www.docs.chipfind.ru
1
LTC4400-1/LTC4400-2
sn4400 4400fas
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
TYPICAL APPLICATIO
U
RF Power Controllers with
450kHz Loop BW and
45dB Dynamic Range
The LTC
4400-1 is a SOT-23 RF power controller for fast
turn-on RF power amplifiers operating in the 300MHz to
2.7GHz range. Examples include the Hitachi PF08109B,
PF08122B, PF08123B, PF08107B and RF Micro Devices
RF3108. For slow turn-on RF power amplifiers refer to the
LTC4401-1/LTC4401-2.
RF power is controlled by driving the RF amplifier power
control pin and sensing the resultant RF output power via
a directional coupler or capacitive tap. The RF input
voltage is peak detected using an on-chip Schottky diode.
This detected voltage is compared to the DAC voltage at
the PCTL pin to control the output power. The RF power
amplifier is protected against high power control pin
voltages.
Internal and external offsets are cancelled over tempera-
ture by an autozero control loop, allowing accurate low
power programming. The shutdown feature disables the
part and reduces the supply current to <10
A.
A dual control channel version (LTC4400-2) is also
available in an 8-pin MSOP package.
s
RF Power Amplifier Control in ThinSOT
TM
Package
s
Internal Schottky Diode Detector with > 45dB Range
s
Wide Input Frequency Range:
300MHz to 2.7GHz (LTC4400-1)
300MHz to 2GHz (LTC4400-2)
s
Autozero Loop Cancels Offset Errors and
Temperature Dependent Offsets
s
Wide V
CC
Range: 2.7V to 6V
s
Automatic Bandwidth Control Improves Low Power
Ramp Response
s
Allows Direct Connection to Battery
s
RF Output Power Set by External DAC
s
Internal Frequency Compensation
s
Rail-to-Rail Power Control Output
s
Power Control Signal Overvoltage Protection
s
Low Operating Current: 1mA
s
Low Shutdown Current: 10
A
s
Two Pole PCTL Input Filtering
s
Low Profile (1mm) ThinSOT (LTC4400-1) and
8-Pin MSOP (LTC4400-2) Packages
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTC4400-1 Dual Band Cellular Telephone Transmitter
s
GSM/GPRS Cellular Telephones
s
PCS Devices
s
Wireless Data Modems
s
U.S. TDMA Cellular Phones
V
CC
SHDN
PCTL
1
5
2
6
4
3
RF
V
PCA
GND
LTC4400-1
SHDN
DAC
1.8GHz
INPUT
900MHz
INPUT
4400 TA01
0.1
F
0.4pF
50
Li-Ion
V
PC
900MHz
OUTPUT
1.8GHz
OUTPUT
PA MODULE
BAND
SELECT
ThinSOT is a trademark of Linear Technology Corporation.
RF INPUT POWER (dBm)
10
PCTL REFERENCED DETECTOR
OUTPUT VOLTAGE (mV)
100
1000
10000
26 22 18 14 10 6 2 2
6
10 14 18
1
4400 TA04
T
A
= 25
C
V
CC
= 3.6V
900MHz
1800MHz
LTC4400-1 Detector Characteristics at
900MHz and 1800MHz
2
LTC4400-1/LTC4400-2
sn4400 4400fas
ABSOLUTE AXI U RATI GS
W
W
W
U
V
CC
to GND .............................................. 0.3V to 6.5V
V
PCA/B
Voltage to GND ............................ 0.3V to 3.2V
PCTL Voltage to GND ................. 0.3V to (V
CC
+ 0.3V)
RF Voltage to GND ............................ (V
CC
2.6V) to 7V
BSEL, SHDN Voltage to GND ...... 0.3V to (V
CC
+ 0.3V)
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
C. V
CC
= 3.6V, SHDN = HI, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
PACKAGE/ORDER I FOR ATIO
U
U
W
I
VPCA/B
.................................................................. 10mA
Operating Temperature Range (Note 2) .. 40
C to 85
C
Storage Temperature Range ................ 65
C to 150
C
