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 ISSUE 3 - FEBRUARY 2001 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, T = -55°C to +125°C A 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 ISSUE 3 - FEBUARY 2001 2 ZXCM209 ZXCM210 ELECTRICAL CHARACTERISTICS ZXCM209 TEST CONDITIONS (unless otherwise stated) V = full range, T = -55°C to +125°C CC SYMBOL PARAMETER CONDITIONS A 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) V = full range, T = -55°C to +125°C CC SYMBOL PARAMETER CONDITIONS A 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 CC >V TH >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 ISSUE 3 - FEBRUARY 2001 3 ZXCM209 ZXCM210 TYPICAL CHARACTERISTICS ISSUE 3 - FEBUARY 2001 4 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 V CC 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 3 - FEBRUARY 2001 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 ISSUE 3 - FEBUARY 2001 6 ZXCM209 ZXCM210 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. ISSUE 3 - FEBRUARY 2001 7 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 Streitfeldstraße 19 D-81673 München 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 Zetex (Asia) Ltd. 3701-04 Metroplaza, Tower 1 Hing Fong Road, 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 2001 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 3 - FEBUARY 2001 8