AD5520 datasheet(13/20 Pages) AD

13 / 20 page

REV. A

AD5520

–13–

CIRCUIT OPERATION

Force Voltage

Most PMU measurements are performed while in force voltage

and measure current modes, for example, when the device is

used as a device power supply, or in continuity or leakage

testing. In the force voltage mode, the voltage at analog input

FIN is mapped directly to the voltage forced at the DUT.

When in force voltage and measure current modes, the maxi-

mum voltage applied to the input corresponds to the maximum

current outputs. Figure 4 shows the transfer function when forcing

a voltage.

VDUT

VCLH

RDUT

VCLL

RDUT

VCLH

IDUT

VCLH

VFIN

VCLL

Figure 4. Voltage Force Transfer Function

Measure Current

Figure 5 shows a simplified diagram of the PMU when in force

voltage mode. The control loop consists of the force amplifier

with the voltage sense amplifier making up the feedback path.

Current flowing through the DUT is measured by sensing the

current flowing through a selectable sense resistor, which is in

series with the DUT. The current sense amplifier (Gain = 16)

generates a voltage at its output, which is proportional to the

current flowing through the DUT. This voltage is compared to

the CLL and CLH levels to ensure the clamp voltages have not

been exceeded. Strobing CPCK and

STB will provide information

about the voltage level with respect to the comparator levels,

CPH and CPL.

MEASIHx

MEASIL

G =

MEASVH

MEASVL

G =

FOHx

RDUT

FIN

VMEASIOUT

VMEASVOUT

CLH

CLL

VCLL

VCLH

VFIN

CONDITION

OUTPUT

VDUT = VFIN

VDUT = VCLH

VDUT = VCLL

VCLH > IDUT

VCLL < IDUT

VCLH < IDUT

VCLL < IDUT

VCLH > IDUT

VCLL > IDUT

REFGNDI/V

Figure 5. Voltage Force, Measure Current Mode

Force Current

In the force current mode, the voltage at FIN is now converted

to a current through the following relationship:

Force Current

FIN

SENSE

Figure 6 shows a simplified diagram of the PMU when in

force current mode. The control loop consists of the force

amplifier with the current sense amplifier making up the feed-

back path. In this case, voltage at the DUT is sensed across

the voltage measure amplifier (Gain = 1) and presented at

the MEASVOUT output.

MEASIHx

MEASIL

G =

MEASVH

MEASVL

G =

FOHx

RDUT

FIN

VMEASIOUT

VMEASVOUT

CLH

CLL

VCLL

VCLH

VFIN

REFGNDI/V

CONDITION

OUTPUT

IDUT =

VCLH > VDUT

VCLL < VDUT

VFIN

IDUT =

VCLH

IDUT =

VCLL

VCLH < VDUT

VCLL < VDUT

VCLH > VDUT

VCLL > VDUT

Figure 6. Current Force, Voltage Measure Mode

AD5520 bảng dữ liệu(PDF) 13 Page - Analog Devices

AD5520 bảng dữ liệu(HTML) 13 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

bảng dữ liệu tải về

Link URL