ETC ZXCM210LFTA

ZXCM209
ZXCM210
VERY LOW POWER MICROPROCESSOR RESET DEVICES
DESCRIPTION
The ZXCM209/210 are three terminal supervisory
circuits used to monitor the power supplies in
microprocessor and digital systems. They provide a
high performance economical solution when used
with 5V, 3V or lower powered circuits. Reset
thresholds suitable for operation with a variety of
supply voltages are available.
APPLICATIONS
These devices provide a reset signal whenever the
supply voltage falls below a preset threshold, keeping
it asserted for a minimum delay period of 140ms after
the supply has risen above the reset level. The
ZXCM209 has an active-low RESET output (which is
guaranteed to be in the correct state for supplies down
to 1V), while the ZXCM210 has an active-high RESET
output.
•
Computer systems
•
Controllers
•
Instrumentation
•
Microprocessor power monitoring
•
Microcontroller power monitoring
•
Power supplies
•
Portable/Battery-powered equipment
•
Automotive
APPLICATION CIRCUIT
vcc
The reset comparator has in built hysteresis to prevent
erratic operation and is designed to ignore supply
transients. Low supply current (typically 2µA) makes
the ZXCM209/210 devices ideal for use in portable
equipment. They are available in a 3-pin SOT23
surface mount package with an industry standard
pinout.
vcc
vcc
ZXCM
Micro
Reset
Output
Reset
Input
FEATURES
•
Enhanced alternative to MAX809/810 and similar
parts
•
Precision monitoring of 5V, 3.3V, 3V power
supply voltages
•
1% threshold tolerance
•
2µA typical supply current
•
140ms minimum power on reset pulse width
•
Alternative minimum pulse widths available,
contact your local sales office for availability
•
RESET LOW Output (ZXCM209)
•
RESET HIGH Output (ZXCM210)
•
Power supply transient immunity
•
No latch up
•
No external components
•
3-Pin SOT23 package
Gnd
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1
Gnd
ZXCM209
ZXCM210
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage with respect to GND
VCC
RESET, RESET
Input Current, VCC
Output Current
Rate of Rise, VCC
Continuous Power Dissipation
Operating Temperature Range
Storage Temperature Range
-0.3V to 7.0V
-0.3V to (VCC + 0.3V)
20mA
20mA
250V/µs
500mW
-55°C to +125°C
-65°C to +150°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
These are stress ratings only, and functional operation of the device at these or any other conditions beyond
those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum
conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
TEST CONDITIONS (unless otherwise stated) VCC
= full range, TA = -55°C to +125°C
SYMBOL
PARAMETER
CONDITIONS
LIMITS
VR
V CC Range
T A =0° to 70°C
T A =-55° to 125°C
1.0
1.2
I CC
Supply Current
V TH
Reset Threshold
Suffix L; T A =25°C
Suffix M; T A =25°C
4.58
4.34
Suffix J; T A =25°C
3.96
Suffix T; T A =25°C
Suffix S; T A =25°C
Suffix R; T A =25°C
MIN
V THT
Reset Threshold
Tolerance
∆V TH /°C
Reset Threshold Temp.
Coefficient
VD
V CC to Reset Delay
V TO
Reset Active Timeout
Period
UNITS
TYP
MAX
5.5
5.5
V
V
2
5
µA
4.63
4.68
V
4.38
4.42
V
4.00
4.04
V
3.05
3.08
3.11
V
2.90
2.93
2.96
V
2.60
2.63
2.66
V
5
%
%
1
T A =25°C
T A =-55° to 125°C
50
ppm/°C
µs
30
140
560
ms
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2
ZXCM209
ZXCM210
ELECTRICAL CHARACTERISTICS ZXCM209
TEST CONDITIONS (unless otherwise stated) VCC = full range, TA = -55°C to +125°C
SYMBOL
PARAMETER
CONDITIONS
LIMITS
MIN
V OL
V OH
Reset Output Voltage
Low
Reset Output Voltage
High
UNITS
TYP
MAX
V CC >1V, I OL =100µA (0 to 85°C)
0.3
V
V CC >1.2V, I OL =200µA
0.3
V
V TH >V CC >2.5V, I OL =2.7mA
0.4
V
V CC >V TH max, I OH =1mA
0.8V cc
V
ELECTRICAL CHARACTERISTICS ZXCM210
TEST CONDITIONS (unless otherwise stated) VCC = full range, TA = -55°C to +125°C
SYMBOL
PARAMETER
CONDITIONS
LIMITS
MIN
V OL
V OH
Reset Output Voltage
Low
Reset Output Voltage
High
UNITS
TYP
MAX
V CC >V TH max, I OL =2mA
0.3
V CC >V TH max, I OL =2.7mA
0.4
V
V
V CC >1.5V, I OH =150µA
0.8V cc
V
V TH >V CC >2.5V, I OH =1mA
0.8V cc
V
Note: Device testing is performed at TA=25°C. Device thermal performance is guaranteed by design
TYPICAL CHARACTERISTICS
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ZXCM209
ZXCM210
TYPICAL CHARACTERISTICS
ISSUE 2 - MARCH 2000
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ZXCM209
ZXCM210
APPLICATIONS INFORMATION
Negative going VCC transients
Reset valid down to very low supply voltages
The ZXCM209/210 are, to a good degree, immune to
short duration negative going supply transients. Under
certain circumstances very brief transients are allowed
without inappropriate false triggering of the reset
circuit. The response to supply transients is shown in the
Noise Immunity graph in the typical characteristics. The
graph indicates the typical allowable transient duration
for a specified threshold overdrive such that a reset
pulse is not generated. Addition of a bypass capacitor,
e.g. 0.1µF, as close as possible to the VCC pin will provide
extra transient immunity.
