KIT34673EPEVBE Freescale Semiconductor, KIT34673EPEVBE Datasheet - Page 14

• Manufacturer Part Number: KIT34673EPEVBE
• Description: KIT EVALUATION FOR MC34673
• Manufacturer: Freescale Semiconductor
• Type: Battery Managementr

Specifications of KIT34673EPEVBE

• Main Purpose: Power Management, Battery Charger
• Embedded: No
• Utilized Ic / Part: MC34673
• Primary Attributes: 1 Cell- Li-Ion
• Secondary Attributes: LED Status Indicators
• Input Voltage: 2.6 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Product: Power Management Modules
• Supply Current: 1.2 A
• Silicon Manufacturer: Freescale
• Silicon Core Number: MC34673
• Kit Application Type: Power Management - Battery
• Application Sub Type: Battery Charger
• Kit Contents: Evaluation Board, CD
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: MC34673

CHARGE CYCLE
trickle, constant-current (CC), and constant-voltage (CV)
charge modes, as shown in
CV charge modes are also called fast-charge mode. When
the input voltage rises above an internal power-on-reset
threshold, the PPR pin outputs a low voltage to indicate the
power-supply presence. The charger starts with the trickle-
charge mode until the battery voltage is above 2.7V. The
CHG pin outputs logic low voltage at the beginning of the
trickle-charge mode. If the battery voltage is unable to rise
due to a battery failure, charging will remain in the trickle-
charge mode. When the battery voltage reaches the 2.7V
threshold, the MC34673 softly changes to the CC-mode. The
soft transition minimizes the input-voltage drop and reduces
the requirement of the input decoupling capacitance. In the
fast-charge mode, the FAST pin outputs a low voltage. When
the battery voltage reaches 4.2V, the MC34673 enters the
CV-mode and regulates the output voltage at 4.2V. The
charge current decreases gradually in the CV-mode. When
the current drops to the EOC current threshold, the MC34673
CHARGE CURRENT SETTING
programmes the CC-mode current with the following
equation:
14
34673
FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
The MC34673 uses the standard charge profile with
An external resistor between the ISET pin and the ground
FAST
CHG
4.2V
I
I
2.7V
TRKL
CHG
Figure
Trickle
21. Both the CC and the
Constant Current
FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
Figure 21. Charge Profile
Constant Voltage
Current
Charge
I
EOC
Voltage
Charge
outputs logic high voltage at the CHG pin to indicate that the
charging is completed.
regulate the output to 4.2V, and monitors the output voltage.
If a load is in parallel with the battery, the charger continues
to output the current to the load even the charge is
completed. If the load current exceeds the programmed CC-
mode current, the battery will supply the additional current to
the load and the battery voltage will decline. Once the battery
voltage drops below the recharge voltage threshold, the
MC34673 returns to the fast-charge mode and indicates a
low voltage at the CHG pin.
MC34673 is disabled.
where V
monitors the input and the battery voltages.
diagram.
ground in Ω. In addition, the current out of the ISET pin is
proportional to the charge current. The system may measure
where R
I
CHG
1. V
2. V
3. EN pin is high
After the charging is completed, the MC34673 continues to
When one of the following three conditions happens, the
Figure 22
100mV
IN
IN
=
OS
ISET
> V
- V
-------------------------- -
R
ISET
is the offset voltage for the comparator that
BAT
>I
4000
I
OVP
shows the complete charge-cycle state
LOAD
is the resistor between the ISET pin and the
CHG
+
< V
96
OS
Analog Integrated Circuit Device Data
TIME
TIME
TIME
Freescale Semiconductor
equ. 2