MCP1316 Microchip Technology, MCP1316 Datasheet - Page 32

• Manufacturer Part Number: MCP1316
• Description: Voltage Supervisor
• Manufacturer: Microchip Technology

MCP131X/2X
5.4
Although the MCP131X/2X device has a fixed voltage
trip point (V
custom adjustments. This can be accomplished by
connecting an external resistor divider to the
MCP131X/2X V
age to be at a higher voltage than when the
MCP131X/2X
(Figure 5-5).
To maintain detector accuracy, the bleeder current
through the divider should be significantly higher than
the 10 μA maximum operating current required by the
MCP131X/2X. A reasonable value for this bleeder
current is 1 mA (100 times the 10 μA required by the
MCP131X/2X). For example, if V
desired trip point is 2.5V, the value of R
(2.5V/1 mA). The value of R
the nearest standard value and plugged into the equa-
tion of Figure 5-5 to calculate values for R
tolerance resistors are recommended.
FIGURE 5-5:
External Resistor Divider.
DS21985A-page 32
Where:
Note:
V
R
R
V
SOURCE
SOURCE
2
1
V
Modifying The Trip Point, V
TRIP
V
TRIP
SOURCE
In this example, V
greater than (V
V
DD
= Voltage to be monitored
= Threshold Voltage setting
), it is sometimes necessary to make
input
DD
pin. This causes the V
MCP131X/2X
V
Modify Trip-Point using
SS
equals
------------------- -
R
1
R
1
TRIP
+
1
+ R
R
2
)
it’s
2
SOURCE
TRIP
can be rounded to
V
RST
or RST
TRIP
V
1
= 2V and the
TRIP
+ R
1
SOURCE
and R
must be
2
TRIP
is 2.5 k
voltage
2
. 1%
volt-
5.5
Low operating power and small physical size make the
MCP131X/2X series ideal for many voltage detector
applications. Figure 5-6 shows a low-voltage gate drive
protection circuit that prevents overheating of the
logic-level MOSFET due to insufficient gate voltage.
When the input signal is below the threshold of the
MCP131X/2X, its output grounds the gate of the
MOSFET.
FIGURE 5-6:
Protection.
5.6
In some low-power applications, the longer that the
microcontroller (such as a PICmicro MCU) can be in
the “Sleep mode”, the lower the average system cur-
rent consumption will be.
The WDT feature can be used to “wake-up” the PICmicro
MCU at a regular interval to service the required tasks
before returning to sleep. This “wake-up” occurs after the
PICmicro MCU detects a MCLR reset during Sleep mode
(for mid-range family; POR = ‘1’, BOR = ‘1’, TO = ‘1’ and
PD = ‘1’).
MCP131X/2X
MOSFET Low-Drive Protection
Low-Power Applications
V
TRIP
V
V
SS
DD
270
MOSFET Low-Drive
© 2005 Microchip Technology Inc.
RST
V
DD
MTP3055EL
R
L