EM MICROELECTRONIC - MARIN SA
EM6323/24
Reset Circuit with Manual Reset and Watchdog
Description
Features
The EM6323/24 are low power, high precision reset ICs
featuring a manual reset and a watchdog inputs. They have
different threshold voltages and several timeout reset periods
(tPOR) and watchdog timeout periods (tWD) for maximum
flexibility in the application. EM6323 has a manual reset ( MR
with internal pull-up) and a watchdog input pins. EM6324 has
only a watchdog input pin (WDI). The watchdog function can
be disabled by driving WDI with a three-state driver or by
leaving WDI unconnected. This is useful when the MCU is in
sleep mode.
Small SOT23-5L package as well as ultra-low supply current
of 3.8µA make the EM6323 and the EM6324 an ideal choice
for portable and battery-operated devices.
!
!
!
!
!
!
!
Ultra-low supply current of 3.8µA (VDD=3.3V)
Operating temperature range: -40°C to +125°C
±1.5% reset threshold accuracy
11 reset threshold voltages VTH: 4.63V, 4.4V, 3.08V,
2.93V, 2.63V, 2.2V, 1.8V, 1.66V, 1.57V, 1.38V, 1.31V
200ms reset timeout period (1.6ms, 25ms, 1600ms on
request)
1.6s watchdog timeout period (6.2ms, 102ms, 25.6s on
request)
3 reset output options:
Active-low RESET push-pull
Active-low RESET open-drain
Typical Application
VDD
RESET
RESET
RESET
RESET
EM632x
MR
!
VDD
*
VDD
Applications
!
MPU, DSP
WDI
Active-high RESET push-pull
Detection of microcontroller in sleep mode
!
I/O
!
GND
GND
!
GND
!
* REXT for open-drain version only
!
Fig. 1
!
Block Diagram
Workstations
Point of sales (POS)
Personal computers
Routers, hubs and switches
Handheld GPS
Vending machines and ATM
Automotive systems
VDD
Pin Configuration
Voltage
Reference
MR
-
Reset
Logic
+ Timer
EM6323
RESET
RESET
Filter
GND
Transition
Detector
WDI
Watchdog Logic
+ Timer
RESET
1
GND
2
MR
3
(manual reset,
watchdog)
SOT23-5
5
4
VDD
WDI
top view
EM6324
RESET
1
GND
2
RESET
3
push-pull/open-drain
(watchdog)
EM6324
+
EM6323
Oscillator
5 VDD
4
WDI
push-pull
SOT23-5
top view
Fig. 3
Fig. 2
Pin Description
SOT23-5L
EM6323 EM6324
Name
1
1
RESET
2
2
GND
3
-
MR
-
3
RESET
4
4
WDI
5
5
VDD
Function
Active-low RESET output (push-pull or open-drain)
Ground
Manual Reset input with an internal pull-up 30kΩ resistor. Reset remains active as long as MR is low
and for tPOR after returns high. MR can be driven with a CMOS output or shorted to ground with a switch
Active-high RESET output (push-pull)
Watchdog input. WDI must be driven with a CMOS output. If the microcontroller I/O is put in a high
impedance condition, the circuit will detect this condition as a microcontroller in sleep mode and prevent
its watchdog from timing out
Supply Voltage (5.5V max.)
