|
LTC4403-2_15 Datasheet, PDF (1/12 Pages) Linear Technology – Multiband RF Power Controllers for EDGE/TDMA | |||
|
LTC4403-1/LTC4403-2
Multiband RF Power
Controllers for EDGE/TDMA
FEATURES
s Supports AM Modulation in EDGE/TDMA (ANSI-136)
Applications
s Single Output RF Power Amplifier Control
(LTC4403-1)
s Dual Output RF Power Amplifier Control (LTC4403-2)
s Internal Schottky Diode Detector with >40dB Range
s Wide Input Frequency Range: 300MHz to 2.4GHz
s Autozero Loop Cancels Offset Errors and
Temperature Dependent Offsets
s Wide VIN Range: 2.7V to 6V
s Allows Direct Connection to Battery
s RF Output Power Set by External DAC
s Internal Frequency Compensation
s Rail-to-Rail Power Control Outputs
s Low Operating Current: 1mA
s Low Shutdown Current: < 10µA
s PCTL Input Filter
s Available in a 8-Pin MSOP Package (LTC4403-1)
and 10-Pin MSOP (LTC4403-2)
U
APPLICATIO S
s Multiband GSM/GPRS/EDGE Cellular
Telephones
s PCS Devices
s Wireless Data Modems
s U.S. TDMA Cellular Phones
DESCRIPTIO
The LTC®4403-2 is a multiband RF power controller for
RF power amplifiers operating in the 300MHz to 2.4GHz
range. The LTC4403-2 has two outputs to control dual TX
PA modules with two control inputs. An internal sample
and hold circuit enables the LTC4403-2 to be used with
AM modulation via the carrier or PA supply. The input
voltage range is optimized for operation from a single
lithium-ion cell or 3Ã NiMH.
RF power is controlled by driving the RF amplifier power
control pins and sensing the resultant RF output power.
The RF sense 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 LTC4403-1 is a single output RF power controller
with identical performance to the LTC4403-2. The
LTC4403-1 has one output to control a single TX PA or
dual TX PA module with a single control input and is
available in an 8-pin MSOP package.
Internal and external offsets are cancelled over tempera-
ture by an autozero control loop. The shutdown feature
disables the part and reduces the supply current to
< 10µA.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
LTC4403-2 Multiband EDGE Cellular Telephone Transmitter
Li-Ion
0.1µF
DAC
BSEL
VHOLD
SHDN
LTC4403-2
1
VIN
9
BSEL
8
VHOLD
7
SHDN
10
RF
2
VPCA
3
VPCB
4
GND
6
PCTL
5
GND
850MHz/
900MHz
50â¦
RF PA
DIPLEXER
0.4pF
± 0.05pF
1.8GHz /
1.9GHz
RF PA
4403 TA01
4403f
1
|
▷ |