PS121 Version : A.012 Issue Date : 2003/07/08 File Name : SP-PS121-A.012.doc Total Pages: 7 Voltage Detecting IC 新竹市科學園區展業一路 9 號 7 樓之 1 SILICON TOUCH TECHNOLOGY INC. 9-7F-1, Prosperity Road I, Science Based Industrial Park, Hsin-Chu, Taiwan 300, R.O.C. Fax：886-3-5645626 Tel：886-3-5645656 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 PS121 Voltage Detecting IC General Description PS121 is specially designed for +5V power good signal generating. Power good signal notifies microprocessor whether the +5V supply voltage is ready, therefore it can provide a stable and reliable power supply and computing environment. Delay circuit is also built-in to provide delay time by adding an external capacitor. Features 1. Power Good Logic to Check +5V 2. Adjustable delay time 3. 4-pin SIP package Block Diagram +5V INPUT 2 1.1K Id 23.6K 1 PG OUTPUT 10K 1.25 V 4 GND Voltage Detecting IC Vth_cd 3 DELAY CAPACITOR - 1 - Version：A.012 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 Function Diagram +5V INPUT VOLTAGE 4.3 4.3-Vhy t PG OUTPUT td td t Pin Descriptions Pin No PIN NAME 1 PG 2 +5V(VDD) 3 Cd 4 VSS Descriptions Power good output signal pin +5V(VDD) input pin External capacitor for PG delay Ground Absolute Maximum Ratings Parameter Supply Voltage Symbol VDD Output Sink Current Isink Output Voltage VPG Power Dissipation Pd Storage Temperature Tstg Operating Temperature Junction Temperature Package Thermal Resistance Voltage Detecting IC Topr Rating -0.5 ~ +7.5 V 30 -0.5 ~ mA +7.5 300 -40 -30 ~ ~ Tj 150 θ JA 160 - 2 - Unit V mW +125 o +90 o C C o C o C/W Version：A.012 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 Electrical characteristics, Vcc=5V, Ta = 25 oC. (unless otherwise specified) Parameter Test Condition MIN TYP MAX Unit Vth Detecting Threshold Voltage 4.05 4.30 4.55 V Vhy Vth Hysteresis Voltage 0.1 0.2 0.3 V IDD Circuit Current VCC=5V 0.97 2.5 mA Td Delay Time Cd=0.1µF 21.4 Id Constant Current at Cd Pin Vsat PG Output Saturation Voltage Vthcd Threshold Voltage in Pin Cd ΔT Temperature coefficient Voltage Detecting IC -8.0 V+5=4.0V, Isink=10mA 1.75 -8.7 -9.4 µA 0.128 0.192 V 1.85 1.95 V +1 - 3 - ms +2 mV/°C Version：A.012 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 Typical Application (1) For Forward Type S.P.S Secondary Side +5V OUTPUT X = or X +5V INPUT I2 Vpgi 2 Id Cd D1 3 N-PG 4 R1 1 PG GND (2) For Flyback Type S.P.S Secondary Side +5V OUTPUT X = or +5V INPUT X I2 2 Id Vpgi Cd D1 3 N-PG 4 R1 Voltage Detecting IC - 4 - 1 PG GND Version：A.012 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 Note1: Once AC power is turned on, Vpgi will be pulled high before +5V input. At this time, diode D1 will be turn off. The PG delay time is dependent on Cd as follows, C × Vth C d × 1.85 = Td −ON = 0.216 × C d ( pF ) µ sec, T = d 8.7 µ Id Note2: Diode D1 is connected to Vpgi to control the PG delay time when AC is off. The AC off delay time can be controlled as follows, V − Vth Td−OFF = +5 V × Cd I2 − I d Note3: Since the maximum threshold voltage at Pin 3(Cd) is 1.95V, the voltage across R1 has to be higher than 2V at normal operation. Note4: In PCB layout condition, when the input-pin(VDD) smaller than detecting threshold voltage(Vth), the power good signal of PS121 will connect to LOW, so the ground-pin(VSS) must connect to the most clean ground of the power supply system to avoid noise appear. Voltage Detecting IC - 5 - Version：A.012 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 Package Specification I (TO-93) (TO-93 4-pin) s D I θ2 N-PG 1 2 3 E θ1 A L1 4 L2 L3 b1 e1 e1 c e1 e 0 5 0.0 Symbol A b1 c D e e1 E I L1 L2 L3 s θ1 θ2 10 15 0.5 Dimension in mm Dimension in inch 3.65 ± 0.05 0.144 ± 0.002 0.38 ± 0.03 0.015 ± 0.001 0.35 ± 0.03 0.014 ± 0.001 5.17 ± 0.05 0.204 ± 0.002 7.62 ± 0.06 0.300 ± 0.002 2.54 ± 0.03 0.100 ± 0.001 1.50 ± 0.05 0.059 ± 0.002 4.04 ± 0.14 0.159 ± 0.006 2.00 ± 0.10 0.079 ± 0.004 1.00 ± 0.10 0.039 ± 0.004 ± 0.20 0.123 ± 0.008 3.3 ± 0.10 ± 0.004 1.23 0.048 (TYP) 5.0°° (TYP) 5.0°° 3.0°° (TYP) 3.0°° (TYP) Voltage Detecting IC 20 25 1.0 mm inch NOTE PINOUT: Pin1 PG Pin2 +5V / Vcc Pin3 Cd Pin4 Vss - 6 - Version：A.012 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 The products listed herein are designed for ordinary electronic applications, such as electrical appliances, audio-visual equipment, communications devices and so on. Hence, it is advisable that the devices should not be used in medical instruments, surgical implants, aerospace machinery, nuclear power control systems, disaster/crime-prevention equipment and the like. Misusing those products may directly or indirectly endanger human life, or cause injury and property loss. Silicon Touch Technology, Inc. will not take any responsibilities regarding the misusage of the products mentioned above. Anyone who purchases any products described herein with the above-mentioned intention or with such misused applications should accept full responsibility and indemnify. Silicon Touch Technology, Inc. and its distributors and all their officers and employees shall defend jointly and severally against any and all claims and litigation and all damages, cost and expenses associated with such intention and manipulation. Voltage Detecting IC - 7 - Version：A.012