LMV232
Dual-Channel Integrated Mean Square Power Detector
for CDMA & WCDMA
General Description
The LMV232 dual RF detector is designed for RF transmit
power measurement in mobile phones. This dual mean
square IC is especially suited for accurate power measure-
ment of RF signals exhibiting high peak-to-average ratios
used in 3G and UMTS/CDMA applications. The LMV232
saves calibration steps and system certification and is highly
accurate. The circuit operates with a single supply from 2.5
to 3.3V.
The LMV232 contains a mean square detector with two
sequentially selectable RF inputs. The RF input power range
of the device has been optimized for use with a 20 dB
directional coupler, without the need for additional external
components. A single external RC combination between FB
and OUT provides an externally configurable gain and LF
filter bandwidth of the device.
The device has two digital interfaces. A shutdown function is
available to set the device in a low-power shutdown mode. In
case SD = HIGH, the device is in shutdown, if SD = LOW the
device is active. The Band-Select function controls the se-
lection of the active RF input channel. In case BS = HIGH,
RF
IN
1 is active. In case BS = LOW, RF
IN
2 is active.
The dual mean square detector is offered in an 8-bump
micro SMD 1.5 x 1.5 x 0.6 mm package. This micro SMD
package has the smallest footprint and height.
Features
n>20 dB square-law detection range
n2 sequentially selectable RF inputs
nLow power consumption shutdown mode
nExternally configurable gain and LF filter bandwidth.
nInternal 50RF termination impedance
nOptimized for use with 20 dB directional coupler
nLead free 8-bump micro SMD package 1.5 x 1.5 x 0.6
mm
Applications
n3G mobile communications
nUMTS
nWCDMA
nCDMA2000
nTD-SCDMA
nRF control
nWireless LAN
nPC Card and GPS modules
Typical Application
20127801
April 2005
LMV232 Dual-Channel Integrated Mean Square Power Detector for CDMA & WCDMA
© 2005 National Semiconductor Corporation DS201278 www.national.com
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage
V
DD
- GND 3.6V Max
ESD Tolerance (Note 2)
Human Body Model 2000V
Machine Model 200V
Storage Temperature Range -65˚C to 150˚C
Junction Temperature (Note 3) 150˚C Max
Mounting Temperature
Infrared or Convection (20 sec) 235˚C
Operating Ratings (Note 1)
Supply Voltage 2.5V to 3.3V
Operating Temperature Range -40˚C to +85˚C
RF Frequency Range 50 MHz to 2 GHz
2.7 DC and AC Electrical Characteristics
Unless otherwise specified, all limits are guaranteed to V
DD
= 2.7V; T
J
= 25˚C. Boldface limits apply at temperature extremes.
(Note 4)
Symbol Parameter Condition Min Typ Max Units
I
DD
Supply Current Active Mode: SD = LOW, No RF Input
Power Present
9.8 11
13 mA
Shutdown: SD = 1.8V, No RF Input
Power Present
0.09 5
30
µA
V
LOW
BS and SD Logic Low Level
(Note 6)
0.8 V
V
HIGH
BS and SD Logic High Level
(Note 6)
1.8 V
I
BS
,I
SD
Current into BS and SD pins 5µA
V
OUT
Output Voltage Swing From Positive Rail, Sourcing,
FB = 0V, I
OUT
=1mA
20 80
90 mV
From Negative Rail, Sinking,
FB = 2.7V, I
OUT
=−1mA
20 60
70 mV
I
OUT
Output Short Circuit Sourcing, FB = 0V, V
OUT
= 2.6V 3.7
2.7
5.1
mA
Sinking, FB = 2.7V, V
OUT
= 0.1V 3.7
2.7
5.5
V
OUT
Output Voltage (Pedestal) No RF Input Power 235
230
254 275
280 mV
V
PED
Pedestal Variation Over
Temperature (Note 10)
5.4 mV
I
OS
Offset Current Variation Over
Temperature (Note 10)
1.17 µA
t
ON
Turn-on-Time (Note 9) No RF Input Power Present, Output
Loaded with 10 pF
2.0 6.0 µs
t
R
Rise Time (Note 7) Step from No Power to 0 dBm
Applied, Output Loaded with 10 pF
4.5 µs
e
n
Output Referred Voltage Noise RF Input = 1800 MHz, -10 dBm,
Measured at 10 kHz
400 nV/
GBW Gain Bandwidth Product 3.7 MHz
SR Slew Rate 1.8
1.0
3.0 V/µs
R
IN
DC Resistance (Note 7) 50.8
P
IN
RF Input Power Range RF Input Frequency = 900 MHz -11
+13
dBm
-24
0
dBV
LMV232
www.national.com 2
2.7 DC and AC Electrical Characteristics (Continued)
Unless otherwise specified, all limits are guaranteed to V
DD
= 2.7V; T
J
= 25˚C. Boldface limits apply at temperature extremes.
