Analog Comparator

Functional Description

The analog comparator is an analog general purpose comparator that can be used as analog wakeup, or for any other measurement that can be performed by means of a coarse comparator. The comparator inputs can be routed to any of the GPIO pins. Reference voltage can be selected from WEDAC voltage (the same that is used in SDAC) or PMU reference. The comparator has three modes: low-power, normal, and high-speed. Each mode provides different power consumption and delay trade-offs. The comparator employs a configurable hysteresis window for noisy input signals. It can also operate without any active hysteresis configuration.

Block Diagram

The "Analog Comparator Block  Diagram" figure shows the internal structure of the analog comparator.

Figure: Analog Comparator Block  Diagram

Analog Comparator Electrical Specifications (table) shows the Analog Comparator’s electrical specifications.

Table: Analog Comparator Electrical Specifications

Voltage Type

Voltage Range and Details

Input voltage: VBAT rail

Input common mode range: 

  • 0 V to VBAT rail voltage, when VDDO voltage ≥ VBAT
  • Otherwise, input range is 0 V to VDDO voltage

Input offset voltage

Maximum 10 mV

Low-power mode comparator hysteresis

Adjustable from 40 mV to 90 mV

  • Delay: mihnimum 120 μs, maximum 800 μs
  • Power consumption: minimum 10 nA, maximum 50 nA

Normal mode comparator hysteresis

Adjustable from 40 mV to 100 mV

  • Delay: minimum 1.5 μs, maximum 10 μs
  • Power consumption: minimum 1.5 μA, maximum 5 μA

High-speed mode comparator hysteresis

Adjustable from 40 mV to 200 mV

  • Delay: minimum 0.2 μs, maximum 3 μs
  • Power consumption: minim um 18 μA, maximum 70 μA

For registers, see Analog Comparator Registers.