EM MICROELECTRONIC
-MARIN SA
Reset Circuit with Adjustable Delay
Description
The EM6354 is an ultra-low current reset circuit available in a
large variety of configurations and very small packages for
maximum flexibility in all end-applications up to 125°C and
using power supplies between 1.5V and 5.5V.
This circuit monitors the supply voltage of any electronic
system, and generates the appropriate reset signal. The
threshold defines the minimum allowed voltage which
guarantees the good functionality of the system. When V
DD
rises above V
TH
, the output remains active for an additional
delay time. This allows the system to stabilize before going
fully active. This delay time, or reset timeout period, can be
adjusted using an external capacitor.
The output is guaranteed to be in the correct state for V
DD
down to 0.8V. There are 11 reset threshold voltages starting
as low as 1.31V and up to 4.63V. The EM6354 features
three output types: active-low push-pull, active-low open-
drain and active-high push-pull.
Small SC70 and SOT23 packages as well as ultra-low
supply current of 2.9µA make the EM6354 an ideal choice
for portable and battery-operated devices.
EM6354
Features
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Adjustable reset timeout period using an external
capacitor
Ultra-low supply current of 2.9µA (V
DD
=3.3V)
Operating temperature range: -40°C to +125°C
±1.5%
reset threshold accuracy
11 reset threshold voltages V
TH
: 4.63V, 4.4V, 3.08V,
2.93V, 2.63V, 2.2V, 1.8V, 1.66V, 1.57V, 1.38V, 1.31V
3 reset output options:
Active-low
RESET
push-pull
Active-low
RESET
open-drain
Active-high
RESET
push-pull
Immune to short negative V
DD
transients
Guaranteed Reset valid down to 0.8V
Threshold hysteresis: 2.1% of V
TH
Very small SOT23-5L and SC70-4L (SC-82AB)
packages
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Typical Application
V
DD
V
DD
RESET
Applications
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V
DD
RESET
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EM6354
C
D
GND
MPU, DSP
GND
GND
*
R
EXT
for open-drain version only
Home appliances
Modems
Routers, hubs and gateways
WAN, LAN
Handheld GPS
Metering and Instrumentation
TV sets
Automotive systems
Block Diagram
V
DD
Voltage
Reference
1
2
4
3
GND
Pin Configuration
(top view)
RESET
(RESET)
V
DD
GND
1
2
3
4 NC
5
C
D
RESET
(RESET)
V
DD
-
+
Delay
Circuit
RESET
(RESET)
C
D
SOT23-5L
SC70-4L
(SC-82AB)
GND
C
D
Pin Description
Pin
SOT23-5L
SC70-4L
1
2
3
4
5
1
RESET
2
4
-
3
V
DD
GND
N.C.
C
D
Name
RESET
Function
Active-low
RESET
output.
RESET
remains low for the reset timeout period after all reset
conditions are deasserted and then goes high.
Active-high RESET output. RESET remains high for the reset timeout period after all reset
conditions are deasserted and then goes low.
Supply Voltage (5.5V max.)
Ground
Not connected. Not internally connected
Connect a capacitor between C
D
and GND to set the timeout period
(C
D
min=1nF; C
D
max=10000nF). Reset Timeout Period in [ms] is equal to C
D
in [nF]
Copyright
©
2006, EM Microelectronic-Marin SA
03/06 – rev.I
1
www.emmicroelectronic.com
EMMICRO [ EM MICROELECTRONIC - MARIN SA ]
