SSR811 SMC | Alldatasheet
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 10
Technical content
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Description: SSR811/SSR812 are low-power microprocessor ( μP) supervisory circuits used to monitor power supplies in μP and digital systems. They provide applications with benefits of circuit reliability and low cost by eliminating external components. SSR811/SSR812 also offer a manual reset input. These devices perform as valid singles in applications with Vcc ranging from 6.0V down to 0.9V. The reset signal lasts for a minimum period of 140ms whenever VCC supply voltage falls below preset threshold. Both SSR811 and SSR812 were designed with a reset comparator to help identify invalid signals, which last less than 140ms. The only difference between them is that they have an active-low RESET output and active-high RESET output, respectively. Low supply current (1 μA) makes SSR811/SSR812 ideal for portable equipment. The devices are available in SOT-23-5 package. Features:
- Ultra Low Supply Current 1μA(typ.)
- Guaranteed Reset Valid to Vcc=0.9V
- Available in two Output Types: Push-Pull Active Low (SSR811), Push-Pull Active High (SSR812)
- 140ms Min. Power-On Reset Pulse Width
- Tight Voltage Threshold Tolerance: 1.5%
- Low Profile Package: SOT-23-5. Applications:
- Notebook Computers
- Digital Still Cameras
- PDAs
- Critical Microprocessor Monitoring Typical application circuit:
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Ordering Information: SSR811 -XXXXX SSR812 -XXXXX Marking Diagram: PIN CONFIGURATION SOT-23-5 TOP VIEW 1: GND 2: NC 3: RESET (RESET) 4: MR ——— 5: VCC Part No. Marking SSR811-26DTR BQ26G SSR811-29DTR BQ29G SSR811-31DTR BQ31G SSR811-44DTR BQ44G SSR811-46DTR BQ46G SSR812-23DTR BR23G SSR812-26DTR BR26G SSR812-29DTR BR29G SSR812-31DTR BR31G SSR812-40DTR BR40G SSR812-44DTR BR44G SSR812-46DTR BR46G PACKING TYPE TB: TUBE TR: TAPING & REEL PACKAGING TYPE D: SOT-23-5 RESET THRESHOLD VOLTAGE 23: 2.3V 26: 2.6V 27: 2.7V 29: 2.9V 31: 3.1V 40: 4.0V 44: 4.4V 46: 4.6V
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Absolute Maximum Ratings: RESET, R ESE T Input Current (VCC, MR ——— Output Current (RESET or R E SET Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Test Circuit
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Electrical Characteristics (Typical values are at TA=25°C, unless otherwise specified.) (Note 1) Note: 1. Specifications are production tested at TA=25°C. Specifications over the -40°C to 85°C operating temperature range are assured by design, characterization and correlation with Statistical Quality Controls (SQC). 2. RESET output is for SSR811; RESET output is for SSR812.
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Typical Performance Characteristics
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Block Diagram Pin Descriptions GND Pin : Ground. RESET Pin (SSR811) : Active low output pin. RESET Output remains low while Vcc is below the reset threshold. RESET Pin (SSR812) : Active high output pin. RESET output remains high while Vcc is below the reset threshold. MR ——— Pin : Logic low manual reset input. This active-low input has an internal 20k Ω pull-up resistor. It can be driven by a TTL or CMOS, or shorted to ground with a switch. Leave open when unused. Vcc Pin : Supply voltage.
