PIC16F688-I/SL Microchip Technology, PIC16F688-I/SL Datasheet - Page 70

• Manufacturer Part Number: PIC16F688-I/SL
• Description: IC PIC MCU FLASH 4KX14 14SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F688-I/SL

• Program Memory Type: FLASH
• Program Memory Size: 7KB (4K x 14)
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: UART/USART
• Peripherals: Brown-out Detect/Reset, POR, WDT
• Number Of I /o: 12
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: SCI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 1
• 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
• On-chip Adc: 8 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT14SO-1 - SOCKET TRANSITION 14SOIC 150/208AC162061 - HEADER INTRFC MPLAB ICD2 20PINAC162056 - HEADER INTERFACE ICD2 16F688
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC16F688
8.2
For the A/D converter to meet its specified accuracy,
the charge holding capacitor (C
to fully charge to the input channel voltage level. The
analog input model is shown in Figure 8-4. The source
impedance (R
impedance directly affect the time required to charge
the capacitor C
impedance varies over the device voltage (V
Figure 8-4.
impedance for analog sources is 10 k .
EQUATION 8-1:
FIGURE 8-4:
DS41203B-page 68
Note 1: The reference voltage (V
Legend: C
T
T
ACQ
ACQ
T
2: The charge holding capacitor (C
3: The maximum recommended impedance for analog sources is 10 k . This is required to meet the pin
A/D Acquisition Requirements
C
= C
= Amplifier Settling Time + Hold Capacitor Charging Time + Temperature Coefficient
= T
= 2 s + T
= -120 pF(1 k + 7 k + 10 k ) In(0.0004885)
= 2 s + 16.47 s + [(50°C -25°C)(0.05 s/°C)]
= 19.72 s
= 16.47 s
leakage specification.
V
I
R
SS
C
LEAKAGE
S
T
AMP
PIN
IC
HOLD
) and the internal sampling switch (R
HOLD
The
HOLD
+ T
(R
C
VA
. The sampling switch (R
ACQUISITION TIME
C
ANALOG INPUT MODEL
IC
= Input Capacitance
= Threshold Voltage
= Leakage Current at the pin due to
= Interconnect Resistance
= Sampling Switch
= Sample/Hold Capacitance (from DAC)
+ [(Temperature -25°C)(0.05 s/°C)]
maximum
+ T
R
various junctions
+ R
S
COFF
SS
ANx
C
5 pF
HOLD
+ R
PIN
S
) must be allowed
) In(1/2047)
REF
recommended
) has no effect on the equation, since it cancels itself out.
HOLD
V
DD
DD
), see
) is not discharged after each conversion.
V
V
T
T
Preliminary
SS
SS
= 0.6V
= 0.6V
)
)
I
± 500 nA
LEAKAGE
As the impedance is decreased, the acquisition time
may be decreased. After the analog input channel is
selected (changed), this acquisition must be done
before the conversion can be started.
To calculate the minimum acquisition time, Equation 8-1
may be used. This equation assumes that 1/2 LSb error is
used (1024 steps for the A/D). The 1/2 LSb error is the
maximum error allowed for the A/D to meet its specified
resolution.
To calculate the minimum acquisition time, T
the “PICmicro
Manual” (DS33023).
R
IC
1k
V
SS R
DD
Sampling
Switch
6V
5V
4V
3V
2V
®
SS
Mid-Range MCU Family Reference
Sampling Switch
5 6 7 8 9 10 11
V
 2004 Microchip Technology Inc.
C
= DAC capacitance
= 120 pF
SS
(k )
HOLD
ACQ
, see