Z8F0830HH020SG Datasheet, PDF (116/257 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore!^® F0830 Series
Product Specification
98
Analog-to-Digital Converter
The Z8 Encore! MCU includes an eight-channel Successive Approximation Register
(SAR) Analog-to-Digital Converter (ADC). The ADC converts an analog input signal to a
10-bit binary number. The features of the SAR ADC include:
• Eight analog input sources multiplexed with general purpose I/O ports
• Fast conversion time, less than 11.9µs
• Programmable timing controls
• Interrupt on conversion complete
• Internal voltage reference generator
• Ability to select external reference voltage
• When configuring an ADC using external V_REF, PB5 is used as V_REF in the 28-pin
package
Architecture
The ADC architecture, displayed in Figure 11, consists of an 8-input multiplexer, sample-
and-hold amplifier and 10-bit SAR ADC. The ADC digitizes the signal on a selected
channel and stores the digitized data in the ADC data registers. In an environment with
high electrical noise, an external RC filter must be added at the input pins to reduce high-
frequency noise.
T_CONV = T_S/H + T_CON
T_CONV = T_S + T_H + 13 * SCLK * 16
where:
SCLK = System Clock
T_CONV = Total conversion time
T_S = Sample time (SCLK * ADCST)
T_CON = Conversion time (13 * SCLK * 16)
T_H = Hold time (SCLK * ADCSST)
DIV = 16 (fixed to divide by 16 for F0830 Series products)
Example: For an F0830 Series MCU running @ 20 MHz:
T_CONV = 1µs + 0.5µs + 13 * SCLK * DIV
T_CONV = 1 µs + 0.5 µs + 13 * (1/20 MHz) * 16 = 11.9 µs
PS025113-1212
Analog-to-Digital Converter