RT9027A/B Linear Fan Driver General Description Features The RT9027A/B is a high performance positive voltage regulator designed for very low dropout voltage up to 0.5 Amps. The VSET voltage must be larger than 1V to guarantee that VOUT is 1.6 times of VSET. When VSET is less than 1V, the IC will be shutdown. The FON pin turns VOUT to fullyon when FON is given low. For RT9027B (EN version), FON pin is equivalent to EN pin. The RT9027A/B provides excellent regulation over variations in line, load and temperature. The RT9027A/B is available in the SOP-8 package. z VOUT Follows 1.6 Times of VSET z 150mV Dropout @ 0.5A Over Current and Over Temperature Protection FON Pin Turns VOUT Fully On RoHS Compliant and 100% Lead (Pb)-Free z z z Applications z z z z Ordering Information RT9027 Notebook Computer Fan Driver Battery Powered System Motherboard Peripheral Card Pin Configurations Package Type S : SOP-8 (TOP VIEW) Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) FON A : FON Function B : EN Function VIN 2 7 GND VOUT 3 6 GND VSET 4 5 GND EN Richtek products are : ` GND RT9027A Note : ` 8 8 GND RoHS compliant and compatible with the current require- VIN 2 7 GND VOUT 3 6 GND ments of IPC/JEDEC J-STD-020. VSET 4 5 GND Suitable for use in SnPb or Pb-free soldering processes. RT9027B SOP-8 Typical Application Circuit 2 VIN VIN CIN 2.2uF VSET FON/EN DS9027A/B-02 April 2011 VOUT 3 RT9027A/B 4 1 VSET FON/EN GND VOUT COUT 2.2uF 5 to 8 www.richtek.com 1 RT9027A/B Functional Pin Description Pin No. Pin Name FON 1 EN Pin Function Internal pulled high. For RT9027A, the IC will be fully turned on when this pin’s voltage is below 0.4V. Internal pulled high. For RT9027B, the IC will be shutdown when this pin’s voltage is below 0.4V. 2 VIN Input Voltage Pin. 3 VOUT Output Voltage Pin. 4 VSET This pin is used for output voltage setting. It is necessary to make this pin higher than 1V to guarantee V OUT to be 1.6 times of VSET. The IC will be shutdown when this pin voltage is below 1V. 5 to 8 GND Ground. Function Block Diagram VIN VIN POR BIAS+Thermal Shutdown VSET POR (Enable) VSET + OCP EA VOUT FON/EN GND www.richtek.com 2 Logic 0.6 1 DS9027A/B-02 April 2011 RT9027A/B Absolute Maximum Ratings z z z z z z z z (Note 1) Supply Input Voltage, VIN ---------------------------------------------------------------------------------------------EN, FON, VSET Voltage ----------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C SOP-8 ---------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) SOP-8, θJA ----------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ----------------------------------------------------------------------------Junction Temperature --------------------------------------------------------------------------------------------------Storage Temperature Range ------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM -----------------------------------------------------------------------------------------------------------------------MM -------------------------------------------------------------------------------------------------------------------------- Recommended Operating Conditions z z z 6V 6V 1.053W 95°C/W 260°C 150°C −65°C to 150°C 2kV 200V (Note 4) Supply Input Voltage, VIN ---------------------------------------------------------------------------------------------- 