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
1
www.emmicroelectronic.com
EM6323/24
Ordering Information
EM6323 L X SP5B - 2.9 +
RoHS Compliance:
+ = lead-free/green mold compliant
[blank] = leaded
Delays tPOR & tWD :
Reset Threshold Voltage:
tPOR [ms]
EM6323/24:
1.6 25 200 1600
6.2 A
B
C
D
102 E
F
G
H
1600 J
K
L
M
25600 N
P
Q
R
("L" is the standard version")
1.3 = 1.31V
1.4 = 1.38V
1.6 = 1.57V
1.7 = 1.66V
tWD [ms]
Part Number:
EM6323 = manual reset & watchdog
EM6324 = watchdog
1.8 = 1.80V
2.2 = 2.20V
2.6 = 2.63V
2.9 = 2.93V
3.1 = 3.08V
4.4 = 4.40V
4.6 = 4.63V
Package:
SP5B = 5-pin SOT23-5, tape&reel, 3000 pcs
Reset Output Type:
X = Active-low /RESET push-pull (Active-high RESET push-pull also for EM6324)
Y = Active-low /RESET open-drain (Active-high RESET push-pull also for EM6324)
Z = Active-high RESET push-pull (EM6323 only)
Note:
subject to availability (see standard versions list below). Please give complete Part Number when ordering
Standard Versions (Top Marking)
Watchdog timer (tWD)
2.6V
200ms/1600ms
2)
Output Type
Package
Part Number
Top
Top Marking
1)
with 4
Marking
2)
characters
Active-high push-pull RESET
SOT23-5L
EM6323LZSP5B-2.6
APL5
EM6323LXSP5B-2.6
APLG
2.63V
200ms/1600ms
Active-low push-pull RESET
SOT23-5L
2.63V
200ms/1600ms
Active-low push-pull RESET
SOT23-5L
EM6323LXSP5B-2.6+
2.93V
200ms/1600ms
Active-low push-pull RESET
SOT23-5L
EM6323LXSP5B-2.9
2.93V
200ms/1600ms
Active-low push-pull RESET
SOT23-5L
EM6323LXSP5B-2.9+
3.08V
200ms/1600ms
Active-low push-pull RESET
SOT23-5L
EM6323LXSP5B-3.1
APLJ
2.93V
200ms/1600ms
Active-low open-drain RESET
SOT23-5L
EM6323LYSP5B-2.9
APLU
2.93V
200ms/1600ms
Active-low open-drain RESET
SOT23-5L
EM6323LYSP5B-2.9+
Active-low open-drain RESET
SOT23-5L
EM6323LYSP5B-3.1
APLV
EM6323LXSP5B-3.1
APLJ
AQMK
3.1V
1)
Delay (tPOR)/
Threshold
Voltage
200ms/1600ms
KF##
BPLG
APLH
K0##
K6##
BPLH
BPLU
3.1V
200ms/1600ms
Active-low push-pull RESET
SOT23-5L
4.40V
200ms/1600ms
Active-low push-pull RESET
SOT23-5L
EM6324LXSP5B-4.4
4.40V
200ms/1600ms
Active-low push-pull RESET
SOT23-5L
EM6324LXSP5B-4.4+
2.9V
200ms/1600ms
Active-low open-drain RESET
SOT23-5L
EM6324LYSP5B-2.9
AQLU
1.38V
200ms/25600ms
Active-low push-pull RESET
SOT23-5L
EM6324QXSP5B-1.4
AQQB
K9##
BQMK
Top marking is standard from 2006. No bottom marking exists. Where ## refers to the lot number (EM internal reference
only)
Top marking with 4 characters is standard from 2003. For lead-free/green mold (RoHS) parts, the first letter of top
marking with 4 characters begins with letter “B” instead of letter “A”. Bottom marking indicates the lot number.
Standard Versions (samples)
Part Number
Part Number
EM6323LXSP5B-2.6+
EM6323LYSP5B-2.9+
EM6323LXSP5B-2.9+
EM6324LXSP5B-4.4+
Sample stock is generally held on standard versions only. Non standard versions have a 30,000 pieces minimum order
quantity. Please contact factory for other versions not shown here and for availability of non standard versions.
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
2
www.emmicroelectronic.com
EM6323/24
Absolute Maximum Ratings
Parameter
Handling Procedures
Symbol
Conditions
Voltage at VDD to GND
Minimum voltage at any signal pin
Maximum voltage at any signal pin
VDD
VMIN
VMAX
-0.3V to +6V
GND - 0.3V
VDD + 0.3V
Electrostatic discharge max. to
MIL-STD-883C method 3015.7
with ref. to VSS
VESD
2000V
Max. soldering conditions
Storage Temperature Range
TMAX
TSTG
250°C x 10s
-65°C to +150°C
This device has built-in protection against high static
voltages or electric fields; however, anti-static
precautions must be taken as for any other CMOS
component. Unless otherwise specified, proper
operation can only occur when all terminal voltages are
kept within the voltage range. Unused inputs must
always be tied to a defined logic voltage level.
Operating Conditions
Parameter
Stresses above these listed maximum ratings may
cause permanent damages to the device. Exposure
beyond specified operating conditions may affect device
reliability or cause malfunction.
Symbol Min Max Unit
Supply voltage
Operating Temperature
Input transition rise and fall rate
VDD
TA
tR/tF
on MR and WDI
0.9 5.5
V
-40 +125 °C
-
100 ns/V
Electrical Characteristics
Unless otherwise specified: VDD= 0.9V to 5.5V, TA=-40°C to +125°C (note 1).
