NCT3940S TR

Nuvoton 1.6 Times Linear Fan Driver NCT3940S/ NCT3940S-A NCT3940S/ NCT3940S-A Table of Content1. GENERAL DESCRIPTION...............................................................................................................................1 2. FEATURES ......................................................................................................................................................1 3. BLOCK DIAGRAM ...........................................................................................................................................2 4. PIN CONFIGURATION AND TYPICAL APPLICATION CIRCUIT....................................................................2 5. PIN DESCRIPTION..........................................................................................................................................3 6. 7. FUNCTIONAL DESCRIPTION.........................................................................................................................4 6.1 GENERAL DESCRIPTION.......................................................................................................................4 6.2 UNDER VOLTAGE LOCKOUT, UVLO.....................................................................................................4 6.3 FULL ON FUNCTION...............................................................................................................................4 6.4 VSET SETTING .......................................................................................................................................4 6.5 CURRENT LIMIT......................................................................................................................................4 6.6 THERMAL SHUTDOWN ..........................................................................................................................5 6.7 VIN DECOUPLING...................................................................................................................................5 6.8 VOUT STABILITY ....................................................................................................................................5 ELECTRICAL CHARACTERISTIC...................................................................................................................6 7.1 ABSOLUTE MAXIMUM RATINGS ...........................................................................................................6 7.2 THERMAL INFORMATION ......................................................................................................................6 7.3 RECOMMENDED OPERATING CONDITIONS .......................................................................................6 7.4 ELECTRICAL CHARACTERISTICS ........................................................................................................7 8. TYPICAL OPERATING WAVEFORMS............................................................................................................8 9. PACKAGE DIMENSION.................................................................................................................................10 10. ORDERING INFORMATION..........................................................................................................................11 11. TOP MARKING SPECIFICATION..................................................................................................................11 12. REVISION HISTORY .....................................................................................................................................12 -I- Publication Date: Mar., 2011 Revision A3 NCT3940S/NCT3940S-A 1. GENERAL DESCRIPTION The NCT3940S/ NCT3940S-A is a simply linear fan driver. It is designed for noisesensitive or power-sensitive applications that require system cooling. The NCT3940S/ NCT3940S-A is a low quiescent current, low dropout linear regulator which is designed with a P-channel MOSFET to power a DC fan and delivers output current up to 500mA. The output voltage follows the 1.6 times on the voltage of VSET pin to dynamic adjust the DC fan speed. NCT3940S supports enable pin to control the output voltage. NCT3940S-A is power-on by the VSET pin voltage threshold and supports fully turn-on function. The internal power MOSFET can be fully turned on directly when FON# is at low level. NCT3940S/ NCT3940S-A is available in SOP-8 package. 