Texas Instruments AMC21C12DENR

Overview

AMC21C12 from Texas Instruments is a functionally isolated, fast-response window comparator with galvanic isolation barrier, adjustable ±20 mV to ±300 mV trip threshold, 280 ns typical propagation delay, and open-drain output with latch/transparent mode selection. It monitors analog signals across high-voltage domains in telecom power supplies and motor drives.

For engineers reviewing the AMC21C12 datasheet, AMC21C12 pinout, AMC21C12 application, or AMC21C12 equivalent, this page delivers verified functional isolation specs, precise threshold error (±1% max at 250 mV), CMTI (55 V/ns min), working voltage (200 VRMS), and temperature range (–40°C to +125°C) for safety-critical overvoltage/overcurrent detection design.

Technical Context

The AMC21C12 implements dual comparators (Cmp0 and Cmp1) referenced to a 100 μA ±1% internal current source, enabling precise window-comparator operation centered at 0 V. Threshold adjustment is achieved via a single external resistor on the REF pin, supporting both window mode (±20–300 mV) and positive-only mode (600 mV–2.7 V).

Its SiO₂-based capacitive isolation barrier provides functional isolation with 200 VRMS working voltage and 570 VRMS transient overvoltage rating. The open-drain output operates in transparent mode (LATCH = low) or latched mode (LATCH = high), with deglitch timing of 1.8–3.2 µs on LATCH input and 10–100 µs for comparator enable/disable transitions.

Key Specifications

Pinout & Package

AMC21C12 is housed in an 8-pin VSON package (DEN) with 3.5 mm × 2.7 mm footprint, 0.65-mm pitch, and ≥1 mm creepage/clearance - optimized for compact, high-density isolated sensing layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated comparator applications.

Compared with AMC1301QDWVRQ1 and ISO224BDWVR, the AMC21C12 uniquely integrates functional isolation, window comparison, and latch functionality in a single 8-pin VSON package - eliminating external components while delivering 280 ns response and ±1% threshold accuracy for deterministic overcurrent/overvoltage protection.

Availability

AMC21C12 is available at Aetrix Electronics and suitable for telecom power supplies, analog I/O modules, motor drives, and frequency inverters requiring stable component supply and guaranteed long-term manufacturability.

Supply support for AMC21C12 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 focused on analog and embedded processing technologies, with broad portfolio coverage in power management, signal chain, and isolation solutions.

The AMC21C12 belongs to TI's isolated analog sensing product line, designed specifically for high-reliability overvoltage/overcurrent detection in industrial power systems where speed, precision, and galvanic separation are critical.

FAQ

What is the maximum adjustable trip threshold range for the AMC21C12 in window-comparator mode?

The AMC21C12 supports an adjustable window-comparator threshold range of ±20 mV to ±300 mV, set by a single external resistor connected to the REF pin and driven by the device's internal 100 μA ±1% reference current. This range is explicitly specified in the datasheet's Recommended Operating Conditions table and validated across –40°C to +125°C.

Does the AMC21C12 provide reinforced or functional isolation?

The AMC21C12 provides functional isolation only - it is rated for 200 VRMS working voltage and 570 VRMS transient overvoltage (60 s), but does not meet reinforced isolation standards such as UL 1577 or VDE 0884-11. Its isolation barrier is intended for signal-level separation, not user safety, and must be used within system-level safety architecture.

How does the LATCH pin affect the behavior of the AMC21C12 output?

When the LATCH pin is held high, the AMC21C12 output enters latch mode: once the OUT pin pulls low due to a threshold violation, it remains low until the LATCH pin is toggled low then high again. When LATCH is low, the device operates in transparent mode: OUT follows the input state in real time, returning high immediately when |VIN| falls back within the window.

What is the typical propagation delay of the AMC21C12, and under what conditions is it measured?

The AMC21C12 has a typical propagation delay of 280 ns, measured with VDD2 = 3.3 V, VREF = 250 mV, 10 mV overdrive, and CL = 15 pF load. This value is specified in the Switching Characteristics table (Section 5.7) and confirmed across temperature and supply variations in Figures 5-33 through 5-36 of the datasheet.

Can the AMC21C12 be used to monitor positive-only voltage rails, and how is that configured?

Yes - when the voltage on the REF pin exceeds 550 mV (VMSEL threshold), the AMC21C12 disables its negative comparator (Cmp1) and operates in positive-comparator mode only. In this mode, the trip threshold is adjustable from 600 mV to 2.7 V, making it suitable for monitoring DC supply rails like 3.3 V, 5 V, or 12 V outputs.