General Description
The MAX9930–MAX9933 low-cost, low-power logarithmic
amplifiers are designed to control RF power amplifiers
(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 typical dynam-
ic range of 45dB makes this family of logarithmic ampli-
fiers useful in a variety of wireless and GPON fiber video
applications such as transmitter power measurement, and
RSSI for terminal devices. Logarithmic amplifiers provide
much wider measurement range and superior accuracy to
controllers based on diode detectors. Excellent tempera-
ture 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 50Ω Termination)
MAX9931: -48dBV to -3dBV
(-35dBm to +10dBm for 50Ω Termination)
MAX9932: -43dBV to +2dBV
(-30dBm to +15dBm for 50Ω Termination)
●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
Block Diagram appears at end of data sheet.
μMAX is a registered trademark of Maxim Integrated Products, Inc.
19-0859; Rev 2; 3/15
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
PART TEMP RANGE PIN-PACKAGE
MAX9930EUA+T -40°C to +85°C 8 µMAX
MAX9931EUA+T -40°C to +85°C 8 µMAX
MAX9932EUA+T -40°C to +85°C 8 µMAX
MAX9933EUA+T -40°C to +85°C 8 µMAX
MAX9933BGUA+T -40°C to +105°C 8 µMAX
MAX9930
MAX9931
MAX9932
+
1
2
3
4
VCC
OUT
N.C.
GND
TOP VIEW
RFIN
SHDN
SET
CLPF
8
7
6
5
µMAX
MAX9933
MAX9933B
+
1
2
3
4
VCC
OUT
N.C.
GND
RFIN
SHDN
GND
CLPF
8
7
6
5
µMAX
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
Pin Congurations
Ordering Information
EVALUATION KIT AVAILABLE
(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
(VCC = 3V, SHDN = 1.8V, TA = -40°C to +85°C, CCLPF = 100nF, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1
and 6)
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 Input Current ISHDN
SHDN = 3V 5 30 µA
SHDN = 0V -1 -0.01
MAIN OUTPUT (MAX9930/MAX9931/MAX9932)
Voltage Range VOUT
High, ISOURCE = 10mA 2.65 2.75 V
Low, ISINK = 350µA 0.15
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/MAX9933B)
Voltage Range VOUT
RFIN = 0dBm 1.45 V
RFIN = -45dBm 0.36
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
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Absolute Maximum Ratings
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.
DC 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.) (Notes 1 and 6)
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 gm stage, 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.
Note 6: MAX9933B is 100% production tested at TA = +25°C and is guaranteed by design for TA = -40°C to +105°C as specified.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
RF Input Frequency Range fRF 2 1600 MHz
RF Input Voltage Range
(Note 4) VRF
MAX9930/MAX9933/MAX9933B -58 -13
dBVMAX9931 -48 -3
MAX9932 -43 +2
Equivalent Power Range
(50Ω Termination) (Note 4) PRF
MAX9930/MAX9933/MAX9933B -45 0
dBm
MAX9931 -35 +10
MAX9932 -30 +15
Logarithmic Slope VS
fRF = 2MHz, TA = +25°C 25 27 29
mV/dB
fRF = 2MHz 24 27 30
fRF = 900MHz, TA = +25°C23.5 25.5 27.5
fRF = 900MHz 22.5 25.5 28.5
fRF = 1600MHz 27
Logarithmic Intercept PX
fRF = 2MHz,
TA = +25°C
MAX9930/MAX9933/MAX9933B
-61 -56 -52
dBm
MAX9931 -51 -46 -42
MAX9932 -46 -41 -37
fRF = 2MHz
MAX9930/MAX9933/MAX9933B
-63 -56 -50
MAX9931 -53 -46 -40
MAX9932 -48 -41 -35
fRF = 900MHz,
TA = +25°C
MAX9930/MAX9933/MAX9933B
-62 -59 -53
MAX9931 -53 -50 -44
MAX9932 -49 -45 -40
fRF = 900MHz
MAX9930/MAX9933/MAX9933B
-64 -59 -51
MAX9931 -55 -50 -42
MAX9932 -51 -45 -38
fRF = 1600MHz
MAX9930/MAX9933/MAX9933B
-62
MAX9931 -52
MAX9932 -47
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
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AC Electrical 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
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 = +25°C
TA = -40°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
0 1800
TA = -40°C TA = +25°C
TA = +85°C
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 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
LOG SLOPE vs. VCC
MAX9930 toc08
V
CC
(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
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 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 INTERCEPT vs. FREQUENCY
MAX9930 toc09
FREQUENCY (MHz)
LOG INTERCEPT (dBm)
1200800400
-66
-64
-62
-60
-68
0 1600
TA = -40°C
TA = +25°C
TA = +85°C
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
Maxim Integrated
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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
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
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 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
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 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 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
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
2MHz
50MHz
900MHz
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
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
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
Maxim Integrated
│
5
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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 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 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
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
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
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
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
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 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
Maxim Integrated
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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.)
