MCP1631RD-MCC2 Microchip Technology, MCP1631RD-MCC2 Datasheet - Page 2

• Manufacturer Part Number: MCP1631RD-MCC2
• Description: REFERENCE DESIGN MCP1631HV
• Manufacturer: Microchip Technology

Specifications of MCP1631RD-MCC2

• Main Purpose: Power Management, Battery Charger
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: MCP1631HV, PIC16F883
• Primary Attributes: 1 ~ 2 Cell- Li-Ion, 1 ~ 5 Cell- NiCd/NiMH, 1 ~ 2 1W LEDs
• Secondary Attributes: Status LEDs
• Silicon Manufacturer: Microchip
• Application Sub Type: Battery Charger
• Kit Application Type: Power Management - Battery
• Silicon Core Number: MCP1631HV, PIC16F883
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AN1137
FIGURE 1:
Li-Ion Charge Profile
The charge profile for Li-Ion batteries starts with cell
qualification. The cell voltage should be greater than
3.0V per cell before initiating a fast or high current
charge. If the cell voltage is less than 3.0V per cell, a
low value conditioning current is used to start the
charge cycle. Once the cell voltage is above the 3.0V
threshold, a fast charge or high current charge is
initiated (0.5C to 1.0C). As the battery cell voltage
rises, it reaches the maximum voltage value before it
reaches full capacity. As an example, most Li-Ion
batteries constant voltage level is 4.2V, where the
battery charger now transitions into a constant voltage
source (regulating voltage instead of current). The
charge cycle continues as the charge current
decreases while in the constant voltage mode. Once
the charge current decreases to about 7% of the fast
charge value, charge is terminated. Continuing the
charge cycle past this point can damage the battery so
the charge must be terminated. Once terminated a new
charge cycle can be initiated when the battery voltage
decreases to approximately 4.0V.
DS01137A-page 2
V
ICH (A)
CELL
T(°C)
(V)
I
Stage 1
Pre-Charge
CH
NiMH / NiCd Charge Profile.
= 0.2C
0.8V
Stage 2
Fast Charge
NiMH and NiCd Charge Profile
V
Pack T (°C)
CELL
I
CH
= 1.0C
Stage 3
End Fast Charge
-dV/dt
-dT/dt
© 2007 Microchip Technology Inc.
I
1 hour
CH
= 0.05C
Stage 4
Top Off Charge