Texas Instruments TIC12400DCPR

Overview

TIC12400DCPR from Texas Instruments is a 24-input Multiple Switch Detection Interface (MSDI) IC designed for industrial switch monitoring between mechanical switches and low-voltage MCUs. It supports 6.5–35 V supply voltage, offers six programmable wetting current settings (0/1/2/5/10/15 mA), integrates a 10-bit ADC for analog switch position sensing, and delivers ultra-low 68 µA typical polling-mode current with interrupt-driven wake-up capability - enabling robust, low-power PLC and DCS front-end I/O conditioning.

For engineers reviewing the TIC12400DCPR datasheet, TIC12400DCPR pinout, TIC12400DCPR application, or TIC12400DCPR equivalent, this page provides verified technical context on its dual-mode operation (continuous/polling), SPI interface timing (up to 4 MHz), ±8 kV IEC 61000-4-2 ESD protection on all 24 inputs, integrated comparator with four programmable thresholds, and thermal performance in the 38-pin TSSOP package.

Technical Context

The TIC12400DCPR implements a configurable input architecture: 14 dedicated ground-referenced inputs and 10 bidirectional inputs programmable for ground- or supply-referenced switch detection. Its internal pre-regulator and dual LDOs (analog/digital) enable stable operation across wide VS range while maintaining independent 3.0–5.5 V logic supply (VDD) for SPI compatibility.

Switch status acquisition uses either wetting-current-based digital sampling (with 100 Ω closed / 5 kΩ open resistance thresholds) or analog measurement via the 10-bit ADC, with comparator-based digital monitoring operating independently of MCU polling. Fault detection includes over-voltage (35 V trip), under-voltage (3.85 V rising threshold), and thermal shutdown, all signaled via open-drain /INT output.

Key Specifications

Pinout & Package

38-pin TSSOP package (9.70 mm × 4.40 mm), thermally enhanced with exposed pad (EP) requiring board-level grounding for rated thermal (R_θJA = 33.6 °C/W) and ESD performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multiple switch detection interface applications.

Compared with TIC12400QPWRQ1 and MAX14914AATJ+, the TIC12400DCPR uniquely balances 24-channel scalability, programmable wetting current, integrated 10-bit ADC, and ultra-low polling-mode current - making it optimal for cost-sensitive, space-constrained industrial I/O modules where analog switch position sensing and flexible power management are critical.

Availability

TIC12400DCPR is available at Aetrix Electronics and suitable for PLC digital input modules, industrial HMI keypads, DCS remote I/O terminals, and factory automation safety interlocks requiring stable component supply, long-term industrial lifecycle support, and traceable sourcing.

Supply support for TIC12400DCPR 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and communications markets.

The TIC12400DCPR belongs to TI's industrial interface portfolio, engineered specifically for high-reliability switch monitoring in programmable logic controllers, distributed control systems, and factory automation equipment - emphasizing robustness, low power, and integration density.

FAQ

What is the maximum supply voltage the TIC12400DCPR can withstand on its VS pin?

The TIC12400DCPR supports a recommended operating range of 6.5 V to 35 V on the VS pin, with absolute maximum rating of 40 V. An over-voltage condition is flagged at 35 V (VOV_R), triggering /INT assertion and setting the OV bit in INT_STAT. This allows safe operation across standard 24 V industrial rails while providing fault detection before damage occurs - critical for unregulated or transient-prone power environments where the TIC12400DCPR serves as primary I/O conditioner.

Does the TIC12400DCPR require external components to operate, and if so, which ones are mandatory?

Yes, the TIC12400DCPR requires three external capacitors: 1 µF on CAP_Pre (pre-regulator), and 100 nF each on CAP_A (analog LDO) and CAP_D (digital LDO). These are mandatory for stable internal regulation and cannot be omitted. Additionally, /INT requires an external pull-up resistor, and RESET should be grounded if unused. No external current-limiting resistors or TVS diodes are needed on IN0–IN23 due to built-in ±8 kV ESD protection and −24 V to +40 V input tolerance - simplifying bill-of-materials for the TIC12400DCPR in industrial designs.

How does the TIC12400DCPR handle switch debouncing and contact bounce mitigation?

The TIC12400DCPR does not implement hardware debouncing; instead, it relies on programmable timing parameters and firmware-controlled sampling. In polling mode, the device samples inputs only during brief active windows (tPOLL_ACT = 128 µs typical), minimizing exposure to bounce. The microcontroller reads status via SPI after each poll and applies software debounce algorithms using consecutive valid readings. The integrated comparator and ADC provide clean, noise-filtered signals - enabling reliable bounce rejection in firmware without adding external RC networks or dedicated debounce ICs to the TIC12400DCPR interface.

Can the TIC12400DCPR monitor switches connected to the positive supply rail (high-side switching), and how is this configured?

Yes, the TIC12400DCPR supports high-side switch monitoring on 10 of its 24 inputs (IN0–IN9). These inputs are configurable via register settings to operate in CSI (current sink) mode - sourcing wetting current from VS through the switch to the TIC12400DCPR input pin. Configuration is done by writing to the EN_INx and MODE_INx bits in the device's register map. This eliminates the need for external level shifters or PNP transistor buffers when interfacing with supply-referenced switches - a key differentiator of the TIC12400DCPR versus basic GPIO expanders.

What is the purpose of the TRIGGER bit in the CONFIG register of the TIC12400DCPR?

The TRIGGER bit (bit 0 of CONFIG register) acts as the master enable for switch monitoring functionality in the TIC12400DCPR. When set to logic 1, it activates wetting current sources and begins sampling inputs in the selected mode (continuous or polling). When cleared to logic 0, it disables all wetting current and halts monitoring - preserving register contents but stopping status updates. This allows safe reconfiguration without power cycling, and is essential for dynamic adaptation in systems where switch groups are enabled/disabled based on operational mode - a core control mechanism within the TIC12400DCPR architecture.