AS1901

AS1901, AS1902, AS1903 Ultra Low-Power µP Supervisory Circuit D a ta S he e t 1 General Description The AS1901/2/3 family is an ultra low-power supervisory circuit device. The device can be used to monitor the supply voltage of digital systems and microprocessors and initiate a reset when the voltage goes below a predefined threshold. The duration of the reset is 5/20/100/500ms (typ.) after the supply voltage has risen above the threshold. The AS1901/2/3 exhibit excellent reliability and can reduce application costs by eliminating all external components. The device is available with different output drivers: ! 2 Key Features ! ! Low 230nA (typ) Supply Current Precision Monitoring of 2.5-, 3-, and 3.3V-Power Supplies Supply Voltage Range: 1.0 to 3.6V Reset Threshold Range: 2.2 to 3.1V Available in 3 Versions: - AS1901 Push Pull RESETN - AS1902 Push Pull RESET - AS1903 Open Drain RESETN ! ! ! The AS1901 has a push-pull driver with an active low reset. The AS1902 uses the same output stage as the AS1901, but has an active high reset. The AS1903 has an open drain output with active low reset. ! ! ! ! 4 Time-Out Periods Ranging from 5 to 500ms Detection Voltage Accuracy: ±1.5% Temperature Range: -40 to +85°C Package: SOT23-3 ! ! All devices operate down to a voltage of 1V. The reset thresholds are factory-trimmable between 2.2V and 3.08V in steps of approximately 100mV. Each device of the AS1901/2/3 family is offered with four time-out periods of 5/20/100/500ms. The extremely low current consumption of only 230nA (typ) at 3.3V makes the device ideal for use in portable applications. All devices are available in a 3-pin SOT23 package. 3 Applications The devices are ideal for computers, intelligent instruments, controllers, critical microprocessor and microcontroller, power monitoring and portable/batterypowered equipment. Figure 1. Functional Block Diagrams VCC 3 VDD VCC VCC 3 VDD VCC AS1901 AS1902 RESETN, RESET GND 1 2 Microprocessor AS1903 2 Microprocessor RESET RESETN RESET I/O GND GND 1 GND www.austriamicrosystems.com Revision 1.51 1-9 AS1901, AS1902, AS1903 Data Sheet - P i n o u t 4 Pinout Pin Assignments Figure 2. Pin Assignments (Top View) Top View GND 1 AS1901 AS1902 AS1903 3 VDD RESETN, RESET 2 SOT23-3 Pin Descriptions Table 1. Pin Descriptions Pin Number AS1901/AS1903 1 2 AS1902 1 Pin Name GND RESETN Description Ground Active-low reset output. RESETN remains low while VDD is below the reset threshold and for tTP after VDD rises above the reset threshold. RESETN is open-drain on the AS1903 and push-pull on the AS1901. Active-high reset output. RESET remains high while VDD is below the reset threshold and for tTP after VDD rises above the reset threshold. Supply voltage. 3 2 3 RESET VDD www.austriamicrosystems.com Revision 1.51 2-9 AS1901, AS1902, AS1903 Data Sheet - A b s o l u t e M a x i m u m R a t i n g s 5 Absolute Maximum Ratings Stresses beyond those listed in Table 2 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 Section 6 Electrical Characteristics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2. Absolute Maximum Ratings (TA = 25°C Unless Otherwise Noted) Parameter Limits Unit VDD to GND RESET/RESETN to GND Input Current (VDD) Output Current (RESET, RESETN) Rate of Rise (VDD) Operating Temperature Range (TA) Storage Temperature Range -0.3 to +5 -0.3 to VDD + 0.3 20 20 100 -40 to +85 -65 to +150 V V mA mA V/µs °C °C The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD-020C “Moisture/Reflow Sensitivity Classification for non-hermetic Solid State Surface Mount Devices” Notes Package-Body Peak Temperature +260 °C www.austriamicrosystems.com Revision 1.51 3-9 AS1901, AS1902, AS1903 Data Sheet - E l e c t r i c a l C h a r a c t e r i s t i c s 6 Electrical Characteristics VDD = Full Range; TA = -40 to +85ºC; Unless Otherwise Specified Table 3. Electrical Characteristics Parameter VDD Range Supply Current (AS1901/2/3) Reset Threshold Voltage1 VDD to Reset Delay2 Reset Active Time-Out Period3 Symbol VDD IDD VTH TA = -40 to +85°C tRD tTP ISINK = 1.2mA, VDD = 2.1V, Reset Asserted ISINK = 400µA, VDD = 1.2V, Reset Asserted ISOURCE = 1.2mA, VDD = 3.2V ISOURCE = 500µA, VDD = 2.1V, Reset Asserted ISOURCE = 100µA, VDD = 1.2V, Reset Asserted ISINK = 1.2mA, VDD = 3.2V, Reset Not Asserted 10 0.1 0.8 x VDD 0.8 x VDD 0.8 x VDD 0.4 VDD = VTH to (VTH - 100mV) tTP 40% Conditions TA = 0 to +70°C TA = -40 to +85°C VDD = 3.3V, No Load TA = +25°C VTH 1.5% VTH 2.5% Min 1.0 1.2 230 VTH VTH 20 tTP Typ Max 3.6 3.6 430 VTH + 1.5% VTH + 2.5% 50 tTP + 60% 0.4 0.4 Unit V nA V µs ms V V V V V V mV µA RESETN Output Voltage (AS1901/3) VOL RESETN Output Voltage (AS1901) VOH VOH RESET Output Voltage (AS1902) VOL RESET Threshold Hysteresis Open-Drain RESETN Output Leakage Current (AS1903) Notes: 1 2 VHYST ILEAK See Table 6, “Coding of Factory-Trimmed Reset Threshold Voltages,” on page 6. Guaranteed by design. Table 4, “Coding of Factory-trimmed Reset Active Time-Out Period,” on page 6. 