LM9076M National Semiconductor, LM9076M Datasheet - Page 6

• Manufacturer Part Number: LM9076M
• Description: 150mA Ultra-Low Quiescent Current LDO Regulator with Delayed Reset Output
• Manufacturer: National Semiconductor

www.national.com
Application Information
RESET DELAY TIME
When the regulator output is switched On, or after recovery
from brief V
be programmed to remain low for an additional delay time.
This will give time for any system reference voltages, clock
signals, etc., to stabilize before the micro-controller resumes
normal operation.
This delay time is controlled by the capacitor value on the
C
charged to near V
RESET pin to go low, the C
charged to ground. When the V
V
capacitor begins charging at a typical constant 0.420uA rate.
When the voltage on the C
potential as the V
return high.
The typical RESET delay time can be calculated with the
following formula:
For a C
0.475uA the typical RESET delay time is:
DELAY
OUT
returns to the normal operating value, the C
pin. During normal operation the C
DELAY
OUT
t
DELAY
value of 0.001uF and a I
fault condition, the RESET flag can be can
OUT
= V
OUT
pin the RESET pin will be allowed to
OUT
. When a V
DELAY
X (C
DELAY
DELAY
capacitor reaches the same
OUT
capacitor is quickly dis-
OUT
fault is removed, and
/ I
DELAY
DELAY
(Continued)
fault causes the
DELAY
)
capacitor is
value of
DELAY
6
THERMAL PROTECTION
Device operational range is limited by the maximum junction
temperature (T
the ambient temperature (T
age (V
maximum load currents the input voltage and/or ambient
temperature will be limited. When operating with maximum
input voltage the load current and/or the ambient tempera-
ture will be limited.
Even though the LM9076 is equipped with circuitry to protect
itself from excessive thermal dissipation, it is not recom-
mended that the LM9076 be operated at, or near, the maxi-
mum recommended die junction temperature (T
may impair long term device reliability.
The thermal protection circuity monitors the temperature at
the die level. When the die temperature exceeds typically
160C the voltage regulator output will be switched off.
t
IN
DELAY
), and the output load current. When operating with
t
DELAY
= 5.0V X (0.001uF / 0.420uA) = 11.9ms
J
). The junction temperature is influenced by
= V
OUT
X (0.001uF / 0.475uA)
A
), package selection, input volt-
J
) as this