WT7527 PC POWER SUPPLY SUPERVISOR. Data Sheet. Version June 22, 2007

Transcription

1 偉 詮 電 子 股 份 有 限 公 司 WT7527 PC POWER SUPPLY SUPERVISOR Data Sheet Version 1.20 June 22, 2007 The information in this document is subject to change without notice. All Rights Reserved. 新 竹 市 科 學 工 業 園 區 工 業 東 九 路 24 號 2 樓 2F, No. 24, Industry E. 9 th RD., Science-Based Industrial Park, Hsin-Chu, Taiwan TEL: FAX: [email protected]

2 GENERAL DESCRIPTION The WT7527 provides protection circuits, power good output (), fault protection latch (), and a protection detector function () control. It can minimize external components of switching power supply systems in personal computer. The Over Voltage Detector (OVD) monitors VX, V33, V5, and V12B input voltage level. The Under Voltage Detector (UVD) monitors V33, V5, and V12B input voltage level. The Over Current Detector (OCD) monitor I33&V33, I5&V5, I12A& and I12B&V12B input current sense. The pin VX provides an extra protection function. When OVD or UVD or OCD or VX detect the fault voltage level, the is latched HIGH and go low. The latch can be reset by go HIGH. There is 4 ms delay time for turn off. When OVD and UVD and OCD detect the right voltage level, the power good output () will be issue. FEATURES The Over Voltage Detector (OVD) monitors VX, V33, V5, and V12B input voltage. The Under Voltage Detector (UVD) monitors V33, V5, and V12B input voltage. The Over Current Detector (OCD) monitors I33&33, I5&V5, I12A& and I12B&V12B input pins. The VX > 1.2V provide an extra protection. Both of the power good output () and fault protection latch () are Open Drain Output. 75 / 600 ms time delay for UVD / OCD / VX. 300 ms time delay for. 38 ms for input signal De bounce. 14 us for OVD internal signal De glitch. 60 us for UVD / VX internal signal De glitch. 20 ms for OCD internal signal De glitch. 73 us for internal signal De glitch. 4 ms for turn-off. PIN ASSIGNMENT AND PACKAGE TYPE Pin assignment WT GND 2 15 VCC 3 14 V V33 I12A 5 12 RI 6 11 I33 I12B 7 10 I5 V12B 8 9 VX Page 2

3 ORDERING INFORMATION Part Number Package Type Note WT7527 NN160 1D WT7527 NN161 1D 16-Pin Plastic DIP, Pb-free WT7527 SN160 1D WT7527 SN161 1D 16-Pin Plastic SOP, Pb-free PIN DESCRIPTION Pin Name I/O Description I Power good input signal pin GND P Ground O Fault protection output pin, open drain output I On/Off switch input I12A I 12VA over current protection sense input RI I Current sense adjust input I12B I 12VB over current protection sense input V12B I 12VB over voltage & under voltage & over current sense input pin VX I Extra protection sense input I5 I 5V over current protection sense input I33 I 3.3V over current protection sense input I 12VA over voltage & under voltage & over current sense input pin V33 I 3.3V over voltage & under voltage & over current sense input pin V5 I 5V over voltage & under voltage & over current sense input pin VCC I Power supply O Power good output signal pin, open drain output Page 3

4 BLOCK DIAGRAM WT VCC PWR Power On Reset PWR VCCI 1.2V ~ 1.8V 38ms debounce 4ms delay V33 VREF = 1.2V - UN OV + 75ms / 600ms delay Bandgap Reference Internal Power VREF = 1.2V VCCI = 3.6V V5 - UN + PWR - OV + - UN + OSC CLK V12B - OV UN + 60us debounce OV 14us debounce R S Q VX OV 73us debounce 300ms delay I33 IREF * 8 I5 VREF = 1.2V + - IREF=VREF / RI RI IREF * 8 I12A I12B IREF * 8 20ms debounce IREF * 8 Page 4

