EM MICROELECTRONIC-MARIN SA
A6250
High Efficiency Linear Power Supply with Accurate
Power Surveillance and Software Monitoring
Features
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Highly accurate 5 V, 250 mA guaranteed output
Low dropout voltage, typically 260 mV at 250 mA
Low quiescent current, typically 175 µA
Standby mode, maximum current 340 µA (with
100 µA load on OUTPUT)
Unregulated DC input can withstand -20 V reverse
battery and +60 V power transients
Fully operational for unregulated DC input voltage up
to 40 V and regulated output voltage down to 3.0 V
Reset output guaranteed for regulated output voltage
down to 1.2 V
No reverse output current
Very low temperature coefficient for the regulated
output
Current limiting
Comparator for voltage monitoring, voltage reference
1.52 V
Programmable reset voltage monitoring
Programmable power on reset (POR) delay
Watchdog with programmable time windows
guarantees a minimum time and a maximum time
between software clearing of the watchdog
Time base accuracy ±10%
System enable output offers added security
TTL/CMOS compatible
-40 to +125°C temperature range
PSOP2-16 package
software clears the watchdog too quickly (incorrect cycle
time) or too slowly (incorrect execution) it will cause the
system to be reset. The system enable output prevents
critical control functions being activated until software has
successfully cleared the watchdog three times. Such a se-
curity could be used to prevent motor controls being ener-
gized on repeated resets of a faulty system.
Applications
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Industrial electronics
Cellular telephones
Security systems
Battery powered products
High efficiency linear power supplies
Automotive electronics
Typical Operating Configuration
A6250
Description
The A6250 offers a high level of integration by combining
voltage regulation, voltage monitoring and software moni-
toring in a 16 lead package. The voltage regulator has a
low dropout voltage (typ. 260 mV at 250 mA) and a low
quiescent current (175 µA). The quiescent current in-
creases only slightly in dropout prolonging battery life.
Built-in protection includes a positive transient absorber
for up to 60 V (load dump) and the ability to survive an un-
regulated input voltage of -20 V (reverse battery). The in-
put may be connected to ground or a reverse voltage
without reverse current flow from the output to the input. A
comparator monitors the voltage applied at the V
IN
input
comparing it with an internal 1.52 V reference. The
power-on reset function is initialized after V
IN
reaches 1.52
V and takes the reset output inactive after T
POR
depending
of external resistance. The reset output goes active low
when the V
IN
voltage is less than 1.52 V. The RES and EN
outputs are guaranteed to be in a correct state for a regu-
lated output voltage as low as 1.2 V. The watchdog func-
tion monitors software cycle time and execution. If
Fig. 1
Pin Assignment
A6250
Fig. 2
1
EMMICRO [ EM MICROELECTRONIC - MARIN SA ]
