Datasheet

www.microchip.com/power 5
Power Supply Design Integration Levels
Level 3 Integration: Topology Control
This level permits the standard analog design to be reconfigured in addition to Level 1 and Level 2 features.
Changing the analog loop configuration and swapping between two different analog control loop filters can be
achieved. For example, a power supply can change from a PWM control loop to a hysteretic control loop at light
loads. This change would allow
a continuous inductor current
design to operate in discontinuous
conduction mode, increasing system
efficiency. Switching frequency
adjustment can also be used to
minimize losses. Microchip’s entire
range of MCUs and DSCs can assist
in Level 3 control applications. In
particular, mixed-signal solutions
such as the PIC16F785 integrate
an MCU with analog peripherals
and are well-suited for topology
control. In addition, the MCP1630
and MCP1631 PWM controllers are
designed for MCU power controller
applications.
The PIC16HV785 can be used in
a Level 3 application due to the
on-chip analog peripherals. The
device has two analog PWM modules
that can control power stages. Two
error amplifiers and two high-speed
comparators can be connected
to the PWM modules in many ways through digital configuration. All pins associated with the error amplifiers and
comparators are available externally so any type of analog control loop can be created. Twelve ADC inputs are
available to monitor power supply operating parameters.
PIC16HV785
Digital IO
OA1
COMP1
OA2
COMP2
V
BUS
LED
String
CPU
Int OSC
Voltage
Ref.
5V Reg.
BOR
Temperature
Sensor
(MCP9700A)
PWM
MCP1402
–
+
–
+
–
+
–
+
10-bit ADC
PIC16HV785 Boost LED Driver Application
OSCIN
VREF
OVIN
OSCDIS
Up to
16V
CS
FB
SHDN
MCP1631HV
1.2V
Error Amp
G = -10
G = +1
V
DD
ISIN
ISOUT
VSIN
VSOUT
VEXT
Over
Voltage
Under Voltage
1A Gate
Driver
R
SQ
Shutdown
5V or 3.3V
Regulator
UVLO
–
+
A1
–
+
C2
C1
A3
A2
MCP1631HV Block Diagram
The MCP1631 high-speed PWM controller
can be used as a building block for
intelligent power supplies. The MCP1631
supplies the necessary analog peripherals,
including the error amplifier, comparator
and a high current output driver. The
voltage reference and switching clock are
supplied externally from an MCU. The MCU
can set the switching frequency of the
power stage, limit the maximum duty cycle
and adjust the phase of the switching clock
with respect to other power stages. The
rich feature set of the MCP1631 device
makes it a good fit for Level 2 and Level 3
intelligent power applications.