Parameter
Symbol
Conditions
Min
+25°C
-40°C to +125°C
+25°C
-40°C to +125°C
+25°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
+25°C
-40°C to +85°C
-40°C to +125°C
1.290
1.245
1.221
1.359
1.311
1.286
1.546
1.492
1.463
1.635
1.577
1.547
1.773
1.710
1.678
2.167
2.090
2.050
2.591
2.499
2.451
2.886
2.784
2.731
3.034
2.926
2.871
4.334
4.180
4.101
4.561
4.399
4.315
VDD=1.5V
Supply current (note 2)
IDD
VDD=3.3V
VDD=5.0V
EM6323/24 – 1.3
EM6323/24 – 1.4
EM6323/24 – 1.6
EM6323/24 – 1.7
EM6323/24 – 1.8
Threshold voltage
(note 3)
VTH
EM6323/24 – 2.2
EM6323/24 – 2.6
EM6323/24 – 2.9
EM6323/24 – 3.1
EM6323/24 – 4.4
EM6323/24 – 4.6
Typ
2.4
3.86
5.89
1.31
1.38
1.57
1.66
1.80
2.20
2.63
2.93
3.08
4.40
4.63
Max
4.4
6.8
6.1
9.9
8.6
11.6
1.330
1.382
1.387
1.401
1.456
1.461
1.594
1.656
1.663
1.685
1.751
1.758
1.827
1.899
1.906
2.233
2.321
2.330
2.669
2.775
2.785
2.974
3.091
3.103
3.126
3.249
3.262
4.466
4.642
4.660
4.699
4.885
4.903
Unit
µA
V
Note 1: Production tested at +25°C only. Over temperature limits are guaranteed by design, not production tested.
Note 3: Threshold voltage is specified for VDD falling.
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
3
www.emmicroelectronic.com
EM6323/24
Electrical Characteristics
(continued)
Unless otherwise specified: VDD= 0.9V to 5.5V, TA=-40°C to +125° C (note 1).
Parameter
Threshold hysteresis
Reset timeout period
Symbol
Conditions
Min
Typ
Max
Unit
VHYS
TA=+25°C
-
2.1%•VTH
-
V
tPOR
Propagation delay time
VDD to RESET (RESET)
delay
tP
VDD from 0V to VTH (typ)+15%
TA= +25°C
(note 2 and 4)
VOL
VOL
Push-pull RESET / RESET
Output voltage
VOH
Output leakage current
ILEAK
160
200
240
EM6323/24 A-E-J-N
0.7
1.56
3.8
EM6323/24 B-F-K-P
20
25
30
EM6323/24 D-H-M-R
1280
1600
1920
2
70
255
-
-
0.3
VDD drops from VTH (typ)+0.2V to VTH (typ)-0.2V
(note 2). TA= +25°C
IOL=100µA
VDD>1V
Open-drain RESET output
Voltage
EM6323/24 C-G-L-Q
VDD>2.5V
IOL=1.5mA
-
-
0.3
VDD>5V
IOL=3mA
-
-
0.35
VDD>1V
IOL=100µA
-
-
0.3
VDD>2.5V
IOL=1.5mA
-
-
0.3
VDD>5V
IOL=3mA
-
-
0.35
VDD>1.1V
IOH=-30µA
0.8
-
-
ms
µs
V
V
VDD>2.5V
IOH=-1.5mA
2
-
-
VDD>5V
IOH=-3mA
4
-
-
-
-
0.5
µA
-
-
0.3•VDD
V
0.7•VDD
-
-
V
µs
Only for EM6323/24_Y (open-drain)
WATCHDOG INPUT (WDI)
WDI Input low
VWDI low
WDI Input high
VWDI high
Pulse width at WDI
TA= +25°C
tWP
(note 6)
1
-
-
EM6323/24 J-K-L-M
1280
1600
1920
EM6323/24 A-B-C-D
5
6.25
7.5
EM6323/24 E-F-G-H
80
100
120
EM6323/24 N-P-Q-R
Watchdog timeout period
tWD
ms
20480
25600
30720
High-level Input Current
IIH
WDI connected to VDD, TA= +25°C
-
18
-
µA
Low-level Input Current
IIL
WDI connected to GND, TA= +25°C
-
8.3
-
µA
MANUAL RESET ( MR ) – EM6323 only
MR Input low
VMRT low
-
-
0.3•VDD
V
MR Input high
VMRT high
0.7•VDD
-
-
V
MR to Reset delay
tMD
Pulse width at MR (note 5)
tPMD
MR Internal Pull-up
resistor
RMR
TA= +25°C
TA=-40°C to +125°C
-
0.3
-
µs
1
-
-
µs
7
30
74
kΩ
Note 1:
Note 2:
Note 3:
Note 4:
Production tested at +25°C only. Over temperature limits are guaranteed by design, not production tested.
WDI, MR and RESET (RESET) open.
Threshold voltage is specified for VDD falling.
Standard version for tPOR is 200ms (typ). Other option (1.6ms, 25ms, 1600ms) are available by mask option and
upon minimum order quantity. Please contact EM sales.
Note 5: Pulse width must be greater than 1µs to ensure the RESET (RESET) to go active.
Note 6: Standard version for tWD is 1600ms (typ). Other option (6.2ms, 102ms, 25.6s) are available by mask option and
upon minimum order quantity. Please contact EM sales.
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
4
www.emmicroelectronic.com
EM6323/24
Timing Waveforms
tSEN
VDD
VHYS
VTH
Overdrive
0.9V
t
logic "1"
tPMD
MR
logic "0"
t
logic "1"
tPOR
RESET
tP
tMD
logic "0"
t
logic "1"
tPOR
RESET
logic "0"
t
Fig. 4
logic "1"
tWP
WDI
tWD
tWD
logic "0"
t
logic "1"
RESET
logic "0"
t
logic "1"
tPOR
RESET
logic "0"
t
Fig. 5
Note 7: tSEN = Maximum Transient Duration. Please refer to figure on the next page.
Note 8: Overdrive = VTH -VDD. Please refer to figure on the next page.
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
5
www.emmicroelectronic.com
EM6323/24
Typical Operating Characteristics
(Typical values are at TA=+25°C unless otherwise noted. WDI, MR , RESET and RESET open.)
9
6%
8
4%
VDD 5 . 0 V
7
2%
6
5
[ uA ]
4
0%
VDD 3 . 3 V
-2%
3
VDD 1. 5 V
2
-4%
1
0
-50
-6%
-25
0
25
50
[ °C ]
75
100
-50
125
-25
0
25
50
[ °C ]
75
100 125
Fig. 6
Fig. 7
IDD vs. Temperature
Threshold Voltage Variation vs. Temperature
(normalized)
160%
160%
tPOR (°C)
140%
tWD (°C)
tWD (25°C)
140%
tPOR (25°C)
120%
120%
100%
100%
80%
80%
60%
60%
-50
-25
0
25
50
[ °C ]
75
100
-50
125
0
25
50
[ °C ]
75
100
125
Fig. 9
Fig. 8
Watchdog Timeout Period tWD vs. Temperature
(normalized with respect to tWD 25°C)
Reset Timeout Period tPOR vs. Temperature
(normalized with respect to tPOR 25°C)
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
-25
6
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EM6323/24
Typical Operating Characteristics
(Typical values are at TA=+25°C unless otherwise noted. WDI, MR , RESET and RESET open.)
120
120
100
100
80
[ us ]
60
80
[ us ]
60
40
40
20
20
0
-50
Reset occurs above
this line
0
-25
0
25
50
[ °C ]
75
100
125
1
10
[ mV ]
100
1000
Fig. 10
Fig. 11
Propagation Time tPHL vs. Temperature
Maximum Transient Duration tSEN vs.
Overdrive VTH-VD
250
350
225
300
200
250
[ ns ]
[ ns ]
175
200
150
150
125
100
-50
-25
0
25
50
[ °C ]
75
100
-50
100 125
Fig. 12
0
25
50
[ °C ]
75
100
125
Fig. 13
Watchdog Input Pulse Width tWP vs. Temperature
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
-25
Manual Reset Pulse Width tPMD vs. Temperature
7
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EM6323/24
Functional Description
VDD
MR
High Impedance
WDI
RESET
t < tWD
tPOR
t > tWD
tPOR
tPOR
Fig. 14
Reset Outputs
Manual Reset Input (EM6323 only)
A microprocessor (µP) reset input starts the µP in a
known state. The EM6323/24 µP supervisory circuits
assert a reset to prevent code-execution errors during
power-up, power-down, and brownout conditions. RESET
is guaranteed to be a logic low for VDD down to 0.9V.
Once VDD exceeds the reset threshold, an internal timer
keeps RESET low for the specified reset timeout period
(tPOR); after this interval, RESET returns high.
