MCP1631RD-MCC2 Microchip Technology, MCP1631RD-MCC2 Datasheet - Page 52

• 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

© 2009 Microchip Technology Inc.
• R
D.1.4
• SW
• SW
• Worst-Case Capacitor Current is 1.94A.
I
I
I
I
I
I
I
I
- I
Choose a capacitor that is rated for at least the worst-case current.
RIPPLE
1
2
RMS_ON
RIPPLE
1
2
RMS_OFF
Artificial Ramp
= I
= I
= -I
= -I
RMS
ON
OFF
OUT
OUT
IN_WC
IN_WC
, D = 25%, t = 0.5 µs
, D = 75%, t = 1.5 µs
= SQRT (0.750
= 1.94A
= SQRT (I
= t
= t
Coupling Capacitor:
= SQRT(D * (I
= SQRT(0.25 * (1.425
= 0.750A
– ½ I
+ ½ I
= SQRT(D * (I
= SQRT(0.75 * [-2.285
= 1.79A
ON
OFF
– ½ I
+ ½ I
= 10 kΩ (max), use around 5.6 kΩ to 9.1 kΩ for tolerances
* 2V
= τ
RIPPLE
An R value of 5.6 kΩ was used for the Eval Board.
RIPPLE
* 2V
Artificial Ramp
RIPPLE
RIPPLE
RMS_ON
IN
IN
/4L = 0.5 µs * (2)(6V)/(4*10 µH) = 0.150A
/4L = 1.5 µs * (2)(6V)/(4*10 µH) = 0.450A
= 1.5A – 0.075A = 1.425A
= 1.5A + 0.075A = 1.575A
2
1
+ 1.79
1
2
= -2.06A – 0.225A = -2.285A
= -2.06A + 0.225A = -1.835A
2
2
+ I
+ I
+ I
1
/C
1
RMS_OFF
* I
2
Artificial Ramp
2
* I
)
2
+ 1.425 * 1.575 + 1.575
2
2
+ I
+ (-2.285 * (-1.835)) + (-1.835)
+ I
2
2
2
2
)/3) (for a trapezoidal waveform)
2
)
)/3)
= 15.13 µs/1500 pF
Design Example
2
)/3
2
]/3)
DS51791A-page 48