MAX4473 [MAXIM]
Low-Cost, Low-Voltage, PA Power Control Amplifier for GSM Applications in 8-Pin レMAX; 低成本，低电压， PA功率控制放大器采用8引脚レMAX GSM应用
| 型号： | MAX4473 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Low-Cost, Low-Voltage, PA Power Control Amplifier for GSM Applications in 8-Pin レMAX |
| 文件： | 总6页 (文件大小：142K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-1448; Rev 0; 3/99
Lo w -Co s t , Lo w -Vo lt a g e , PA P o w e r Co n t ro l
Am p lifie r fo r GS M Ap p lic a t io n s in 8 -P in µMAX
MAX473
Ge n e ra l De s c rip t io n
Fe a t u re s
The MAX4473 PA p owe r c ontrol IC is inte nd e d for
closed-loop bias control of GSM power amplifiers. The
device facilitates accurate control of the current deliv-
ered to the power amplifier (PA) via a control voltage.
The error amplifier senses the voltage drop across an
external current-sense resistor placed between the
supply and the PA. The output of the error amplifier
adjusts the PA gain until the current is proportional to
the power control voltage applied to the MAX4473. This
uniq ue top olog y is us e ful in time -d ivis ion-multip le -
access (TDMA) systems, such as GSM, where accurate
transmit burst shaping and power control is required.
User-selectable current sensing and gain setting resis-
tors maximize flexibility.
♦ Optimized for GSM Timing Requirements
♦ +2.7V to +6.5V Single-Supply Operation
♦ 1.2mA Supply Current
♦ ≤1µA Supply Current in Shutdown Mode
♦ Guaranteed 1.5µs Enable/Disable Times
♦ Active Output Pull-Down in Shutdown Mode
♦ Rail-to-Rail Error Amplifier Output
♦ Rail-to-Rail Power Control Input
♦ Output Drive Capability—500Ω and 300pF Loads
♦ +1V to V
Current Sense Input Common-Mode
CC
The MAX4473 operates from a single +2.7V to +6.5V
supply and typically draws 1.2mA of supply current.
The error amplifier has a common-mode range that
Voltage Range
♦ No Phase-Reversal for Common-Mode Voltage
extends from +1V to V . The power control input and
CC
from 0 to V
CC
error amplifier outputs swing Rail-to-Rail®. A low-power
shutdown mode reduces supply current to less than
1µA and activates an on-board active pull-down at the
error amplifier output. Fast enable/disable times of
0.9µs reduce average power consumption without com-
p romis ing d yna mic p e rforma nc e . The MAX4473 is
available in a space-saving 8-pin µMAX package.
♦ External Current Sensing and Gain Setting
Resistors Maximize Flexibility
♦ Available in a Space-Saving 8-pin µMAX
Ord e rin g In fo rm a t io n
Ap p lic a t io n s
GSM Cellular Phones
PART
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 µMAX
MAX4473EUA
MAX4473ESA
Cordless Phones
8 SO
Precision Current Control
Pin Configuration appears at end of data sheet.
High-Frequency Servo Loops
Typ ic a l Op e ra t in g Circ u it
V
CC
R
SENSE
0.1µF
RG1
RG2
A3
8
1
SR1
2
SR2
V
CC
4
PC
7
OUT
I
CCPA
A1
BUFFER
GC
IN
V-TO-I
CONVERTER
3R
R
ERROR
AMPLIFIER
V
CC
PA
Q1
A2
MAX4473
3
SHDN
GND
5
SR3
RFIN
V
· RG1
PC
6
I
=
CCPA
4 · RG3 · R
RG3
SENSE
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
Lo w -Co s t , Lo w -Vo lt a g e , PA P o w e r Co n t ro l
Am p lifie r fo r GS M Ap p lic a t io n s in 8 -P in µMAX
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ...........................................................................+7V
Continuous Power Dissipation (T = +70°C)
A
SR1, SR2, SR3, PC, SHDN,
OUT to GND ............................................-0.3V to (V + 0.3V)
µMAX (derate 4.10mW/°C above +70°C) .....................330mW
SO (derate 5.88mW/°C above +70°C)..........................471mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range. ............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
CC
SR1 to SR3......................................................................0 to V
CC
OUT and SR3 Short-Circuit Duration
to V or GND ........................................................Continuous
CC
Current into Any Pin..........................................................±50mA
MAX473
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.
ELECTRICAL CHARACTERISTICS
(V = +2.7V to +6.5V, SHDN > +2.4V, MAX4473 test circuit, RG1 = RG2 = 1kΩ ±1%, RG3 = 2.5kΩ ±1%, R
CC
= 100Ω ±1%, R
L
SENSE
= 10kΩ, C = 300pF, T = T
to T
, unless otherwise noted. Typical values are at V
= +6.0V, V = +1.0V, T = +25°C.)
