LTC1957-2EMS#TR Linear Technology, LTC1957-2EMS#TR Datasheet - Page 4

• Manufacturer Part Number: LTC1957-2EMS#TR
• Description: IC RF PWR CONTROLLR DUAL 10-MSOP
• Manufacturer: Linear Technology

Specifications of LTC1957-2EMS#TR

• Rf Type: Cellular, GSM, GPRS, PCS, Wireless Modem, TDMA
• Frequency: 850MHz ~ 2GHz
• Features: Dual Output
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 6V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 10
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: LTC1957-2EMSTR

PI FU CTIO S
LTC1957-1/LTC1957-2
V
be bypassed with 0.1 F and 100pF ceramic capacitors.
Used as return for RF 200 termination.
RF (Pin 2): RF Feedback Voltage from the Directional
Coupler. Referenced to V
must be used to connect to the ground referenced direc-
tional coupler. The frequency range is 850MHz to 2000MHz.
This pin has an internal 200
Schottky diode detector and peak detector capacitor.
SHDN (Pin 3): Shutdown Input. A logic low on the SHDN
pin places the part in shutdown mode. A logic high places
the part in autozero when TXEN is low. SHDN has an inter-
nal 150k pull-down resistor to ensure that the part is in shut-
down when the drivers are in a three-state condition.
BSEL (Pin 4): (LTC1957-2 Only) Selects V
and V
resistor to ground.
GND (Pin 5/Pin 4): System Ground.
PCTL (Pin 6/Pin 5): Analog Input. The external power
control DAC drives this input. The amplifier servos the RF
TYPICAL PERFOR A CE CHARACTERISTICS
4
IN
U
(Pin 1): Input Supply Voltage, 2.7V to 6V. V
PCB
U
when high. This input has an internal 150k
10000
1000
100
10
1
–26
U
Detector Characteristics
at 900MHz
V
–30 C
IN
= 3V TO 4.4V
–20
IN
(LTC1957-2/LTC1957-1)
. A coupling capacitor of 33pF
RF INPUT POWER (dBm)
W
–14
75 C
25 C
termination, an internal
–8
U
–2
4
PCA
10
1957 G01
when low
IN
16
should
power until the RF detected signal equals the DAC signal.
The input impedance is typically 90k .
TXEN (Pin 7/Pin 6): Transmit Enable Input. A logic high
enables the control amplifier. When TXEN is low and
SHDN is high the part is in the autozero mode. This input
has an internal 150k resistor to ground.
V
Output. This pin drives an external RF power amplifier
power control pin. The maximum load capacitance is
100pF. The output is capable of rail-to-rail swings at low
load currents. Selected when BSEL is high.
V
drives an external RF power amplifier power control pin.
The maximum load capacitance is 100pF. The output is
capable of rail-to-rail swings at low load currents. Selected
when BSEL is low (LTC1957-2 only).
V
has an internal 0.050 sense resistor between V
V
detect overcurrent conditions.
PCB
PCA
CC
CC
that senses the RF power amplifier supply current to
(Pin 10/Pin 8): RF Power Amplifier Supply. This pin
(Pin 9/Pin 7): Power Control Voltage Output. This pin
(Pin 8): (LTC1957-2 Only) Power Control Voltage
10000
1000
100
10
1
–24
Detector Characteristics
at 1800MHz
V
IN
–30 C
–20
= 3V TO 4.4V
75 C
–16 –12 –8 –4
RF INPUT POWER (dBm)
25 C
0
4
8
1957 G02
12 16
IN
and