ADC0816, ADC0817

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SNAS527C – JUNE 1999 – REVISED MARCH 2013

Analog Comparator Inputs

The dynamic comparator input current is caused by the periodic switching of on-chip stray capacitances These

are connected alternately to the output of the resistor ladder/switch tree network and to the comparator input as

part of the operation of the chopper stabilized comparator.

Figure 6.

If no filter capacitors are used at the analog or comparator inputs and the signal source impedances are low, the

comparator input current should not introduce converter errors, as the transient created by the capacitance

discharge will die out before the comparator output is strobed.

If input filter capacitors are desired for noise reduction and signal conditioning they will tend to average out the

dynamic comparator input current. It will then take on the characteristics of a DC bias current whose effect can

be predicted conventionally. See AN-258 for further discussion.

Typical Application

*Address latches needed for 8085 and SC/MP interfacing theADC0816, 17 to a microprocessor

Microprocessor Interface Table

PROCESSOR

READ

WRITE

INTERRUPT(COMMENT)

8080

MEMR

MEMW

INTR (Thru RST Circuit)

8085

RD

WR

INTR (Thru RST Circuit)

Z-80

RD

WR

INT (Thru RST Circuit, Mode 0)

SC/MP

NRDS

NWDS

SA (Thru Sense A)

6800

VMA•

φ2•R/W

IRQA or IRQB (Thru PIA)

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