MCP3421DM-BFG Microchip Technology, MCP3421DM-BFG Datasheet - Page 13

• Manufacturer Part Number: MCP3421DM-BFG
• Description: BOARD DEMO FOR MCP3421
• Manufacturer: Microchip Technology

Specifications of MCP3421DM-BFG

• Main Purpose: Power Management, Battery Gauge
• Utilized Ic / Part: MCP3421
• Processor To Be Evaluated: MCP3421
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

2.1
© 2007 Microchip Technology Inc.
BOARD DESCRIPTION
Chapter 2. Installation and Operation
The major components of the MCP3421 Battery Fuel Gauge Demo Board are:
1. MCP3421 devices (U1 and U5).
2. PIC MCU - PCI18F4550 (U2).
3. MPLAB ICD2 Header (P2).
4. USB connector (Not used for this version).
5. Battery discharging path selection Jumper (JP1).
6. Battery charging path selection Jumper (JP2): When battery recharge feature is
7. 9V Power Supply (BAT 1 and 9V power supply, use only one).
8. 1.5V AAA Battery with battery holder.
9. 2 x 16 LCD (LCD1).
10. MCP73831 device (U3).
11. Switches (SW1, SW2, SW3, SW4, Reset Switch).
12. Potentiometer (R1).
For more detailed circuit information, refer to Appendix A: “Schematics and Layouts”
and Appendix B: Bill of Materials”.
2.1.1
The MCP3421 Battery Fuel Gauge Demo Board needs a 9V power supply to provide
a 5V DC power to all active components including MCU, ADC, battery charger devices,
etc. The user can use a 9V power supply or 9V battery. The MCP3421 Battery Fuel
Gauge Demo Board has two connectors for both the 9V power supply and 9V battery.
Do not use both power sources at same time.
2.1.2
The PIC18F4550 (44-pin, TQFT) is used to control ADC devices, charger, buzzer, and
LCD. All fuel gauge computations are takes place in the MCU.
2.1.3
The LCD display used is a 2 x 16 character dot matrix type display. The PIC18F4550
device writes characters to the LCD.
- U1: Measuring current using the R12 current sensor.
- U5: Measuring battery voltage.
Note:
enabled.
Power Supply
Microcontroller (MCU)
All active electrical components on the board are powered by the 9V power
source. The 1.5V AAA battery that is connected to TP9 (positive) and GND
(negative) terminals DOES NOT power the board components. During the
discharging, the current path of the test battery is from the 1.5V battery to
the ground via a 10 mili-ohm current sensor and an 100Ω resistor. During
the recharging mode (if recharging mode is enabled), the current path is
from the V
LCD Display
MCP3421 BATTERY FUEL GAUGE
BAT
pin of U3 (MCP73831) to the battery via the current sensor.
DEMO BOARD USER’S GUIDE
Draft
DS51683A-page 9