STMicroelectronics STW82102B

Overview

STW82102B from STMicroelectronics is a fully integrated RF down converter with embedded integer-N synthesizer, designed for cellular infrastructure receivers. It delivers 8 dB conversion gain, 10.5 dB noise figure, +25.5 dBm IIP3 linearity, and operates across 1425–1910 MHz RF input with dual auto-calibrating VCOs (LOA: 1500–1800 MHz; LOB: 1900–2200 MHz) for diversity and digital PA linearization loops.

For engineers reviewing the STW82102B datasheet, STW82102B pinout, STW82102B application, or STW82102B equivalent, key selection criteria include its dual VCO calibration, integrated DAC for PIN diode control, SPI/I²C programmability, and 44-pin VFQFPN package with exposed thermal pad - all critical for high-density IF sampling receiver designs.

Technical Context

The STW82102B integrates a passive RF mixer, differential IF amplifier (70–400 MHz), dual-band VCOs with automatic center-frequency calibration, and an integer-N PLL featuring a dual-modulus prescaler (16/17 or 19/20), 10-bit reference divider, adjustable charge pump current, and digital lock detection. Its architecture supports both standard and diversity modes with same- or different-LO configurations.

It embeds an RF balun with internal 50 Ω matching for single-ended RF input, delivers differential 200 Ω-compatible IF outputs, and includes a dual-current-output DAC to drive external PIN diode attenuators - eliminating discrete biasing components while enabling closed-loop ALC in linearization systems.

Key Specifications

Pinout & Package

STW82102B is housed in a 7×7×1.0 mm 44-lead VFQFPN package with exposed thermal pad for enhanced RF power dissipation and thermal stability in continuous transmit-receive operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF down converter with integrated synthesizer applications.

Compared with ADRF6612ACPZ-R7 and MAX2112ETX+, the STW82102B uniquely combines dual auto-calibrating VCOs, integrated DAC for PIN diode control, and cellular-optimized linearity - making it the only option qualified for digital PA linearization in production-grade macrocell infrastructure.

Availability

STW82102B is available at Aetrix Electronics and suitable for cellular infrastructure equipment, IF sampling receivers, and digital PA linearization loops requiring stable component supply across extended product lifecycles.

Supply support for STW82102B 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in automotive, industrial, and communications ICs with vertical manufacturing capability and AEC-Q100/IEC 61508 certified processes.

The STW82102B belongs to ST's RF front-end portfolio targeting wireless infrastructure, specifically engineered to replace discrete mixer-PLL-VCO-DAC subsystems in 3G/4G/LTE base stations with single-chip integration and production-ready calibration.

FAQ

What is the recommended loop filter configuration for the STW82102B PLL?

The datasheet specifies a third-order passive loop filter with REXT_CP (Pin 20) and external RC components connected to ICP (Pin 19) and VCTRL (Pin 18). Typical values use REXT_CP = 5.1 kΩ for 3 mA charge pump current, paired with C1 = 10 nF, C2 = 100 pF, and R = 2.2 kΩ to achieve 200 kHz step response and <1° RMS jitter at 1.65 GHz LO. Layout must minimize trace inductance on the VCTRL node.

Does the STW82102B support external VCO injection, and how is it configured?

Yes - Pins 5 (EXTVCO_INN) and 6 (EXTVCO_INP) accept differential external LO signals in External VCO Mode. Configuration requires setting DBUS_SEL = high, writing SPI register 0x0E[7] = 1, and grounding unused VCO pins. The device disables internal VCOs and uses the external signal for down conversion while retaining full IF amplifier, DAC, and digital interface functionality.

How does the dual VCO calibration process work, and what is its impact on system startup time?

Calibration is initiated via SPI or I²C command and executes automatically per VCO sub-band (LOA/LOB). It measures VCO frequency against reference, adjusts varactor bias, and stores trim codes in on-chip EEPROM. Full dual-VCO calibration adds ≤8 ms to power-on sequence but occurs only once per power cycle unless triggered manually - no runtime overhead during normal operation.

Can the STW82102B's DAC outputs drive PIN diodes directly, and what is the maximum sink current?

Yes - I_PINDRV1 and I_PINDRV2 (Pins 43–44) are PMOS open-drain outputs with programmable current ranging from 0 to 10 mA in 32 steps (LSB = 312.5 µA). They directly bias common-cathode PIN diodes without external transistors; maximum total sink current is 20 mA (10 mA per channel), sufficient for 30 dB analog attenuation in typical 50 Ω RF paths.