(Note 4)
Symbol Parameter Condition Min Typ Max Units
K
DET
Detection Slope 900 MHz 21
µA/mW
1800 MHz 10
1900 MHz 10
2000 MHz 10
f
LOW
LF Input Corner Frequency Lower −3 dB Point of Detection Slope 60 MHz
f
HIGH
HF Input Corner Frequency Upper −3 dB Point of Detection Slope 1.0 GHz
A
ISO
Channel Isolation 900 MHz 58
dB
1800 MHz 62
1900 MHz 58
2000 MHz 55
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.
Note 2: Human body model: 1.5 kin series with 100 pF. Machine model, 0in series with 100 pF.
Note 3: The maximum power dissipation is a function of TJ(MAX) ,θJA and TA. The maximum allowable power dissipation at any ambient temperature is PD=
(TJ(MAX) -T
A)/θJA. All numbers apply for packages soldered directly into a PC board.
Note 4: Electrical Table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very limited self-heating of
the device such that TJ=T
A. No guarantee of parametric performance is indicated in the electrical tables under conditions of internal self-heating where TJ>TA.
Note 5: Power in dBV = dBm + 13 when the impedance is 50.
Note 6: All limits are guaranteed by design or statistical analysis.
Note 7: Typical values represent the most likely parametric norm.
Note 8: Device is set in active mode with a 10 kresistor from VDD to RFIN/EN. RF signal is applied using a 50RF signal generator AC coupled to the RFIN/EN
pin using a 100 pF coupling capacitor.
Note 9: Turn-on time is measured by connecting a 10 kresistor to the RFIN/ENpin. Be aware that in the actual application on the front page, the RC-time constant
of resistor R2 and capacitor C adds an additional delay.
Note 10: Typical numbers represent the 3-sigma value of 10k units. 3-sigma value of variation between −40˚C / 25˚C and variation between 25˚C / 85˚C.
LMV232
www.national.com3
Connection Diagram
8-Bump micro SMD
20127802
Top View
Pin Description
Pin Name Description
Power Supply B3 V
DD
Positive Supply Voltage
B1 GND Power Ground
Digital Inputs C3 SD Schmitt-triggered Shutdown. The device is active for SD = LOW. For SD = HIGH, it is
brought into a low-power shutdown mode.
C2 BS Schmitt-triggered Band Select pin. When BS = HIGH, RF
IN
1 is selected, when BS =
LOW, RF
IN
2 is selected.
Analog Inputs A1 RF
IN
1 RF Input connected to the coupler output with optional attenuation to measure the
Power Amplifier (PA) / Antenna RF power levels. Both RF inputs of the device are
internally terminated with a 50resistance.
C1 RF
IN
2
Feedback A2 FB Connected to inverting input of output amplifier. Enables user-configurable gain and
bandwidth through external feedback network.
Output A3 Out Amplifier output
Ordering Information
Package Part Number Package Marking Transport Media NSC Drawing
8-Bump micro SMD LMV232TL A
I02
250 Units Tape and Reel TLA08AAA
LMV232TLX 3k Units Tape and Reel
Note: This product is only offered with lead free bumps.