2. FEATURES 2.1. General z VOUT Follows 1.6 Times of VSET z 150mV Dropout @ 0.5A Output Current z 5uA Quiescent Current is Shutdown Mode z UVLO Function z Full On Function z Over Current, Short Circuit and Over Temperature Protections z Low External Component Count z Low Cost and Easy to Use 2.2. Package z SOP-8 150mil with Exposed Pad Package z Lead Free (ROHS Compliant) and Halogen Free 2.3. Application z Notebook/ Netbook Fan Driver z Peripheral Add-in Cards z Motherboards z Battery Powered Systems -1- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A 3. BLOCK DIAGRAM EN/ FON# Full On Logic GND VIN 3 VOUT UVLO 1 VSET 2 Current Limit Thermal Shutdown 4 R1 5~8 R2 R1=0.6R2 Note: FON# function was supported by NCT3940S-A only. 4. PIN CONFIGURATION AND TYPICAL APPLICATION CIRCUIT EN 1 8 GND FON# 1 8 GND VIN 2 7 GND VIN 2 7 GND VOUT 3 6 GND VOUT 3 6 GND VSET 4 5 GND VSET 4 5 GND NCT3940S NCT3940S-A (Top View) (Top View) -2- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A VCC EN/ FON# VIN EN/ Full on Mode CIN 4.7uF VOUT COUT 4.7uF VSET DC Voltage GND FAN Typical Application Circuits 5. PIN DESCRIPTION NO PIN NAME NCT3940S PIN TYPE DESCRIPTION NCT3940S-A FON# N/A 1 I EN 1 N/A I Only for NCT3940S-A device. Full On mode selection pin. Output voltage follows 1.6 times of VSET pin voltage when FON# pin at high level. The internal power MOSFET full turns on when FON# pin at low level. Internal pull up resistor connected to VIN. Only for NCT3940S device. Enable pin. Output voltage follows 1.6 times of VSET pin voltage when Enable pin at high level. VIN 2 POWER DC power supply input. Connect a bypass capacitor (4.7uF, typically) is recommended. VOUT 3 AO Voltage output pin. Connect a low ESR ceramic capacitor (4.7uF, typically) to ground to assure stability. VSET 4 AIN Output voltage setting pin. The inputs could be DC voltage. The input voltage must be larger that 1V. -3- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A GND PIN TYPE 5~8 Output pin (Analog) AIN Input pin (Analog) I Input pin (Digital) GROUND Power supply ground. PIN Attribute AO POWER GROUND Positive power supply input Power supply ground 6. FUNCTIONAL DESCRIPTION 6.1 General Description The NCT3940S/ NCT3940S-A is a low quiescent current, low dropout linear regulator which is designed with a P-channel MOSFET to power a DC fan. It can deliver output current up to 500mA. The output voltage follows the 1.6 times on the voltage of VSET pin to dynamic adjust the DC fan speed. NCT3940S supports enable pin to control the output voltage. NCT3940S-A is power-on by the VSET pin and supports fully turn-on function. 6.2 Under Voltage Lockout, UVLO The NCT3940S/ NCT3940S-A was built-in a UVLO protection to keep the output off until the internal circuitry is operating properly. Typical UVLO threshold is 2.5V with 0.15V hysteresis. 6.3 Full On Function The function is for NCT3940S-A only. The input voltage level of FON# can control the internal regulator fully turn on or following 1.6 times of VSET voltage. When pulling this pin below 0.4V, the regulator will be fully turned on. When pulling this pin above 1.6V, the output voltage will follow 1.6 times of VSET voltage. 6.4 VSET Setting The output voltage is 1.6 times of VSET pin voltage. If the input voltage of VSET is under 1V, the internal regulator will be turned off. When the VSET voltage exceeds 1V, the output voltage will follow 1.6 times of VSET voltage. 6.5 Current Limit -4- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A The NCT3940S/ NCT3940S-A provides a current limit circuitry, which monitors the output current and controls PMOS gate voltage to limit the output current at a specific value. 6.6 Thermal Shutdown The NCT3940S/ NCT3940S-A has a thermal shutdown circuitry to limit the junction temperature. When the junction temperature exceeds 150° C, the thermal shutdown circuits disable the output, allowing the device to cool down. The output circuitry is enabled again after the junction temperature cools down by 30° C, resulting in a pulsed output during continuous thermal overload conditions. The thermal protection is designed to protect the IC in the event of over temperature conditions. For reliabile operation, the junction temperature cannot exceed 125° C. 6.7 VIN Decoupling To achieve the best results when using the NCT3940S/ NCT3940S-A, decouple the power supply with a 4.7uF capacitor. Use a high quality ceramic surface mount capacitor if possible. Surface mount components minimize lead inductance, which improves performance, and ceramic capacitors tend to have adequate high frequency response for decoupling applications. 6.8 VOUT Stability To maintain circuit stability and improve transient response over temperature and current, the NCT3940S/ NCT3940S-A needs a suitable output capacitor. In order to insure the circuit stability, the suitable output capacitor should be larger than 4.7uF. -5- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A 7. 7.1 ELECTRICAL CHARACTERISTIC Absolute Maximum Ratings PARAMETER RATING UNIT Power Supply Voltage -0.3 to 7V V Voltage on Other Pins -0.3 to 7V V Storage Temperature -50 to 150 °C Soldering Temperature Refer to IPC/JEDEC J-STD-020 Specification ESD Protection Human Body Mode 2 kV Machine Mode 200 V Latch-up 100 mA Note: Exposure to conditions beyond those listed under Absolute Maximum Ratings may adversely affect the life and reliability of the device. 