LTC1758-1 データシートの表示（PDF） - Linear Technology

部品番号

コンポーネント説明

メーカー

LTC1758-1

RF Power Controllers with 250kHz Control Loop Bandwidth and 40dB Dynamic Range

Linear Technology 

LTC1758-1/LTC1758-2

PI FU CTIO S (LTC1758-2/LTC1758-1)

VIN (Pin 1): Input Supply Voltage, 2.7V to 6V. VIN should

be bypassed with 0.1µF and 100pF ceramic capacitors.

Used as return for RF 200Ω termination.

RF (Pin 2): RF Feedback Voltage from the Directional

Coupler. Referenced to VIN. A coupling capacitor of 33pF

must be used to connect to the ground referenced direc-

tional coupler. The frequency range is 850MHz to 2000MHz.

This pin has an internal 200Ω termination, an internal

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): (LTC1758-2 Only) Selects VPCA when low

and VPCB when high. This input has an internal 150k

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

power until the RF detected signal equals the DAC signal.

The input impedance is typically 90kΩ.

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.

VPCB (Pin 8): (LTC1758-2 Only) Power Control Voltage

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.

VPCA (Pin 9/Pin 7): Power Control Voltage 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 low (LTC1758-2 only).

VCC (Pin 10/Pin 8): RF Power Amplifier Supply. This pin

has an internal 0.090Ω sense resistor between VIN and

VCC that senses the RF power amplifier supply current to

detect overcurrent conditions.

4

Share Link: