LM9076M National Semiconductor, LM9076M Datasheet - Page 5

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

Typical Performance Characteristics
Application Information
REGULATOR BASICS
This regulator is suitable for Automotive applications where
continuous connection to the battery is required (refer to the
Typical Application circuit).
The pass transistor of the regulator is an PNP device. A 10uF
capacitor on the V
in most circumstances. There is no maximum value for the
regulator output bypass capacitance.
INPUT CAPACITOR
The LM9076 requires a low source impedance to maintain
regulator stability because portions of the internal bias cir-
cuitry are connected directly to V
ceramic capacitor should be placed between the LM9076
V
OUTPUT CAPACITOR
An output capacitor is also required for stability. This capaci-
tor must be placed between the LM9076 V
pins, as close as is physically possible, using traces that are
not part of the main load current path.
The output capacitor must meet the requirements for mini-
mum capacitance and also maintain the appropriate ESR
value of the full operating ambient temperature range to
assure stability. There is no maximum limit for the output
capacitance value, as long as ESR is maintained. See the
Typical Performance Characteristics curves for details.
Solid tantalum capacitors are recommended as they gener-
ally maintain capacitance and ESR ratings over a wide tem-
perature range.
Ceramic capacitor types XR7 and X5R may be used if a
series resistor is added to simulate the ESR requirement.
Aluminum electrolytic capacitors are not recommend, as
they are subject to wide changes in capacitance and ESR
values across temperature.
DELAY CAPACITOR
The capacitor on the Delay pin must be a low leakage type
since the charge current is minimal (500nA typical) and the
pin must fully charge to 5V. Ceramic, Mylar, and polystyrene
IN
and Ground pins, as close as is physically possible.
Output Voltage vs Junction Temperature
OUT
pin will provide adequate performance
IN
. At a minimum, at 0.1µF
OUT
and Ground
20083038
5
(Continued)
capacitor types are generally recommended, although
changes in capacitance values across temperature changes
will have some effect on the delay timing.
SHUTDOWN PIN
The basic On/Off control of the regulator is accomplished
with the SHUTDOWN pin. By pulling the SHUTDOWN pin
high the regulator output is switched Off. When the regulator
is switched Off the load on the battery will be primarily due to
the SHUTDOWN pin current.
When the SHUTDOWN pin is low, or left open, the regulator
is switched On. When an unregulated supply, such as V
BATTERY , is used to pull the SHUTDOWN pin high a series
resistor in the range of 10KΩ to 50KΩ is recommended to
provide reverse voltage transient protection of the SHUT-
DOWN pin. Adding a small capacitor (0.001uF typical) from
the SHUTDOWN pin to Ground will add noise immunity to
prevent accidental turn on due to noise on the supply line.
RESET FLAG
Proper operation of the RESET circuity is not guaranteed for
V
information on the status of the regulator V
Any condition that causes the V
cally 89% normal would cause the RESET pin to go low. This
will warn of a system Vcc supply that may cause abnormal
operation.
Of course, when the regulator is switched Off in normal
operation the RESET pin will be low.
If the regulator is On, and then switched off, the RESET flag
will go low when the V
capacitor has decayed adequately.
Excessive thermal dissipation of the device such that the
Thermal Shutdown circuit is activated which then switches
the regulator output Off, would cause the RESET pin to go
low.
The RESET pin is an open collector output and requires an
external pull-up resistor to V
tor should be in the range of 10KΩ to 200KΩ.
IN
voltages of less than 2.0V. The RESET pin will provide
OUT
OUT
voltage stored on the output
OUT
. The external pull-up resis-
voltage to drop to typi-
OUT
voltage level.
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