If a brownout condition occurs (VDD dips below the reset
threshold), RESET goes low. Each time RESET is
asserted it stays low for the reset timeout period. Any
time VDD goes below the reset threshold the internal
timer restarts. RESET is the inverse of RESET.
A logic low on MR asserts a reset. Reset remains
asserted while MR is low, and for tPOR (200ms nominal for
EM6323 C-G-L-Q) after it returns high. MR has an
internal 30kΩ pull-up resistor, so it can be left open if
unused. This input can be driven with CMOS logic levels
or with open-drain outputs. Connect a normally open
momentary switch from MR to VSS to create a manualreset function; debounce circuitry is integrated. If MR is
driven from long cable or the device is used in a noisy
environment, connect a 0.1µF capacitor from MR to VSS
to provide additional noise immunity (stronger external
additional pull-up resistor can also be added).
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
8
www.emmicroelectronic.com
EM6323/24
Watchdog Input
When WDI is left unconnected, this internal driver clears
the 1.6s timer every 1.5s. When WDI is three-stated or
unconnected, the maximum allowable leakage current is
0.5µA.
To minimized the overall system power consumption and
therefore for a minimum watchdog input current leave
WDI low for the majority of the watchdog timeout period,
pulsing it low-high-low once within the first 15/16 of the
watchdog timeout period to reset the watchdog timer. If
WDI is externally driven high for the majority of the
timeout period, up to 35µA can flow into WDI. Meanwhile
when the microcontroller is not in sleep mode, the output
of the microcontroller which drives WDI has to be strong
enough to fight the 35µA.
If the watchdog timer has not been cleared within tWD
(1.6s typ.), reset asserts. The internal 1.6s timer is
cleared by either a reset pulse or by toggling WDI. While
reset is asserted, the timer remains cleared and does not
count. As soon as reset is released, the timer starts
counting.
If the microcontroller I/O connected to WDI is put in a
high impedance condition, the circuit will detect this
condition as a microcontroller in sleep mode and prevent
its watchdog from timing out. To monitor a high
impedance or a three state condition on WDI, the
watchdog input is internally driven low during the first
15/16 of the watchdog timeout period and high for the
last 1/16 of the watchdog timeout period.
VDD
VDD
Pullup
RESET
1/16 tWD
WDI Pullup OFF
ON
OFF
WDI Pulldown ON
OFF
ON
tPOR
15/16 tWD
Transition
Detector
WDI
Watchdog Logic
+ Timer
15/16 tWD
1/16 tWD
Pulldown
tWD
GND
Fig. 16
Fig. 15
WDI Input Stage Block Schematic
WDI Input Timing Diagram
15.0
25.0
12.0
20.0
9.0
[ uA ]
[ uA ]
6.0
10.0
3.0
5.0
0.0
-50
0.0
15.0
-25
0
25
50
75
100
125
-50
[ °C ]
0
25
50
75
100 125
[ °C ]
Fig. 17
Fig. 18
WDI Input Current Low-level IIL vs. Temperature
(VDD=5.5V)
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
-25
WDI Input Current High-Level IIH vs. Temperature
(VDD=5.5V)
9
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EM6323/24
Package Information
D
E1
SOT23-5L
C
A1 A2 A
b
E
e
SYM BOL
A
A1
A2
b
C
D
E
E1
e
e1
L
e1
M IN
0.90
0.05
0.90
0.35
0.08
2.80
2.60
1.50
L
TYP M AX
1.30 1.45
0.08 0.15
1.15 1.30
0.50
0.20
2.90 3.00
2.80 3.00
1.75
0.95
1.90
0.45
Dimensions are in mm
Fig. 19
Traceability for small packages
Due to the limited space on the package surface, the bottom marking contains a limited number of characters that provide only partial
information for lot traceability. Full information for complete traceability is however provided on the packing labels of the product at
delivery from EM. It is highly recommended that the customer insures full lot traceability of EM product in his final product.
EM Microelectronic-Marin SA (EM) makes no warranty for the use of its products, other than those expressly contained in the Company's
standard warranty which is detailed in EM's General Terms of Sale located on the Company's web site. EM assumes no responsibility for
any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without
notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual
property of EM are granted in connection with the sale of EM products, expressly or by implications. EM's products are not authorized for
use as components in life support devices or systems.
Product qualification is performed according to internal EM quality standards for industrial products. For any special requirement (eg. automotive grade) please
contact EM Microelectronic-Marin S.A.
Copyright © 2006, EM Microelectronic-Marin SA
03/06 - rev.H
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