Datasheet

Data Sheet AD7294
Rev. H | Page 13 of 48
TQFP Pin No. LFCSP Pin No. Mnemonic Description
40 35 SCL Serial I
2
C Bus Clock. The data transfer rate in I
2
C mode is compatible with both
100 kHz and 400 kHz operating modes. Open-drain input; external pull-up
resistor required.
41 36 OPGND Dedicated Ground Pin for I
2
C Interface.
42 37 V
DRIVE
Logic Power Supply. The voltage supplied at this pin determines at what
voltage the interface operates. Decouple this pin to DGND. The voltage range
on this pin is 2.7 V to 5.5 V and may be different to the voltage level at AV
DD
and DV
DD
, but should never exceed either by more than 0.3 V. To set the input
and output thresholds, connect this pin to the supply to which the I
2
C bus is
pulled.
43, 47, 48 38, 42 DGND Digital Ground. This pin is the ground for all digital circuitry.
44 39 DV
DD
Logic Power Supply. The operating range is 4.5 V to 5.5 V. These pins provide
the supply voltage for all the digital circuitry on the AD7294. Connect the AV
DD
and DV
DD
pins together to ensure that all supply pins are at the same potential.
Decouple this supply to DGND with a10 µF tantalum capacitor and a 0.1 µF
ceramic capacitor.
46, 45 41, 40 I
SENSE
1
OVERRANGE,
I
SENSE
2
OVERRANGE
Fault Comparator Outputs. These pins connect to the high-side current sense
amplifiers.
49, 50, 51, 52 43, 44, 45, 46 V
IN
3 to V
IN
0 Uncommitted ADC Analog Inputs. These pins are programmable as four
single-ended channels or two true differential analog input channel pairs. See
Table 1 and Table 13 for more details.
53 47 REF
OUT
/REF
IN
ADC ADC Reference Input/Output Pin. The REF
OUT
/REF
IN
ADC pin provides the
reference source for the ADC. Upon power-up, the default configuration of this
pin is external reference (REF
IN
). Enable the internal reference by writing to the
power-down register; see Table 27. Connect decoupling capacitors (220 nF
recommended) to this pin to decouple the reference buffer. Provided the
output is buffered, the on-chip reference can be taken from this pin and
applied externally to the rest of a system. A maximum external reference
voltage of 2.5 V can be supplied to the REF
OUT
portion of the REF
OUT
/REF
IN
ADC pin.
54 48 DCAP External Decoupling Capacitor Input for Internal Temperature Sensor.
Decouple this pin to AGND using a 0.1 μF capacitor. In normal operation, the
voltage is typically 3.7 V.
62, 63 55, 56 V
PP
1, V
PP
2 Current Sensor Supply Pins. Power supply pins for the high-side current sense
amplifiers. Operating range is from AV
DD
to 59.4 V. Decouple this supply to
AGND. See the Current Sense Filtering section.
EP Exposed Pad The exposed pad is located on the underside of the package. Connect the
exposed pad to the ground plane of the PCB using multiple vias.