AD5522JSVDZ datasheet(60/65 Pages) AD

60 / 65 page

Data Sheet

AD5522

Rev. E | Page 59 of 64

CHANGING MODES

There are different ways of handling a mode change.

1. Load any DAC X1 values that require changes. Remember

that for force amplifier and comparator DACs, X1 registers

are available per voltage and current range, so the user can

preload new DAC values to make DAC updates ahead of

time; the calibration engine calculates the X2 values and

stores them.

2. Change to the new PMU mode (FI or FV). This action

loads the new switch conditions to the PMU circuitry and

loads the DAC register with the stored X2 data.

The following steps describe another method for changing modes:

1. In the PMU register (Bit 20 and Bit 19), enable the high-Z

voltage or high-Z current mode to make the amplifier high

impedance (SW5 open).

2. Load any DAC X1 values that require changes. Remember

that for force amplifier and comparator DACs, X1 registers

are available per voltage and current range, so the user can

preload new DAC values to make DAC updates ahead of

time; the calibration engine calculates the X2 values and

stores them.

3. When the high-Z (voltage or current) mode is used, the

relevant DAC outputs are automatically updated (FIN,

CLL, and CLH DACs). For example, in high-Z voltage

mode, when new X1 writes occur, the FIN voltage X2 result

is calculated, cached, and loaded to the FIN DAC. When

forcing a voltage, current clamps are engaged, so the CLL

current register can be loaded, and the gain and offset

corrected and loaded to the DAC register. (The CLH

current register works the same way.)

4. Change to the new PMU mode (FI or FV). This action

loads the new switch conditions to the PMU circuitry.

Because the DAC outputs are already loaded, transients are

minimized when changing current or voltage mode.

REQUIRED EXTERNAL COMPONENTS

The minimum required external components for use with

the AD5522 are shown in Figure 58. Decoupling is greatly

dependent on the type of supplies used, other decoupling on

the board, and the noise in the system. It is possible that more

or less decoupling may be required.

DUTGND

DUT

EXTMEASIH3

EXTMEASIL3

FOH3

EXTFOH3

CCOMP[0:3]

VREF

MEASVH3

CFF3

REF

AVDD

AVSS

DVCC

AVDD

AVSS

DVCC

DUT

EXTMEASIH2

EXTMEASIL2

FOH2

EXTFOH2

MEASVH2

CFF2

DUT

EXTMEASIH0

EXTMEASIL0

FOH0

EXTFOH0

MEASVH0

CFF0

DUT

EXTMEASIH1

EXTMEASIL1

FOH1

EXTFOH1

MEASVH1

CFF1

10µF

0.1µF

RSENSE

(UP TO

±80mA)

RSENSE

(UP TO

±80mA)

RSENSE

(UP TO

±80mA)

RSENSE

(UP TO

±80mA)

Figure 58. External Components Required for Use with the AD5522

AD5522JSVDZ датащи(PDF) 60 Page - Analog Devices

AD5522JSVDZ датащи(HTML) 60 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

датащи скачать

ссылки URL