LTC4403-1 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 T_X
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 3× 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 T_X PA or
dual T_X 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
V_HOLD
SHDN
LTC4403-2
1
V_IN
9
BSEL
8
V_HOLD
7
SHDN
10
RF
2
V_PCA
3
V_PCB
4
GND
6
PCTL
5
GND
850MHz/
900MHz
50Ω
RF PA
DIPLEXER
0.4pF
± 0.05pF
1.8GHz /
1.9GHz
RF PA
4403 TA01
4403f
1