minimize sampling errors with higher source imped-

ances, connect a 100pF capacitor from the analog

input to GND. This input capacitor forms an RC filter

with the source impedance limiting the analog input

bandwidth. For larger source impedances, use a buffer

amplifier to maintain analog input signal integrity.

When operating in internal clock mode, the T/H circuitry

enters its tracking mode on the ninth falling clock edge

of the address byte (see the

Slave Address section).

The T/H circuitry enters hold mode two internal clock

cycles later. A conversion or a series of conversions is

then internally clocked (eight clock cycles per conver-

sion) and the MAX11600–MAX11605 hold SCL low.

When operating in external clock mode, the T/H circuit-

ry enters track mode on the seventh falling edge of a

valid slave address byte. Hold mode is then entered on

the falling edge of the eighth clock cycle. The conver-

sion is performed during the next eight clock cycles.

The time required for the T/H circuitry to acquire an

input signal is a function of input capacitance. If the

analog input source impedance is high, the acquisition

time lengthens and more time must be allowed

minimum time needed for the signal to be acquired. It is

calculated by:

clock mode. For internal clock mode, the acquisition

for clock frequency variations.

2.7V to 3.6V and 4.5V to 5.5V, Low-Power,

4-/8-/12-Channel 2-Wire Serial 8-Bit ADCs

_______________________________________________________________________________________

9

S

Sr

A

SCL

SDA

PS

S

Sr

A

SCL

SDA

S

HS MODE

F/S MODE

t

400pF

SDA

Figure 2. Load Circuit