Typical Ac Setup And Response - Analog Devices AD8556-EVALZ User Manual

UG-896
Table 1. Evaluation Software Dialog Box Button Functions
Button Function
Start Select the connector and the product, and then click Start to begin evaluation.
Connector
Selects the physical connector on the SDP board that is used to connect to the evaluation board. The connectors are
labeled on the top silkscreen of the SDP board.
Product Selects the device under evaluation.
Simulate Configures the device according to the specified pattern. This button does not blow any fuses.
Program Blows fuses according to the specified pattern. Blown fuses cannot be reprogrammed.
Blow Parity Fuse Blows the parity fuse. The parity fuse keeps track of the state of the blown fuses. If, for any reason, the state of this fuse
is changed either intentionally or unintentionally, the parity flag is set and the alarm is set.
Blow Master Fuse Permanently sets the device to the programmed gain and offset and prevents future programming. Click this button
only after selecting and programming the gain and the offset. Prior to blowing the master fuse, make sure to first
blow the parity fuse, if prompted.
Read Fuse Values Reads back the state of the programmed fuses after they have been blown. The options are as follows:
Low sense current: when dropped across a blown fuse (high impedance), creates a voltage that can trigger an internal
comparator and provide the right level in the output.
High sense current: reads back the fuse states to make sure that the fuses are blown. A code for blown fuses appears
in a pop-up box.
See the AD8555/AD8556/AD8557
information on the theory of operation; simulation,
programming, and read modes; and parity error detection.
The AD8555/AD8556/AD8557
information on programming procedures for the device.

TYPICAL AC SETUP AND RESPONSE

AC Input Example
Setup requirements are as follows:

Power supplies

Function generator

Scope

BNCs and cables
Results
When the device is powered with ±2.5 V, and 50 mV of input is
applied, the default conditions are

V = 2.5 V
CC

V = −2.5 V
SS

Gain 1 = 4

Gain 2 = 17.5

Offset = V
SS
The overall gain is 70.
When the switches are placed in V
set of outputs. When the switches are changed to V
V P1, the exact voltage is produced, but with the opposite
POS
polarity.
When both switches are on one side (for example, V
V P1), the inputs are shorted together.
POS
RT0 and RT1 are the trim potentiometers used for pulse width
shaping. Do not change their settings. RT0 is adjusted to create
a 5 μs pulse; RT1 is adjusted to create an 80 μs pulse.
data sheet for more
data sheet also contains more
P1 and V P2, there is one
NEG POS
P2 and
NEG
P1 and
NEG
AD8556-EVALZ/AD8556CP-EBZ User Guide
Figure 4 shows the output on Channel 2 under these conditions
and configuration.
T
1
2
Ch1 50.0mV
Figure 5 shows the results of the previous conditions with
V = 2.5 V or Code 128.
OFF
T
1
2
Ch1 50.0mV
Figure 5. Output on Channel 2, V
Rev. A | Page 6 of 9
[ ]
T
Ch2
B W 2.00V B W M 400ms A Ch1
T 9.600%
Figure 4. Output on Channel 2
[ ]
T
B W Ch2 2.00V B W M 400ms A Ch1
T 9.600%
= 2.5 V
OFF
2.00mV
2.00mV