NCT3942S TR

Nuvoton 1.6 Times Linear Fan Driver NCT3942S/S-A NCT3942Y/Y-A NCT3942 Series Table of Content1. GENERAL DESCRIPTION ............................................................................................................................ 1 2. FEATURES ................................................................................................................................................. 1 3. APPLICATIOINS ......................................................................................................................................... 1 4. BLOCK DIAGRAM ...................................................................................................................................... 2 5. PIN CONFIGURATION AND TYPICAL APPLICATION CIRCUIT ...................................................................... 3 6. PIN DESCRIPTION ..................................................................................................................................... 4 7. FUNCTIONAL DESCRIPTION ...................................................................................................................... 5 8. TYPICAL WAVEFORM ................................................................................................................................ 7 9. ELECTRICAL CHARACTERISTIC ................................................................................................................... 9 10. PACKAGE DIMENSION ........................................................................................................................ 11 11. ORDERING INFORMATION .................................................................................................................. 13 12. TOP MARKING SPECIFICATION............................................................................................................ 14 13. REVISION HISTORY ............................................................................................................................. 15 -I- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 1. GENERAL DESCRIPTION The NCT3942 is a simply linear fan driver. It is designed for noise-sensitive or powersensitive applications that require system cooling. The NCT3942 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. It builds internal Soft-start to reduce the inrush current when power on. The output voltage follows the 1.6 times on the voltage of VSET pin to dynamic adjust the DC fan speed. NCT3942 supports enable pin to control the output voltage. NCT3942S-A/Y-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. NCT3942S/S-A is available in SOP-8 package. NCT3942Y/Y-A is available in DFN-8 package. 2. FEATURES             VOUT Follows 1.6 Times of VSET 150mV Dropout @ 0.5A Output Current 5uA Quiescent Current is Shutdown Mode Internal Soft-Start UVLO Function Full On Function Over Current, Short Circuit and Over Temperature Protections Low External Component Count Low Cost and Easy to Use SOP-8 150mil Package DFN8 (2.0x 2.0 mm^2) Package Lead Free (ROHS Compliant) and Halogen Free 3. APPLICATIOINS      PC Stick/ mini PC Notebook/ Netbook Fan Driver Peripheral Add-in Cards Motherboards Battery Powered Systems -1- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 4. BLOCK DIAGRAM VIN EN/ FON# UVLO & Soft Start Current Limit Full On Logic Thermal Shutdown VSET VOUT R1 GND R1=0.6R2 R2 Note: FON# function was supported by NCT3942S-A/Y-A only. -2- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 5. 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 NCT3942S-A (Top View) EN VIN VIN GND FON# VIN VIN GND NCT3942S (Top View) 8 7 6 5 8 7 6 5 9. EX-PAD 1 VOUT VSET NC NCT3942Y (Top View) 2 3 4 VSET 4 VOUT 3 VOUT 2 VOUT NC 1 9. EX-PAD NCT3942Y-A (Top View) -3- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series VCC VIN EN/ FON# EN/ Full on Mode CIN 4.7uF VOUT COUT 4.7uF VSET DC Voltage GND FAN Typical Application Circuit 6. PIN DESCRIPTION PIN NAME FON# EN Number DESCRIPTION S S-A -- 1 1 -- Y Y-A -- 8 8 Only for NCT3942S-A/Y-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 NCT3942S/Y device. Enable pin. Output voltage follows 1.6 times of VSET pin voltage when Enable pin at high level. Internal pull up resistor connected to VIN. VIN 2 6~7 DC power supply input. Connect a bypass capacitor (4.7uF, typically) is recommended. VOUT 3 2~3 Voltage output pin. Connect a low ESR ceramic capacitor (4.7uF, typically) to ground to assure stability. VSET 4 4 Output voltage setting pin. The inputs could be DC voltage. The input voltage must be larger than 1V. GND 5~8 5 Power supply ground. EX-PAD 9 9 Exposed Pad. Connect to ground for better thermal dissipation. -4- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 7. FUNCTIONAL DESCRIPTION 7.1 General Description The NCT3942 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. NCT3942S/Y supports enable pin to control the output voltage. NCT3942S-A/Y-A is power-on by the VSET pin and supports fully turn-on function. 7.2 Under Voltage Lockout, UVLO The NCT3942 was built-in a UVLO protection to keep the output off until the internal circuitry is operating properly. The UVLO function initiates a soft start process after input voltage exceeds its rising UVLO threshold during power on. Typical UVLO threshold is 2.5V with 0.15V hysteresis. 