MCP1316 Microchip Technology, MCP1316 Datasheet - Page 27

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

4.1.1
As the device V
remain active until the voltage rises above the “actual”
trip point (V
Figure 4-13 shows a power-up sequence and the
waveform of the RST and RST pins.
As the device powers up, the voltage will start below
the valid operating voltage of the device. At this volt-
age, the Reset output value is not valid. Once the volt-
age is above the minimum operating voltage (1V) and
below the selected V
active.
Once the device voltage rises above the “actual” trip
point (V
timer (t
out, the Reset output (RST/RST) is driven inactive.
FIGURE 4-13:
Power-up.
FIGURE 4-14:
© 2005 Microchip Technology Inc.
Note:
V
RST
RST
RST
TRIP
DD
) starts. When the Reset delay timer times
TRIP
) plus the hysteresis (V
POWER-UP/RISING V
While the Reset delay timer (t
active, additional system current is con-
sumed.
V
RST
1V
) plus the hysteresis (V
DD
V
DD
TRIPMIN
rises, the device’s Reset circuit will
V
V
TRIPMAX
Reset pin Operation on a
RST
TRIP
TRIPMAX
V
V
TRIP
TRIPMIN
, the Reset output will be
t
RPD
Operation as determined by the V
HYS
V
1V
TRIP
DD
), the Reset delay
HYS
t
RST
+ V
).
< 1V is outside the
device specifications
HYS
RST
) is
V
TRIP
+ V
HYS
4.1.2
As the device powers-down/brown-outs, the voltage
(V
(V
will be between the minimum trip point (V
the maximum trip point (V
voltage (V
will be forced to the active state. There is a hysteresis
on this trip point. This is so that noise on the device volt-
age (V
“jitter” (change between driving an active and inactive).
Figure 4-14 shows the waveform of the RST pin as
determined by the V
the state of the RST pin.
4.1.2.1
The internal pull-up resistor has a typical value of
4.7 k . The internal pull-up eliminates the need for an
external resistor.
To reduce the current consumption of the device, when
the RST pin is driving low, the resistor is disconnected.
TRIP
DD
TRIP
Note:
) falls from a voltage above the devices trip point
). The devices “actual” trip point voltage (V
DD
and V
) does not cause the Reset pin (RST/RST) to
DD
POWER-DOWN/BROWN-OUTS
Only the MCP1316M, MCP1318M and
MCP1319M devices have an open-drain
RST output pin with an internal pull-up
resistor.
) goes below this voltage, the Reset pin(s)
V
Operation of RST pin with Internal
Pull-Up Resistor
HYS
t
RST
TRIP
t
.
RPD
DD
MCP131X/2X
voltage, while Table 4-1 shows
TRIPMAX
V
TRIP
t
). Once the device
RST
DS21985A-page 27
TRIPMIN
) and
TRIP
)