PIC12C672T-10/SM Microchip Technology, PIC12C672T-10/SM Datasheet - Page 437

• Manufacturer Part Number: PIC12C672T-10/SM
• Description: IC MCU OTP 2KX14 A/D 8-SOIJ
• Manufacturer: Microchip Technology
• Series: PIC® 12Cr

Specifications of PIC12C672T-10/SM

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 10MHz
• Peripherals: POR, WDT
• Number Of I /o: 5
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: OTP
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 4x8b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 8-SOIC (5.3mm Width), 8-SOP, 8-SOEIAJ
• For Use With: XLT08SO-1 - SOCKET TRANSITION 8SOIC 150/208AC164312 - MODULE SKT FOR PM3 16SOIC309-1048 - ADAPTER 8-SOIC TO 8-DIP309-1047 - ADAPTER 8-SOIC TO 8-DIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Connectivity: -

Section 23. 10-bit A/D Converter
23.10
A/D Accuracy/Error
In systems where the device frequency is low, use of the A/D RC clock is preferred. At moderate
to high frequencies, T
should be derived from the device oscillator.
AD
The absolute accuracy specified for the A/D converter includes the sum of all contributions for
quantization error, integral error, differential error, full scale error, offset error, and monotonicity.
It is defined as the maximum deviation from an actual transition versus an ideal transition for any
code. The absolute error of the A/D converter is specified at < 1 LSb for V
= V
(over the
DD
REF
device’s specified operating range). However, the accuracy of the A/D converter will degrade as
V
diverges from V
.
DD
REF
For a given range of analog inputs, the output digital code will be the same. This is due to the
quantization of the analog input to a digital code. Quantization error is typically
1/2 LSb and is
inherent in the analog to digital conversion process. The only way to reduce quantization error is
to increase the resolution of the A/D converter.
Offset error measures the first actual transition of a code versus the first ideal transition of a code.
Offset error shifts the entire transfer function. Offset error can be calibrated out of a system or
introduced into a system through the interaction of the total leakage current and source imped-
ance at the analog input.
Gain error measures the maximum deviation of the last actual transition and the last ideal tran-
sition adjusted for offset error. This error appears as a change in slope of the transfer function.
The difference in gain error to full scale error is that full scale does not take offset error into
account. Gain error can be calibrated out in software.
Linearity error refers to the uniformity of the code changes. Linearity errors cannot be calibrated
out of the system. Integral non-linearity error measures the actual code transition versus the ideal
23
code transition adjusted by the gain error for each code.
Differential non-linearity measures the maximum actual code width versus the ideal code width.
This measure is unadjusted.
The maximum pin leakage current is specified in the Device Data Sheet electrical specification
parameter
D060.
In systems where the device frequency is low, use of the A/D RC clock is preferred. At moderate
to high frequencies, T
should be derived from the device oscillator. T
must not violate the
AD
AD
minimum and should be minimized to reduce inaccuracies due to noise and sampling capacitor
bleed off.
In systems where the device will enter SLEEP mode after the start of the A/D conversion, the RC
clock source selection is required. In this mode, the digital noise from the modules in SLEEP are
stopped. This method gives high accuracy.
Preliminary
1997 Microchip Technology Inc.
DS31023A-page 23-15