3 See www.austriamicrosystems.com Revision 1.51 4-9 AS1901, AS1902, AS1903 Data Sheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s 7 Typical Operating Characteristics Figure 3. Supply Current vs. Temperature 0.5 Figure 4. Power Down Reset Delay vs. Temp. 200 175 VOD = 10mV . . Reset Delay (µs) 0.4 Supply Current (mA) 150 125 100 75 50 25 0.3 0.2 0.1 0 -40 -15 10 35 60 85 0 -40 -15 10 35 60 85 Temperature(°C) Temperature(°C) Figure 5. Power-Up Reset Timeout vs. Temperature . 200 Figure 6. Max. Trans. Duration vs. Reset Th. Overdrive 200 . Power-Up Reset Timeout (ms) Max. Transient Duration (µs) 175 150 125 100 75 50 25 0 -40 175 150 125 100 75 50 25 0 -15 10 35 60 85 1 10 100 1000 Temperature(°C) Reset Th. Overdrive VTH-VCC (mV) www.austriamicrosystems.com Revision 1.51 5-9 AS1901, AS1902, AS1903 Data Sheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description Interfacing to Microprocessors with Bi-Directional Reset Pins The device has an open drain RESETN output, which enables easy interfacing to microprocessors (µP) with bi-directional reset pins, such as the Motorola 68HC11. The RESETN pin of the microcontroller (µC) can be connected directly to the µP supervisor's RESETN output with a single pull-up resistor (see Figure 1 on page 1). Negative-Going VDD Transients The device is optimized to ignore short-duration, negative-going VDD transients (glitches) in order to avoid incorrect resets. In the graph Maximum Transient Duration vs. Reset Threshold Overdrive (page 6), the conditions are shown, for which the reset pulses are not generated. In the graph the maximum pulse width that a negative VDD transient may have when a reset signal is generated. As the amplitude of the transient increases, the maximum allowable pulse width decreases. Options Table 4. Coding of Factory-trimmed Reset Active Time-Out Period Device AS190x_xx AS190x_xx AS190x_xx AS190x_xx Table 5. Output Variants Device AS1901xxx AS1902xxx AS1903xxx Output Functionality Active Low (RESETN) Active High (RESET) Open Drain (RESETN) Suffix A B C D tTP in Milliseconds Min 3 12 60 300 Typ 5 20 100 500 Max 8 32 160 800 Table 6. Coding of Factory-Trimmed Reset Threshold Voltages Reset Threshold Voltage, VTH in V Device AS190xx__ AS190xx__ AS190xx__ AS190xx__ AS190xx__ AS190xx__ AS190xx__ AS190xx__ AS190xx__ AS190xx__ Suffix Min 22 23 24 25 26 27 28 29 30 31 2.167 2.285 2.364 2.463 2.591 2.660 2.758 2.886 2.955 3.034 TA = +25°C Typ 2.2 2.32 2.4 2.5 2.63 2.7 2.8 2.93 3.0 3.08 Max 2.233 2.355 2.436 2.538 2.669 2.741 2.842 2.974 3.045 3.126 TA = -40 to +85°C Min 2.145 2.262 2.340 2.438 2.564 2.633 2.730 2.857 2.925 3.003 Max 2.255 2.378 2.460 2.563 2.696 2.768 2.870 3.003 3.075 3.157 www.austriamicrosystems.com Revision 1.51 6-9 AS1901, AS1902, AS1903 Data Sheet - P a c k a g e D r a w i n g s a n d M a r k i n g s 9 Package Drawings and Markings The device is available in a 3-pin SOT-23 package. Figure 7. 3-Pin SOT-23 Package. www.austriamicrosystems.com Revision 1.51 7-9 AS1901, AS1902, AS1903 Data Sheet - O r d e r i n g I n f o r m a t i o n 10 Ordering Information The device is available in the following standard versions. Standard Part AS1901C23 AS1901C26 AS1901C31 AS1902C23 AS1902C26 AS1902C31 AS1903C23 AS1903C26 AS1903C31 Threshold 2.32 2.63 3.08 2.32 2.63 3.08 2.32 2.63 3.08 Duration 100ms 100ms 100ms 100ms 100ms 100ms 100ms 100ms 100ms Marking ASBA ASBD ASBI ASBK ASBN ASBS ASBU ASBX ASB3 Non-standard versions require a minimum order of 30,000 units. Contact austriamicrosystems for availability of nonstandard versions. www.austriamicrosystems.com Revision 1.51 8-9 AS1901, AS1902, AS1903 Data Sheet Copyrights Copyright © 1997-2007, austriamicrosystems AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies. Disclaimer Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or lifesustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. Contact Information Headquarters austriamicrosystems AG A-8141 Schloss Premstaetten, Austria Tel: +43 (0) 3136 500 0 Fax: +43 (0) 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: http://www.austriamicrosystems.com/contact www.austriamicrosystems.com Revision 1.51 9-9