ZXCM209

ZXCM209 ZETEX | Alldatasheet

Document overview

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Technical content

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 VERY LOW POWER MICROPROCESSOR RESET DEVICES APPLICATION CIRCUIT vcc ZXCM Reset Output Gnd vcc vcc Micro Reset Input Gnd

Terminal Voltage with respect to GND VCC -0.3V to 7.0V RESET, RESET -0.3V to (VCC + 0.3V) Input Current, VCC 20mA Output Current 20mA Rate of Rise, V CC 250V/µs Continuous Power Dissipation 500mW Operating Temperature Range -55°C to +125°C Storage Temperature Range -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 UNITS MIN TYP MAX VR VCC Range T A=0° to 70°C TA=-55° to 125°C 1.0 1.2 5.5 5.5 V V ICC Supply Current 2 5 µA VTH Reset Threshold Suffix L; T A=25°C 4.58 4.63 4.68 V Suffix M; T A=25°C 4.34 4.38 4.42 V Suffix J; T A=25°C 3.96 4.00 4.04 V Suffix T; T A=25°C 3.05 3.08 3.11 V Suffix S; T A=25°C 2.90 2.93 2.96 V Suffix R; T A=25°C 2.60 2.63 2.66 V VTHT Reset Threshold Tolerance TA=25°C TA=-55° to 125°C ∆ VTH/°C Reset Threshold Temp. Coefficient 50 ppm/°C VD VCC to Reset Delay 30 µs VTO Reset Active Timeout Period 140 560 ms ISSUE 3 - FEBUARY 2001

ELECTRICAL CHARACTERISTICS ZXCM209 TEST CONDITIONS (unless otherwise stated) VCC = full range, TA = -55°C to +125°C SYMBOL PARAMETER CONDITIONS LIMITS UNITS MIN TYP MAX VOL Reset Output Voltage Low VCC>1V, I OL=100µA (0 to 85°C) 0.3 V VCC>1.2V, I OL=200µA 0.3 V VTH>VCC>2.5V, I OL=2.7mA 0.4 V VOH Reset Output Voltage High VCC>VTHmax, 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 UNITS MIN TYP MAX VOL Reset Output Voltage Low VCC>VTHmax, I OL=2mA 0.3 V VCC>VTHmax, I OL=2.7mA 0.4 V VOH Reset Output Voltage High VCC>1.5V, I OH=150µA 0.8V cc V VCC>VTH>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

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 V CC pin will provide extra transient immunity. Reset valid down to very low supply voltages With V CC between 0V and 1V the output of the ZXCM209/210 may be in an undefined state. In many systems this is inconsequential as the 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 V CC < 1V. The resistor value is non critical: a value of 100k Ω is recommended. For the ZXCM209 the resistor should be applied between reset output and ground: for the ZXCM210 between reset output and V CC. Figure 1 shows the connection diagram for the ZXCM devices in these configurations. vcc ZXCM210 Reset Output Gnd vcc Micro Reset Input Gnd vcc 100kvcc ZXCM209 Reset Output Gnd vcc Micro Reset Input Gnd vcc 100k Figure 1 Circuit for operation of ZXCM with reset valid down to very low supply voltage.

4.7kΩ to other circuits 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. PIN DESCRIPTION Pin Number Pin Name Pin Function 1V CC Supply voltage (+5, +3.3, +3 volts)

2 RESET

(ZXCM209) RESET (ZXCM210) Output remains low while Vcc is below the reset threshold, and for a minimum 140ms after V CC rises above the reset threshold. Output remains high while V CC is below the reset threshold, and for a minimum 140ms after V CC rises above the reset threshold.

3 Gnd Ground

Interfacing to µP’s with bidirectional reset I/O.

ORDERING INFORMATION

PART NUMBER TEMPERATURE RANGE PACKAGE RESET OUTPUT ZXCM209xF -55 to 125°C SOT23 LOW ZXCM210LF -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 The only Reset High variant currently available is the ZXCM210LF. Contact your local Zetex Office for more details.

N PACKAGE DIMENSIONS PAD LAYOUT DETAILS 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 0.021 F 0.085 0.15 0.0033 0.0059 G NOM 1.9 NOM 0.075 K 0.01 0.10 0.0004 0.004 L 2.10 2.50 0.0825 0.0985 N NOM 0.95 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 Zetex Inc. Zetex (Asia) Ltd. These are supported by Streitfeldstraße 19 47 Mall Drive, Unit 4 3701-04 Metroplaza, Tower 1 agents and distributors in D-81673 München Commack NY 11725 Hing Fong Road, major countries world-wide Germany USA Kwai Fong, Hong Kong © Zetex plc 2001 Telefon: (49) 89 45 49 49 0 Telephone: (631) 543-7100 Telephone:(852) 26100 611 Fax: (49) 89 45 49 49 49 Fax: (631) 864-7630 Fax: (852) 24250 494 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.