5 ABSOLUTE MAXIMUM RATINGS Parameter Min. Max. Unit Supply voltage, VCC, V, VCC + 0.3(Max. 7V) V Input voltage V5, I5, V33, I (Max. 7V) V I12A, V12B, I12B + 0.3(Max. 16V) V Output voltage 0.3 VCC + 0.3(Max. 7V) V V Operating temperature Storage temperature *Note: Stresses above those listed may cause permanent damage to the devices RECOMMENDED OPERATING CONDITIONS Parameter Conditions Min. Typ. Max. Unit Supply voltage, VCC V Input voltage,, V5, V33 7 V, V12B 16 V Output voltage 7 V 16 V Output sink current 0.3V 10 ma 0.3V 10 ma Output current for RI RI ua ELECTRICAL CHARACTERISTICS, at Ta=25 C and V CC =5V. Over Voltage Detection Parameter Condition Min. Typ. Max. Unit V V Over voltage threshold V V B V VX Use UVD timing V I LEAKAGE Leakage current () V() = 5V 5 ua V OL Low level output voltage () I sink =10mA 0.3 V and Parameter Condition Min. Typ. Max. Unit V V Under voltage threshold V V B V Input threshold voltage() V I LEAKAGE Leakage current() = 5V 5 ua V OL Low level output voltage() I sink =10mA 0.3 V Offset Voltage of OCP comparators 6 6 mv Parameter Condition Min. Typ. Max. Unit Input pull-up current = 0V 150 ua High-level input voltage 1.8 V Low-level input voltage 1.2 V Page 5

6 TOTAL DEVICE Parameter Condition Min. Typ. Max. Unit Icc Supply current = 5V 1 ma Vcc operation start up voltage V Vcc under lockout voltage V SWITCHING CHARACTERISTICS, at Ta=-40 ~125 Parameter Condition Min. Typ. Max. Unit to Delay Time Td ms Td ms Short circuit Delay Time For ms Td2-1 For 161 ms to Delay Time Td ms Under Voltage Delay Time Td µs Over Current Delay Time Td ms Over Voltage Delay Time Td us VX Delay Time Td µs De-bounce Time Tb ms De-bounce Time Tb µs APPLICATION CIRCUIT +5VSB +5VSB WT V 1K R4=100 D1 +5VSB +5VSB GND VCC R5=300 10K 0.01uF 30K, 1% I12A RI I12B V5 V33 I33 I5 22uF R12, 1% 22uF R10, 1% +3.3V +5V V12B VX +12VA 22uF R14, 1% +12VB 22uF R16, 1% NOTE1:The series resistor R5 at can not be omitted.(r5 = 300Ω is suggested) NOTE2:The series resistor R4 = 100Ω and diode D1 at is suggested. Page 6

7 APPLICATION NOTE When the load current increased, the voltage (VL) cross the inductor is increased. And when inductor voltage exceeds the resistor voltage (VR), the OCP is active. Sometimes power-on or load dynamics will cause false output of over-current detection. It can be solved by connecting a capacitor between VS pin and IS pin. In typical case, C 0.47uF is suggested. OCP point can be calculated by the following equation: Let VR = VL R IR= RL IL VREF Q IR = 8 IREF = 8 RI RL IL R= VREF 8 RI For example: Assume RI=30KΩ, RL=5mΩ, OCP IL=20A. Sol:R = ( IL * RL ) / ( 8 * IREF ) = ( 20A * 5mΩ) / { 8 * ( 1.2V / 30KΩ)} = 312.5Ω Page 7

8 APPLICATION TIMMING 1.) (UNDER_VOLTAGE): t d3 t b2 Page 8

9 2.) V33, V5, V12 (UNDER_VOLTAGE) or I33, I5, I12 (OVER_CURRENT) or VX (OVER_VOLTAGE): t d3 V33/V5/V12 I33/I5/I12/VX t d2 =75mS t d2 +t d4 / t d5 / t d7 t d3 V33/V5/V12 I33/I5/I12/VX t d2-1 =600mS t d2-1 +t d4 / t d5 / t d7 t b3 V33/V5/V12 I33/I5/I12/VX Page 9

10 3.) V33, V5, V12 (OVER_VOLTAGE): t d3 V33/V5/V12 t d6 t d3 V33/V5/V12 Page 10

11 MECHANICAL INFORMATION PLASTIC DUAL IN LINE PACKAGE NOTE 1:All linear dimensions are in inches(millimeters). NOTE 2:This drawing is subject to change without notice. NOTE 3:Falls within JEDEC MS 001 Page 11

12 PLASTIC SMALL OUTLINE PACKAGE NOTE 1:All linear dimensions are in inches(millimeters). NOTE 2:This drawing is subject to change without notice. NOTE 3:Falls within JEDEC MS 012 Page 12