company blog about Recycle ST Data Converters:A/D - D/A Converter,Isolated ADC,Metering IC

Recycle ST Data Converters:A/D - D/A Converter,Isolated ADC,Metering IC

Shenzhen Mingjiada Electronics Co., Ltd. is a globally renowned electronic component recycling company with a long-standing specialisation in the recycling of various high-value electronic components. Through our professional recycling channels, we assist clients in optimising their inventory and recovering capital.

Recyclable products include: 5G chips, new energy ICs, IoT ICs, Bluetooth ICs, in-vehicle infotainment system ICs, automotive-grade ICs, communications ICs, artificial intelligence chips, memory ICs, sensor ICs, microcontroller ICs, transceiver ICs, Ethernet ICs, Wi-Fi chips, wireless communication modules, connectors and related products.

Recycling Process

Inventory Classification: Clients need only provide basic information such as model number, brand, date of manufacture and quantity to complete the inventory classification.

Submit Inventory List: Send the inventory list to our valuation team via email or fax.

Professional Quotation: Our valuation team will provide a competitive quotation within 24 hours of receiving the list.

Transaction and Delivery: Once an agreement has been reached, both parties will mutually agree on the delivery method; we provide global logistics support.

I. Basic Overview of General-Purpose A/D and D/A Converters

Data converters act as a ‘communication bridge’ between the analogue world and digital chips. A/D converters (analogue-to-digital converters) are responsible for converting continuously varying analogue voltage and current signals into discrete digital signals for processing by digital chips such as MCUs and DSPs; D/A converters (digital-to-analogue converters), on the other hand, operate in the opposite direction, converting digital control signals back into analogue signals to drive actuators, analogue output devices and the like. ST’s general-purpose converter chips are characterised by their excellent value for money, low power consumption, compact size and high compatibility, covering both consumer and general industrial applications whilst meeting diverse requirements for precision and conversion rates.

1.1 General Product Features of ST A/D Converters (ADCs)

ST’s general-purpose ADC product range is extensive. By precision, it comprises mainstream specifications of 8-bit, 10-bit, 12-bit and 16-bit; by architecture, it covers the two mainstream types—Successive Approximation Register (SAR) and Sigma-Delta (Σ-Δ)—to meet diverse sampling rate and precision requirements. Among these, SAR ADCs are designed for medium-to-high sampling rates and low latency, making them suitable for industrial real-time data acquisition and motor control; Σ-Δ ADCs, utilising oversampling and noise-shaping techniques, offer ultra-high signal-to-noise ratios and measurement accuracy, making them suitable for low-speed, high-precision measurement applications.

Key general-purpose features include: a wide operating voltage range, low-power design (supporting sleep mode), multi-channel synchronous/independent sampling, an integrated reference voltage source, and compatibility with mainstream digital interfaces such as I²C and SPI, enabling the rapid setup of data acquisition systems without the need for complex peripheral circuits. Representative series, such as STMCU-integrated ADCs and standalone general-purpose ADC chips, are widely used in applications including home appliance control, sensor data acquisition and portable devices.

1.2 General Product Features of ST D/A Converters (DACs)

ST’s general-purpose DACs cover 8–16-bit resolution and include both voltage-output and current-output types. They support single-channel and multi-channel configurations and offer the advantages of fast conversion rates, high linearity and low temperature drift. The products emphasise low noise and high stability, enabling the precise output of analogue voltage and current signals, and are suitable for applications such as signal conditioning, power supply calibration, volume control and servo drives.

Compared to traditional discrete solutions, ST’s general-purpose DACs offer higher integration and feature built-in output buffer amplifiers, eliminating the need for additional operational amplifier circuits and significantly simplifying hardware design. They also incorporate overvoltage and overcurrent protection features to enhance system stability, making them ideally suited to the lightweight design requirements of consumer electronics and general-purpose industrial control applications.

II. ST Isolated ADCs (Core Featured Products)

In industrial high-voltage applications, power storage, photovoltaic inverters and charging points, systems are subject to issues such as shared ground between high and low voltage circuits, high-voltage interference and surge impacts. Ordinary non-isolated ADCs are susceptible to damage from such interference and are unable to achieve electrical isolation between high and low voltage circuits. ST’s isolated ADCs are high-precision analogue-to-digital conversion chips designed specifically for high-voltage industrial applications. Based on a second-order Σ-Δ modulation architecture and incorporating an electrical isolation barrier, they serve as core components for high-voltage signal acquisition.

2.1 Core Operating Principles and Technical Advantages

At the heart of ST’s isolated ADCs lies a second-order Σ-Δ modulator, which converts analogue voltage and current signals into a high-speed 1-bit digital bitstream. When paired with a downstream digital filter, this enables high-precision analogue-to-digital conversion with up to 16 bits of resolution and zero lost codes. The chip incorporates a dedicated electrical isolation barrier, enabling complete electrical isolation between the high- and low-voltage sides. This prevents common-mode voltages, transient interference and surge impacts from the high-voltage side from damaging the low-voltage control circuitry, whilst significantly enhancing the signal acquisition’s immunity to interference.

