EVM Set-Up and Operation
5
EVM Set-Up and Operation
This section describes the general operation of the AMC1305EVM.
5.1
Power and Analog Inputs: J1, J2, and J5
In the EVM default configuration, the isolated onboard supply is used. In other words, power to pin 7 of the
AMC1305 is provided from the supply connected to J1 by means of an isolation transformer and the
SN6501 transformer driver. This configuration provides an isolated, regulated source to the AMC1305. For
power provided from high-side isolated rails (such as from a gate drive supply), move the shunt on jumper
JP1 to the
Ext
position (as shown in
) so that the two-wire screw terminal at J5 can be used.
Use a voltage between 3 V dc and 5.5 V dc for the supply provided to J1 and a voltage between 4.4 V dc
and 5.5 V dc for the supply provided to J5.
The analog inputs to the AMC1305EVM PCB can be applied directly to the two-wire screw terminal at J2.
CAUTION
Carefully review the
for the limitations of the
analog input range, and ensure that the appropriate analog and digital supply
voltages are applied before connecting any analog input to the EVM.
Note that the AMC1305EVM is designed for evaluation of the electrical
characteristics of the AMC1305 only. The EVM is not meant for isolation tests
and is not designed to be used in a high-voltage environment.
The transformer used to derive the isolated, unregulated power source to the
LDO input has isolation ratings different from those of the AMC1305. Consult
the transformer manufacturer for more information on the isolation capabilities
of the transformer.
5.2
Device Operation
When the analog and digital power sources are applied to the AMC1305EVM, the digital output activates
when an external modulator clock source is applied. The internal reference of the AMC1305 is used as the
conversion reference.
Additionally, an analog input signal can be applied directly at screw terminal J2. See
for more
details.
lists additional details about the analog input ranges and interfaces available in the device
family.
Table 1. AMC1305 Family Information
Input Voltage
Product
Range
Interface
Input Bandwidth
AMC1305M05
±50 mV
CMOS
1 MHz
AMC1305M25
±250 mV
CMOS
1.8 MHz
AMC1305L25
±250 mV
LVDS
1.8 MHz
When the input voltage approaches the upper end of the specified full-scale range (50 mV or 250 mV,
depending on the AMC1305 device type), the ones density of the modulator output approaches 90%.
When the input voltage approaches the lower end of the specified full-scale range (–50 mV or –250 mV,
depending on the AMC1305 device type), the ones density of the modulator output approaches 10%.
7
SBAU237 – September 2014
AMC1305xxEVM User's Guide
Copyright © 2014, Texas Instruments Incorporated