (OUT for the
MAX9933). The Log Conformance vs. Input Power plots
(see
Typical Operating Characteristics
) show the dynam-
ic range of the log amp family. Dynamic range is the
range for which the error remains within a band of ±1dB.
The intercept is defined as the point where the linear
response, when extrapolated, intersects the y-axis of
the Log Conformance vs. Input Power plot. Using these
parameters, the input power can be calculated at any SET
voltage level (OUT voltage level for the MAX9933) within
the specified input range with the following equations:
RFIN = (SET / SLOPE) + IP
(MAX9930/MAX9931/MAX9932)
RFIN = (OUT / SLOPE) + IP
(MAX9933)
where SET is the set-point voltage, OUT is the output
voltage for the MAX9933, SLOPE is the logarithmic slope
(V/dB), RFIN is in either dBm or dBV and IP is the loga-
rithmic intercept point utilizing the same units as RFIN.
______________________________________________________________________________________ 11
VCC
OUT
N.C.
GND
CCLPF
50Ω
50Ω
RFIN
SHDN
CLPF
GND
DAC
ADC
0.01µF
CC
XX
VCC
PA
BASEBAND
IC
TRANSMITTER
MAX9933
Figure 2. MAX9933 Typical Application Circuit
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
______________________________________________________________________________________ 11
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
12 ______________________________________________________________________________________
Applications Information
Controller Mode
(MAX9930/MAX9931/MAX9932)
Figure 3 provides a circuit example of the MAX9930/
MAX9931/MAX9932 configured as a controller. The
MAX9930/MAX9931/MAX9932 require a 2.7V to 5.25V
supply voltage. Place a 0.1µF low-ESR, surface-mount
ceramic capacitor close to VCC to decouple the supply.
Electrically isolate the RF input from other pins (espe-
cially SET) to maximize performance at high frequen-
cies (especially at the high-power levels of the
MAX9932). The MAX9930/MAX9931/MAX9932 require
external AC-coupling. Achieve 50Ωinput matching by
connecting a 50Ωresistor between the AC-coupling
capacitor of RFIN and ground.
The MAX9930/MAX9931/MAX9932 logarithmic ampli-
fiers function as both the detector and controller in
power-control loops. Use a directional coupler to couple
a portion of the PA’s output power to the log amp’s RF
input. For applications requiring dual-mode operation
and where there are two PAs and two directional cou-
plers, passively combine the outputs of the directional
couplers before applying to the log amp. Apply a set-
point voltage to SET from a controlling source (usually a
DAC). OUT, which drives the automatic gain-control
input of the PA, corrects any inequality between the RF
input level and the corresponding set-point level. This is
valid assuming the gain control of the variable gain ele-
ment is positive, such that increasing OUT voltage
increases gain. The OUT voltage can range from 150mV
to within 250mV of the positive supply rail while sourcing
10mA. Use a suitable load resistor between OUT and
GND for PA control inputs that source current. The
Typical Operating Characteristics
has the Maximum Out
Voltage vs. VCC By Load Current graph that shows the
sourcing capabilities and output swing of OUT.
SHDN
and Power-On
The MAX9930–MAX9933 can be placed in shutdown by
pulling SHDN to ground. Shutdown reduces supply cur-
rent to typically 13µA. A graph of SHDN Response Time
is included in the
Typical Operating Characteristics
.
Connect SHDN and VCC together for continuous on
operation.
Power Convention
Expressing power in dBm, decibels above 1mW, is the
most common convention in RF systems. Log amp
input levels specified in terms of power are a result of
the following common convention. Note that input
power does not refer to power, but rather to input volt-
age relative to a 50Ωimpedance. Use of dBV, decibels
with respect to a 1VRMS sine wave, yields a less
ambiguous result. The dBV convention has its own pit-
falls in that log amp response is also dependent on
waveform. A complex input, such as CDMA, does not
have the exact same output response as the sinusoidal
signal. The MAX9930–MAX9933 performance specifi-
cations are in both dBV and dBm, with equivalent dBm
levels for a 50Ωenvironment. To convert dBV values
into dBm in a 50Ωnetwork, add 13dB. For CATV appli-
cations, to convert dBV values to dBm in a 75Ωnet-
work, add 11.25dB. Table 1 shows the different input
power ranges in different conventions for the
MAX9930–MAX9933.
Table 1. Power Ranges of the MAX9930–
MAX9933
INPUT POWER RANGE
PART dBV dBm IN A 50Ω
NETWORK
dBm IN A 75Ω
NETWORK
MAX9930 -58 to -13 -45 to 0 -46.75 to -1.75
MAX9931 -48 to -3 -35 to +10 -36.75 to +8.25
MAX9932 -43 to +2 -30 to +15 -31.75 to +13.25
MAX9933 -58 to -13 -45 to 0 -46.75 to -1.75
VCC
OUT
N.C.