4.5V to 5.5V Junction Temperature Range ------------------------------------------------------------------------------------------ −40°C to 125°C Ambient Temperature Range ------------------------------------------------------------------------------------------ −40°C to 85°C Electrical Characteristics (VSET = 2V, VIN = 5V, IOUT = 0.5A, CIN = COUT = 2.2uF, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit 4.5 -- 5.5 V IOUT = 0A -- 300 -- uA VSET = 0V -- 10 --- VEN = 0V -- 10 -- 1.552 1.6 1.648 Input Voltage Input Voltage Range VIN Quiescent Current IQ Shutdown Current RT9027A RT9027B ISHDN uA Output Voltage VOUT/VSET V Line Regulation ΔVLINE -- 0.2 0.5 Load Regulation ΔVLOAD -- 0.2 0.8 -- 0.15 0.3 Ω IOUT = 0.5A, VIN = 5V, VSET = 3.3V RON % Current Limit ILIM 1.6 2 3.5 A Short Current ISC -- 1.1 -- A -- 2.5 -- -- 0.7 -- -- 0.8 -- -- 0.1 -- VIN UVLO Threshold Rising VIN UVLO Hysteresis VSET UVLO Threshold VSET UVLO Hysteresis Rising V V To be continued DS9027A/B-02 April 2011 www.richtek.com 3 RT9027A/B Parameter Symbol Test Conditions Min Typ Max Unit -- -- 0.4 V 1.6 -- -- V -- 1.5 15 uA Logic-Low Voltage VIL -- -- 0.4 V Logic-High Voltage VIH 1.6 -- -- V -- 10 15 uA -- 140 -- °C -- 30 -- °C FON Function (RT9027A) Logic-Low Voltage FON Threshold Logic-High Voltage VFON = 0 FON Bias Pin Current EN Function (RT9027B) EN Threshold EN Bias Pin Current IEN VEN = 0 Over Temperature Protection Thermal Shutdown Temperature TSD Thermal Shutdown Hysteresis Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2. θJA is measured in the natural convection at TA = 25°C on a high effective four layers thermal conductivity test board of JEDEC 51-7 thermal measurement standard. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. www.richtek.com 4 DS9027A/B-02 April 2011 RT9027A/B Typical Operating Characteristics Output Voltage vs. VSET Voltage Output Voltage vs. Output Current 6 1.615 1.610 4 Output Voltage (V) Output Voltage (V) 5 IOUT = 0A IOUT = 0.5A 3 2 1 1.605 1.600 1.595 1.590 1.585 1.580 VSET = 1V 1.575 0 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 Output Current (A) VSET Voltage (V) Output Voltage vs. Output Current 4.815 3.215 4.810 3.210 4.805 Output Voltage (V) Output Voltage (V) Output Voltage vs. Output Current 3.220 3.205 3.200 3.195 3.190 3.185 4.800 4.795 4.790 4.785 4.780 VSET = 2V 3.180 VSET = 3V 4.775 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 Output Current (A) Output Current (A) Output Voltage vs. Input Voltage 3.210 1.599 3.208 1.598 3.206 IOUT = 0.5A 1.597 Output Voltage (V) Output Voltage (V) Output Voltage vs. Input Voltage 1.600 1.596 IOUT = 0A 1.595 1.594 1.593 3.204 3.202 IOUT = 0.5A 3.200 3.198 IOUT = 0A 3.196 3.194 1.592 1.591 VSET = 1V 1.590 4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 Input Voltage (V) DS9027A/B-02 April 2011 5.3 5.4 5.5 3.192 VSET = 2V 3.190 4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5 Input Voltage (V) www.richtek.com 5 RT9027A/B Output Voltage vs. Temperature 3.24 1.63 3.23 1.62 3.22 Output Voltage (V) Output Voltage (V) Output Voltage vs. Temperature 1.64 1.61 1.60 1.59 1.58 1.57 3.21 3.20 3.19 3.18 3.17 VSET = 1V, IOUT = 0A VSET = 2V, IOUT = 0A 3.16 1.56 -50 -25 0 25 50 75 100 -50 125 -25 Output Voltage vs. Temperature 5.0 4.82 4.5 4.81 4.80 4.79 4.78 4.77 4.76 75 100 