s-8426a Seiko Instruments Inc., s-8426a Datasheet
s-8426a
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s-8426a Summary of contents
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... Package Name 8-Pin TSSOP 8-Pin SOP(JEDEC) The S-8426A Series is a CMOS IC designed for use in the switching circuits of primary and backup power supplies on a single chip. It consists of two voltage regulators, three voltage detectors, a power supply switch and its controller, as well as other functions. ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series Block Diagram VIN CS Voltage CS detector 2 VOUT REG2 V sw1 Detector V SW2 Detector Switch controller VSS Figure 1 Seiko Instruments Inc. M1 PREEND Voltage detector RESET Voltage detector REG1 Rev.1.0 _00 VBAT PREEND RESET VRO ...
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... DET1 ) − 0.8} ÷ 372 DET1 SW1 × 0.77 DET1 , +V × 0. × 0.77 DET4 DET4 Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series RESET PREEND PREEND Voltage Voltage Voltage − DET3 DET3 DET2 DET2 3.068 2.100 2 ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series Pin Configurations 8-Pin TSSOP Top view Figure 2 8-Pin SOP(JEDEC) Top view Figure 3 4 Pin No. Symbol 1 VSS 8 2 PREEND 7 3 VBAT RESET 6 VOUT 7 VIN 8 VRO *1. Mount capacitors between VSS (GND pin) and the VIN, VBAT, VOUT, and VRO pins. (Refer to the “ ...
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... T stg 1200 1000 800 8-Pin SOP(JEDEC) 8-Pin TSSOP 600 400 200 100 Ambient Temperature (Ta) [°C] Seiko Instruments Inc. S-8426A Series (Unless otherwise specified °C) Absolute Maximum Tatings −0 + −0 + −0 +0 − ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series Electrical Characteristics 1. S-8426AAA Item Output voltage 1 Dropout voltage 1 Load stability 1 Input stability 1 Output voltage temperature coefficient 1 Output voltage 2 Dropout voltage 2 Load stability 2 Input stability 2 Output voltage temperature coefficient 2 Primary power input voltage V CS detection voltage CS release voltage ...
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... V, no load BAT1 IN BAT V = Open BAT2 load BAT − V BAT with the following equation. DET1 ) − 0.8} ÷ 372 Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series Min. Typ. Max DET4 DET4 DET4 × 0.75 × 0.77 × 0. OUT OUT OUT × ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series Test Circuits VIN VRO or VOUT V IN VSS Figure 5 Test Circuit 1 VBAT VOUT VIN PREEND V IN VSS RESET Figure 7 Test Circuit 3 VOUT VIN F.G. VSS CS VBAT V BAT Figure 9 Test Circuit 5 VIN VBAT VSS BAT Leave open and measure the value after applying VIN ...
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... The functions and operations of the above-listed elements are described below. 1. Voltage Regulators The S-8426A Series features on-chip voltage regulators with a small dropout voltage. The voltage of the VRO and VOUT pins (the output pins of the voltage regulator) can separately be selected for the output voltage in 0.1 V steps between the range of 2 ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series 2. 2 PREEND Voltage Detector The PREEND voltage detector monitors input voltage (V selected in the range of 1 0.1 V step. By using this function, IC notifies if the backup battery is scarce. The result of detection is output at the PREEND pin: “Low” for lower voltages than the detection level and “ ...
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... IN ) reaches more than the CS release voltage (+V IN Voltage Regulator 2 Switch Transistor M1 ON OFF Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series and sends the results of detection to the switch IN which is calculated with the DET4 ). DET1 voltage due to an undershoot. )) sequence: a special BAT ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series 3. 4 Switch Transistor M1 Voltage regulator 2 is also used to switch from VIN pin to VOUT pin. Therefore, no reverse current flows from VOUT pin to VIN pin when voltage regulator 2 is OFF. The output voltage of voltage regulator 2 can be selected from between 2.3 V and 5 0.1 V steps. ...
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... Rev.1.0 _00 Timing Chart (V) OUT V (V) BAT V ( (V) PREEND V (V) RESET Remark CS, PREEND and RESET are pulled BATTERY BACKUP SWITCHING IC . Y-axis is an arbitrary scale. OUT Figure 16 Operation Timing Chart Seiko Instruments Inc. S-8426A Series 13 ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series Standard Circuit + µF Be sure to add a 10 µF or more capacitor to the VOUT and VRO pins. Caution 1. 2. The above connections and values will not guarantee correct operation. Before setting these values, perform sufficient evaluation on the application to be actually used. ...
