PIC18F4680-H/ML Microchip Technology, PIC18F4680-H/ML Datasheet - Page 272

• Manufacturer Part Number: PIC18F4680-H/ML
• Description: IC MCU 8BIT 64KB FLASH 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4680-H/ML

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 3.25K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 44-VQFN Exposed Pad
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F2585/2680/4585/4680
FIGURE 22-3:
22.5
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 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 22-4 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
application a time window, represented by the
difference between T
DS39625C-page 270
A
, the HLVD logic generates an interrupt at time T
CASE 1:
CASE 2:
Applications
Enable HLVD
Enable HLVD
B
. The HLVD, thus, would give the
HLVDIF
HLVDIF
IRVST
IRVST
V
V
DD
DD
A
HIGH-VOLTAGE DETECT OPERATION (VDIRMAG =
and T
HLVDIF may not be set
Internal Reference is stable
B
, to safely exit.
Internal Reference is stable
Preliminary
A
T
T
.
IRVST
IRVST
FIGURE 22-4:
HLVDIF cleared in software,
HLVDIF remains set since HLVD condition still exists
V
V
A
B
Legend:
V
V
HLVDIF cleared in software
A
B
1
= HLVD trip point
= Minimum valid device
)
TYPICAL LOW-VOLTAGE
DETECT APPLICATION
operating voltage
© 2007 Microchip Technology Inc.
Time
HLVDIF cleared in software
T
A
V
V
LVD
LVD
T
B