PIC16F877-20I/PT Microchip Technology, PIC16F877-20I/PT Datasheet - Page 364

• Manufacturer Part Number: PIC16F877-20I/PT
• Description: IC MCU FLASH 8KX14 EE 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877-20I/PT

• Program Memory Type: FLASH
• Program Memory Size: 14KB (8K x 14)
• Package / Case: 44-TQFP, 44-VQFP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 368 B
• Interface Type: MSSP/PSP/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44PT3 - SOCKET TRAN ICE 44MQFP/TQFPAC164305 - MODULE SKT FOR PM3 44TQFP444-1001 - DEMO BOARD FOR PICMICRO MCUAC164020 - MODULE SKT PROMATEII 44TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PICmicro MID-RANGE MCU FAMILY
19.3
DS31019A-page 19-4
Configuring the Voltage Reference
The Voltage Reference can output 16 distinct voltage levels for each range.
The equations used to calculate the output of the Voltage Reference are as follows:
The settling time of the Voltage Reference must be considered when changing the V
Example 19-1
of 1.25V with V
Generally the V
load into VR3:VR0.
some error since VR3:VR0 can only be an integer, and the V
so that the result is not greater then 15.
Equation 19-1:
When VRR = 1
When VRR = 0
if VRR = 1: V
if VRR = 0: V
shows an example of how to configure the Voltage Reference for an output voltage
DD
REF
REF
REF
VR3:VR0 =
VR3:VR0 =
Calculating VR3:VR0
= 5.0V.
and V
Equation 19-1
= (VR3:VR0/24) x V
= (V
DD
DD
x 1/4) + (VR3:VR0/32) x V
of the system will be known and you need to determine the value to
V
V
V
REF
REF
DD
shows how to calculate the VR3:VR0 value. There will be
V
- V
DD
X 24
DD
DD
/4
X 32
DD
REF
and V
1997 Microchip Technology Inc.
DD
levels must be chosen
REF
output.