SSR811/SSR812 Technical Data Data Sheet N1594 Rev. - Reset Circuits with Manual Reset Input 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 ———————— R E S E T output and active-high RESET output, respectively. Low supply current (1μA) 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 Internally Fixed Threshold 2.3V, 2.6V, 2.7V, 2.9V, 3.1V, 4.0V, 4.4V, and 4.6V 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: • China - Germany - Korea - Singapore - United States • • http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Reset Circuits with Manual Reset Input Technical Data Data Sheet N1594 Rev. - Ordering Information: PIN CONFIGURATION SSR811 -XXXXX SSR812 -XXXXX SOT-23-5 PACKING TYPE TB: TUBE TR: TAPING & REEL TOP VIEW 1: GND 2: NC ———————— 3: R E S E T (RESET) ——— PACKAGING TYPE D: SOT-23-5 4: MR 5: VCC 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 Marking Diagram: Part No. Marking SSR811-26DTR SSR811-29DTR SSR811-31DTR SSR811-44DTR SSR811-46DTR SSR812-23DTR SSR812-26DTR SSR812-29DTR SSR812-31DTR SSR812-40DTR SSR812-44DTR SSR812-46DTR BQ26G BQ29G BQ31G BQ44G BQ46G BR23G BR26G BR29G BR31G BR40G BR44G BR46G • China - Germany - Korea - Singapore - United States • • http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Reset Circuits with Manual Reset Input Technical Data Data Sheet N1594 Rev. - Absolute Maximum Ratings: VCC ………..................…………………………………………………………………………….-0.3V~6.5V ———————— RESET, R E S E T ………………………...............……………………………………-0.3V ~ (VCC+0.3V) ——— Input Current (VCC, MR)………………………………………………………………….................. 20mA ———————— Output Current (RESET or R E S E T )………………………...............……………………………20mA Continuous Power Dissipation (TA = +70°C) ...……………………………………………….. 320mW Operating Junction Temperature Range ...………………………………………….… –40°C to 85°C Junction Temperature ………………………………………………………………………………..125°C Storage Temperature Range ……………………………………………………………..–65°C ~ 150°C Lead Temperature (Soldering) 10 sec. ……………………………………………………………260°C Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Test Circuit • China - Germany - Korea - Singapore - United States • • http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Technical Data Data Sheet N1594 Rev. - Reset Circuits with Manual Reset Input 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. R E S E T output is for SSR811; RESET output is for SSR812. • China - Germany - Korea - Singapore - United States • • http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Technical Data Data Sheet N1594 Rev. - Reset Circuits with Manual Reset Input Typical Performance Characteristics • China - Germany - Korea - Singapore - United States • • http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Reset Circuits with Manual Reset Input Technical Data Data Sheet N1594 Rev. - 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 20kΩ pull-up Vcc Pin resistor. It can be driven by a TTL or CMOS, or shorted to ground with a switch. Leave open when unused. : Supply voltage. • China - Germany - Korea - Singapore - United States • • http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Reset Circuits with Manual Reset Input Technical Data Data Sheet N1594 Rev. - 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 >VCC>0.9V. Once VCC exceeds the reset threshold, an TH ——————— ——————— 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 ) after MR returns high. This input has an internal 20KΩ pull-up resistor, so it can be RP ——— 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. • China - Germany - Korea - Singapore - United States • • http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Reset Circuits with Manual Reset Input Technical Data Data Sheet N1594 Rev. - 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, adding a pull-down resistor 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. • China - Germany - Korea - Singapore - United States • • http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Technical Data Data Sheet N1594 Rev. - Reset Circuits with Manual Reset Input 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. • China - Germany - Korea - Singapore - United States • • http://www.smc-diodes.com - sales@ smc-diodes.com • SSR811/SSR812 Technical Data Data Sheet N1594 Rev. - Reset Circuits with Manual Reset Input 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). 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