EM6151 EM6152 Fact Sheet

R
EM MICROELECTRONIC - MARIN SA
EM6151/52
Windowed Watchdog IC with 5V LDO
Description
Features
The EM6151/52 are microprocessor voltage supervisory
circuits including voltage monitoring, reset timeout period
and windowed watchdog. Moreover, the EM6152 includes a
5V low-dropout voltage regulator on-chip.
The watchdog timer, the reset timeout period and the
voltage threshold are set by external resistors.
The windowed watchdog timer function offers increased
security compared to a standard watchdog timer.
‰ Windowed watchdog function
Benefits
‰ Open-drain active-low RESET output
‰
‰ Push-pull active-low ENABLE output
‰
‰
‰
‰
Greatly improves security:
9 Prevents endless loops
9 Reinitializes the system in case of SW code errors
9 Avoids conflict between master and slaves MCUs
9 Catches a malfunctioning crystal oscillator
Increased flexibility:
9 Short or long ratio for opened/closed watchdog
window
9 Parameters set by external resistors
Detects events that are expected within a time interval
that has both a minimum and a maximum
Better heat dissipation (EM6152)
One-chip solution to reduce drastically PCB size and
mounting costs (EM6152)
‰ Voltage monitoring and power-on reset function
‰ Separate ENABLE output for peripheral: the circuit
waits 3 acknowledgements from μP to ensure full
working system before activation of peripheral (e.g.
motor drivers, actuators)
‰ CAN sleep mode function
‰ -40°C to +125°C operating temperature
‰ Low supply current: 35µA / 145µA (EM6151/52)
‰ 5V LDO Voltage Regulator, up to 400mA (EM6152)
‰ SO-8 and PSOP-16 power package (EM6152)
High Flexibility and Accuracy
‰
‰
‰
Adjustable reset threshold voltage with ±3% accuracy
Adjustable watchdog timer (TWD = 10ms to 1sec,
accuracy ±10%) using one external resistor
Adjustable reset timeout period TPOR using one
external resistor
Typical Application
Windowed Watchdog
EM6152
A sophisticated watchdog timer detects when the processor
is running outside of an expected (opened) window of
operation. A reset is asserted whenever a TCL is not
received while the watchdog window is opened. Two ratios
for the opened/closed windows are available: 33%/67% for
increased security or 67%/33% for increased programming
flexibility.
Window:
Opened
Opened
Closed
Closed
Unregulated V DD
(up to +40V)
VDD
5V regulated V DD
VDD
VDD
To adjust
voltage
threshold
Opened
Closed
LDO
Voltage
Regulator
VIN
RES
RESET
(open-drain)
Closed
TCL
MPU,MCU
I/O
EM6151
TCL incorrect - too fast
RES will go active:
ROSC
EN
TCL incorrect - too slow
To adjust
TWD and T POR
RES will go active:
GND
EN
Peripheral,
Actuator
GND
GND
TCL correct
RES will NOT go active:
Product Offering
3 correct TCL service
EN goes active:
t
Copyright © 2005, EM Microelectronic-Marin SA
Subject to change without notice
Rev. A, 08/05
Part Number
LDO Voltage Regulator
(VOUT / VDROPOUT @ IOUT)
Input
Voltage
Package
EM6151_SO8
-
1.2 to 5.5V
SO-8
EM6152_SO8
5V / 250mV @ 100mA
2.3 to 40V
SO-8
EM6152_PS16
5V / 250mV @ 250mA
2.3 to 40V
PSOP-16
Phone: +41.32.755-5111, Fax: +41.32.755-5403
www.emmicroelectronic.com
info@emmicroelectronic.com