MCP1630DM-DDBK4 Microchip Technology, MCP1630DM-DDBK4 Datasheet - Page 13

• Manufacturer Part Number: MCP1630DM-DDBK4
• Description: BOARD CONV DEMO MCP1630 TRPL-OUT
• Manufacturer: Microchip Technology
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of MCP1630DM-DDBK4

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 3, Non-Isolated
• Voltage - Output: 3.3V, 1.2V, 4.7V
• Current - Output: 1.2A, 600mA, 150mA
• Voltage - Input: 6.5 ~ 40V
• Regulator Topology: Buck
• Frequency - Switching: 250kHz
• Board Type: Fully Populated
• Utilized Ic / Part: MCP1630
• Silicon Manufacturer: Microchip
• Application Sub Type: PWM Controllers
• Kit Application Type: Power Management - Voltage Regulator
• Silicon Core Number: MCP1630, PIC12F683
• Input Voltage: 6.5 V to 40 V
• Output Voltage: 1.2 V to 4.7 V
• Product: Power Management Modules
• Kit Contents: Board
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: MCP1630, PIC12F683
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Not applicable / Not applicable

© 2006 Microchip Technology Inc.
2.3.1.2
A variable resistive load can be used to verify the line regulation, load regulation and
cross regulation. The load resistance for the three outputs can be connected
accordingly. Note that the currents should not exceed the maximum current limit of
individual outputs i.e: 1.2A (maximum) for V
150 mA (maximum) for V
the test points TP3 and TP4 for V
between test points TP5 and TP6 for V
the common point of multimeter to TP3 and the positive terminal to TP4 for V
ilarly, to measure the output voltages of V
of multimeter to TP8 for V
V
The load regulation and cross regulation can be verified by varying the load from 50%
to 100%, with different combination of loads on all the outputs. Similarly, by varying the
line voltage from 6.5V to 40V and checking the output voltage, the line regulation can
be calculated.
Evaluating the Application
The best way to evaluate the MCP1630 Automotive Input Triple Output Converter
Demo Board is to dig into the circuit. Measure voltages and currents with a DVM and
probe the board with an oscilloscope.
The firmware program in the PIC12F683 can also be edited to modify the operation of
the application.
Firmware
The PIC12F683 comes pre programmed with firmware to operate the system as
described above. The file listing and firmware flow diagram are shown in Appendix
C. “Demo Board Firmware”.
The program is fairly simple and straight forward. There is an initialization routine at the
beginning of the program.
The internal oscillator clock is set to 8 MHz.The TRISIO is configured to set GP2
(Oscillator pulses to the MCP1630) and GP4 (V
port and GP3 (Switch SW1) as Input Port.The OPTION register is configured to
wake-up on Port pin change of GP3.
The Capture/Compare/PWM (CCP) module contains a 16-bit register which can
operate in PWM mode. The PWM period can be calculated by writing to the PR2
register. The PWM duty cycle is specified by writing to the CCPR1L register and to the
CCP1CON <5:4> bits. Up to 10-bit resolution is available. The CCPR1L contains the
eight MSbs and the CCP1CON <5:4> contains the two LSbs. This 10-bit value is
represented by CCPR1L:CCP1CON<5:4>. The switching frequency is set to 250 kHz.
Upon powering on, the processor enters into SLEEP mode after the ports are initialized
and registers configured. The processor wakes-up from SLEEP mode, if the Switch
SW1 on GP3 is pressed.
Once the processor is on after the switch SW1 is pressed, the three output voltages of
3.3V, 1.2V and 4.7V are generated by set by generating V
signal. TMR0 is configured to generate the V
During normal operation, a subsequent pressing of switch SW1 will make the converter
to go into SLEEP mode.
The switch SW1 is used to perform a simple ON/OFF operation.
OUT2
and TP5 for V
APPLYING LOAD TO MCP1630 AUTOMOTIVE INPUT TRIPLE OUTPUT
CONVERTER DEMO BOARD
OUT3
OUT3
OUT2
.
, respectively. The load resistance is connected between
and TP6 for V
OUT1
, between test points TP7 and TP8 for V
OUT3
OUT2
. To measure the output voltage, connect
OUT1
OUT3
REF
and V
REF
, 600 mA (maximum) for V
voltage.
and the positive terminal to TP7 for
Voltage to MCP1630) as an output
OUT3
, connect the common point
REF
voltage and the PWM
DS51627A-page 9
OUT2
OUT1
OUT2
. Sim-
and
and