MIC2775-17BM5 TR Micrel Inc, MIC2775-17BM5 TR Datasheet - Page 6

• Manufacturer Part Number: MIC2775-17BM5 TR
• Description: IC SUPERVISOR MICROPOWER SOT23-5
• Manufacturer: Micrel Inc
• Type: Simple Reset/Power-On Resetr

Specifications of MIC2775-17BM5 TR

• Number Of Voltages Monitored: 1
• Output: Complementary
• Reset: Active High/Active Low
• Reset Timeout: 140 ms Minimum
• Voltage - Threshold: 1.69V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-5, SC-74A, SOT-25
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: MIC2775-17BM5TR; MIC2775-17BM5TR

Application Information
Ensuring Proper Operation at Low Supply
At levels of V
not turn on sufficiently to produce a valid logic-low on /RST.
In this situation, circuits driven by /RST could be allowed to
float, causing undesired operation. (In most cases, however,
it is expected that the circuits driven by the MIC2775 will be
similarly inoperative at V
If a given application requires that /RST be valid below V
= 1.2V, this can be accomplished by adding a pull-down re-
sistor to the /RST output. A value of 100kΩ is recommended
as this is usually an acceptable compromise of quiescent
current and pull-down current. The resistor’s value is not
critical, however. See Figure 1.
The statements above also apply to the MIC2775’s RST
output. That is, to ensure valid RST signal levels at V
1.2V, a pull-up resistor (as opposed to a pull-down) should
be added to the RST output. A value of 100kΩ is typical for
this application as well. See Figure 2.
MIC2775
V
V
CC
CC
Manual
Reset
Figure 1. MIC2775 Valid /Reset Below 1.2V
Figure 2. MIC2775 Valid Reset Below 1.2V
Manual
Reset
DD
below 1.2V, the MIC2775’s /RST output can-
MIC2775-XX
VDD
/MR
VDD
/MR
MIC2775-XX
/RST
GND
RST
DD
/RST
GND
RST
≤ 1.2V.)
100k
100k
MICROPROCESSOR
MICROPROCESSOR
VCC
/RESET
VCC
/RESET
GND
GND
DD
DD
<
6
Transient response
The MIC2775 is inherently immune to very short negative-
going “glitches.” Very brief transients may exceed the voltage
threshold without tripping the output.
As shown in Figure 3, in general the narrower the transient,
the deeper the threshold overdrive that will be ignored by
the MIC2775. The graph represents the typical allowable
transient duration for a given amount of threshold overdrive
that will not generate a reset.
Figure 3. Typical V
RESET COMP. OVERDRIVE, V
100
80
60
40
20
0
0
Transient Response
500
Typical V
DD
1000
Transient Response
DD
1500
REF
–V
2000
DD
(mV)
June 2009