MIC2776NBM5 Micrel Inc, MIC2776NBM5 Datasheet - Page 5

• Manufacturer Part Number: MIC2776NBM5
• Manufacturer: Micrel Inc

Specifications of MIC2776NBM5

• Number Of Voltage Supervisors: 1
• Monitored Supervisor Voltage: 0.3
• Reset Threshold Voltage (min): 295mV
• Reset Threshold Voltage (max): 305mV
• Operating Supply Voltage (min): 1.5V
• Operating Supply Voltage (max): 5.5V
• Package Type: SOT-23
• Operating Temperature Classification: Industrial
• Operating Temp Range: -40C to 85C
• Pin Count: 5
• Mounting: Surface Mount
• Lead Free Status / Rohs Status: Not Compliant

Functional Diagram
Functional Description
IN, Under-Voltage Detector Input
The voltage present at the IN pin is compared to the internal
300mV reference voltage. A reset is triggered if and when
V
scale the input voltage to be monitored such that V
below V
desired trip-point. Hysteresis is employed to prevent chat-
tering due to noise.
RST, /RST Reset Output
Typically, the MIC2776 is used to monitor the power supply
of intelligent circuits such as microcontrollers and micropro-
cessors. By connecting the reset output of a MIC2776 to the
reset input of a µC or µP, the processor will be properly reset
at power-on and during power-down and brown-out condi-
tions. In addition, asserting /MR, the manual reset input, will
activate the reset function.
November 2005
IN
falls below V
REF
as the voltage being monitored falls below the
REF
GND
/MR
. Typically, a resistor divider is used to
IN
* Pinout and polarity vary by device type.
See ordering information table.
V
DD
V
REF
I
PU
IN
will fall
Delay
5
The reset outputs are asserted any time /MR is asserted or
if V
remain asserted for t
above the threshold boundary and /MR is released. A reset
pulse is also generated at power-on.
/MR, Manual Reset Input
The ability to initiate a reset via external logic or a manual
switch is provided in addition to the MIC2776’s automatic
supervisory functions. Driving the /MR input to a logic low
causes an immediate and unconditional reset to occur. As-
suming V
high), the reset output will be de-asserted no less than t
later. /MR may be driven by a logic signal, or mechanical
switch. Typically, a momentary push-button switch is con-
nected such that /MR is shorted to ground when the switch
contacts close. The switch may be connected directly between
/MR and GND. /MR has an internal 100nA pull-up current to
V
DD
One Shot
IN
and may be left open if unused.
drops below the threshold voltage. The reset outputs
IN
is within tolerance when /MR is released (returns
R
S
RST
Q
/Q
(min) after V
MIC2776
/RST*
RST*
IN
subsequently returns
MIC2776
RST