LSB of the control word. Successive conversions are

initiated after the last bit of the previous conversion

result has been clocked out. Resultant data is only

available after conversion is complete.

The time required for the T/H to acquire an input signal

is a function of how quickly its input capacitance is

charged. If the input signal’s source impedance is high,

the acquisition time lengthens, and more time must be

culated by the following equation:

Characteristics table.

Conversion Progress

The comparator’s negative input is connected to the

auto-zero rail. Since the device requires only a single

supply, the ZERO node at the input of the comparator

to have no voltage difference at the comparator inputs

within the limits of an 8-bit resolution.

Input Voltage Range

Internal protection diodes that clamp the analog input

However, for accurate conversions, the input must not

The valid input range for the analog input is from GND

negative input voltage is applied, and full scale (FS)

when the input voltage exceeds the reference.

Input Bandwidth

The ADC’s input tracking circuitry has a 2.5MHz full-

power bandwidth, so it is possible to digitize high-

speed transient events and measure periodic signals

with bandwidths exceeding the ADC’s sampling rate by

using undersampling techniques. To avoid high-fre-

quency signals being aliased into the frequency band

of interest, low-pass filters such as the MAX7418–

MAX7426 are recommended.

Digital-to-Analog Converter

The MAX1102/MAX1103/MAX1104 DAC section uses

an R-2R ladder network that converts the 8-bit digital

input into an equivalent analog output voltage propor-

tional to the applied reference voltage (Figure 3). The

DAC features a double-buffered input, and a buffered

analog output.

8-Bit CODECs

_______________________________________________________________________________________

9

AIN

HOLD

HOLD

TRACK

5pF

TRACK

ZERO

CAPACITIVE

DAC

GND

15pF

MAX1102

MAX1103

MAX1104

2R

R

R

R

R

2R

2R

2R

2R

2R

REF

GND

NOTE: SWITCH POSITIONS SHOWN FOR DAC CODE FFhex.

DAC_ REGISTER

OUT

MSB

LSB

2R

R

R

R

2R

2R

2R

2R

Figure 2. Equivalent Input Circuit

Figure 3. DAC Simplified Circuit Diagram