Microchip Technology MCP1630DM-DDBS1 Data Sheet
2004-2013 Microchip Technology Inc.
DS21896C-page 11
MCP1630/MCP1630V
3.0
MCP1630 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
PIN FUNCTION TABLE
3.1
Error Amplifier Output Pin (COMP)
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 (typ.). 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.
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 (typ.). 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
Error Amplifier Inverting Input
(FB)
(FB)
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
feedback is used.
output (voltage or current) is sensed and fed back to
the FB pin for regulation. Inverting or negative
feedback is used.
3.3
Current Sensing Input (CS)
CS is the current sense input pin used for cycle-by-
cycle control for Peak Current mode converters. The
MCP1630 is typically used for sensed current
applications to reduce the current sense signal, thus
reducing power dissipation.
cycle control for Peak Current mode converters. The
MCP1630 is typically used for sensed current
applications to reduce the current sense signal, thus
reducing power dissipation.
For Voltage mode or Average Current mode
applications, a ramp is used to compare the error
amplifier output voltage with producing the PWM duty
cycle. For applications that require higher signal levels,
the MCP1630V is used to increase the level from a
maximum of 0.9V (MCP1630) to 2.7V (MCP1630V).
The common mode voltage range for the MCP1630V
CS input is V
applications, a ramp is used to compare the error
amplifier output voltage with producing the PWM duty
cycle. For applications that require higher signal levels,
the MCP1630V is used to increase the level from a
maximum of 0.9V (MCP1630) to 2.7V (MCP1630V).
The common mode voltage range for the MCP1630V
CS input is V
IN
-1.4V. For normal PWM operation, the
CS input should be less than or equal to V
IN
- 1.4V at
all times.
3.4
Oscillator Input (OSC)
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 pin (V
microcontroller I/O pin is used to generate the OSC
input. When high, the output driver pin (V
EXT
) is driven
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.
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.
3.5
Ground (GND)
Connect the circuit ground to the GND pin. For most
applications, 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.
applications, 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
External Driver Output Pin (V
EXT
)
V
EXT
is an external driver output pin, 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
side drives, this output should be connected to the logic-
level input of the MOSFET driver. For low-power, low-
side applications, the V
EXT
pin can be used to directly
drive the gate of an N-channel MOSFET.
3.7
Input Bias Pin (V
IN
)
V
IN
is an input voltage pin. Connect the input voltage
source to the V
IN
pin. For normal operation, the voltage
on the V
IN
pin should be between +3.0V and +5.5V. A
0.1 µF bypass capacitor should be connected between
the V
the V
IN
pin and the GND pin.
3.8
Reference Voltage Input (V
REF
)
V
REF
is an external reference input pin used to regulate
the output of the power system. By changing the V
REF
input, the output (voltage or current) of the power sys-
tem can be changed. The reference voltage can range
from 0V to V
tem can be changed. The reference voltage can range
from 0V to V
IN
(rail-to-rail).
DFN/MSOP
Name
Function
1
COMP
Error Amplifier Output pin
2
FB
Error Amplifier Inverting Input
3
CS
Current Sense Input pin (MCP1630) or Voltage Ramp Input pin (MCP1630V)
4
OSC IN
Oscillator Input pin
5
GND
Circuit Ground pin
6
V
EXT
External Driver Output pin
7
V
IN
Input Bias pin
8
V
REF
Reference Voltage Input pin