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... RESET Main CPU + 10 µF VOUT 100 kΩ VIN + S-8426A CS Series VBAT PREEND RESET VRO + VSS 100 kΩ INT Address data Figure 18 Application Circuit 1 Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series in the primary CPU PREEND 100 kΩ VCC CS Timer microcontroller RESET 15 ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series 2. When Using Secondary Battery as Backup Battery + 10 µ 0.1 µF Remark The backup battery can be floating-recharged by using voltage regulator 1. 3. Memory Card V IN 100 kΩ 100 kΩ BDT2 BDT1 CS Caution The above connections and values will not guarantee correct operation. Before setting these values, perform sufficient evaluation on the application to be actually used ...
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... Fast amplifier Overshoot Undershoot P.G. VRO pin mA ° OUT Input Voltage Output Voltage Figure 24 Ringing Waveform of Power Supply Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series VIN VOUT S-8426A Series VSS C OUT Figure 22 Test Circuit = 22 µ mA ° ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series 1. 2 Power supply variation and 10 V square waves 10 V Input voltage 6 V Output Overshoot voltage Figure 25 Power Supply Variation and 10 V Square Waves VOUT pin Input Voltage V/div) Output Voltage (50 mV/div) Figure 27 Ringing Waveform of Power Supply Variation (VOUT Pin) ...
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... ° (mA) OUT (b) VRO pin = 6↔ ° (µF) OUT Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series ), load capacitance (C ), input variation width OUT ), and temperature (Ta µ 6↔ ° 0.25 0.20 0.15 0.10 0.05 0. ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series (3) ∆V Dependency IN ∆V shows the difference between the low voltage fixed and the high voltage. IN For example, ∆ means the difference between 6 V and (a) VOUT pin mA, C OUT 0.30 0.25 0.20 0.15 0.10 0.05 0. Figure 33 (4) Temperature Dependency ...
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... Figure 40 Ringing Waveform due to Load Variation (VRO Pin) Overshoot Undershoot 10 µA t (500 ms/div) 10 µA t (20 ms/div) Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series VIN VOUT S-8426A Series VSS C OUT Figure 38 Test Circuit = 22 µ ° 6 OUT µA t (50 µ ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series 2. 2 Reference data: Dependency of input voltage (V (∆I ), and temperature (Ta) OUT (1) V Dependency IN (a) VOUT pin = 22 µ ↔ 10 µ °C C OUT OUT 0.12 0.10 0.08 0.06 0.04 0.02 0.00 4 Figure 41 (2) C Dependency OUT (a) VOUT pin = 50 mA ↔ 10 µ ° 6 OUT 0 ...
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... VRO pin = 6 ° ∆I (mA) OUT (b) VRO pin = 22 µ F OUT 0 50 100 Ta ( ° C) Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series = 22 µ 6 ° 0.12 0.10 0.08 0.06 0.04 0.02 0. ∆I (mA) RO Figure ↔ ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series Characteristics (Typical Data) 1. Voltage Regulator Unit ( Input Voltage (V ) vs. Output Voltage ( °C 5.2 5.0 4.8 4.6 4.4 4.2 4.0 4.0 5.0 ( −40 °C 5.2 5.0 4.8 4.6 4.4 4.2 4.0 4.0 5 Input Voltage (V ) vs. Output Voltage ( °C 5.2 5.0 4.8 4.6 4.4 4.2 4.0 4.0 5.0 ( −40 °C 5.2 5.0 4.8 4.6 4.4 4.2 4.0 4 OUT ) Characteristics (REG1 °C ...
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... Output voltage (V voltage when ° [° Input Stability ( [°C] Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series ) vs. Dropout Voltage (V OUT drop2 1.0 0 °C 0 °C 0 −40 °C 0 0.02 0.04 I [A] OUT ) vs. Output Voltage (V ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series 1. 11 Load Stability (V ) Temperature Characteristics −25 − Voltage Detector Voltage Detector (−V (1) Detection voltage (−V DET1 Based − −10 −20 −40 −25 0 (3) Output current (I ) temperature characteristics SINK ...
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... DET3 (2) Output current (I ) voltage when ° C DET3 [° BAT [°C] Seiko Instruments Inc. BATTERY BACKUP SWITCHING IC S-8426A Series ) characteristics SINK ° 1.0 2 characteristics SINK °C ...
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... BATTERY BACKUP SWITCHING IC S-8426A Series 3. Switch Unit 3. 1 Switch Voltage (V ) Temperature Characteristics SW1 Based −10 −20 −25 − Input Voltage (V ) vs. VBAT Switch Resistance (R BAT Switch Leakage Current (I BAT − ...
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... Use of the information described herein for other purposes and/or reproduction or copying without the express permission of Seiko Instruments Inc. is strictly prohibited. The products described herein cannot be used as part of any device or equipment affecting the human body, such as exercise equipment, medical equipment, security systems, gas equipment, or any apparatus installed in airplanes and other vehicles, without prior written permission of Seiko Instruments Inc ...