Document
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. 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. 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. 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
APPLICATIONS • • • • • • • • Computer systems Controllers Instrumentation Microprocessor power monitoring Microcontroller power monitoring Power supplies Portable/Battery-powered equipment Automotive
APPLICATION CIRCUIT
vcc vcc ZXCM
Reset Output
vcc Micro
Reset Input
Gnd
Gnd
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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
SYMBOL PARAMETER
= full range, T = -55°C to +125°C
A
CONDITIONS
LIMITS MIN TYP MAX 5.5 5.5 2 5 4.68 4.42 4.04 3.11 2.96 2.66 5 50 30 140 560
UNITS
VR I CC V TH
V CC Range Supply Current Reset Threshold
T A =0° to 70°C T A =-55° to 125°C Suffix L; T A =25°C Suffix M; T A =25°C Suffix J; T A =25°C Suffix T; T A =25°C Suffix S; T A =25°C Suffix R; T A =25°C
1.0 1.2
V V µA V V V V V V % % ppm/°C µs ms
4.58 4.34 3.96 3.05 2.90 2.60
4.63 4.38 4.00 3.08 2.93 2.63 1
V THT ∆ V TH /°C VD V TO
Reset Threshold Tolerance Reset Threshold Temp. Coefficient V CC to Reset Delay Reset Active Timeout Period
T A =25°C T A =-55° to 125°C
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ZXCM209 ZXCM210
ELECTRICAL CHARACTERISTICS ZXCM209 TEST CONDITIONS (unless otherwise stated) V = full range, T = -55°C to +125°C
CC A
SYMBOL
PARAMETER
CONDITIONS
LIMITS MIN TYP MAX 0.3 0.3 0.4 0.8V cc
UNITS
V OL
Reset Output Voltage Low
V CC >1V, I OL =100µA (0 to 85°C) V CC >1.2V, I OL =200µA V TH >V CC >2.5V, I OL =2.7mA V CC >V TH max, I OH =1mA
V V V V
V OH
Reset Output Voltage High
ELECTRICAL CHARACTERISTICS ZXCM210 TEST CONDITIONS (unless otherwise stated) V = full range, T = -55°C to +125°C
CC A
SYMBOL
PARAMETER
CONDITIONS
LIMITS MIN TYP MAX 0.3 0.4 0.8V cc 0.8V cc
UNITS
V OL V OH
Reset Output Voltage Low Reset Output Voltage High
V CC >V TH max, I OL =2mA V CC >V TH max, I OL =2.7mA V CC >1.5V, I OH =150µA V CC >V TH >2.5V, I OH =1mA
V V V 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
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ZXCM209 ZXCM210
APPLICATIONS INFORMATION Negative going VCC transients
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.
Reset valid down to very low supply v.