CC PC A
L
A
MIN
MAX
(Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
GENERAL
Supply Voltage
2.7
6.5
2
V
mA
µA
V
Supply Current
V
= 0
1.2
PC
Shutdown Supply Current
SHDN Input High Voltage
SHDN Input Low Voltage
SHDN Input Current
ERROR AMPLIFIER
0.03
1
SHDN < 0.4V, R = 10kΩ
L
2.4
0.4
V
±0.5
µA
SHDN = 0 to V
CC
SR1, SR2 Input Offset Voltage
1V < V , V
< V
±0.5
10
±2
mV
SR1 SR2
CC
µV/°C
SR1, SR2 Input Offset Voltage Drift
1V < V , V
< V
SR1 SR2 CC
SR1, SR2 Input Common-Mode
Voltage Range
Inferred from CMRR test; V = GND (Note 2)
1
V
CC
V
PC
1V < V , V
SR3 = unconnected
< V , V = GND,
CC PC
SR1 SR2
SR1, SR2 Input Bias Current
±0.04
±1
µA
1V < V , V < V , V = GND,
SR3 = unconnected
SR1 SR2
CC PC
SR1, SR2 Input Bias Offset Current
SR1, SR2 Shutdown Leakage Current
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
±0.001
±0.2
±0.5
µA
µA
dB
dB
±0.001
85
SHDN < 0.4V, V
= V
= V
CC
SR1
SR2
V
CC
= 2.7V
= 6.5V
65
75
1V < V , V
< V
,
SR1 SR2
CC
V
= GND
PC
V
CC
95
2.7V < V < 6.5V, V = GND
80
90
CC
PC
V
= 6.5V, 0.3V < V < 6V
OUT
80
130
125
130
120
R
= 10kΩ
CC
CC
L
to V / 2
V
CC
= 2.7V, 0.3V < V
< 2.4V
< 5.5V
< 2.2V
80
OUT
Large Signal-Gain
dB
V
CC
= 6.5V, 0.7V < V
OUT
80
R
= 500Ω
CC
L
to V / 2
V
CC
= 2.7V, 0.7V < V
80
OUT
R
R
= 10kΩ to V / 2
0.15
0.5
V
-
L
L
CC
0.15
CC
Output Voltage Swing
V
= 500Ω to V / 2
V
-
0.5
CC
CC
Output Current Limit
Gain-Bandwidth Product
Phase Margin
V
R
= V / 2
20
2
mA
MHz
OUT
CC
= 10kΩ, C = 300pF, f = 10kHz
L
L
o
R
= 10kΩ, C = 300pF
60
degrees
L
L
Measured from 30% to 70% of V
, R = 10kΩ,
OUT L
Slew Rate
1.8
V/µs
C
= 300pF
L
2
_______________________________________________________________________________________
Lo w -Co s t , Lo w -Vo lt a g e , PA P o w e r Co n t ro l
Am p lifie r fo r GS M Ap p lic a t io n s in 8 -P in µMAX
MAX473
ELECTRICAL CHARACTERISTICS (continued)
(V = +2.7V to +6.5V, SHDN > +2.4V, MAX4473 test circuit, RG1 = RG2 = 1kΩ ±1%, RG3 = 2.5kΩ ±1%, R
CC
= 100Ω ±1%, R
L
SENSE
= 10kΩ, C = 300pF, T = T
to T
, unless otherwise noted. Typical values are at V
= +6.0V, V = +1.0V, T = +25°C.)
CC PC A
L
A
MIN
MAX
(Note 1)
PARAMETER
CONDITIONS
No sustained oscillations (Note 3)
From 50% of SHDN edge to V
MIN
TYP
MAX
UNITS
pF
Capacitive Load Stability
Enable/Disable Time
0
300
1.5
0.9
µs
= 1V, V = 2V
OUT
PC
GAIN CONTROL BUFFER AND V-TO-I CONVERTER
PC Input Bias Current
GND < V < V - 0.15V
±0.04
±1
µA
mA
PC
CC
SR3 Output Current Limit
V
PC
= 2.55V, SR1 = SR2 = V
0.750
0.095
4
0.1
2
CC
V
PC
to V
Ratio
Measure voltage across RG1, 0.3V < V < 2.55V (Note 4)
0.105
V/V
MHz
RG1
PC
PC Input Bandwidth
Bandwidth from V to V
PC RG1
Note 1: Limits over temperature are guaranteed by design.
Note 2: No output phase-reversal for input common-mode voltage range from GND to V . Common-mode range limited by voltage
CC
drop across Q1 and RG3.
Note 3: Guaranteed by design.