LMV232
www.national.com 4
Block Diagrams
20127864
LMV232
LMV232
www.national.com5
Typical Performance Characteristics Unless otherwise specified, V
DD
= 2.7V, T
J
= 25˚C,
R1 = 6.2 kand C1 = 1.5 nF (See typical application on the frontpage).
Supply Current vs. Supply Voltage V
OUT
-V
PEDESTAL
vs. RF Input Power
20127877 20127867
V
OUT
-V
PEDESTAL
vs. RF Input Power @900 MHz Input Referred Error vs. RF Input Power @900 MHz
20127868 20127869
V
OUT
-V
PEDESTAL
vs. RF Input Power @1800 MHz Input Referred Error vs. RF Input Power @1800 MHz
20127870 20127871
LMV232
www.national.com 6
Typical Performance Characteristics Unless otherwise specified, V
DD
= 2.7V, T
J
= 25˚C,
R1 = 6.2 kand C1 = 1.5 nF (See typical application on the frontpage). (Continued)
V
OUT
-V
PEDESTAL
vs. RF Input Power @1900 MHz Input Referred Error vs. RF Input Power @1900 MHz
20127872 20127873
V
OUT
-V
PEDESTAL
vs. RF Input Power @2000 MHz Input Referred Error vs. RF Input Power @2000 MHz
20127874 20127875
V
OUT
-V
PEDESTAL
vs. RF Input Power @1900 MHz Input Referred Error vs. RF Input Power @1900 MHz
20127882 20127883
LMV232
www.national.com7
Typical Performance Characteristics Unless otherwise specified, V
DD
= 2.7V, T
J
= 25˚C,
R1 = 6.2 kand C1 = 1.5 nF (See typical application on the frontpage). (Continued)
RF Input Impedance vs. Frequency
@Resistance and Reactance Gain and Phase vs. Frequency
20127876 20127804
Sourcing Current vs. Output Voltage Sinking Current vs. Output Voltage
20127878 20127879
Output Voltage vs. Sourcing Current Output Voltage vs. Sinking Current
20127880 20127881
LMV232
www.national.com 8
Application Notes
The LMV232 mean square power detector is particularly
suited for accurate power measurement of RF modulated
signals that exhibit large peak to average ratios, i.e. large
variations of the signal envelope. Such noise-like signals are
encountered e.g. in CDMA and Wide-band CDMA cell-
phones. Many power detection circuits, particularly those
devised for constant-envelope modulated signals as in
GSM, are based on peak detection and provide accurate
power measurements for constant envelope or low-crest
factor (ratio of peak to RMS) signals only. Such detectors are
therefore not particularly suited for CDMA and WCDMA ap-
plications.
TYPICAL APPLICATION
The LMV232 is especially suited for CDMA and WCDMA
applications with 2 Power Amplifiers (PA’s). A typical setup is
given in Figure 1. The output power of one PA is measured at
a time, depending on the bandselect pin (BS). If the BS =
High RF
IN
1 is used for measurements, if BS = Low RF
IN
2is
used. The measured output voltage of the LMV232 is read
by the ADC of the baseband chip and the gain of the PA gain
is adjusted if necessary. With an input impedance of 50,
the LMV232 can be directly connected to a 20 dB directional
coupler without the need for an additional external attenua-
tor. The setup can be adjusted to various PA output ranges
by selection of a directional coupler or insertion of an addi-
tional (resistive) attenuator between the coupler outputs and
the LMV232 RF inputs.
The LMV232 conversion gain and bandwidth are configured
by a resistor and a capacitor. Resistor R1 sets the conver-
sion gain from RF
IN
to the output voltage. A higher resistor
value will result in a higher conversion gain. The maximum
dynamic range is achieved when the resistor value is as high
as possible, i.e. the output signal just doesn’t clip and the
voltage stays within the baseband ADC input range. The
filter bandwidth is adjusted by capacitor C1. The capacitor
value should be chosen such that the response time of the
device is fast enough and modulation on the RF input signal
is not visible at the output (ripple suppression). The −3 dB
filter bandwidth of the output filter is determined by the time
constant R1*C1. Generally a capacitor value of 1.5 nF is a
good choice.