Compared to standard ADCs, its core advantages lie in three key areas: firstly, ultra-high isolation withstand voltage, with a peak isolation voltage of up to 6,000 V, meeting industrial high-voltage safety standards; secondly, a high signal-to-noise ratio and wide bandwidth, with oversampling and noise-shaping technologies effectively suppressing high-frequency interference to ensure acquisition accuracy under harsh operating conditions; thirdly, high transient immunity, making it suitable for applications with strong electromagnetic interference, such as motor control and high-frequency inverters, thereby ensuring the continuity and stability of data acquisition.

2.2 Flagship Products: ISOSD61/ISOSD61L

The ISOSD61 and ISOSD61L are ST’s flagship high-performance isolated Σ-Δ ADC modulators and benchmark products for industrial high-voltage data acquisition, specifically designed for high-precision current and voltage detection. Both chips utilise an on-chip integrated isolation architecture, eliminating the need for external isolation components, which significantly simplifies PCB layout and reduces system costs.

Key performance parameters: Support for a peak isolation withstand voltage of 6,000 V; a second-order Σ-Δ architecture ensuring high linearity; compatibility with high-frequency external clock inputs; wide bandwidth and excellent signal-to-noise ratio; when paired with a digital filter, 16-bit high-precision conversion can be achieved without code loss. The ISOSD61 supports TTL levels, whilst the ISOSD61L is compatible with low-voltage logic levels, enabling adaptation to different host circuit voltage standards.

Core application scenarios: high-voltage industrial applications such as industrial motor drives, new energy charging points, photovoltaic inverters, UPS (uninterruptible power supply) systems, server and telecommunications power supplies, and high-voltage power sampling.

III. ST Metering ICs (Specialised High-Precision Energy Metering Chips)

Metering ICs are specialised mixed-signal chips designed specifically for the precise measurement of electrical parameters. As customised high-precision data converters, they integrate multi-channel high-precision ADCs, dedicated energy calculation hardware and digital processing units. Without the need for complex calculations by a master control chip, they can independently perform the acquisition, calculation and statistical analysis of electrical parameters, making them core components in smart meters, power monitoring terminals and power analysers. ST metering ICs offer ultra-high metering accuracy, high integration and strong adaptability to operating conditions as their core advantages, making them suitable for both domestic and industrial power metering applications.

3.1 Core Functions and Technical Features

ST metering ICs feature multiple internally integrated synchronous-sampling Σ-Δ ADCs, capable of simultaneously acquiring instantaneous voltage and current waveforms from the power grid. Through hardware-based algorithms, they calculate key power parameters—such as root-mean-square (RMS) voltage and current, active power, reactive power, apparent power, cumulative energy, and power factor—in real time. They also support harmonic monitoring, overvoltage and overcurrent fault detection, and temperature compensation.

Compared to general-purpose ADC-plus-microcontroller solutions, ST’s dedicated metering ICs offer three key advantages: firstly, higher metering accuracy with minimal error across all operating conditions, meeting State Grid’s high-precision metering standards; secondly, hardware-embedded metering algorithms that do not require microcontroller resources, thereby reducing the complexity of firmware development; thirdly, compatibility with a wide range of sampling sensors, including Rogowski coils, current transformers and shunt resistors, enabling adaptation to different power system architectures.

3.2 Flagship Products: STPM3x Series

The STPM3x series, including the STPM32 and STPM33, comprises ST’s mainstream high-precision metering ICs. Designed specifically for precise measurement in power line systems, these are dedicated ASSP metering chips that integrate multiple high-precision ADCs on the analogue side and a dedicated metering processing unit on the digital side, making them core products for industrial and domestic power monitoring.

Key Performance and Features: Supports instantaneous acquisition of voltage and current waveforms, accurately calculating root mean square (RMS) values, various power parameters and energy metrics; supports multi-channel synchronous sampling, suitable for single-phase and three-phase power systems; compatible with a variety of sampling solutions including Rogowski coils, current transformers and shunts; features a wide operating temperature range, with no significant drift in metering accuracy under high or low temperature conditions, and strong resistance to grid harmonic interference.

Typical application scenarios: smart single-phase/three-phase electricity meters, PV grid-connected power monitoring terminals, industrial power distribution monitoring modules, energy metering equipment for charging points, UPS power consumption statistics, and smart home power monitoring devices.

IV. Comparison and Selection Guide for the Three Core Product Categories

To accommodate different design requirements and clearly distinguish the application boundaries between general-purpose converters, isolated ADCs and metering ICs, the following serves as a core selection reference:

1. General-purpose A/D and D/A converters: Suitable for general-purpose scenarios without high-voltage isolation requirements or the need for specialised power metering, such as sensor data acquisition in household appliances, standard analogue signal output and signal conditioning in portable devices; these products emphasise high cost-effectiveness and versatility.

2. Isolated ADCs (ISOSD series): Suitable for high-precision signal acquisition scenarios involving high voltage, strong electromagnetic interference or requiring electrical isolation, such as industrial high-voltage control and new energy power equipment. Their core value lies in high-voltage isolation, interference resistance and high reliability; they handle signal conversion only and do not incorporate dedicated metering algorithms.

3. Metering ICs (STPM3x Series): Suitable for specialised applications involving precise measurement of electrical parameters and energy consumption statistics. These integrate conversion and calculation functions, eliminating the need for additional algorithm development, and meet high-precision electricity metering compliance requirements; they are dedicated chips for smart power equipment.