MCP1630EMS MICROCHIP [Microchip Technology], MCP1630EMS Datasheet - Page 9

• Manufacturer Part Number: MCP1630EMS
• Description: High-Speed, Microcontroller-Adaptable, Pulse Width Modulator
• Manufacturer: MICROCHIP [Microchip Technology]

3.0
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
3.1
COMP is an internal error amplifier output pin. External
compensation is connected from the FB pin to the
COMP pin for control-loop stabilization. An internal
voltage clamp is used to limit the maximum COMP pin
voltage to 2.7V typical. This clamp is used to set the
maximum peak current in the power system switch by
setting a maximum limit on the CS input for peak
current mode control systems.
3.2
FB is an internal error amplifier inverting input pin. The
output (voltage or current) is sensed and fed back to
the FB pin for regulation. Inverting or negative feed
back is used.
3.3
CS is the current sense input pin used for cycle-by-
cycle control for peak current mode converters. A ramp
can be placed on this input for voltage or average
current mode converters.
3.4
OSC is an external oscillator input pin. Typically, a
microcontroller I/O pin is used to generate the OSC
input. When high, the output driver (V
low. The high-to-low transition initiates the start of a
new cycle. The duty cycle of the OSC input pin deter-
mines the maximum duty cycle of the power converter.
For example, if the OSC input is low for 75% of the time
and high for 25% of the time, the duty cycle range for
the power converter is 0% to 75% maximum.
 2004 Microchip Technology Inc.
Pin No.
1
2
3
4
5
6
7
8
MCP1630 PIN DESCRIPTIONS
COMP Pin
FB Pin
CS Input
OSC Input
OSC IN
COMP
Name
GND
V
V
PIN FUNCTION TABLE
CS
V
FB
EXT
REF
IN
Error Amplifier Output Pin
Error Amplifier Inverting Input
Current Sense Input pin
Oscillator Input pin
Circuit Ground Pin
External driver output pin
Input bias pin
Reference Voltage Input Pin
EXT
) pin is driven
3.5
Connect circuit ground to the GND pin. For most appli-
cations, this should be connected to the analog or quiet
ground plane. Noise on this ground can affect the
sensitive cycle-by-cycle comparison between the CS
input and the error amplifier output.
3.6
V
used to determine the power system duty cycle. For
high-power or high-side drives, this output should be
connected to the logic-level input of the MOSFET driver.
For low-power, low-side applications, the V
be used to directly drive the gate of an N-channel
MOSFET.
3.7
V
source to the V
on the V
0.1 µF bypass capacitor should be connected between
the V
3.8
V
the output of the power system. By changing the V
input, the output (voltage or current) of the power sys-
tem can be changed. The reference voltage can range
from 0V to V
EXT
IN
REF
is an input voltage pin. Connect the input voltage
Function
IN
is an external reference input pin used to regulate
is an external driver output pin. This output pin is
pin and the GND pin.
IN
GND
V
V
V
EXT
IN
REF
pin should be between +3.0V and +5.5V. A
IN
Pin
IN
(rail to rail).
Pin
Input
pin. For normal operation, the voltage
MCP1630
DS21896A-page 9
EXT
pin can
REF