GND
CCLPF
DAC
50Ω
RFIN
SHDN
CLPF
SET
0.1µF
RF INPUT
VCC
CC
XX
ANTENNA POWER AMPLIFIER
MAX9930
MAX9931
MAX9932
Figure 3. Control Mode Application Circuit Block
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
______________________________________________________________________________________ 13
Filter Capacitor and Transient Response
In general, for the MAX9930/MAX9931/MAX9932, the
choice of filter capacitor only partially determines the
time-domain response of a PA control loop. However,
some simple conventions can be applied to affect tran-
sient response. A large filter capacitor, CCLPF, domi-
nates time-domain response, but the loop bandwidth
remains a factor of the PA gain-control range. The
bandwidth is maximized at power outputs near the cen-
ter of the PA’s range, and minimized at the low and
high power levels, where the slope of the gain-control
curve is lowest.
A smaller valued CCLPF results in an increased loop
bandwidth inversely proportional to the capacitor value.
Inherent phase lag in the PA’s control path, usually
caused by parasitics at OUT, ultimately results in the
addition of complex poles in the AC loop equation. To
avoid this secondary effect, experimentally determine
the lowest usable CCLPF for the power amplifier of inter-
est. This requires full consideration to the intricacies of
the PA control function. The worst-case condition,
where the PA output is smallest (gain function is steep-
est) should be used because the PA control function is
typically nonlinear. An additional zero can be added to
improve loop dynamics by placing a resistor in series
with CCLPF. See Figure 4 for the gain and phase
response for different CCLPF values.
Additional Input Coupling
There are three common methods for input coupling:
broadband resistive, narrowband reactive, and series
attenuation. A broadband resistive match is implement-
ed by connecting a resistor to ground at the external
AC-coupling capacitor at RFIN as shown in Figure 5. A
50Ωresistor (use other values for different input imped-
ances) in this configuration, in parallel with the input
impedance of the MAX9930–MAX9933, presents an
input impedance of approximately 50Ω. These devices
require an additional external coupling capacitor in
series with the RF input. As the operating frequency
increases over 2GHz, input impedance is reduced,
resulting in the need for a larger-valued shunt resistor.
Use a Smith Chart for calculating the ideal shunt resis-
tor value. Refer to the MAX4000/MAX4001/MAX4002
data sheet for narrowband reactive and series attenua-
tion input coupling.
GAIN AND PHASE vs. FREQUENCY
MAX9930 fig04
FREQUENCY (Hz)
GAIN (dB)
PHASE (DEGREES)
10M1M10k 100k1k100
-80
-60
-40
-20
0
20
40
60
80
-100
-180
-135
-90
-45
0
45
90
135
180
-225
10 100M
GAIN
PHASE
CCLPF = 2000pF
CCLPF = 2000pF
CCLPF = 200pF
CCLPF = 200pF
SMALL-SIGNAL BANDWIDTH vs. CCLPF
MAX9930 fig04
CCLPF (pF)
FREQUENCY (MHz)
1000 10,000
0.1
1
10
0.01
100 100,000
Figure 4. Gain and Phase vs. Frequency
CIN
RS
50Ω
VCC
CC
50Ω
RIN
RFIN
50Ω SOURCE
MAX9930
MAX9931
MAX9932
MAX9933
Figure 5. Broadband Resistive Matching
Waveform Considerations
The MAX9930–MAX9933 family of logarithmic amplifiers
respond to voltage, not power, even though input levels
are specified in dBm. It is important to realize that input
signals with identical RMS power but unique waveforms
result in different log amp outputs. Differing signal wave-
forms result in either an upward or downward shift in the
logarithmic intercept. However, the logarithmic slope
remains the same; it is possible to compensate for known
waveform shapes by baseband process.
It must also be noted that the output waveform is generat-
ed by first rectifying and then averaging the input signal.
This method should not be confused with RMS or peak-
detection methods.
Layout Considerations
As with any RF circuit, the layout of the MAX9930–
MAX9933 circuits affects performance. Use a short 50Ω
line at the input with multiple ground vias along the
length of the line. The input capacitor and resistor
should both be placed as close as possible to the IC.
VCC should be bypassed as close as possible to the IC
with multiple vias connecting the capacitor to the
ground plane. It is recommended that good RF compo-
nents be chosen for the desired operating frequency
range. Electrically isolate RF input from other pins
(especially SET) to maximize performance at high
frequencies (especially at the high power levels of
the MAX9932).
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
14 ______________________________________________________________________________________
BUFFER
GND
OUTPUT-
ENABLE
DELAY
LOG
DETECTOR
x1
V-I*
SHDN
VCC
RFIN
SET
CCLPF
OUT
BUFFER
GND
OUTPUT-
ENABLE
DELAY
LOG
DETECTOR
x1
V-I*
*INVERTING VOLTAGE TO CURRENT CONVERTER.
SHDN
VCC
RFIN
CCLPF
OUT
MAX9933
MAX9930
MAX9931
MAX9932
gm
BLOCK
gm
BLOCK
Block Diagram
Chip Information
PROCESS: High-Frequency Bipolar
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
______________________________________________________________________________________ 15
α
α
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
8 µMAX U8-1 21-0140
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
MAX9930–MAX9933
2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
16
____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 8/07 Initial release —
1 3/09 Added TOC46 to Typical Operating Characteristics 9