PIC16F628A-I/ML Microchip Technology, PIC16F628A-I/ML Datasheet - Page 100

• Manufacturer Part Number: PIC16F628A-I/ML
• Description: IC MCU FLASH 2KX14 EEPROM 28QFN
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F628A-I/ML

• Core Size: 8-Bit
• Program Memory Size: 3.5KB (2K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 224 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Controller Family/series: PIC16F
• No. Of I/o's: 16
• Eeprom Memory Size: 128Byte
• Ram Memory Size: 224Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 224 B
• Interface Type: SCI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 1 x 16 bit
• 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, DM163014, DM164120-4
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164324 - MODULE SKT FOR MPLAB 8DFN/16QFNXLT28QFN3 - SOCKET TRAN ICE 18DIP/28QFNI3DBF648 - BOARD DAUGHTER ICEPIC3AC164033 - ADAPTER 28QFN TO 18DIPAC162053 - HEADER INTERFACE ICD,ICD2 18DIPDV007003 - PROGRAMMER UNIVERSAL PROMATE II
• Data Converters: -
• Lead Free Status / Rohs Status: Details

PIC16F627A/628A/648A
14.2.3
Either a prepackaged oscillator can be used or a simple
oscillator circuit with TTL gates can be built.
Prepackaged oscillators provide a wide operating
range and better stability. A well-designed crystal
oscillator will provide good performance with TTL
gates. Two types of crystal oscillator circuits can be
used; one with series resonance, or one with parallel
resonance.
Figure 14-2 shows implementation of a parallel
resonant oscillator circuit. The circuit is designed to
use the fundamental frequency of the crystal. The
74AS04 inverter performs the 180° phase shift that a
parallel oscillator requires. The 4.7 kΩ resistor
provides the negative feedback for stability. The
10 kΩ potentiometers bias the 74AS04 in the linear
region. This could be used for external oscillator
designs.
FIGURE 14-2:
Figure 14-3 shows a series resonant oscillator circuit.
This circuit is also designed to use the fundamental
frequency of the crystal. The inverter performs a 180°
phase shift in a series resonant oscillator circuit. The
330 kΩ resistors provide the negative feedback to bias
the inverters in their linear region.
DS40044G-page 100
10K
+5V
10K
C1
74AS04
XTAL
4.7K
EXTERNAL CRYSTAL OSCILLATOR
CIRCUIT
C2
10K
EXTERNAL PARALLEL
RESONANT CRYSTAL
OSCILLATOR CIRCUIT
74AS04
To other
Devices
PIC16F627A/628A/648A
CLKIN
FIGURE 14-3:
14.2.4
The internal precision oscillator provides a fixed 4 MHz
(nominal) system clock at V
Section 17.0 “Electrical Specifications”, for informa-
tion on variation over voltage and temperature.
14.2.5
For applications where a clock is already available
elsewhere, users may directly drive the PIC16F627A/
628A/648A provided that this external clock source meets
the AC/DC timing requirements listed in Section 17.6
“Timing Diagrams and Specifications”. Figure 14-4
below shows how an external clock circuit should be
configured.
FIGURE 14-4:
74AS04
Clock from
ext. system
330 KΩ
RA6
PRECISION INTERNAL 4 MH
OSCILLATOR
EXTERNAL CLOCK IN
0.1 pF
XTAL
74AS04
330 KΩ
EXTERNAL SERIES
RESONANT CRYSTAL
OSCILLATOR CIRCUIT
EXTERNAL CLOCK INPUT
OPERATION (EC, HS, XT
OR LP OSC
CONFIGURATION)
© 2009 Microchip Technology Inc.
PIC16F627A/628A/648A
RA6/OSC2/CLKOUT
RA7/OSC1/CLKIN
DD
74AS04
= 5V and 25°C. See
To other
Devices
PIC16F627A/
628A/648A
Z
CLKIN