PAC1921 datasheet(25/56 Pages) MICROCHIP

25 / 56 page

Hardware Description

 2015 Microchip Technology Inc.

DS50002376A-page 25

3.7

DEMO MODE SETUP AND OPERATION

Demo mode uses an on-board current source to exercise and demonstrate the features

of the PAC1921 power monitor. The 100 mV constant-current source is provided using

a +5V USB as the supply. Parallel sense resistors are provided to convert the current

to a corresponding voltage for the PAC1921 to read at the SENSE+ and SENSE-

inputs. The evaluation board is assembled with jumpers J3 and J4 positioned for Demo

mode (see Section 3.5 “Jumper Settings”). Current is controlled by the evaluation

board Demo Configuration section of the evaluation board GUI (see

Section 4.2.6 “EVB Demo Configuration Panel”).

3.8

SYS MODE SETUP AND OPERATION

Sys mode uses external current sources to exercise and demonstrate the features of

the PAC1921 power monitor.

3.8.1

Jumper Positions

To use Sys mode, reposition jumpers J3 and J4 (see Table 3-2) to disconnect the

on-board demonstration current sources.

3.8.2

Load Connection

A 5 milliohm (1% tolerance) sense resistor, connected between J1 and J2, is provided

on-board the PAC1921 evaluation board to measure system current.

Load connections to the system can be established, as shown in Figure 3-3.

FIGURE 3-3:

Load Connection Location.

J11 GND

Connect to

System Ground

J2 VSOURCE-

Connect to

System DC

Load or Supply

J1 VSOURCE+

Connect to

System DC

Load or Supply

PAC1921 Datasheet(PDF) 25 Page - Microchip Technology