Maxim-integrated MAXQ7667 Manual do Utilizador descarregar pdf (Página 235)

14-3 __________________________________________________________________________________________________________

MAXQ7667 User’s Guide

SECTION 14: SAR ADC MODULE

The MAXQ7667 incorporates a 12-bit SAR ADC with built-in sample-and-hold and a conversion rate up to 125ksps. The ADC allows gen-

eral-purpose measurements for temperature, supply voltage, diagnostics, or other parameters. Some of the features include the following:

• Low-power, 125ksps, SAR (successive approximation) ADC, available as 12 bits.

• ADC can measure up to five external, single-ended signals or two differential signals.

• ADC has unipolar and bipolar modes with respective input ranges 0V to REF and -REF/2 to REF/2 (where REF is the reference

voltage).

• An internal 2.5V bandgap-based voltage reference.

• An external voltage reference between 1V and AVDD.

• ADC can be used to measure the analog supply voltage, AVDD, without external connections.

• ADC can use AVDD as its reference voltage, allowing ratiometric measurements proportional to the AVDD,

• Selectable ADC conversion start source from on-chip timers, ADC conversion pin, and software write.

14.1 Architecture

Figure 14-1 shows the SAR ADC block diagram. The analog module is composed of a 12-bit SAR ADC and voltage reference blocks.

The input to the SAR ADC is fed through a multiplexer section. The input to the multiplexer can be set through software to measure five

single-ended or two differential inputs. The ADC can be configured to be in unipolar mode or bipolar mode.

Figure 14-1. SAR ADC Block Diagram

SARC[2:0]:SARS[2:0]

SARC[11:9]:SARMX[2:0]

REFERENCE TO

SIGMA-DELTA ADC

(SECTION 17)

ADC DATA

READY INTERRUPT

ASR.0:SARRDY

APE.12:BGE

APE.14:RBUFE

AIE.0:SARIE

BANDGAP

REF

SARC.3:SARBY

SARC.6:SARDUL

SARC.4:SARASD

SARC.7:SARBIP

SARC.8:SARDIF

OSCC[3:2]:SARCD[1:0]

ADC

CLOCK

DIV

TIMER 0

TIMER 1

TIMER 2

APE.4:SARE ADCCLK

AVDD

REF

MUX

SARC[11:9]:SARMX[2:0]

12-BIT

ADC

AIN0

MUX

AIN1

AIN2

AIN3

DATA BUS[15:0]

AIN4

REF

AGND

AVDD

AGND

REFBG

ADCCTL

REF

SYSCLK

BUF

x1.0

1 2 ... 230 231 232 233 234 235 236 237 238 239 240 ... 346 347

Comentários a estes Manuais

Sem comentários

Maxim-integrated MAXQ7667 Manual do Utilizador Página 235

Comentários a estes Manuais

Manuais e produtos relacionados com Hardware Maxim-integrated MAXQ7667