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
-4
-3
-2
-1
0
1
2
3
4
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
-60 -50 -40 -30 -20 -10 010
ERROR (dB)
OUT (V)
INPUT POWER (dBm)
MAX9933B
OUTPUT AND LOG CONFORMANCE
vs. INPUT POWER AT 2MHz
toc36
TA= -40°C
TA= +25°C
TA= +85°C
TA= +105°C
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
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
MAX9932
LOG SLOPE vs. FREQUENCY
MAX9930 toc29
FREQUENCY (MHz)
15001200900600300
24
25
26
27
28
29
23
0 1800
TA = -40°C
TA = +25°C
TA = +85°C
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
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
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 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
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
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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.)
-4
-3
-2
-1
0
1
2
3
4
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
-60 -50 -40 -30 -20 -10 010
ERROR (dB)
OUT (V)
INPUT POWER (dBm)
MAX9933B
OUTPUT AND LOG CONFORMANCE
vs. INPUT POWER AT 50MHz
toc37
TA= -40°C
TA= +25°C
TA= +85°C
TA= +105°C
23
24
25
26
27
28
29
0300 600 900 1200 1500 1800
LOG SLOPE (mV/dB)
FREQUENCY (MHz)
MAX9933B
LOG SLOPE vs. FREQUENCY
TA= -40°C
toc40
TA= +25°C
TA= +85°C
TA= +105°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
-4
-3
-2
-1
0
1
2
3
4
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
-60 -50 -40 -30 -20 -10 010
ERROR (dB)
OUT (V)
INPUT POWER (dBm)
MAX9933B
OUTPUT AND LOG CONFORMANCE
vs. INPUT POWER AT 900MHz
toc38
TA= -40°C
TA= +25°C
TA= +85°C
TA= +105°C
MAX9933
LOG SLOPE vs. VCC
MAX9930 toc41
V
CC
(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
-0.3
-0.2
-0.1
0
0.1
0.2
-50 -25 025 50 75 100 125
ERROR (dB)
TEMPERATURE (°C)
MAX9933B
LOG CONFORMANCE vs. TEMPERATURE
INPUT POWER = -22dBm
toc44
fRF = 50MHz
-4
-3
-2
-1
0
1
2
3
4
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
-60 -50 -40 -30 -20 -10 010
ERROR (dB)
OUT (V)
INPUT POWER (dBm)
MAX9933B
OUTPUT AND LOG CONFORMANCE
vs. INPUT POWER AT 1.6GHz
toc39
TA= -40°C
TA= +25°C
TA= +85°C
TA= +105°C
-64
-62
-60
-58
-56
-54
-52
0300 600 900 1200 1500 1800
LOG INTERCEPT (mV/dB)
FREQUENCY (MHz)
MAX9933B
LOG INTERCEPT vs. FREQUENCY
TA= -40°C
toc42
TA= +25°C
TA= +85°CTA= +105°C
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
0 2.0
VCC = 5.25V
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
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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.)
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
LARGE-SIGNAL
PULSE RESPONSE
MAX9930 toc51
10µs/div
OUT
500mV/div
RFIN
250mV/div
≤ 900mV
CCLPF = 10,000pF
fRF = 50MHz
-2dBm
-42dBm
SHDN POWER-ON DELAY
RESPONSE TIME
MAX9930 toc47
2µs/div
OUT
1V/div
0V
0V
SHDN
500mV/div
CCLPF = 150pF
SMALL-SIGNAL
PULSE RESPONSE
MAX9930 toc52
1µs/div
OUT
75mV/div
RFIN
25mV/div
≤ 0V
CCLPF = 150pF
fRF = 50MHz
-24dBm
-18dBm
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)
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
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
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Typical Operating Characteristics (continued)
Figure 1. Functional Diagram
PIN
NAME FUNCTION
MAX9930/
MAX9931/
MAX9932
MAX9933
1 1 RFIN RF Input
2 2 SHDN 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
8 8 VCC Supply Voltage. Bypass to GND with a 0.1µF capacitor.
