Garmin MC34676B 3 Application Diagram

Using the Dual 28V Input Voltage Charger with Linear Regulator, Rev. 1.0

2Freescale Semiconductor

Application Diagram

3 Application Diagram

3.1 Dual-Input Standalone Charger

The MC34676B can be used as a dual-input standalone Li-Ion charger. Figure 1 is the typical application circuit. Two

LEDs indicate the charge status.

Figure 1. The dual-input Li-Ion Charger

3.2 Embedded Charger

When the MC34676B is embedded in the system, the system MCU can control the charger through the USBEN pin and

get the charge status through PPR and CHG pins. Figure 2 is the typical application circuit.

Figure 2. The Li-Ion Charger Embedded in the Hand Held System

MC34676B

CHG

ISET

PPR

USB USBOUT

BAT

BATDET

USBEN

GND

IMIN IUSB

OFF

RIMIN RIUSB RISET

USB

GND

IMIN

IUSB ISET CHG

PPR

USBOUT

BAT

VDDIO

MCU

MC34676B

USB

C1 C2

RIMIN RIUSB RISET

USBEN

BATDET

Contents

Main Freescale Semiconductor Users Guide Document Number: KT34676BUG Rev. 1.0, 2/2009 1Purpose Using the High Input Voltage Charger for Single Cell Li-Ion Batteries (KIT34676EPEVBE) Contents Using the Dual 28V Input Voltage Charger with Linear Regulator, Rev. 1.0 Application Diagram 3 Application Diagram 3.1 Dual-Input Standalone Charger Figure 2. The Li-Ion Charger Embedded in the Hand Held System Figure 1. The dual-input Li-Ion Charger 3.2 Embedded Charger 4 Evaluation Board Specification Figure 3. The Schematic Circuit of the Evaluation Board 5 Component Selection 5.1 Input capacitors C1 and C3 5.2 Output capacitors C4 and C5 5.3 AC CC-mode charge current setting resistors R1, R2, and R3 5.4 USB CC-mode charge current setting resistors R8 and R9 5.5 End-of-charge current setting resistors R10 and R11 Table 2. The USB CC-mode Charge Current Settings Table 3. The EOC Current Settings Page Page 6.2 Layout considerations 7 Evaluation Board Configuration 7.1 Pin Headers Table 4. The Default Settings of the Pin Headers 7.2 Connector Pads Table 4. The Default Settings of the Pin Headers 7.3 Test Points 8 Test Setup with the Evaluation Board Figure 8. The AC Charger Set Up for the Evaluation Board Figure 9. The USB Charger Set Up for the Evaluation Board Using the Dual 28V Input Voltage Charger with Linear Regulator, Rev. 1.0 12 Freescale Semiconductor Bill of Material 9 Bill of Material Item Qty Part Reference Value DESCRIPTION Footprint Mfr PN 10 References How to Reach Us: