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EM MICROELECTRONIC-MARIN SA
A6155
High Efficiency Linear Power Supply with
Extremely Accurate Power Surveillance, Software
Monitoring and Sleep Mode Detection
Features
„ Can-bus sleep mode detector
„ Highly accurate 5 V, 100 mA guaranteed output
„ Low dropout voltage, typically 380 mV at 100 mA
„ Low quiescent current, typically 155 µA
„ Standby mode, maximum current 350 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 26 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
1.275 V
„ ±2.0% voltage reference accuracy at +25 °C (3 to 5.5 V)
„ ±2.7% voltage reference accuracy from –40 to
+85 °C (3 to 5.5 V)
„ Programmable reset voltage monitoring
„ Programmable power-on reset (POR ) delay
„ Watchdog with programmable time windows guarant-
ees 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 +85 °C temperature range
„ DIP8 and SO8 packages
Description
The A6155 offers a high level of integration by combining
voltage regulation, voltage monitoring and software
monitoring in an 8 lead package. The voltage regulator
has a low dropout voltage (typ. 380 mV at 100 mA) and a
low quiescent current (155 µA). The quiescent current
increases 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
unregulated input voltage of –20 V (reverse battery). The
input 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 1.275 V reference. The
power-on reset function is initialized after V
IN
reaches
1.275 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 1.275 V.
The RES and EN outputs are guaranteed to be in a correct
state for a regulated output voltage as low as 1.2 V.
The watchdog function monitors software cycle time
and execution. If 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
security could be used to prevent motor controls
being energized on repeated resets of a faulty system.
If the microcontroller does not work that means no
signal on the TCL input the A6155 goes in a standby
mode (CAN-bus sleep detector).
Applications
„ Automotive systems
„ Cellular telephones
„ Security systems
„ Battery powered products
„ High efficiency linear power supplies
„ Industrial electronics
Typical Operating Configuration
Pin Assignment
DIP8/ SO8
OUTPUT
Fig. 2
V
IN
R
INPUT
A6155
EN
RES
TCL
V
SS
5 V
Fig. 1
GND
A6155
V
IN
TCL
RES
EN
R
V
SS
INPUT OUTPUT
Unregulat-
ed voltage