ST7FMC2S5TC(2004) View Datasheet(PDF) - STMicroelectronics

Part Name

Description

MFG CO.

ST7FMC2S5TC
(Rev.:2004)

8-BIT MCU WITH NESTED INTERRUPTS, FLASH, 10-BIT ADC, BRUSHLESS MOTOR CONTROL, FIVE TIMERS, SPI, LINSCI™

STMicroelectronics 

ST7MC1/ST7MC2

9.8 10-BIT A/D CONVERTER (ADC)

9.8.1 Introduction

The on-chip Analog to Digital Converter (ADC) pe-

ripheral is a 10-bit, successive approximation con-

verter with internal sample and hold circuitry. This

peripheral has up to 16 multiplexed analog input

channels (refer to device pin out description) that

allow the peripheral to convert the analog voltage

levels from up to 16 different sources. 4 of the

channels have dedicated circuitry and pins to re-

duce noise and leakage so as to improve the accu-

racy and reduce the sensitivity to analog source

impedance.

The result of the conversion is stored in 2 8-bit

Data Registers. The A/D converter is controlled

through a Control/Status Register.

9.8.2 Main Features

s 10-bit conversion

s Up to 16 channels with multiplexed input

s 2 software-selectable sample times

s External positive reference voltage VREF+ can

be independent from supply

Figure 125. ADC Block Diagram

s Linear successive approximation

s Data registers (DR) which contain the results

s Conversion complete status flag

s Maskable interrupt

s On/off bit (to reduce consumption)

The block diagram is shown in Figure 125.

9.8.3 Functional Description

9.8.3.1 Analog References

VREF+ and VREF- are the high and low level refer-

ence voltage pins. Conversion accuracy may

therefore be impacted by voltage drops and noise

on these lines. VREF+ can be supplied by an inter-

mediate supply between VDDA and VSSA to

change the conversion voltage range. VREF- must

be tied to VSSA. An internal resistor bridge is im-

plemented between VREF+ and VREF- pins, with a

typical value of 15kΩ

9.8.3.2 Analog Power Supply

VDDA and VSSA are the supply and ground pins

providing power to the converter part. They must

fADC

PRESCALER

EOC PRSC1PRSC0 ADON CS3 CS2 CS1 CS0 ADCCSR

4

IT

request

AIN0

ADSTSADCIE

AIN1

MCCBCR

ANALOG

MUX

ANALOG TO DIGITAL

CONVERTER

AINx

ADCDRMSB D9 D8 D7 D6 D5 D4 D3 D2

ADCDRLSB 0 0 0 0 0 0 D1 D0

232/294

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