1 Features

• Wide high-side supply range: 3 V to 27 V

• Low-side supply range: 2.7 V to 5.5 V

• Adjustable threshold:

– Window-comparator mode: ±20 mV to ±300 mV

– Positive-comparator mode: 600 mV to 2.7 V

• Reference for threshold adjustment: 100 μA, ±1

• Trip threshold error: ±1 (max) at 250 mV

• Open-drain output with optional latch mode

• Propagation delay: 280 ns (typ)

• High CMTI: 55 V/ns (min)

• Functional Isolation:

– Working voltage: 200 VRMS, 280 VDC

– Transient overvoltage (60 s): 570 VRMS, 800

VDC

• Small, 0.65-mm pitch, leadless package with 1-mm

creepage and clearance

• Fully specified over the extended industrial

temperature range: –40°C to +125°C

2 Applications

• Overcurrent or overvoltage detection in:

– Telecom power supplies

– Analog I/O modules

– Motor drives

– Frequency inverters

3 Description

The AMC21C12 is an isolated window comparator

with a short response time. The open-drain output

is galvanically isolated from the input circuitry by an

isolation barrier that is highly resistant to magnetic

interference. The isolation barrier supports a working

voltage up to 200 VRMS or 280 VDC and transient over

voltages of up to 570 VRMS or 800 VDC.

The comparison window is centered at 0 V, meaning

that the comparator trips if the absolute value of the

input voltage exceeds the trip threshold value. The

trip threshold is adjustable from 20 mV to 300 mV

through a single external resistor and, therefore, the

comparison window ranges from ±20 mV to ±300

mV. When the voltage on the REF pin is greater

than 550 mV, the negative comparator is disabled

and only the positive comparator is functional. The

reference voltage in this mode can be as high as

2.7 V. This mode is particularly useful for monitoring

voltage supplies.

The open-drain output on the device supports

transparent mode (LATCH input tied to GND2) where

the output follows the input state, or latch mode,

where the output is cleared on the falling edge of the

latch input signal.

The AMC21C12 is available in an 8-pin, 0.65-mm

pitch VSON package and is specified over the

extended industrial temperature range of –40°C to

+125°C.