MAX6329 Maxim, MAX6329 Datasheet - Page 9

• Manufacturer Part Number: MAX6329
• Description: 150mA / SOT23 / Low-Dropout Linear Regulators with Internal Microprocessor Reset Circuit
• Manufacturer: Maxim

For stable operation over the full temperature range
and with load currents up to 150mA, use a 1µF (min)
output capacitor. To reduce noise and improve load
transient response, stability, and power-supply rejec-
tion, use large output capacitor values such as 10µF.
Note that some ceramic dielectrics exhibit large capac-
itance and ESR variation with temperature. With
dielectrics such as Z5U and Y5V, it may be necessary
to use 2.2µF or more to ensure stability at temperatures
below -10°C. With X7R or X5R dielectrics, 1µF should
be sufficient at all operating temperatures. A graph of
the Region of Stable C
shown in the Typical Operating Characteristics.
To improve power-supply rejection and transient
response use a 1µF capacitor between IN and GND.
A regulator’s minimum input-output voltage differential
(or dropout voltage) determines the lowest useable
supply voltage. In battery powered systems, this will
determine the useful end-of-life battery voltage. Since
the MAX6329/MAX6349 use a P-channel MOSFET pass
transistor, their dropout voltage is a function of R
multiplied by the load current (see Electrical
Characteristics).
These supervisors are relatively immune to short-dura-
tion, negative going OUT transients. The Typical
150mA, SOT23, Low Dropout Linear Regulators
SHDN
SET
GND
with Internal Microprocessor Reset Circuit
2.5V TO 5.5V
MAX6329
Negative Going OUT Transients
Typical Operating Circuit
Input-Output (Dropout) Voltage
IN
_______________________________________________________________________________________
RESET
OUT
Capacitor Selection and
OUT
ESR vs. Load Current is
Regulator Stability
1µF
RESET
V
CC
µP
DS(ON)
GND
Operating Characteristics section shows a graph of the
Maximum Transient Duration vs. Reset Threshold
Overdrive for which reset is not asserted. The graph
was produced using negative going OUT transients
starting at OUT and ending below the reset threshold
by the magnitude indicated (Reset Threshold
Overdrive). The graph shows the maximum pulse width
that a negative going OUT transient can typically have
without triggering a reset pulse. As the amplitude of the
transient increases (i.e., goes further below the reset
threshold), the maximum allowable pulse width
decreases. Typically, an OUT transient that goes only
10mV below the reset threshold and lasts for 75µs will
not trigger a reset pulse.
TRANSISTOR COUNT: 800
PROCESS: BiCMOS
Chip Information
9