Maximum Junction Temperature ........................ 125
C
Lead Temperature (Soldering, 10 sec)................ 300
C
(Note 1)
ORDER PART
NUMBER
S6 PART MARKING
LTC4400-1ES6
LTWZ
T
JMAX
= 125
C,
JA
= 230
C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
1
2
3
4
V
CC
V
PCA
V
PCB
GND
8
7
6
5
RF
BSEL
SHDN
PCTL
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
ORDER PART
NUMBER
MS8 PART MARKING
LTC4400-2EMS8
LTXB
T
JMAX
= 125
C,
JA
= 250
C/W
RF 1
GND 2
PCTL 3
6 V
CC
5 VPCA
4 SHDN
TOP VIEW
S6 PACKAGE
6-LEAD PLASTIC TSOT-23
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
CC
Operating Voltage
q
2.7
6
V
I
VCC
Shutdown Current
SHDN = 0V
q
10
20
A
I
VCC
Operating Current
SHDN = HI, I
VPCA/B
= 0mA
q
1.2
1.9
mA
V
PCA/B
V
OL
R
LOAD
= 400
, Enabled
q
0
0.05
V
V
PCA/B
Dropout Voltage
I
LOAD
= 6mA, V
CC
= 2.7V
q
V
CC
0.25
V
V
PCA/B
Voltage Clamp
PCTL = 1V
q
2.7
2.9
3.1
V
V
PCA/B
Output Current
V
PCA/B
= 2.4V, V
CC
= 3V
q
7
10
mA
V
PCA/B
Enable Time
SHDN = V
CC
(Note 5)
q
9
10.2
s
V
PCA/B
Bandwidth
C
LOAD
= 100pF, R
LOAD
= 400
(Note 8)
PCTL < 80mV
q
350
450
560
kHz
PCTL > 160mV
230
kHz
V
PCA/B
Load Capacitance
q
100
pF
V
PCA/B
Slew Rate
V
PCTL
= 2V Step, C
LOAD
= 100pF,
q
1.8
2.5
3
V/
s
R
LOAD
= 400
(Note 3)
V
PCA/B
Droop
1
V/ms
V
PCA/B
Start Voltage
Open Loop (Note 9)
q
270
450
550
mV
BSEL, SHDN Input Threshold
V
CC
= 2.7V to 6V
q
0.35
1.4
V
BSEL, SHDN Input Current
BSEL = SHDN = 3.6V
q
16
24
36
A
PCTL Input Voltage Range
(Note 7)
q
0
2.4
V
PCTL Input Resistance
q
60
90
120
k
PCTL Input Filter
270
kHz
Autozero Range
(Note 4)
q
400
mV
3
LTC4400-1/LTC4400-2
sn4400 4400fas
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
LTC4400-1 Detector Characteristics
at 900MHz
LTC4400-1 Detector Characteristics
at 1800MHz
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Specifications over the 40
C to 85
C operating temperature range
are assured by design, characterization and correlation with statistical
process controls.
Note 3: Slew rate is measured open loop. The slew time at V
PCA/B
is
measured between 1V and 2V.
Note 4: Maximum DAC zero-scale offset voltage that can be applied to PCTL.
Note 5: This is the time from SHDN rising edge 50% switch point to
V
PCA
= 0.25V.
Note 6: Guaranteed by design. This parameter is not production tested.
Note 7: Includes maximum DAC offset voltage and maximum control
voltage.
Note 8: Bandwidth is calculated using the 10% to 90% rise time:
BW = 0.35/rise time
Note 9: Measured 12
s after SHDN = HI.
RF INPUT POWER (dBm)
10
PCTL REFERENCED DETECTOR OUTPUT VOLTAGE (mV)
100
1000
10000
28
10
2
8
1
22
4
14
16
4401 G01
75
C
25
C
30
C
RF INPUT POWER (dBm)
10
PCTL REFERENCED DETECTOR OUTPUT VOLTAGE (mV)
100
1000
10000
26
14
8
2
4
10
16
1
20
4401 G02
75
C
25
C
30
C
ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
RF Input Frequency Range
LTC4400-1(Note 6)
300
2700
MHz
LTC4400-2(Note 6)
300
2000
MHz
RF Input Power Range
RF Frequency = 900MHz (Note 6)
28
18
dBm
(LTC4400-1)
RF Frequency = 1800MHz (Note 6)
26
18
dBm
RF Frequency = 2400MHz (Note 6)
24
16
dBm
RF Frequency = 2700MHz (Note 6)
22
16
dBm
RF Input Power Range
RF Frequency = 900MHz (Note 6)
28
18
dBm
(LTC4400-2)
RF Frequency = 2000MHz (Note 6)
26
18
dBm
RF Input Resistance
Referenced to V
CC
q
150
250
350
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
C. V
CC
= 3.6V, SHDN = HI, unless otherwise noted.