7.3 Full On Function The function is for NCT3942S-A/Y-A only. The input voltage level of FON# can control the internal regulator fully turn on or following 1.6 times of V SET 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. The FON# is internal pull-high. 7.4 EN Function The NCT3942S/Y goes into shutdown mode when the EN pin is in the logic low condition. During this condition, the pass transistor, error amplifier are turned off, reducing the supply current. The EN pin is internal pull-high, So the NCT3942S/Y will be turned on when EN pin is floating. 7.5 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 with soft start. 7.6 Current Limit The NCT3942 provides a current limit circuitry, which monitors the output current and controls PMOS gate voltage to limit the output current at a specific value. 7.7 Soft-start The NCT3942 builds internal Soft-start to reduce the inrush current and eliminate the voltage drop at Vin supply voltage when enabling. The soft-start interval is typically 150us. -5- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 7.8 Thermal Shutdown The NCT3942 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 with soft start 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. 7.9 VIN Decoupling To achieve the best results when using the NCT3942, decouple the power supply with a 2.2uF 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. 7.10 VOUT Stability To maintain circuit stability and improve transient response over temperature and current, the NCT3942 needs a suitable output capacitor. In order to insure the circuit stability, the suitable output capacitor should be larger than 4.7uF. -6- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 8. TYPICAL WAVEFORM (VSET = 2V, VEN=VIN, VIN = 5V, IO = 0.5A, CIN = COUT = 4.7uF, TA = TJ = 25℃, unless otherwise specified) Figure 01. Power on by VIN Figure 02. Power off by VIN Figure 03. Power on by EN Figure 04. Power on by EN Figure 05. Current limit & OTP Figure 06. OTP -7- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series (VSET = 2V, VEN=VIN, VIN = 5V, IO = 0.5A, CIN = COUT = 4.7uF, TA = TJ = 25℃, unless otherwise specified) VIN = 5V, VOUT = 1.6V Figure 07. Load Regulation Figure 08. Line Regulation Quiescent current (uA) VSET VS. Quiescent current TA = -40℃ TA = 25℃ TA = 85℃ VSET (V) Figure 09. Input voltage vs. Quiescent current Figure 10. VSET vs. Quiescent current IOUT = 500mA IOUT = 300mA IOUT = 100mA Figure 12. Dropout vs. Temp Figure 11. VSET vs. VOUT -8- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 9. 9.1 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. 9.2 Thermal Information ITEM RATING UNIT Internal Limited W Package Thermal Resistance, SOP8, θJA 160 ℃/W Package Thermal Resistance, DFN8, θJA TBD ℃/W RATING UNIT Operating Temperature -40 to 85 C Junction Temperature -40 to 125 C Supply Voltage, VCC 5 ± 10% V Power Dissipation, PD @ TA=25℃ 9.3 Recommended operating conditions PARAMETER -9- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 9.4 Electrical CHARACTERISTICS (VIN=5V, VSET=2V, CIN=COUT=4.7uF, Ta=25 C, unless otherwise speicified) 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 VIN=5.5V, VSET=1V~3.2V 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 VSET Pin Minimum VSET Voltage 1 V 1.0 A Current Limit Protection Current Limit ILIMIT 0.7 Softstart Softstart Time TSS 130 300 us Over Temperature Protection Thermal Shutdown Temperature 145 150 160 C Thermal Shutdown Hysteresis 20 30 40 C -10- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 10. PACKAGE DIMENSION  NCT3942S/S-A: SOP-8 (150mil) 8 5 E 4 1 Control demensions are in milmeters . E  -11- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series  NCT3942Y/Y-A: DFN8 2.0 x 2.0 mm^2 -12- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series  Taping Specification NCT3942S/ S-A SOP8 Package NCT3942Y/ Y-A DFN8 2.0x2.0mm^2 Package 11. ORDERING INFORMATION Part Number Supplied as Package Type Production Flow NCT3942S SOP8 Green Package 2,500 units/T&R NCT3942S-A Commercial, -40℃ to +85℃ NCT3942Y DFN8 (2.0x 2.0 mm^2) Green Package 3,000 units/ T&R NCT3942Y-A -13- Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 12. TOP MARKING SPECIFICATION  NCT3942S/ S-A ３９４２ＳＡ １１６ＧＸ ３９４２Ｓ １１６ＧＸ st 1 Line: 3942S/ 3942S-A nd 2 Line: Tracking code  ─ 116: packages assembled in Year 2011, week 16 ─ A: assembly house ID. ─ X: Internal use only. NCT3942Y/ Y-A 42 XY 42 XY st 1 Line: 42 (NCT3942Y) nd 2 Line: XY (Tracking Code) X means the last code of calendar year. Y means month (1: Jan., 2: Feb., 3: Mar., 4: Apr., 5: May, 6: Jul., 7:Jul., 8: Aug., 9: Sep., A: Oct., B: Nov., C: Dec.) -14- st 1 Line: 42 (w/ under line, NCT3942Y-A) nd 2 Line: XY (w/ under line, Tracking Code) X means the last code of calendar year. Y means month (1: Jan., 2: Feb., 3: Mar., 4: Apr., 5: May, 6: Jul., 7:Jul., 8: Aug., 9: Sep., A: Oct., B: Nov., C: Dec.) Publication Date: Mar., 2016 Revision. A4 NCT3942 Series 13. REVISION HISTORY VERSION DATE PAGE DESCRIPTION A1 04/03/2011 All New Create A2 04/26/2011 7-8 Added waveform A3 12/04/2015 All Added DFN8 package information A4 03/10/2016 1, 12-13 Change DFN8 package outline 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. -15- Publication Date: Mar., 2016 Revision. A4