PIC18F2221-I/ML Microchip Technology, PIC18F2221-I/ML Datasheet - Page 256

• Manufacturer Part Number: PIC18F2221-I/ML
• Description: IC PIC MCU FLASH 2KX16 28QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2221-I/ML

• Core Size: 8-Bit
• Program Memory Size: 4KB (2K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 25
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Controller Family/series: PIC18
• No. Of I/o's: 25
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 512Byte
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Package: 28QFN EP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 25
• Interface Type: I2C/SPI/USART
• On-chip Adc: 10-chx10-bit
• Number Of Timers: 4
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28QFN4 - SOCKET TRANS ICE 28QFN W/CABLEAC164322 - MODULE SOCKET MPLAB PM3 28/44QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PIC18F2221/2321/4221/4321 FAMILY
FIGURE 23-3:
23.5
In many applications, the ability to detect a drop below
or rise above a particular threshold is desirable. For
example, the HLVD module could be periodically
enabled to detect a Universal Serial Bus (USB) attach
or detach. This assumes the device is powered by a
lower voltage source than the USB when detached. An
attach would indicate a high-voltage detect from, for
example, 3.3V to 5V (the voltage on USB) and vice
versa for a detach. This feature could save a design a
few extra components and an attach signal (input pin).
For general battery applications, Figure 23-4 shows a
possible voltage curve. Over time, the device voltage
decreases. When the device voltage reaches voltage
V
The interrupt could cause the execution of an ISR,
which would allow the application to perform “house-
keeping tasks” and perform a controlled shutdown
before the device voltage exits the valid operating
range at T
tion a time window, represented by the difference
between T
DS39689F-page 256
A
, the HLVD logic generates an interrupt at time T
CASE 1:
CASE 2:
Enable HLVD
Enable HLVD
Applications
A
B
. The HLVD, thus, would give the applica-
and T
HLVDIF
HLVDIF
IRVST
IRVST
V
V
B
DD
DD
, to safely exit.
HIGH-VOLTAGE DETECT OPERATION (VDIRMAG = 1)
HLVDIF may not be set
Internal Reference is stable
Internal Reference is stable
T
T
IRVST
IRVST
A
.
HLVDIF cleared in software,
HLVDIF remains set since HLVD condition still exists
FIGURE 23-4:
V
V
A
B
Legend:
HLVDIF cleared in software
V
V
A
B
= HLVD trip point
= Minimum valid device
TYPICAL LOW-VOLTAGE
DETECT APPLICATION
© 2009 Microchip Technology Inc.
operating voltage
Time
HLVDIF cleared in software
T
A
V
V
LVD
LVD
T
B