LTC4400-1 Detector Characteristics
at 2400MHz
RF INPUT POWER (dBm)
10
PCTL REFERENCED DETECTOR OUTPUT VOLTAGE (mV)
100
1000
10000
24
12 8 4
4
0
8
12 16
1
20 16
4401 G03
75
C
25
C
30
C
4
LTC4400-1/LTC4400-2
sn4400 4400fas
RF (Pins 1/8): RF Feedback Voltage. This input is referenced
to V
CC
. The frequency range is 300MHz to 2700MHz for the
LTC4400-1 and 300MHz to 2000MHz for the LTC4400-2.
This pin has an internal 250
termination, an internal
Schottky diode detector and peak detector capacitor.
GND (Pins 2/4): System Ground.
PCTL (Pins 3/5): Analog Input. The external power control
DAC drives this input. The amplifier servos the RF power
until the RF detected signal equals the DAC signal. The
input impedance is typically 90k
.
V
PCB
(Pin 3): (LTC4400-2 Only) Power Control Voltage
Output. This pin drives an external RF power amplifier
power control pin. The maximum load capacitance is
100pF.
SHDN (Pins 4/6): Shutdown Input. A logic low on the SHDN
pin places the part in shutdown mode. A logic high places
the part in enable mode. SHDN has an internal 150k pull-
down resistor to ensure that the part is in shutdown when
the drivers are in a three-state condition.
V
PCA
(Pins 5/2): Power Control Voltage Output. This pin
drives an external RF power amplifier power control pin.
The maximum load capacitance is 100pF.
V
CC
(Pins 6/1): Input Supply Voltage, 2.7V to 6V. V
CC
should be bypassed with 0.1
F and 100pF ceramic capaci-
tors. Used as return for RF 250
termination.
BSEL (Pin 7): (LTC4400-2 Only) Selects V
PCA
when Low
and V
PCB
when High. This input has an internal 150k
resistor to ground.
U
U
U
PI FU CTIO S
(LTC4400-1/LTC4400-2)
LTC4400-1 Detector Characteristics
at 2700MHz
RF INPUT POWER (dBm)
10
PCTL REFERENCED DETECTOR OUTPUT VOLTAGE (mV)
100
1000
10000
22
10 6 2
6
2
10
14
1
18 14
4401 G04
75
C
25
C
30
C
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
RF INPUT POWER (dBm)
10
PCTL REFERENCED DETECTOR OUTPUT VOLTAGE (mV)
100
1000
10000
28
10
2
8
1
22
4
14
16
4400 G05
75
C
25
C
30
C
RF INPUT POWER (dBm)
10
PCTL REFERENCED DETECTOR OUTPUT VOLTAGE (mV)
100
1000
10000
26
14
8
2
4
10
16
1
20
4400 G06
75
C
25
C
30
C
LTC4400-2 Detector Characteristics
at 900MHz
LTC4400-2 Detector Characteristics
at 1800MHz
5
LTC4400-1/LTC4400-2
sn4400 4400fas
+
RF DET
+
GM
80mV
270kHz
FILTER
+
30k
22k
51k
30k
250
28pF
33pF
100
4400-1 BD
12
150k
60
A
60
A
RF
1
V
CC
Li-Ion
6
5
V
PCA
GND
PCTL
3
RF PA
RF IN
AZ
AUTOZERO
TXENB
+
+
CONTROL
4
SHDN
10
s
DELAY
NOTE: THE DIRECTIONAL COUPLER SHOWN IN THIS FIGURE MAY BE REPLACED
WITH A COUPLING CAPACITOR AND RESISTOR AS DESCRIBED IN APPLICATION
NOTE 91 "LOW COST COUPLING METHODS FOR RF POWER DETECTORS REPLACE
DIRECTIONAL COUPLERS"
V
REF
50
2
68
V
REF
GAIN
COMPRESSION
CLAMP
C
C
BUFFER
38k
30k
33.4k
6k
30k
+
+
TXENB
LTC4400-1
VBG
BLOCK DIAGRA
W
(LTC4400-1)
PDF 
ZIP