Note 4: Error dependent on tolerance of RG1, RG2, and RG3. Specified with 0.1% tolerance resistors.
Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s
(See Test Circuit, T = +25°C, unless otherwise noted.)
A
V
RG1
/ V RATIO vs. V RESPONSE
ERROR-AMPLIFIER RESPONSE
MAX4473 toc03
SUPPLY CURRENT vs. SUPPLY VOLTAGE
PC
PC
70
60
50
40
30
0
0.1100
0.1075
0.1050
0.1025
0.1000
0.0975
0.0950
0.0925
0.0900
1.4
1.2
1.0
0.8
0.6
0.4
A
= 1000
V = 6.5V
CC
VCL
V
CC
= 6.0V
-18
-36
-54
-72
T = -40°C
A
V
= V / 2
= 0
CM CC
T = +25°C
A
V
PC
GAIN
PHASE
ERROR
T = +85°C
A
20
10
-90
-108
-126
-144
-162
AMPLIFIER
0
100k
10k
-10
-20
300pF
SHDN = V
CC
100Ω
PC = GND
-30
10
-180
0
1
2
3
4
5
6
100
1k
10k 100k 1M 10M
2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5
SUPPLY VOLTAGE (V)
V
(V)
FREQUENCY
PC
ERROR-AMPLIFIER
OUTPUT LOW VOLTAGE vs. TEMPERATURE
ERROR-AMPLIFIER
OUTPUT HIGH VOLTAGE vs. TEMPERATURE
ENABLE/DISABLE TIME
0.30
0.25
0.20
0.15
0.10
0.05
0
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
V
= 6.5V, R = 500Ω to V / 2
L CC
CC
V
CC
= 6.5V, R = 500Ω to V / 2
L CC
SHDN
2V/div
GND
GND
V
= 6.5V
= 2V
CC
V
PC
V
CC
= 2.7V, R = 500Ω to V / 2
L CC
V
CC
= 2.7V, R = 500Ω to V / 2
L CC
V
CC
= 6.5V, R = 10kΩ to V / 2
L CC
V
CC
= 2.7V, R = 10kΩ to V / 2
L CC
OUT
500mV/div
V
CC
= 6.5V, R = 10kΩ to V / 2
L
CC
V
CC
= 2.7V, R = 10kΩ to V / 2
L
CC
-40
-15
10
35
60
85
-40
-15
10
35
60
85
500ns/div
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
3
Lo w -Co s t , Lo w -Vo lt a g e , PA P o w e r Co n t ro l
Am p lifie r fo r GS M Ap p lic a t io n s in 8 -P in µMAX
P in De s c rip t io n
PIN
NAME
FUNCTION
Inverting Input of Error Amplifier and Drain of V-to-I FET, Q1. Connect to supply side of current-sense resis-
SR1
1
tor, R , through gain resistor RG1.
SENSE
Noninverting Input of Error Amplifier. Connect to load side of current-sense resistor, R
resistor RG2. Set RG2 equal to RG1.
, through gain
SENSE
2
3
SR2
Shutdown Input. Drive SHDN low to disable all amplifiers, pull OUT to GND, set the gate-to-source voltage
of the V-to-I FET (Q1) to 0, and reduce supply current to less than 1µA. Drive high or connect to V for nor-
MAX473
SHDN
CC
mal operation.
4
5
PC
Power Control Input. Apply a voltage to PC to set a DC current through the sense resistor to control PA bias.
Ground
GND
Inverting Input of V-to-I Converter and Source of V-to-I FET, Q1. Connect to ground through gain resistor
RG3.
6
SR3
7
8
OUT
Output of Error Amplifier. Connect to gain control pin of power amplifier in bias control applications.
+2.7V to +6.5V Voltage Supply Input. Bypass to ground with a 0.1µF capacitor.
V
CC
four by a resistor-divider network. A2 forces its inverting
De t a ile d De s c rip t io n
input and the source of Q1 to V / 4, thus setting a
PC
The MAX4473 is a voltage-controlled, unidirectional,
hig h-s id e c urre nt s e tting a mp lifie r for a p p lic a tions
where accurate control of PA supply current is desired.
