MIC2772 Datasheet, PDF (7/9 Pages) Micrel Semiconductor – Dual Voltage Supervisor

Micrel
Transients on VCC
The MIC2772 is inherently immune to very short
“glitches” on VCC. In the case of very brief
transients, VCC may drop below the reset-voltage
threshold without triggering a reset. As shown in the
graph, the MIC2772 is relatively immune to
transients with typical duration of 25us. The lines on
the graph represent the typical allowable transient
duration for a given amount of threshold overdrive
that will not generate a reset. The data was taken by
adding negative-going square-wave pulse to a DC
input voltage set at 0.5V above actual measured
threshold for the part being characterized. Figure 1
shows the graph for the MIC2772[UP3] and Figure 2
shows the graph for the MIC2772[UP5]
Typical Transient
Response
35
30
25
20
15
10
5
V = 4.393V
TH
0
0 200 400 600 800 1000
RESET COMP. OVERDRIVE V_TH - V_CC (mV)
Figure 1
Typical Transient
Response
40
35
30
25
20
15
10
5
V = 2.933V
TH
0
0 200 400 600 800 1000
RESET COMP. OVERDRIVE V_TH - V_CC (mV)
Figure 2
Interfacing to Processors with Bi-directional
Reset Pins
Some microprocessors have reset signal pins that
are bi-directional, rather than input only. The
MIC2772
Motorola 68HC11 family is one example. Because
the MIC2772’s output is active-low, open-drain, it
can be connected directly to the processor’s reset
pin with only the pull-up resistor normally required.
MIC2772 Replaces Single Supervisor
The table below lists common single voltage
supervisors that can be considered for replacement
by MIC2772.
P/N Suffix
L2L3
M2M3
L3L3
M3M3
T3T3
S3S3
T2T3
S2S3
L3T3
M3S3
Supervisor #1
MIC6315-46D2
MIC6315-44D2
MIC1810-5,
MIC6315-46D3,
MIC809L, MIC811L
MIC1810-10,
MIC6315-44D3,
MIC809M,
MIC811M
MIC6315-31D3,
MIC809T, MIC811T
MIC1815-10,
MIC6315-29D3,
MIC809S, MIC811S
MIC6315-31D2
MIC6315-29D2
MIC1810-5,
MIC6315-46D3,
MIC809L, MIC811L
MIC1810-10,
MIC6315-44D3,
MIC809M,
MIC811M
Supervisor #2
MIC1810-5,
MIC6315-46D3,
MIC809L, MIC811L
MIC1810-10,
MIC6315-44D3,
MIC809M,
MIC811M
MIC1810-5,
MIC6315-46D3,
MIC809L, MIC811L
MIC1810-10,
MIC6315-44D3,
MIC809M,
MIC811M
MIC6315-31D3,
MIC809T, MIC811T
MIC1815-10,
MIC6315-29D3,
MIC809S, MIC811S
MIC6315-31D3,
MIC809T, MIC811T
MIC1815-10,
MIC6315-29D3,
MIC809S, MIC811S
MIC6315-31D3,
MIC809T, MIC811T
MIC1815-10,
MIC6315-29D3,
MIC809S, MIC811S
April 2005
7
M9999-042605
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