PIC16F873A-I/SS Microchip Technology, PIC16F873A-I/SS Datasheet - Page 494

• Manufacturer Part Number: PIC16F873A-I/SS
• Description: IC MCU FLASH 4KX14 EE 28SSOP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F873A-I/SS

• Core Size: 8-Bit
• Program Memory Size: 7KB (4K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SSOP
• Controller Family/series: PIC16F
• No. Of I/o's: 22
• Eeprom Memory Size: 128Byte
• Ram Memory Size: 192Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Core: PIC
• Processor Series: PIC16F
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 20 MHz
• Data Ram Size: 192 B
• Data Rom Size: 128 B
• On-chip Adc: Yes
• Number Of Programmable I/os: 22
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Mounting Style: SMD/SMT
• A/d Bit Size: 10 bit
• A/d Channels Available: 5
• Height: 1.75 mm
• Interface Type: I2C, SPI, USART
• Length: 10.2 mm
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4 V
• Width: 5.3 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164307 - MODULE SKT FOR PM3 28SSOPAC164020 - MODULE SKT PROMATEII 44TQFPXLT28SS-1 - SOCKET TRANSITION ICE 28SSOP
• Lead Free Status / Rohs Status: Details
• Other names: PIC16F873AI/SS

PICmicro MID-RANGE MCU FAMILY
26.6
DS31026A-page 26-10
Design Tips
Question 1:
Answer 1:
The WDT was not designed to be a recovery from a brown-out condition. It was designed to
recover from errant software operation (the device remaining in the specified operating ranges).
If your system can be subjected to brown-outs, either the on-chip brown-out circuitry should be
enabled or an external brown-out circuit should be implemented.
Question 2:
Answer 2:
Make sure that the loop with the CLRWDT instruction meets the minimum specification of the WDT
(not the typical).
Question 3:
Answer 3:
On power-up, you must take into account the Oscillator Start-up time (Tost). Sometimes it helps
to put the CLRWDT instruction at the beginning of the loop, since this start-up time may be variable.
My system voltage drops and then returns to the specified device voltage
range. The device is not operating correctly and the WDT does not reset and
return the device to proper operation.
Device resets even though I do the CLRWDT instruction in my loop.
Device never gets out of resets.
1997 Microchip Technology Inc.