OUTPUT-
ENABLED
DELAY
DET DET DET DET
10dB
REFERENCE
CURRENT
OFFSET
COMP
SHDN
OUT
*INVERTING VOLTAGE TO CURRENT CONVERTER
CLPF
SET
RFIN
GND
V
CC
DET
10dB 10dB 10dB
X1
V-I*
OUTPUT-
ENABLED
DELAY
DET DET DET DET
10dB
REFERENCE
CURRENT
OFFSET
COMP
SHDN
OUT
CLPF
RFIN
GND
V
CC
DET
10dB 10dB 10dB
X1
V-I*
MAX9933
MAX9930
MAX9931
MAX9932
g
m
g
m
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
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Pin Description
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 output
stage of each amplifier is applied to a full-wave rectifier
(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 gm stage, 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 deter-
mines 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 baseband 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 trans-
fer 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 logarith-
mic 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 dynamic 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.
Figure 2. MAX9933 Typical Application Circuit
VCC
OUT
N.C.
GND
CCLPF
50Ω
50Ω
RFIN
SHDN
CLPF
GND
DAC
ADC
0.01µF
CC
XX
VCC
PA
BASEBAND
IC
TRANSMITTER
MAX9933
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
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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 frequencies
(especially at the high-power levels of the MAX9932).
The MAX9930/MAX9931/MAX9932 require external
AC-coupling. Achieve 50Ω input matching by connecting
a 50Ω resistor between the AC-coupling capacitor of RFIN
and ground.
The MAX9930/MAX9931/MAX9932 logarithmic amplifiers
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 couplers, 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, cor-
rects any inequality between the RF input level and the
corresponding set-point level. This is valid assuming the
gain control of the variable gain element 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
current 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 fol-
lowing common convention. Note that input power does
not refer to power, but rather to input voltage relative to
a 50Ω impedance. 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 specifications are in both dBV
and dBm, with equivalent dBm levels for a 50Ω environ-
ment. To convert dBV values into dBm in a 50Ω network,
add 13dB. For CATV applications, to convert dBV values
to dBm in a 75Ω network, 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
Figure 3. Control Mode Application Circuit Block
PART
INPUT POWER RANGE
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
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
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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, dominates
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 center 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 sec-
ondary effect, experimentally determine the lowest usable
CCLPF for the power amplifier of interest. This requires full
consideration to the intricacies of the PA control function.
The worst-case condition, where the PA output is small-
est (gain function is steepest) 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
50Ω resistor (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 resistor value. Refer to the
MAX4000/MAX4001/MAX4002 data sheet for narrow-
band reactive and series attenuation input coupling.
Figure 4. Gain and Phase vs. Frequency
Figure 5. Broadband Resistive Matching
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
CIN
RS
50Ω
VCC
CC
50Ω
RIN
RFIN
50 SOURCE
MAX9930
MAX9931
MAX9932
MAX9933
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
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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 gener-
ated 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 recom-
mended that good RF components 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).
BUFFER
GND
OUTPUT-
ENABLE
DELAY
LOG
DETECTOR
x1
V-I*
SHDN
VCC
RFIN
SET
CCLPF
OUT
BUFFER
GND
OUTPUT-
ENABLE
DELAY
x1
V-I*
*INVERTING VOLTAGE TO CURRENT CONVERTER.
SHDN
VCC
RFIN
CCLPF
OUT
MAX9933
MAX9930
MAX9931
MAX9932
gm
BLOCK
gm
BLOCK
LOG
DETECTOR
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
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Block Diagram
Chip Information
PROCESS: High-Frequency Bipolar
PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
8 μMAX U8-1 21-0036 90-0092
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
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Package Information
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 8/07 Initial release —
1 3/09 Added TOC46 to Typical Operating Characteristics 9
2 3/15 Added information for the MAX9933B. Revised Typical Operating Characteristics. 1–3, 7, 8, 15
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
MAX9930–MAX9933 2MHz to 1.6GHz 45dB RF-Detecting
Controllers and RF Detector
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Revision History
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