Analog Devices Inc./Maxim Integrated MAX22193ATP+

Overview

MAX22193ATP+ from Analog Devices is a high-speed, quad-channel industrial digital input IC that translates 24V field inputs into parallel CMOS-compatible logic outputs (OP1–OP4). It delivers ≤300ns propagation delay, ≤40ns channel-to-channel skew, and supports IEC 61131-2 Type 1/2/3 configurations via external resistor selection. Designed for PLC input modules, it operates directly from 7V–65V field supply and interfaces seamlessly with 3.3V/5V microcontrollers.

For engineers reviewing the MAX22193ATP+ datasheet, MAX22193ATP+ pinout, MAX22193ATP+ application, or MAX22193ATP+ equivalent, this page provides verified technical context, real-world timing behavior, validated pin functions, confirmed IEC 61131-2 compliance modes, and field-proven fault diagnostics including VDD24 monitoring, thermal shutdown, and REFDI short detection.

Technical Context

The MAX22193ATP+ integrates four independent current-limited input channels with programmable trip thresholds, each featuring energyless LED drivers and internal reference generation tied to a single REFDI pin. Its architecture includes an integrated 3.3V LDO regulator (VDD3 output) powered from VDD24 (7V–65V), enabling direct field-side power delivery up to 25mA.

It implements dual-supply operation: VDD24 powers field-side circuitry and enables built-in diagnostics (VDD24 monitor, overtemperature, REFDI fault), while VDD3 serves as logic supply (3.0V–5.5V) or LDO output. The READY open-drain output asserts only when all five conditions are met-VDD3 UVLO cleared, VDD24 valid (if used), no REFDI short, no thermal shutdown, and RDYEN high-enabling robust system-level fault signaling.

Key Specifications

Pinout & Package

MAX22193ATP+ uses a 4mm × 4mm, 20-pin TQFN package (exposed pad) with wettable flanks, optimized for automated optical inspection and thermal performance in high-density industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar industrial digital input applications.

Compared with TI ISO1211 and ST STL215A, the MAX22193ATP+ uniquely combines quad parallel outputs, sub-300ns timing, integrated field-side power regulation, and comprehensive hardware diagnostics-making it optimal for space-constrained, high-reliability PLC and DCS input modules requiring deterministic response and fault transparency.

Availability

MAX22193ATP+ is available at Aetrix Electronics and suitable for programmable logic controllers, distributed control systems, and motor control interfaces requiring stable component supply, long-term industrial lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX22193ATP+ 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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving industrial, automotive, communications, and healthcare markets with precision, reliability, and innovation.

The MAX22193ATP+ belongs to Analog Devices' industrial interface portfolio, designed specifically for robust, high-speed digital input conditioning in harsh environments-emphasizing IEC 61131-2 compliance, field-side diagnostics, and seamless integration into PLC and DCS architectures.

FAQ

What is the maximum propagation delay specification for the MAX22193ATP+?

The MAX22193ATP+ has a maximum propagation delay of 300ns from any input (IN1–IN4) to its corresponding output (OP1–OP4), measured under worst-case conditions (RIN = 470Ω, VINF_ = 11V or 36V). This value is guaranteed across the full −40°C to +125°C operating temperature range and ensures deterministic timing in high-speed PLC scan cycles. The typical delay is 280ns, and channel-to-channel skew remains within ±20ns.

How does the MAX22193ATP+ support IEC 61131-2 Type 1, 2, and 3 digital inputs?

The MAX22193ATP+ supports all three IEC 61131-2 types through external resistor configuration: a 18kΩ resistor from REFDI to GND and 1.5kΩ series resistors on IN1–IN4 configure Type 1/3 inputs (2.05–2.75mA limit), while a 6kΩ REFDI resistor and 470Ω series resistors configure Type 2 (6–8.9mA limit). The device's internal current-limiting architecture and precise threshold hysteresis ensure compliance without external active components-verified across voltage, temperature, and process corners.

Can the MAX22193ATP+ operate without a 24V field supply?

Yes-the MAX22193ATP+ can be powered solely from a 3.0V–5.5V supply applied to VDD3, with VDD24 left floating and EXTVM connected to VDD3 to disable VDD24 monitoring. In this mode, the internal LDO is disabled, reducing quiescent current and heat dissipation. All core functions-including input sensing, LED driving, READY signaling, and OP1–OP4 outputs-remain fully operational, making it suitable for low-power or isolated logic-side implementations.

What happens to the outputs OP1–OP4 during thermal shutdown?

During thermal shutdown (triggered at 165°C junction temperature), the MAX22193ATP+ disables its internal LDO, input channels, and REFDI circuitry-and drives OP1–OP4 into high-impedance state. This prevents erroneous logic levels from propagating to downstream circuitry. The READY output also goes high-impedance unless RDYEN is held high and other fault conditions are absent. Recovery occurs automatically once the die temperature falls below the 155°C hysteresis threshold.

How is the READY signal used for system-level fault detection?

The READY signal on the MAX22193ATP+ is an open-drain output that asserts high only when five conditions are simultaneously satisfied: VDD3 above UVLO (2.4V), VDD24 valid (if used and EXTVM ≠ VDD3), no REFDI short (current <550μA), no thermal shutdown, and RDYEN high. This allows microcontrollers or isolators to distinguish between a valid "all inputs low" state and a field-side fault condition-enabling fail-safe behavior in safety-critical automation systems without software polling.