PAC1934 EVALUATION BOARD
(ADM00805) USER’S GUIDE
2017 Microchip Technology Inc.
DS50002673A-page 11
Chapter 1. Product Overview
1.1
INTRODUCTION
The ADM00805 Evaluation Board for PAC1934 provides a flexible platform for evalu-
ating PAC1934 and demonstrating the features of the PAC1934. A PAC1934 device in
a wafer level chip scale package (WLCSP) is mounted to the board.
The ADM00805 has a USB connector to connect to a computer for device communi-
cation. The PAC1934 device may be powered directly by V
BUS
from the USB connector
or by an external connection for V
DD
.
I
2
C communication can be provided over USB using the on-board MCP2221 USB to
I
2
C Bridge. There is also a header that facilitates direct I
2
C communication by connect-
ing the V
DD_IO
, Ground, SDA and SCL to an external source such as a PC motherboard
or a Linux system. See
Section 4.9 “Direct External I2C Connection”
for important
details if using direct I
2
C connection.
The shorting shunts and the switch on the board facilitate either simple demonstration
of the device functions using on-board current sources or detailed evaluation of
function and performance with external sources, including prototyping the system.
1.2
PAC1934 DEVICE FEATURES
The PAC1934 is a four-channel DC power/energy monitor with accumulator. There is
a16-bit ADC for monitoring power rail voltages connected by a multiplexer to the posi-
tive (+) input pin of each channel, producing results named V
BUS
. There is a second
16-bit ADC for measuring the voltage across a current sense resistor. This ADC is con-
nected by a differential multiplexer to the +input and –input pins for each channel, pro-
ducing results called V
SENSE
. Channel selection for the multiplexers is controlled in
sequential fashion to scan all four channels up to 1024 samples per second (sps).
The device also computes V
POWER
by multiplying V
BUS
by V
SENSE
and accumulates
these power results in an Accumulator. The device registers also hold eight times aver-
aged V
BUS
and V
SENSE
results for very accurate low noise voltage and current mea-
surements. All the results are stored in registers. The values in the Results Registers
only change when a REFRESH or a REFRESH_V command is sent. Software applica-
tions are available for plotting, displaying and logging data. These applications also
calculate energy based on the accumulated power and accumulation time.
1.3
ADM00805 EVALUATION BOARD FOR PAC1934
1.3.1
Hardware Overview
The ADM00805 Evaluation Board has a PAC1934 device mounted on the board and
enables direct control of all device pins and easy measurements of on-board or exter-
nal voltages and currents. The I
2
C address is connected as 0x20 by default. Removing
a shunt gives 0x22. Other addresses are possible by replacing R22 with a new value.
Sampling rate is 1024 sps by default, due to the shorting shunt on the SLOW pin con-
nector (J23) tying the SLOW pin to ground. Remove this shunt for the SLOW sampling
rate of 8 sps.
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from