STMicroelectronics DA112S1

Overview

DA112S1 from STMicroelectronics is a 12-diode ESD protection array in SO-8 package, configured as six dual-diode cells for bidirectional transient clamping on I/O lines. It delivers 18 V repetitive peak reverse voltage per diode, 12 A 8/20 µs surge current handling, and ≤2 µA reverse leakage at 15 V, enabling robust digital line protection in microcontroller interfaces and ISDN S-interface logic-side circuits.

For engineers reviewing the DA112S1 datasheet, DA112S1 pinout, DA112S1 application, or DA112S1 equivalent, key selection criteria include its ±9 V / 0–18 V dual-reference clamping range, 9–12 V peak forward voltage under 12 A surge, low 1.2 V DC forward voltage at 50 mA, and SO-8 footprint compatibility with space-constrained PCB layouts.

Technical Context

The DA112S1 implements a monolithic array of 12 silicon diodes arranged in six independent dual-diode cells, each cell connecting between an I/O pin and one of four reference terminals (REF1–REF4). Each diode provides unidirectional clamping to its assigned reference rail, supporting both single-supply (0 V to +18 V) and split-supply (±9 V) configurations.

Its thermal design targets 170 °C/W junction-to-ambient resistance and 0.73 W power dissipation, enabling operation across –55 °C to +150 °C junction temperature range. Input capacitance remains below 36 pF at 5 V DC bias, preserving signal integrity on high-speed digital lines up to several MHz.

Key Specifications

Pinout & Package

DA112S1 uses an SO-8 surface-mount package with standard 1.27 mm pitch, compliant with JEDEC MS-012 and UL94 V0 epoxy. Pin 1 is marked by a beveled corner or dot.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ESD protection array applications.

Compared with ESDALC6V1-1U2 and TPD2E001DRYR, DA112S1 offers higher surge current rating (12 A vs ≤5 A), broader voltage range support (±9 V or 0–18 V), and 12-line density in SO-8-making it optimal for multi-signal industrial I/O banks where cost-per-line and PCB area are critical.

Availability

DA112S1 is available at Aetrix Electronics and suitable for ISDN interface protection, microcontroller I/O hardening, industrial sensor interfacing, and RS-485 transceiver safeguarding requiring stable component supply across extended production lifecycles.

Supply support for DA112S1 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 analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The DA112S1 belongs to ST's ESD protection diode array product line, engineered specifically for high-density, low-capacitance transient suppression in industrial digital interfaces and telecom infrastructure equipment.

FAQ

What reference voltages must be applied to REF1 and REF2 for proper DA112S1 operation?

REF1 and REF2 must be externally biased to establish the clamping window: either REF1 = 0 V and REF2 = +18 V for 0–18 V unipolar operation, or REF1 = –9 V and REF2 = +9 V for ±9 V bipolar operation. These rails must be low-impedance and capable of sinking/source surge current during clamping events.

Can DA112S1 protect bidirectional data lines like I²C or SPI without signal distortion?

Yes-its ≤36 pF input capacitance and 1.2 V forward voltage at 50 mA ensure minimal impact on rise/fall times for standard-speed I²C (≤400 kHz) and SPI (≤10 MHz) buses. However, for >20 MHz clocked interfaces, lower-capacitance alternatives like ESDALC6V1-1U2 are recommended.

How does DA112S1 handle multiple simultaneous ESD strikes on different I/O pins?

Each of the six dual-diode cells operates independently; simultaneous strikes on I/O1 and I/O3 will clamp to their shared REF1/REF2 rails without cross-talk. Thermal coupling is negligible due to monolithic construction, and the 0.73 W power rating supports sequential surges if ambient temperature remains within –55 °C to +150 °C.

Is DA112S1 compatible with lead-free reflow soldering processes?

Yes-DA112S1 is supplied in ECOPACK®-compliant SO-8 packages with lead-free second-level interconnects, rated for maximum lead temperature of 260 °C for 10 seconds, fully compatible with standard Pb-free reflow profiles including J-STD-020 Class 3.