PEAK TO AVERAGE RATIO SENSITIVITY
The LMV232 power detector provides an accurate power
measurement for arbitrary input signals, low and high peak-
to-average ratios and crest factors. This is because its op-
eration is not based on peak detection, but on direct deter-
mination of the mean square value. This is the most accurate
power measurement, since it exactly implements the defini-
tion of power. A mean-square detector measures V
RMS2
for
all waveforms. Peak detection is less accurate because the
relation between peak detection and mean square detection
depends on the waveform. A peak detector measures P =
V
PEAK2
for all waveforms, while it should measures P =
V
PEAK2
/2(forR=1) for a sine wave and P = V
PEAK2
/3 for
a triangle wave for instance. For a CDMA signal, the mea-
surement error can be in the order of 5 to 6 dB. For many
wave forms, specially those with high peak-to-average ra-
tios, peak detection is not accurate enough and therefore a
mean square detector is recommended.
MEAN SQUARE CONFORMANCE ERROR
The LMV232 is a mean square detector and therefore
should have an output voltage (in Volts) that linearly relates
to the RF input power (in mW). The input referred error, with
respect to an ideal linear mean square detector, is deter-
mined as a measure for the accuracy of the detector.
20127801
FIGURE 1. Typical Application
LMV232
www.national.com9
Application Notes (Continued)
The detection curves of Figure 2 show the detector response
to RF input power. To show the complete dynamic range on
a logarithmic scale, the pedestal voltage (V
PEDESTAL
) is sub-
tracted from the output. The pedestal voltage is defined as
the output voltage in the absence of an RF input signal (at
25˚C). The best-fit ideal mean square response is repre-
sented by the fitted curve in Figure 2. The input referred error
of the detection curves with respect to this best-fit mean
square response is determined as follows:
Determine the best-fit mean square response.
Determine the output referred error between the actual
detector response and the ideal mean square response.
Translate the output referred error to an input referred
error.
The best-fit linear curve is obtained from the detector re-
sponse by means of linear regression. The output referred
error is calculated with the formula:
Error
dBV
= 20*log[ (V
OUT
-V
PEDESTAL
)/(K
DET
*P
IN
)]
Where,
Conversion gain of the ideal fitted curve K
DET
is in V/mW
and the RF input power P
IN
in mW.
To translate this output referred error (in dB) to an input
referred error, it has to be divided by a factor of 2. This is due
to the mean square characteristic of the device. The re-
sponse of a mean square detector changes by 2 dB for every
dB change of the input power. Figure 3 depicts the resulting
curve.
Analyzing Figure 3 shows that three sections can be distin-
guished:
At higher power levels the error increases.
A middle section where the error is constant and rela-
tively small.
At lower power levels the error increases again.
These three sections are leading back to three error mecha-
nisms. At higher power levels the detectors output starts to
saturate because the output voltage approaches the maxi-
mum signal swing that the detector can handle. The maxi-
mum output voltage of the device thus limits the upper end of
the detection range. Also the maximum allowed ADC voltage
of the baseband chip can limit the detection range at higher
power levels. By adjusting the feedback resistor R
FB
of
Figure 1 the upper end of the range can be shifted. This is
valid until the detector cell inside the LMV232 is the limiting
factor.
The middle section of the error curve shows a small error
variation. This is the section where the detector is used and
is called the detection range of the detector. This range is
limited on both sides by a maximum allowed error.
For low input power levels, the variation of output voltage is
very small. Therefore the measurement resolution ADC is
important in order to measure those small variations. Offsets
and temperature variation impact the accuracy at low power
levels as well.
DETECTION ERROR OVER TEMPERATURE
Like any power detector device, the output signal of the
LMV232 mean square power detector shows some residual
variation over temperature that limits it’s dynamic range. The
variation determines the accuracy and range of input power
levels for which the detector produces an accurate output
signal.
The error over temperature is mainly caused by the variation
of the pedestal voltage. Besides this, a minimal error contri-
bution leads back to the conversion gain variation of the
detector. This conversion gain error is visible in the mid-
power range, where the temperature error curves of Figure 3
run parallel to each other. Since the conversion gain varia-
tion is acceptable, the focus will be on the pedestal voltage
variation over temperature.
