LTC4401 - RF Power Controllers with 250kHz Loop BW and 45dB Dynamic Range


  • RF Power Amplifier Control in ThinSOT™ Package
  • Internal Schottky Diode Detector with > 45dB Range
  • Wide Input Frequency Range:
    300MHz to 2.7GHz (LTC4401-1)
    300MHz to 2GHz (LTC4401-2)
  • Autozero Loop Cancels Offset Errors and Temperature Dependent Offsets
  • Wide VCC Range: 2.7V to 6V
  • Automatic Bandwidth Control Improves Low Power Ramp Response
  • Allows Direct Connection to Battery
  • RF Output Power Set by External DAC
  • Internal Frequency Compensation
  • Rail-to-Rail Power Control Output
  • Power Control Signal Overvoltage Protection
  • Low Operating Current: 1mA
  • Low Shutdown Current: 10µA
  • Two Pole PCTL Input Filtering
  • Low Profile (1mm) SOT-23 (ThinSOT™) (LTC4401-1) and 8-Pin MSOP (LTC4401-2) Packages

Typical Application

LTC4401 Typical Application


The LTC4401-1 is a SOT-23 RF power controller for slow turn-on RF power amplifiers operating in the 300MHz to 2.7GHz range. The loop bandwidth is set at 250kHz to improve frequency stability when controlling slow turn-on RF power amplifiers such as the Conexant CX77301/CX77302, CX77304, CX77314, Anadigics AWT6107 and the RF Micro Devices RF3160.

RF power is controlled by driving the RF amplifier power control pins and sensing the resultant RF output power via a directional coupler. 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 RF power amplifier is protected against high power control pin voltages.

Internal and external offsets are cancelled over temperature by an autozero control loop, allowing accurate low power programming. The shutdown feature disables the part and reduces the supply current to <10µA.

A dual control channel version (LTC4401-2) is also available in an 8-pin MSOP package.


CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LTC4401-1ES6#PBF SOT-23 S6 E 05-08-1636 Yes
LTC4401-1ES6#TRMPBF SOT-23 S6 E 05-08-1636 Yes
LTC4401-1ES6#TRPBF SOT-23 S6 E 05-08-1636 Yes

LTC4401 Package Drawing
LTC4401 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LTC4401-1ES6#PBF SOT-23 E $1.47 Yes
LTC4401-1ES6#TRMPBF SOT-23 E $1.47 $1.27 Yes
LTC4401-1ES6#TRPBF SOT-23 E $1.47 $1.25 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

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