PIC14000-04/SS Microchip Technology, PIC14000-04/SS Datasheet - Page 64

• Manufacturer Part Number: PIC14000-04/SS
• Description: IC MCU OTP 4KX14 A/D 28SSOP
• Manufacturer: Microchip Technology
• Series: PIC® 14r

Specifications of PIC14000-04/SS

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: I²C
• Peripherals: POR, Temp Sensor, WDT
• Number Of I /o: 20
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: OTP
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 6 V
• Data Converters: Slope A/D
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-SSOP
• Processor Series: PIC14000
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 192 B
• Interface Type: SPI, UART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 1
• Operating Supply Voltage: 2.7 V to 6 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: ICE2000
• Minimum Operating Temperature: 0 C
• On-chip Adc: 14 bit
• For Use With: 309-1025 - ADAPTER 28-SSOP TO 28-DIPXLT28SS-1 - SOCKET TRANSITION ICE 28SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

PIC14000
8.8
The conversion time for the A/D converter on the
PIC14000 can be calculated using the equation:
Where Fosc is the oscillator frequency and N is the
number of bits of resolution desired.
Therefore at 4MHz, the conversion time for 16 bits is
16.384 msec. Conversely, it is 256 sec for 10 bits.
TABLE 8-6:
DS40122B-page 64
Resolution
Conversion Time = (1/Fosc) x 2
Note: Assumes F
(Bits)
A/D
16
14
12
16
14
12
A/D Speed, Resolution and Capacitor
Selection
CDAC CAPACITOR SELECTION (EXAMPLES FOR FULL SCALE OF 3.5V AND 1.5V)
Conversion Time
OSC
(Seconds)
0.016384
0.004096
0.001024
0.016384
0.004096
0.001024
of 4 MHz.
N
Full Scale
(Volts)
3.5
3.5
3.5
1.5
1.5
1.5
Preliminary
Source Output
A/D Current
( amps)
Choosing the correct ramp capacitor for the CDAC pin
is required to achieve the desired resolution, conver-
sion time and full scale input voltage. The equation for
selecting the ramp capacitor value is:
Table 8-6 provides example capacitor values for the
desired A/D resolution, conversion time, and full scale
voltage measurement.
24.75
24.75
24.75
24.75
24.75
24.75
Capacitor = (conversion time in seconds) X
(current source output in amps) / (full scale in volts)
Calculated
Capacitor
1.17E-07
2.93E-08
7.31E-09
2.73E-07
6.83E-08
1.71E-08
(Farads)
CDAC
1996 Microchip Technology Inc.
Nearest Standard
CDAC Capacitor
6800pF
.022uF
0.22 F
Value
68nF
15nF
.1uF