PS121 SITI | Alldatasheet
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Technical content
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 PS121 Version : A.017 Issue Date : 2008/11/04 File Name : SP-PS121-A.017.DOC Total Pages: 9 Voltage Detecting IC
點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Voltage Detecting IC -1 - Version：A.017 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
- Power Good Logic to Check +5V 2. Adjustable delay time 3. 4-pin SIP package Block Diagram +5V INPUT GND DELAY CAPACITOR PG OUTPUT 4 3 1.25 V 23.6K 10K Id Vth_cd 10K
點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Voltage Detecting IC -2 - Version：A.017 PS121 Function Diagram Pin Descriptions TO-93 Pin No PIN NAME Descriptions
1 PG Power good output signal pin
2 +5V(VDD) +5V(VDD) input pin
3 C d External capacitor for PG delay
4 VSS Ground
Pin No PIN NAME Descriptions
1 NC NO connect
2 VSS Ground
3 PG Power good output signal pin
4 +5V(VDD) +5V(VDD) input pin
5 C d External capacitor for PG delay
6 NC NO connect
4.3 td +5V INPUT VOLTAGE PG OUTPUT t t 4.3-Vhy
點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Voltage Detecting IC -3 - Version：A.017 PS121 Absolute Maximum Ratings Parameter Symbol Rating Unit Supply Voltage VDD -0.5 ~ +7.5 V Output Sink Current I sink 30 mA Output Voltage V PG -0.5 ~ +7.5 V Power Dissipation P d 300 mW Storage Temperature T stg -40 ~ +125 oC Operating Temperature T opr -30 ~ +90 oC Junction Temperature T j 150 oC Package Thermal Resistance JAθ 160 oC/W 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=0.1 μF 21.4 ms Id Constant Current at C d Pin 8.0 8.7 9.4 μA Vsat PG Output Saturation Voltage V+5=4.0V, Isink=10mA 0.128 0.192 V VDD = 0Æ 5 1.79 1.87 1.95 Vthcd Threshold Voltage in Pin C d VDD = 5Æ 0 1.72 1.77 1.82 V ΔT Temperature coefficient +1 +2 mV/°C
點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Voltage Detecting IC -4 - Version：A.017 PS121 Typical Application (1) For Forward Type
3 N-PG
+5V INPUT Cd GND PG IdI2 Vpgi or S.P.S Secondary Side +5V OUTPUT Rx Cx = orX2 Vz=6V C>0.01uF (2) For Flyback Type +5V INPUT Cd GND PG IdI2 Vpgi or Rx Cx = orX2 Vz=6V C>0.01uF S.P.S Secondary Side +5V OUTPUT
點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Voltage Detecting IC -5 - Version：A.017 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, ⎛ ×=×=×= μμ 7.8 85.1sec,)(216.0 d ONd thcdd dONd C I VCTpFCT 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, 2 )85.1(2 85.1 )(2 R V C R VV VC I VC II VCT Cd d thcdCd thcdd OFFd thcdd d thcdd OFFd ×=×=− − ≒ Among OFFdT − equation, the )(2 thcdCd VV +× is discharged average current. Note3: Since the maximum threshold voltage at Pin 3(C d) 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(V th), the power good signal of PS121 will connect to LOW, so the ground-pin(VSS) must connect to the mo st 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 X 1 and R1 to cut down Vpgi voltage. Note7: Suggested using component X 2 to avoid overshoot voltage damages IC.
點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Voltage Detecting IC -6 - Version：A.017 PS121 Package Specification (SOT-26) NOTE L 0.450
0.6 REF
0.15± Symbol Dimension in mm A b c D 1.225 0.075 1.000 0.4 0.165 2.9
0.95 BSC
1.90 BSC
0.075 0.3 0.1 0.085 0.2 0.225 E1 1.600 0.2 ± R0 . 1 ( T Y P ) e R1 0.1 (TYP) θ 5 ° (TYP)
0.25 BSC
2 VSS
4 +5V(VDD)
5 C d
θ11 0 ° (TYP) E 2.8 0.2±
點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Voltage Detecting IC -7 - Version：A.017 PS121 Package Specification (TO-93) (TO-93 4-pin) NOTE s 2.70 1.50 5.0° 0.5 0.5± ± 0.11 0.06 5.0° 0.02 0.02 (TYP) (TYP) Symbol Dimension in mm Dimension in inch A D e E I 3.65 0.38 5.22 6.9 2.3 1.55 4.20 1.75 0.1 0.1 1.0 0.75 0.1 0.14 0.5 0.1 ± 0.144 0.015 0.20 0.27 0.09 0.06 0.16 0.07 0.004 0.004 0.004 0.02 0.03 0.004 0.006 0.02 1 2 3 4 N-PG A I θ2 θ1E Ds PINOUT: Pin1 Pin2 Pin3 Pin4 PG +5V / Vcc Cd Vss L2 2.10 0.5 ± 0.08 0.02± θ23 . 0 ° (TYP) 3.0 ° (TYP) θ3 46.0 ° (TYP) 46.0 ° (TYP) e e1 e1
點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Voltage Detecting IC -8 - Version：A.017 PS121 The products listed herein are designed for ordina ry 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 medi cal instruments, surgic al implants, aerospace machinery, nuclear power control systems, disa ster/crime-prevention equipment and the like. Misusing those products may direct ly or indirectly endanger huma n life, or cause injury and property loss. Silicon Touch Technology, Inc. will not take an y responsibilities regarding the misusage o f 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. a nd its distributors and all their officers and employees shall defend jointly an d severally against a ny and all claims and litigation and all damages, cost and expenses associated with such intention and manipulation.