PS121

PS121 Version : A.017 Issue Date : 2008/11/04 File Name : SP-PS121-A.017.DOC Total Pages: 9 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. Tel：886-3-5645656 Fax：886-3-5645626 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 23.6K Id 10K 1 PG OUTPUT 10K 1.25 V Vth_cd 4 GND 3 DELAY CAPACITOR Voltage Detecting IC -1 - Version：A.017 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 PG OUTPUT td td t t Pin Descriptions TO-93 Pin No 1 2 3 4 PIN NAME PG +5V(VDD) Cd VSS +5V(VDD) input pin External capacitor for PG delay Ground Descriptions Power good output signal pin SOT-26 Pin No 1 2 3 4 5 6 PIN NAME NC VSS PG +5V(VDD) Cd NC NO connect Ground Power good output signal pin +5V(VDD) input pin External capacitor for PG delay NO connect Descriptions Voltage Detecting IC -2 - Version：A.017 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 Absolute Maximum Ratings Parameter Supply Voltage Output Sink Current Output Voltage Power Dissipation Storage Temperature Operating Temperature Junction Temperature Package Thermal Resistance Symbol VDD Isink VPG Pd Tstg Topr Tj -40 -30 -0.5 -0.5 Rating ~ 30 ~ 300 ~ ~ 150 160 o Unit +7.5 V mA +7.5 +125 +90 V mW o o o C C C θ JA C/W Electrical characteristics, Vcc=5V, Ta = 25 oC. (unless otherwise specified) Parameter Vth Vhy IDD Td Id Vsat Vthcd Detecting Threshold Voltage Vth Hysteresis Voltage Circuit Current Delay Time Constant Current at Cd Pin PG Output Saturation Voltage Threshold Voltage in Pin Cd Temperature coefficient V+5=4.0V, Isink=10mA VDD = 0 VDD = 5 5 0 1.79 1.72 VCC=5V Cd=0.1μF 8.0 Test Condition MIN 4.05 0.1 TYP 4.30 0.2 0.97 21.4 8.7 0.128 1.87 1.77 +1 9.4 0.192 1.95 1.82 +2 MAX 4.55 0.3 2.5 Unit V V mA ms μA V V mV/°C ΔT Voltage Detecting IC -3 - Version：A.017 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 Rx X1 = or X2 = Vz=6V or C>0.01uF X1 Vpgi D1 Cx R1 I2 Id Cd 3 2 +5V INPUT N-PG 4 1 PG GND X2 (2) For Flyback Type S.P.S Secondary Side +5V OUTPUT Rx X1 = or X2 = Vz=6V or C>0.01uF X1 Vpgi D1 Cx R1 I2 Id Cd 3 2 +5V INPUT N-PG 4 1 PG GND X2 Voltage Detecting IC -4 - Version：A.017 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 × Vthcd Cd × 1.85 = Td −ON = 0.216 × Cd ( pF ) μ sec, ⎜ T = d ⎜ 8 .7 μ I d −ON ⎝ ⎞ ⎟ ⎟ ⎠ 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, Td −OFF ≒ Cd × Vthcd Cd × Vthcd C d × Vthcd C d × 1.85 = = = 1 1 I2 − Id I d −OFF × (VCd + Vthcd ) × (VCd + 1.85) 2 2 R1 R1 1 Among Td −OFF equation, the × (VCd + Vthcd ) is discharged average current. 2 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. Note5: Suggested using RC filter circuit (Rx and Cx) to decrease ripples. Note6: Suggested using component X1 and R1 to cut down Vpgi voltage. Note7: Suggested using component X2 to avoid overshoot voltage damages IC. Voltage Detecting IC -5 - Version：A.017 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 Package Specification (SOT-26) Symbol A A1 A2 b c D e e1 E1 L L1 L2 R R1 θ θ1 E Dimension in mm ± 0.225 1.225 ± 0.075 0.075 1.000 ± 0.3 0.4 ± 0.1 0.165 ± 0.085 2.9 ± 0.2 0.95 BSC 1.90 BSC 1.600 ± 0.2 0.450 ± 0.15 0.6 REF 0.25 BSC 0.1 (TYP) 0.1 (TYP) 5° (TYP) 10 ° (TYP) ± 0.2 2.8 NOTE Pin No 1 2 3 4 5 6 PIN NAME NC VSS PG +5V(VDD) Cd NC Voltage Detecting IC -6 - Version：A.017 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. PS121 Package Specification (TO-93) (TO-93 4-pin) s D I θ2 E θ1 N-PG 1 2 3 4 A L1 θ3 L2 L3 b1 e1 e1 e e1 NOTE Symbol A b1 D e e1 E I L1 L2 L3 s θ1 θ2 θ3 Dimension in mm Dimension in inch ± 0.1 ± 0.004 0.144 3.65 ± 0.1 0.015 ± 0.004 0.38 ± 0.1 0.20 5.22 ± 0.004 ± 1.0 0.27 6.9 ± 0.02 ± 0.75 0.09 2.3 ± 0.03 0.06 ± 0.1 1.55 ± 0.004 ± 0.14 4.20 0.16 ± 0.006 ± 0.5 1.75 0.07 ± 0.02 2.10 ± 0.5 0.08 ± 0.02 2.70 ± 0.5 0.11 ± 0.02 1.50 ± 0.5 0.06 ± 0.02 (TYP) 5.0° 5.0° (TYP) 3.0° (TYP) 3.0° (TYP) 46.0° (TYP) 46.0° (TYP) PINOUT : Pin1 PG Pin2 +5V / Vcc Pin3 Cd Pin4 Vss Voltage Detecting IC -7 - Version：A.017 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 -8 - Version：A.017