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
n
2 sequentially selectable RF inputs
n
Low power consumption shutdown mode
n
Externally configurable gain and LF filter bandwidth.
n
Internal 50
RF termination impedance
n
Optimized for use with 20 dB directional coupler
n
Lead free 8-bump micro SMD package 1.5 x 1.5 x 0.6
mm
Applications
n
3G mobile communications
n
UMTS
n
WCDMA
n
CDMA2000
n
TD-SCDMA
n
RF control
n
Wireless LAN
n
PC Card and GPS modules
Typical Application
20127801
February 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
-65C to 150C
Junction Temperature (Note 3)
150C Max
Mounting Temperature
Infrared or Convection (20 sec)
235C
Operating Ratings
(Note 1)
Supply Voltage
2.5V to 3.3V
Operating Temperature Range
-40C to +85C
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
= 25C. 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
A
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
5
A
V
OUT
Output Voltage Swing
From Positive Rail, Sourcing,
FB = 0V, I
OUT
= 1 mA
20
80
90
mV
From Negative Rail, Sinking,
FB = 2.7V, I
OUT
= -1 mA
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
A
t
ON
Turn-on-Time (Note 9)
No RF Input Power Present, Output
Loaded with 10 pF
2.0
6.0
s
t
R
Rise Time (Note 7)
Step from No Power to 0 dBm
Applied, Output Loaded with 10 pF
4.5
s
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/s
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
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2
2.7 DC and AC Electrical Characteristics
(Continued)
Unless otherwise specified, all limits are guaranteed to V
DD
= 2.7V; T
J
= 25C. Boldface limits apply at temperature extremes.
(Note 4)
Symbol
Parameter
Condition
Min
Typ
Max
Units
K
DET
Detection Slope
900 MHz
21
A/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 k
in series with 100 pF. Machine model, 0 in series with 100 pF.
Note 3: The maximum power dissipation is a function of T
J(MAX)
,
JA
and T
A
. The maximum allowable power dissipation at any ambient temperature is P
D
=
(T
J(MAX)
- T
A
)/
JA
. 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 T
J
= T
A
. No guarantee of parametric performance is indicated in the electrical tables under conditions of internal self-heating where T
J
>
T
A
.
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 k
resistor from V
DD
to RF
IN
/E
N
. RF signal is applied using a 50
RF signal generator AC coupled to the RF
IN
/E
N
pin using a 100 pF coupling capacitor.
Note 9: Turn-on time is measured by connecting a 10 k
resistor to the RF
IN
/E
N
pin. 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 -40C / 25C and variation between 25C / 85C.
LMV232
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3
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 50
resistance.
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
I 02
250 Units Tape and Reel
TLA08AAA
LMV232TLX
3k Units Tape and Reel
Note: This product is only offered with lead free bumps.
LMV232
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4
Block Diagrams
20127864
LMV232
LMV232
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5
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