STMicroelectronics STA5620TR

Overview

STA5620TR from STMicroelectronics is a fully integrated RF front-end receiver IC for GPS L1-band (1575.42 MHz) applications, implementing low-IF architecture with 4.092 MHz IF output, 2-bit ADC (SIGN/MAG), on-chip programmable PLL, crystal oscillator supporting 10–40 MHz TCXO/XTAL, and SPI interface. It delivers 4.5 dB typical noise figure, 55 dB VGA dynamic range, and operates at 2.7 V supply.

For engineers reviewing the STA5620TR datasheet, STA5620TR pinout, STA5620TR application, or STA5620TR equivalent, this device is selected for GPS baseband interfacing where low-power, high-linearity RF downconversion, integrated AGC control via MAG duty cycle regulation, and minimal external component count are critical design requirements.

Technical Context

The STA5620TR uses a low-IF architecture (f_IF = 4f_O = 4.092 MHz) with image-reject mixer and polyphase VCO to achieve ≥20 dB image rejection. Its RF amplifier, mixer, IF filter, and VGA chain are co-designed in BiCMOS SiGe to maintain <4.5 dB NF and >−57 dBm P_1dB while enabling robust operation in noisy RF environments.

It integrates a fully programmable integer-N PLL (R-divider: 1–63; N-divider: 56–4095), charge pump current selection (50–200 µA), and calibrated IF filter with 6 MHz 3-dB bandwidth and 20 dB attenuation at 12.276 MHz. The AGC loop self-regulates MAG duty cycle to 33% using internal integration and external capacitor on AGC_CTRL.

Key Specifications

Pinout & Package

STA5620TR is housed in a 5 mm × 5 mm × 1.0 mm VFQFPN32 (QFN-32) package with exposed thermal pad. Pin numbering follows standard bottom-view layout (pin 1 at top-left corner).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar GPS L1 RF front-end applications.

Compared with MAX2769CTJ+ and GN101, the STA5620TR offers unique integration of low-IF signal chain, self-tuning AGC, and calibrated IF filtering-reducing design risk in cost-sensitive, single-constellation GPS modules where rapid time-to-fix and low quiescent current are mandatory.

Availability

STA5620TR is available at Aetrix Electronics and suitable for portable GPS navigation devices, automotive telematics modules, asset tracking beacons, and marine chartplotters requiring stable component supply across extended production lifecycles.

Supply support for STA5620TR 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, specializing in analog, power, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.

The STA5620TR belongs to ST's GPS RF front-end product line, engineered specifically for ultra-low-power, high-sensitivity L1-band reception in space- and energy-constrained portable navigation systems.

FAQ

What is the function of the AGC_CTRL pin, and how is it used?

The AGC_CTRL pin accepts an analog voltage (0–V_CC) that directly controls the variable gain amplifier (VGA) chain. Internally, the device integrates the MAG output to self-adjust this voltage and maintain a stable 33% MAG duty cycle-eliminating need for external AGC computation. An external capacitor (~10 µF) on AGC_CTRL sets loop bandwidth; grounding the pin forces maximum VGA gain for weak-signal scenarios.

Can the STA5620TR operate with a TCXO instead of a crystal?

Yes. The STA5620TR supports both fundamental-mode crystals (10–40 MHz) and TCXOs. When using a TCXO, connect its output to the XTAL_IN pin and leave XTAL_OUT unconnected. The internal crystal oscillator circuitry automatically disables, and the TCXO signal drives the PLL reference path and GPS_CLK generation-preserving timing accuracy and temperature stability.

What are the power-down modes, and how are they controlled?

The STA5620TR offers three hardware-controlled power states: (1) Standby (CHIP_EN = low): draws 1 µA; (2) Clock-only (CHIP_EN = high, RF_EN = low): enables crystal oscillator and one output buffer (XTAL_CLK or GPS_CLK per MODE pin); (3) Full RX (CHIP_EN = high, RF_EN = high): activates entire signal chain. No software command is needed-mode selection is purely pin-strapped at power-up.

Is the GPS_CLK output synchronized to the incoming GPS signal?

No-GPS_CLK is a free-running 16.368 MHz clock derived from either the crystal oscillator (divided by 1) or the VCO (divided by 96), not phase-locked to the RF input. Its purpose is to provide a stable sampling reference for the baseband correlator; timing alignment with satellite signals is performed digitally in the baseband processor using the SIGN/MAG data stream and known PRN code structure.