7.2 Thermal Information ITEM RATING UNIT Internal Limited W 160 ℃/W RATING UNIT 0 to 70 °C Junction Temperature -40 to 125 °C Supply Voltage, VCC 5 ± 10% V Power Dissipation, PD @ TA=25℃ Package Thermal Resistance, SOP8, θJA 7.3 Recommended operating conditions PARAMETER Operating Temperature -6- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A 7.4 Electrical CHARACTERISTICS VIN=5V, VSET=2V, CIN=COUT=2.2uF, Ta=25° C PARAMETER SYM. MIN. VIN 4.5 TYP. MAX. UNIT 5.5 V 2.9 V CONDITIONS Supply Input Voltage Supply Input Voltage Under Voltage Lockout (UVLO) VIN UVLO Threshold 2.1 VIN UVLO Hysteresis 2.5 0.15 VIN rising V EN Pin EN Voltage High 2.0 V EN Voltage Low EN Pin Bias Current 1.5 0.4 V 10 uA 0.4 V EN=0V FON# Pin Low Voltage VIL High Voltage VIH FON# Pin Bias Current 1.6 V IFON# 1.5 10 uA FON#=0V IQ 0.5 1 mA VOUT = 5V 1.6 1.648 V/V Load Regulation 30 40 mV 10mA≦IOUT≦500mA Line Regulation 0.2 0.5 % Vin=4.5V to 5.5V Output Resistance 0.3 0.4 Ω IOUT=500mA, VSET=3.4V 0 1 uA VSET < 1V Supply Input Current Quiescent Current Output Voltage VOUT Voltage / VSET Voltage 1.552 Output Leakage VIN=5.5V, VSET=1V~3.2V VSET Pin Minimum VSET Voltage 1 V 0.7 1.0 A Thermal Shutdown Temperature 145 150 160 °C Thermal Shutdown Hysteresis 20 30 40 °C Current Limit Protection Current Limit ILIMIT Over Temperature Protection -7- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A 8. TYPICAL OPERATING WAVEFORMS VSET = 2V, VEN=VIN, VIN = 5V, IO = 0.5A, CIN = COUT = 4.7uF, TA = TJ = 25℃, unless otherwise specified Figure 01. Power on Figure 02. Power off Figure 03. Current Limit, OTP Figure 04. OTP Figure 05. Load Transient Figure 06. Line Transient -8- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A VSET VS. Quiescent current Input voltage VS. Quiescent current 700 400 Quiescent current (uA) Quiescent current (uA) 450 350 300 250 200 150 100 50 0 600 TA = -40℃ 500 400 TA = 25℃ 300 200 TA = 85℃ 100 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 0 0.5 1.0 1.5 Input voltage (V) Figure 07. Input Voltage vs. Quiescent Current 2.5 3.0 Figure 08. VSET vs. Quiescent Current VSET VS. VOUT EN & FON threshold VS. Temp. 6 1.60 5 Rising 1.20 4 Voltage (V) VOUT (V) 2.0 VSET (V) 3 2 0.80 Falling 0.40 1 0.00 0 0.05 0.55 1.05 1.55 2.05 2.55 -40 3.05 -30 -20 -10 0 10 20 30 40 50 60 Temp VSET (V) Figure 09. VSET vs. VOUT Figure 10. EN & FON Threshold vs. Temperature Dropout VS. Temp. Dropout voltage (mV) 180 160 140 IOUT = 500mA 120 100 80 IOUT = 300mA 60 40 IOUT = 100mA 20 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 85 Temp. Figure 11. Dropout Voltage vs. Temperature -9- Publication Date: Mar., 2011 Revision A3 70 80 85 NCT3940S/ NCT3940S-A 9. PACKAGE DIMENSION SOP-8 (150mil) 8 5 c E HE L 4 1 0.25 D O A Y e SEATING PLANE GAUGE PLANE A1 b Control demensions are in milmeters . SYMBOL A A1 b c E D e HE Y L θ DIMENSION IN MM MIN. MAX. 1.35 1.75 0.10 0.25 0.33 0.51 0.19 0.25 3.80 4.00 4.80 5.00 1.27 BSC 6.20 5.80 0.10 1.27 0.40 0 10 DIMENSION IN INCH MIN. MAX. 0.053 0.069 0.010 0.004 0.020 0.013 0.010 0.008 0.157 0.150 0.188 0.196 0.050 BSC 0.228 0.016 0 0.244 0.004 0.050 10 9.1 Taping Specification 8 Pin SOP Package -10- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A 10. ORDERING INFORMATION Part Number Supplied as Package Type Production Flow NCT3940S 8PIN SOP (Green Package) E Shape: 100 units/Tube T Shape: 2,500 units/T&R Commercial, 0℃ to +70℃ NCT3940S-A 11. TOP MARKING SPECIFICATION 3 9 4 0 S 852AX 3940S-A 852AX 1st Line: 3940S/ 3940S-A 2nd Line: Tracking code z 852: packages assembled in Year 2008, week 52 z A: assembly house ID. z X: IC version. (A means A; B means B and C means C…etc.) -11- Publication Date: Mar., 2011 Revision A3 NCT3940S/ NCT3940S-A 12. REVISION HISTORY VERSION DATE PAGE A1 11/28/2008 All A2 11/28/2008 P8, P9 A3 03/07/2011 All DESCRIPTION New Create Added waveforms, fixed some description Fixed some description Important Notice Nuvoton Products are neither intended nor warranted for usage in systems or equipment, any malfunction or failure of which may cause loss of human life, bodily injury or severe property damage. Such applications are deemed, “Insecure Usage”. Insecure usage includes, but is not limited to: equipment for surgical implementation, atomic energy control instruments, airplane or spaceship instruments, the control or operation of dynamic, brake or safety systems designed for vehicular use, traffic signal instruments, all types of safety devices, and other applications intended to support or sustain life. All Insecure Usage shall be made at customer’s risk, and in the event that third parties lay claims to Nuvoton as a result of customer’s Insecure Usage, customer shall indemnify the damages and liabilities thus incurred by Nuvoton. -12- Publication Date: Mar., 2011 Revision A3