Datasheet

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POWER DOWN MODES

Global Powerdown

Standby

Output Buffer Disable

Input Clock Stop

Power Supply Sequence

ADS6125, ADS6124

ADS6123, ADS6122

SLAS560A – OCTOBER 2007 – REVISED MARCH 2008

ADS612X has four power-down modes – global power down, standby, output buffer disable and input clock

stopped. These modes can be set using the serial interface or using the parallel interface (pins SDATA and

PDN).

Table 16. Power Down Modes

POWER DOWN PARALLEL INTERFACE SERIAL INTERFACE

TOTAL POWER, WAKE-UP TIME

MODES REGISTER BIT

mW (to valid data)

SDATA PDN

(Table 5 )

Normal operation Low Low <PDN OBUF>=0 and 417 -

<STBY>=0

Standby Low High <PDN OBUF>=0 and 72 Slow (50 µ s)

<STBY>=1

Output buffer disable High Low <PDN OBUF>=1 and 408 Fast (200 ns)

<STBY>=0

Global power down High High <PDN OBUF>=1 and 30 Slow (50 µ s)

<STBY>=1

In this mode, the A/D converter, internal references and the output buffers are powered down and the total power

dissipation reduces to about 30 mW. The output buffers are in high impedance state. The wake-up time from the

global power down to output data becoming valid in the normal mode is maximum 50 µ s. Note that after coming

out of global power down, optimum performance will be achieved after the internal reference voltages have

stabilized (about 1 ms).

Here, only the A/D converter is powered down and the total power dissipation is about 72 mW. The wake-up time

from standby to output data becoming valid is maximum 50 µ s.

The data output buffers can be disabled, reducing the total power to about 408 mW. With the buffers disabled,

the outputs are in high impedance state. The wake-up time from this mode to data becoming valid in normal

mode is maximum 500 ns in LVDS mode and 200 ns in CMOS mode.

The converter enters this mode when the input clock frequency falls below 1 MSPS. The power dissipation is

about 120 mW, and the wake-up time from this mode to data becoming valid in normal mode is maximum 50 µ s.

During power-up, the AVDD and DRVDD supplies can come up in any sequence. The two supplies are

separated inside the device. Externally, they can be driven from separate supplies or from a single supply.

Product Folder Link(s): ADS6125, ADS6124 ADS6123, ADS6122