20127884
FIGURE 2. Detection Curve
20127869
FIGURE 3. Input referred Error vs. RF Input Power
LMV232
www.national.com 10
Application Notes (Continued)
The pedestal voltage at 25˚C is subtracted from the output
voltage of each curve. Variations of the pedestal voltage
over temperature are thus included in the error.
The pedestal voltage variation itself consists of 2 error
sources. One is the variation of the reference voltage V
REF
.
The other is an offset current I
OS
that is generated inside the
detector. This depicted in Figure 4. Depending on the mea-
surement strategy one or both error sources can be elimi-
nated.
The error sources of the pedestal voltage can be shown in a
formula for V
OUT
:
V
OUT
=V
REF
+(I
OS
+I
DET
)*R
FB
Where I
DET
represents the intended detector output signal.
In the absence of RF input power I
DET
equals zero. The
formula for the pedestal voltage can therefore be written as:
V
PEDESTAL
=V
REF
+I
OS
*R
FB
For low input power levels, the pedestal variation V
PEDESTAL
is the dominant cause of error. Besides temperature varia-
tion of the pedestal voltage, which limits the lower end of the
range, the pedestal voltage can also vary from part-to-part.
By applying a suitable measurement strategy, the pedestal
voltage error contribution can be significantly reduced or
eliminated completely.
POWER MEASUREMENT STRATEGIES
This section describes the measurement strategies to re-
duce or eliminate the pedestal voltage variation. Which strat-
egy is chosen depends on the possibilities for a factory trim
and implementation of calibration procedures.
Since the pedestal voltage is the reference level for the
LMV232, it needs to be calibrated/measured at least once to
eliminate part-to-part spread. This is required to determine
the exact detector output signal. Because of process toler-
ances, the absolute part-to-part variation of the output volt-
age in the absence of RF input power will be in the order of
5 - 10%. All measurement strategies discussed eliminate this
part-to-part spread.
Strategy 1: Elimination of Part-to-Part Spread at Room
Temperature Only
In this strategy, the pedestal voltage is determined once
during manufacturing and stored into the memory of the
phone. At each power measurement this stored pedestal
level is digitally subtracted from the measured output signal
of the LMV232 during normal operation. The procedure is
thus:
Measure the detector output in the absence of RF power
during manufacturing.
Store the output voltage value in the cell phone memory
(after it is analog-to-digital converted).
Subtract the stored value from each detector output read-
ing.
The advantage of this strategy is that calibration is required
only once during manufacturing and not during normal op-
eration. The disadvantage is the fact that this method neither
compensates for the residual temperature drift of the refer-
ence voltage V
REF
nor for offset current variations. Only
part-to-part variations at room temperature are eliminated by
this strategy. Especially the residual temperature drift nega-
tively affects the measurement accuracy.
Strategy 2: Elimination of Temperature Spread in V
REF
If software changes need to be reduced to a minimum and
the baseband chip has a differential ADC, strategy 2 can be
used to eliminate temperature variations of the reference
voltage V
REF
. One pin of the ADC is connected to FB and
one is connected to OUT (Figure 6).
The power measurement is independent of the reference
voltage V
REF
, since the ADC reading is:
V
OUT
-V
FB
=(I
OS
+I
DET
)*R
FB
20127805
FIGURE 4. Pedestal Voltage
20127806
FIGURE 5. Strategy 1: Room Temperature Calibration
20127807
FIGURE 6. Strategy 2: Differential Measurement
LMV232
www.national.com11
Application Notes (Continued)
The reading of the ADC obviously doesn’t contain the refer-
ence voltage source V
REF
anymore, but the contribution of
the offset current remains present. This measurement is
performed during normal operation. Therefore, it eliminates
voltage reference variations over temperatures, as opposed
to strategy 1. Also offset variations in the op amp are elimi-
nated in this strategy.