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Detail Descriptions of Technical Terms RESET OUTPUT μP will be activated at a valid reset state. These μP supervisory circuits assert reset to prevent code execution errors during power-up, power-down, or brownout conditions. RESET is guaranteed to be a logic low for V TH >VCC>0.9V. Once VCC exceeds the reset threshold, an internal timer keeps RESET low for the reset timeout period; after this interval, RESET goes high. If a brownout condition occurs (VCC drops below the reset threshold), RESET goes low. Any time VCC goes below the reset threshold, the internal timer resets to zero, and RESET goes low. The internal timer is activated after VCC returns above the reset threshold, and RESET remains low for the reset timeout period. The manual reset input (MR ——— ) can also initiate a reset. SSR812 has an active-high RESET output that is the inverse of SSR811’s RESET output. MANUAL RESET INPUT Many μP-based products require manual reset capability, allowing operators, test technicians, or external logic circuitry to initiate a reset. Logic low on MR ——— asserts reset. Reset will remain asserted for the Reset Active Timeout Period (t RP ) after MR ——— returns high. This input has an internal 20K Ω pull-up resistor, so it can be floating if it is not used. MR ——— can be driven with TTL or CMOS-logic levels, or with open-drain/collector outputs. Another alternative is to connect a normal switch from MR ——— to GND to create a manual reset function. Connecting a 0.1μF capacitor from MR ——— to ground can provide noise immunity to prevent noise caused by long cables of MR ——— or noisy environment. BENEFITS OF HIGHLY ACCURATE RESET THRESHOLD SSR811/SSR812 with specified voltage as 5V±10% or 3V±10% are ideal for systems using a 5V±5% or 3V±5% power supply. The reset is guaranteed to assert after the power supply falls out of regulation, but before power drops below the minimum specified operating voltage range of the system ICs. The pre-trimmed thresholds are reducing the range over which an undesirable reset may occur.
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812
Application Information
NEGATIVE-GOING VCC TRANSIENTS In addition to issuing a reset to the μP during power-up, power-down, and brownout conditions, SSR811 series are relatively resistant to short-duration negative-going VCC transient. ENSURING A VALID RESET OUTPUT DOWN TO VCC=0 When VCC falls below 0.9V, SSR811 RESET output no longer sinks current; it becomes an open circuit. In this case, high-impedance CMOS logic inputs connecting to RESET can drift to undetermined voltages. Therefore, SSR811/SSR812 with CMOS is perfect for most applications of VCC below 0.9V. However in applications where RESET must be valid down to 0V, addi ng a pull-down resi stor to RESET causes any leakage currents to flow to ground, holding RESET low. INTERFACING TO μP WITH BIDIRECTIONAL RESET PINS μPs with bidirectional reset pins can contend with SSR811/812 reset outputs. If SSR811 RESET output is asserted high and the μP wants to pull it low, indeterminate logic levels may occur. To correct such cases, connect a resistor between SSR811 RESET (or SSR812 RESET ) output and the μP reset I/O. Buffer the reset output to other system components.
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Physical Dimensions SOT-23-5 (unit: mm) Note : 1. Refer to JEDEC MO-178AA. 2. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 10 mil per side. 3. Dimension "E1" does not include inter-lead flash or protrusions. 4. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact.
Technical Data Reset Circuits with Manual Reset Input Data Sheet N1594 Rev. -
- China - Germany - Korea - Singapore - United States •
- http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 DISCLAIMER: 1- The information given herein, including the specifications and dimensions, is subject to change without prior notice to improve product characteristics. Before ordering, purchasers are advised to contact the SMC - Sangdest Microelectronics (Nanjing) Co., Ltd sales department for the latest version of the datasheet(s). 2- In cases where extremely high reliability is required (such as use in nuclear power control, aerospace and aviation, traffic equipment, medical equipment , and safety equipment) , safety should be ensured by using semiconductor devices that feature assured safety or by means of users’ fail-safe precautions or other arrangement . 3- In no event shall SMC - Sangdest Microelectronics (Nanjing) Co., Ltd be liable for any damages that may result from an accident or any other cause during operation of the user’s units according to the datasheet(s). SMC - Sangdest Microelectronics (Nanjing) Co., Ltd assumes no responsibility for any intellectual property claims or any other problems that may result from applications of information, products or circuits described in the datasheets. 4- In no event shall SMC - Sangdest Microelectronics (Nanjing) Co., Ltd be liable for any failure in a semiconductor device or any secondary damage resulting from use at a value exceeding the absolute maximum rating. 5- No license is granted by the datasheet(s) under any patents or other rights of any third party or SMC - Sangdest Microelectronics (Nanjing) Co., Ltd. 6- The datasheet(s) may not be reproduced or duplicated, in any form, in whole or part, without the expressed written permission of SMC - Sangdest Microelectronics (Nanjing) Co., Ltd. 7- The products (technologies) described in the datasheet(s) are not to be provided to any party whose purpose in their application will hinder maintenance of international peace and safety nor are they to be applied to that purpose by their direct purchasers or any third party. When exporting these products (technologies), the necessary procedures are to be taken in accordance with related laws and regulations..