STMicroelectronics ST7570TR

Overview

ST7570TR from STMicroelectronics is a fully integrated narrow-band power line networking system-on-chip (SoC) implementing IEC61334-5-1 S-FSK PHY/MAC protocol stack, featuring embedded 56 MHz PHY processor and 28 MHz protocol controller cores, programmable carrier up to 148.5 kHz in 1 Hz steps, 2.4 Kbps max bit rate at 50 Hz, and integrated 1 A_rms single-ended power amplifier for mains coupling - deployed in smart metering and street lighting control systems.

For engineers reviewing the ST7570TR datasheet, ST7570TR pinout, ST7570TR application, or ST7570TR equivalent, key selection considerations include zero-crossing synchronization capability, integrated AFE with PGA (−18 dB to +30 dB), TX_GAIN programmability (0–31), CL-based current limiting, and compliance with EN50065/FCC Part 15 conducted emission limits.

Technical Context

The ST7570TR implements dual-core architecture: a 56 MHz PHY processor handles S-FSK modulation/demodulation with SNR estimation and RSSI, while a 28 MHz protocol controller executes IEC61334-5-1 MAC layer, alarm management, repeater call, and intelligent search initiator logic. Its analog front end integrates ADC/DAC, PGA with automatic gain control, and configurable active filtering topology.

Zero-crossing synchronization is supported via dual-input paths - analog (ZC_IN_A, ±10 V_p-p, 62–78 mV hysteresis) and digital (ZC_IN_D) - enabling precise timing alignment to AC mains phase. The power amplifier delivers 14 V_p-p output into 50 Ω with THD ≤0.15%, HD2 ≤−63 dBc, and PSRR ≥70 dB at 100 kHz.

Key Specifications

Pinout & Package

VFQFPN48 package with exposed pad; 7 × 7 mm body, 0.5 mm pitch, RoHS-compliant, designed for thermal dissipation in high-power line driver applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power line networking SoC applications.

Compared with MAX2992 and TI PLC230, the ST7570TR uniquely combines full IEC61334-5-1 stack, 1 A_rms PA, auto-gain AFE, and zero-crossing PLL in one die - reducing system latency, component count, and certification effort for EN50065-compliant deployments.

Availability

ST7570TR is available at Aetrix Electronics and suitable for smart metering, street lighting control, and substation command relay applications requiring stable component supply across 10+ year utility deployment lifecycles.

Supply support for ST7570TR 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, designing and manufacturing microcontrollers, power ICs, sensors, and analog/mixed-signal devices for industrial, automotive, and smart infrastructure markets.

The ST7570TR belongs to ST's Power Line Communication (PLC) SoC product line, engineered specifically to deliver certified, low-cost, single-chip S-FSK solutions for utility-grade smart grid endpoints compliant with EN50065 and FCC Part 15.

FAQ

What is the maximum allowable mains voltage coupling for ST7570TR?

The ST7570TR's PA_OUT delivers up to 14 V_p-p into 50 Ω, and its absolute maximum ratings specify V(PA_OUT) tolerance of ±0.3 V relative to VSS/VCC. When coupled to 230 VAC mains via standard 1:1 isolation transformer and LC filter, peak line voltage (325 V) must be attenuated to ≤14 V_p-p at PA_OUT. External coupling network design must ensure CL pin voltage remains below 2.4 V under worst-case load to prevent TX_GAIN throttling.

How does the ST7570TR handle zero-crossing detection jitter in noisy environments?

The ST7570TR uses a dedicated Schmitt-trigger comparator on ZC_IN_A with 62–78 mV hysteresis and symmetrical thresholds (±30–50 mV), rejecting noise spikes below 30 mV. It also supports digital ZC_IN_D input with 50% duty-cycle requirement, allowing external hardware debouncing. Internal PLL locks to detected edges with <1 µs jitter propagation to PRESLOT output, ensuring timing-critical burst transmissions remain aligned within ±2 µs of zero-crossing.

Can the ST7570TR operate without an external crystal?

Yes - the ST7570TR accepts an external clock signal (1.8–5.5 V_p-p) on XIN, with XOUT left floating. Internal oscillator circuitry supports 8 MHz operation, matching the required fCLK_AFE and fCLK_PHY_processor frequencies. Crystal-less operation is validated per datasheet Table 5 (f(XIN) = 8 MHz), but external clock source must meet ±150 ppm stability to maintain IEC61334-5-1 timing accuracy and carrier frequency precision.

What PCB layout guidelines are critical for thermal performance?

Thermal performance depends on the exposed pad (EP) soldered to a minimum 100 mm² copper pour connected to internal ground planes via ≥6 thermal vias (0.3 mm diameter). Per datasheet Figure 3, RthJA drops from 50 °C/W (no EP cooling) to 42 °C/W with 100 s transmission limit. For continuous operation, add 2-layer thermal relief under EP and route VCC/GND traces ≥0.5 mm wide adjacent to EP to reduce junction-to-ambient delta-T below 45 °C at 1 A_rms output.