vcc
With VCC between 0V and 1V the output of the
ZXCM209/210 may be in an undefined state. In many
sy st e m s t h i s i s i n co n se q u e n t i a l a s t h e
microprocessor, and other circuits, will be inoperative
with supplies this low. In applications where this is
important, the addition of an external resistor ensures
that the reset output remains valid for VCC < 1V. The
resistor value is non critical: a value of 100kΩ is
recommended. For the ZXCM209 the resistor should
be applied between reset output and ground: for the
ZXCM210 between reset output and VCC. Figure 1
shows the connection diagram for the ZXCM devices
in these configurations.
vcc
vcc
vcc
vcc
ZXCM209
Micro
ZXCM210
Reset
Output
Gnd
Reset
Input
100k
100k
Reset
Output
Gnd
Gnd
Figure 1
Circuit for operation of ZXCM with reset valid down to very low supply voltage.
ISSUE 2 - MARCH 2000
5
vcc
Micro
Reset
Input
Gnd
ZXCM209
ZXCM210
Interfacing to µP’s with bidirectional reset I/O
The ZXCM series can be used with microprocessors
havng bidirectional reset pins, such as Motorola 68HC11
series. The addition of a 4.7k resistor between the ZXCM
reset output and the processor input ensures correct
operation of the reset circuit. A buffer to other circuit
components is then required to enable the processor
reset drive to operate correctly. The circuit
configuration is shown in Figure 2.
vcc
to other
circuits
vcc
vcc
ZXCM
Micro
Reset
Output
Reset
Input
4.7kΩ
Gnd
Gnd
Figure 2
Interfacing to µP’s with bidirectional reset I/O.
PIN DESCRIPTION
Pin
Number
Pin Name
Pin Function
1
V CC
Supply voltage (+5, +3.3, +3 volts)
RESET
Output remains low while Vcc is below the reset threshold, and for a
minimum 140ms after V CC rises above the reset threshold.
2
(ZXCM209)
RESET
(ZXCM210)
3
Gnd
Output remains high while V CC is below the reset threshold, and for a
minimum 140ms after V CC rises above the reset threshold.
Ground
3
1
2
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ZXCM209
ZXCM210
ORDERING INFORMATION
PART NUMBER
TEMPERATURE RANGE
PACKAGE
RESET OUTPUT
ZXCM209xF
-55 to 125°C
SOT23
LOW
ZXCM210xF
-55 to 125°C
SOT23
HIGH
x=Insert appropriate threshold voltage code.
ZXCM209 Threshold voltage codes
PART MARK
THRESHOLD
CODE
RESET
THRESHOLD (V)
M22
L
4.63
M23
M
4.38
M24
J
4.00
M25
T
3.08
M26
S
2.93
M27
R
2.63
ZXCM210 Threshold voltage codes
PART MARK
THRESHOLD
CODE
RESET
THRESHOLD (V)
M28
L
4.63
M29
M
4.38
M30
J
4.00
M31
T
3.08
M32
S
2.93
M33
R
2.63
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ZXCM209
ZXCM210
PAD LAYOUT DETAILS
N
PACKAGE DIMENSIONS
DIM Millimetres
Inches
Min
Max
Min
Max
A
2.67
3.05
0.105
0.120
B
1.20
1.40
0.047
0.055
C
–
1.10
–
0.043
D
0.37
0.53
0.0145
F
0.085
0.15
0.0033
G
NOM 1.9
K
0.01
0.10
0.0004
L
2.10
2.50
0.0825
N
NOM 0.95
0.021
0.0059
NOM 0.075
0.004
0.0985
NOM 0.037
Zetex plc.
Fields New Road, Chadderton, Oldham, OL9-8NP, United Kingdom.
Telephone: (44)161 622 4422 (Sales), (44)161 622 4444 (General Enquiries)
Fax: (44)161 622 4420
Zetex GmbH
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Germany
Telefon: (49) 89 45 49 49 0
Fax: (49) 89 45 49 49 49
Zetex Inc.
47 Mall Drive, Unit 4
Commack NY 11725
USA
Telephone: (631) 543-7100
Fax: (631) 864-7630
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Kwai Fong, Hong Kong
Telephone:(852) 26100 611
Fax: (852) 24250 494
These are supported by
agents and distributors in
major countries world-wide
© Zetex plc 2000
Internet:http://www.zetex.com
This publication is issued to provide outline information only which (unless agreed by the Company in writing) may not be used, applied or reproduced for
any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. The Company reserves
the right to alter without notice the specification, design, price or conditions of supply of any product or service.
ISSUE 2 - MARCH 2000
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