This device is intended for wireless TDMA based sys-
tems (GSM, DECT), where tight restrictions over the
PA’s transmit burst and output power require closed-
loop control over the PA’s output power. When used
with a PA, the MAX4473 functions as a voltage-con-
trolled constant current source, accurately setting PA
supply current by varying the gain of the PA. If you
know the output power versus supply current profile for
the PA, you can set the PA’s output power by control-
ling the amount of supply current delivered to the PA.
voltage across RG3. The resulting current through RG3
sets the current through RG1. This unique architecture
allows the supply current to be set independent of sup-
ply voltage. Set PA supply current according to the fol-
lowing equation:
I
= ( V · RG1 ) / ( 4 · R
· RG3 )
CCPA
PC
SENSE
S h u t d o w n Mo d e
When SHDN is a logic-level low (SHDN < 0.4V), ampli-
fiers A1, A2, and A3 are off, Q1 is turned off, and the
output of A3 is actively pulled to ground with an N-
channel FET. Supply current is reduced to less than
1µA in shutdown mode. Typical power-up time is 0.9µs
a nd typ ic a l p owe r-d own time is 0.3µs , us ing the
MAX4473 test circuit.
The MAX4473 is composed of an input buffer (A1), a
voltage-to-current converting amplifier (A2), and a rail-
to-rail output error amplifier (A3) (see Typical Operating
Circuit). External gain and sense resistors allow pro-
grammability for a wide range of applications.
Ap p lic a t io n s In fo rm a t io n
Ga in Re s is t o r S e le c t io n
(RG1 , RG2 , RG3 )
For proper operation, do not make the value of external
gain resistors RG1 and RG2 larger than twice the value
of RG3. In most practical applications, choose RG1
smaller than RG3 to limit the voltage drop over RG1
In the Typical Operating Circuit, PA supply current
flows from the system supply, through the external cur-
rent sense resistor (R ), to the PA. The rail-to-rail
SENSE
outputs of the error amplifier, A3, adjust the gain of the
PA until the voltage drop across R equals the
SENSE
and R
. A large voltage drop over R
sub-
SENSE
SENSE
voltage drop across external gain resistor, RG1. The
voltage drop across RG1 sets the voltage drop across
stantially reduces the voltage applied to the PA, thus
reducing PA output power. Set RG2 equal to RG1 to
c omp e ns a te for the inp ut b ia s c urre nts of A3.
Recommended values for RG3 are between 1kΩ and
10kΩ.
R
, with a larger voltage drop resulting in more
SENSE
current delivered to the PA. The voltage drop across
RG1 is set by A1, A2, and the V-to-I FET, Q1. A voltage
applied to the PC input of the input buffer is divided by
4
_______________________________________________________________________________________
Lo w -Co s t , Lo w -Vo lt a g e , PA P o w e r Co n t ro l
Am p lifie r fo r GS M Ap p lic a t io n s in 8 -P in µMAX
MAX473
• Efficiency and Power Dissipation: At high current
levels, the I2R losses in R
are significant. Take
S e n s e Re s is t o r S e le c t io n (R
SENSE
)
S ENS E
based on the following criteria:
Choose R
SENSE
this into consideration when choosing the resistor
value and its power dissipation (wattage) rating.
Als o, the s e ns e re s is tor’s va lue ma y d rift if it is
allowed to heat up excessively.
• Voltage Loss: A hig h R
va lue c a us e s the
SENSE
power-source voltage to degrade through IR loss.
For minimal voltage loss, use low R values.
SENSE
• Accuracy: A high R
value allows lower cur-
SENSE
rents to be measured more accurately because input
offset voltages become less significant when the
sense voltage is larger. For best performance, select
R
to provide approximately 100mV of sense
SENSE
voltage for the full-scale current in each application.
_________________________Te s t Circ u it
P in Co n fig u ra t io n
TOP VIEW
R
SENSE
V
CC
100Ω
0.1%
RG1
1k
RG2
1k
0.1µF
1%
1%
SR1
SR2
1
2
3
4
8
7
6
5
V
CC
V
SR1
SR2
CC
OUT
SR3
MAX4473
PC
2N3904
OUT
SHDN
PC
MAX4473
SR3
C
300pF
L
GND
R
10k
L
SHDN
GND
R
E
750Ω
µMAX/SO
RG3
2.5k
1%
Ch ip In fo rm a t io n
TRANSISTOR COUNT: 348
_______________________________________________________________________________________
5
Lo w -Co s t , Lo w -Vo lt a g e , PA P o w e r Co n t ro l
Am p lifie r fo r GS M Ap p lic a t io n s in 8 -P in µMAX
P a c k a g e In fo rm a t io n
MAX473
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.
6 _____________________Ma x im In t e g ra t e d P ro d u c t s , 1 2 0 S a n Ga b rie l Drive , S u n n yva le , CA 9 4 0 8 6 4 0 8 -7 3 7 -7 6 0 0
© 1999 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
相关型号：
MAX4473ESA
Low-Cost, Low-Voltage, PA Power Control Amplifier for GSM Applications in 8-Pin レMAX
MAXIM
MAX4473EUA
Low-Cost, Low-Voltage, PA Power Control Amplifier for GSM Applications in 8-Pin レMAX
MAXIM
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