Analog Devices Inc. LT5511EFE#TRPBF

Overview

LT5511EFE#TRPBF from Analog Devices (acquired Linear Technology) is a high-linearity, upconverting double-balanced mixer IC designed for CATV downstream transmitters and wireless infrastructure transmit systems. It features integrated differential LO buffer, 16-pin TSSOP exposed-pad package, +17dBm IIP3 at 950MHz, +15.5dBm IIP3 at 1900MHz, and operates from 4.0V to 5.25V supply. It enables single-ended LO drive and supports RF output up to 3000MHz.

For engineers reviewing the LT5511EFE#TRPBF datasheet, LT5511EFE#TRPBF pinout, LT5511EFE#TRPBF application, or LT5511EFE#TRPBF equivalent, key selection criteria include input third-order intercept point across frequency bands, LO drive level tolerance (–15dBm to –5dBm), conversion gain stability over temperature (–40°C to 85°C), enable function timing (2µs turn-on), and RF/IF port return loss performance (≥11.5dB).

Technical Context

The LT5511EFE#TRPBF implements a double-balanced Gilbert-cell mixer core driven by a limiting differential LO buffer amplifier. Its architecture eliminates need for external LO balun via internal biasing (LO+ and LO– pins biased to ~1.4V) and supports both differential and single-ended LO inputs with shunt 62Ω resistive matching below 1.5GHz.

IF input stage uses emitter-driven switching transistors with externally set DC bias (via 75Ω ground resistors), delivering 12.5Ω differential impedance requiring 4:1 broadband transformer matching. RF outputs are collector-driven, biased at VCC, and require external balun or hybrid for optimal LO suppression and 2fLO spur rejection.

Key Specifications

Pinout & Package

LT5511EFE#TRPBF is housed in a 16-lead plastic TSSOP (4.4mm width) with exposed thermal pad (pin 17) that must be soldered to PCB ground plane for thermal and RF performance. Pin 1 = LO–, Pin 16 = LO+, Pin 4 = IF+, Pin 5 = IF–, Pin 12 = RF+, Pin 13 = RF–, Pin 10 = EN, Pins 3/6/8/11/14 = GND, Pins 2/9 = NC, Pin 7 = VCCBIAS, Pin 15 = VCCLO.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-linearity upconverting mixer applications.

Compared with LT5511EFE#TRPBF, LT5512EFE#TRPBF serves complementary downconversion roles with higher IIP3 but incompatible signal flow direction, while ADL5801ACPZ-R7 offers broader bandwidth and better linearity at the expense of package size, cost, and layout compatibility.

Availability

LT5511EFE#TRPBF is available at Aetrix Electronics and suitable for CATV infrastructure, wireless base station development, high-linearity test equipment, and point-to-point radio systems requiring stable component supply and long-term production continuity.

Supply support for LT5511EFE#TRPBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, formed through acquisition of Linear Technology in 2017.

The LT5511EFE#TRPBF belongs to ADI's high-linearity RF mixer product line, engineered specifically for infrastructure-grade upconversion in cable television and wireless communications where distortion performance and thermal robustness are critical.

FAQ

What is the recommended LO drive level for optimal linearity in LT5511EFE#TRPBF?

The LT5511EFE#TRPBF achieves best IIP3 performance with –10dBm differential LO input power, as validated in both 950MHz and 1900MHz test configurations. The device supports a usable range of –15dBm to –5dBm; deviation beyond this window degrades conversion gain and increases LO leakage. For single-ended LO drive, apply signal to LO+ with LO– grounded via DC-blocking capacitor, maintaining –10dBm into 50Ω.

Can LT5511EFE#TRPBF operate with a 3.3V supply?

No, LT5511EFE#TRPBF requires a minimum 4.0V supply voltage per its absolute maximum ratings and electrical characteristics table. Operation below 4.0V risks failure to meet specified IIP3, conversion gain, and enable threshold behavior. Systems using 3.3V rails must implement level-shifting or dedicated 5V regulation for the LT5511EFE#TRPBF and its associated bias networks.

How should the exposed thermal pad on LT5511EFE#TRPBF be connected?

The exposed pad (pin 17) of LT5511EFE#TRPBF must be soldered directly to a low-impedance PCB ground plane using a minimum 4×4 array of thermal vias (0.3mm diameter, spaced ≤1mm apart) to achieve θJA = 38°C/W. Leaving it unconnected or floating causes thermal runaway under sustained RF output, degrading IIP3 by >3dB and risking permanent damage above 85°C ambient.

Does LT5511EFE#TRPBF support high-side or low-side LO injection?

Yes, LT5511EFE#TRPBF supports both high-side and low-side LO injection configurations, confirmed in the Applications Information section (page 11). Its double-balanced mixer core and broadband LO buffer (30–2700MHz) allow flexible system architecture - e.g., 950MHz RF output can be generated using either 900MHz LO + 50MHz IF (low-side) or 1000MHz LO – 50MHz IF (high-side), with identical linearity and gain performance.

What is the purpose of the NC pins (2 and 9) on LT5511EFE#TRPBF?

Pins 2 and 9 on LT5511EFE#TRPBF are internally not connected and serve no functional role. However, Linear Technology's datasheet explicitly recommends connecting them to ground to improve isolation between adjacent signal paths - particularly between LO and RF ports - thereby reducing crosstalk and improving LO-to-RF leakage performance by up to 3dB in high-density layouts.