Strategy 3: Complete Elimination of Temperature
Spread in Pedestal Voltage
The most accurate measurement is strategy 3, which elimi-
nates the temperature variation of both the reference voltage
V
REF
and the offset current I
OS
. In this strategy, the pedestal
voltage is measured regularly during operation of the phone,
and stored in the phone memory. For each power measure-
ment, the stored value is digitally subtracted from the
(analog-to-digital converted) detector output signal. Since it
measures the pedestal voltage itself for calibration it com-
pensates both for the reference voltage V
REF
as well as for
the offset current variation I
OS
. The frequency of the ‘calibra-
tion measurement’ can be significantly lower than those of
power measurements, depending on how fast the tempera-
ture of the device changes.
The calibration measurement procedure can be explained
with the aid of Figure 1, which depicts a typical power
measurement setup using the LMV232. In normal operation,
the two PA’s in the setup will never be active at the same
time. One PA will produce the required transmit power, while
the other one is off, (disabled) and produces no power. The
pedestal voltage should be measured in the absence of RF
power. This can be achieved by switching the Band Select
(BS) pin such that the LMV232 input is selected where the
disabled PA is connected to. The pedestal voltage at no input
power can be read at the output pin.
Using the Band Select (BS) control pin of the LMV232:
Select the RF input that is connected to the disabled PA,
by the BS pin.
Measure the detector output.
Store the result in the phone memory.
Subtract the stored value from each detector power read-
ing, until a new update is performed.
Important advantages of this approach are that no factory
trim is required and the temperature drift of the pedestal can
be cancelled almost completely as well as the part-to-part
spread. The remaining error is determined by the resolution
of the ADC. A slight disadvantage is that on average more
than one detector reading is required per power measure-
ment. This overhead though can be made almost negligible
in normal circumstances.
20127808
FIGURE 7. Strategy 3: Calibration during normal
operation
LMV232
www.national.com 12
Physical Dimensions inches (millimeters) unless otherwise noted
NOTES: UNLESS OTHERWISE SPECIFIED
1. EPOXY COATING
2. FOR SOLDER BUMP COMPOSITION, SEE “SOLDER INFORMATION” IN THE PACKAGING SECTION OF THE NATIONAL SEMICONDUCTOR WEB
(www.national.com).
3. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD.
4. PIN A1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION.
5. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH, X2 IS PACKAGE LENGTH AND X3 IS
PACKAGE HEIGHT.
REFERENCE JEDEC REGISTRATION MO-211, VARIATION DD.
8-Bump micro SMD
NS Package Number TLA08AAA
X1 = 1.514 ±0.030 mm X2 = 1.514 ±0.030 mm X3 = 0.600 ±0.075 mm
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
For the most current product information visit us at www.national.com.
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS
WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body, or
(b) support or sustain life, and whose failure to perform when
properly used in accordance with instructions for use
provided in the labeling, can be reasonably expected to result
in a significant injury to the user.
2. A critical component is any component of a life support
device or system whose failure to perform can be reasonably
expected to cause the failure of the life support device or
system, or to affect its safety or effectiveness.
BANNED SUBSTANCE COMPLIANCE
National Semiconductor manufactures products and uses packing materials that meet the provisions of the Customer Products
Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain
no ‘‘Banned Substances’’ as defined in CSP-9-111S2.
National Semiconductor
Americas Customer
Support Center
Email: new.feedback@nsc.com
Tel: 1-800-272-9959
National Semiconductor
Europe Customer Support Center
Fax: +49 (0) 180-530 85 86
Email: europe.support@nsc.com
Deutsch Tel: +49 (0) 69 9508 6208
English Tel: +44 (0) 870 24 0 2171
Français Tel: +33 (0) 1 41 91 8790
National Semiconductor
Asia Pacific Customer
Support Center
Email: ap.support@nsc.com
National Semiconductor
Japan Customer Support Center
Fax: 81-3-5639-7507
Email: jpn.feedback@nsc.com
Tel: 81-3-5639-7560
www.national.com
LMV232 Dual-Channel Integrated Mean Square Power Detector for CDMA & WCDMA