125 4.0 3.5 Rising 3.0 2.5 2.0 Falling 1.5 1.0 0.5 VSET = 3V, IOUT = 0A 0.0 -50 -25 0 25 50 75 100 125 -50 -25 0 Temperature (°C) 1.5 1.5 1.4 1.4 1.3 1.3 EN Threshold (V) 1.6 1.2 1.1 1.0 Rising 0.8 0.7 50 75 100 125 EN Threshold vs. Temperature 1.6 0.9 25 Temperature (°C) VSET Threshold vs. Temperature VSET Threshold (V) 50 VIN UVLO Threshold vs. Temperature 4.83 VIN UVLO Threshold (V) Output Voltage (V) 25 Temperature (°C) Temperature (°C) 4.75 0 Falling 1.2 1.1 Rising 1.0 0.9 Falling 0.8 0.7 0.6 0.6 0.5 0.5 0.4 0.4 -50 -25 0 25 50 Temperature (°C) www.richtek.com 6 75 100 125 -50 -25 0 25 50 75 100 125 Temperature (°C) DS9027A/B-02 April 2011 RT9027A/B Current Limit vs. VSET Voltage Dropout Voltage vs. Output Current 2.4 2.3 100 125°C Output Current (A) Dropout Voltage (mV) 120 85°C 80 25°C 60 -40°C 40 20 2.2 2.1 2.0 1.9 1.8 1.7 1.6 0 0 50 100 150 200 250 300 350 400 450 500 0.8 1 1.2 1.4 1.6 1.8 Output Current (mA) 3 3.2 Quiescent Current vs. Input Voltage Current Limit vs. Temperature 400 380 2.2 Quiescent Current (uA) VSET = 1V Output Current (A) 2.2 2.4 2.6 2.8 VSET Voltage (V) 2.4 2.0 VSET = 2V 1.8 1.6 1.4 1.2 360 340 320 300 VOUT = 3.2V 280 260 VOUT = 1.6V 240 220 1.0 200 -50 -25 0 25 50 75 100 125 4.5 4.6 4.7 Temperature (°C) 330 14 310 13 Shutdown Current (uA) 15 290 270 VOUT = 3.2V 230 VOUT = 1.6V 210 190 25 50 DS9027A/B-02 April 2011 5.3 5.4 5.5 75 100 125 VSET = 2V 9 8 7 5 Temperature (°C) 5.2 10 150 0 5.1 VSET = 1V 11 6 -25 5 12 170 -50 4.9 Shutdown Current vs. Input Voltage 350 250 4.8 Input Voltage (V) Quiescent Current vs. Temperature Quiescent Current (uA) 2 EN = 0V 4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5 Input Voltage (V) www.richtek.com 7 RT9027A/B Shutdown Current vs. Temperature Start Up for EN 15 Shutdown Current (uA) 14 13 VIN (5V/Div) VSET = 1V 12 VEN (5V/Div) 11 10 VSET = 2V VOUT (1V/Div) 9 8 7 6 EN = 0V 5 -50 -25 0 25 50 75 100 IOUT (0.5A/Div) 125 Time (5us/Div) Temperature (°C) Start Up from VIN Start Up from VSET VIN (5V/Div) VSET = 1V, VIN = VEN = 5V VOUT = 1.6V, IOUT = 500mA VIN (5V/Div) VSET (1V/Div) VOUT (1V/Div) VOUT (1V/Div) IOUT (0.5A/Div) VSET = 1V, VIN = VEN = 5V VOUT = 1.6V, IOUT = 500mA Time (2.5ms/Div) Short-Circuit Protection Short-Circuit Protection VOUT (2V/Div) VSET = 1V, VIN = VEN = 5V VOUT = 1.6V Time (1ms/Div) www.richtek.com 8 VSET = 1V, VIN = VEN = 5V VOUT = 1.6V, IOUT = 500mA Time (50us/Div) VOUT (2V/Div) IOUT (0.5A/Div) IOUT (0.5A/Div) IOUT (1A/Div) VSET = 2V, VIN = VEN = 5V VOUT = 3.2V Time (1ms/Div) DS9027A/B-02 April 2011 RT9027A/B Line Transient Response Line Transient Response VSET = 1V, VEN = 5V, VOUT = 1.6V, IOUT = 10mA VIN 5.5 (V) VSET = 1V, VEN = 5V, VOUT = 1.6V, IOUT = 500mA VIN 5.5 (V) 4.5 4.5 VOUT (10mV/Div) VOUT (10mV/Div) Time (100us/Div) Time (100us/Div) Line Transient Response Line Transient Response VSET = 2V, VEN = 5V, VOUT = 3.2V, IOUT = 10mA VIN 5.5 (V) VIN 5.5 (V) 4.5 4.5 VOUT (10mV/Div) VOUT (10mV/Div) VOUT (10mV/Div) VSET = 2V, VEN = 5V, VOUT = 3.2V, IOUT = 500mA Time (100us/Div) Time (100us/Div) Load Transient Response Load Transient Response VSET = 1V, VIN = VEN = 5V, VOUT = 1.6V IOUT = 50mA to 0.5A IOUT (0.5A/Div) IOUT (0.5A/Div) Time (250us/Div) DS9027A/B-02 April 2011 VOUT (10mV/Div) VSET = 2V, VIN = VEN = 5V, VOUT = 3.2V IOUT = 50mA to 0.5A Time (250us/Div) www.richtek.com 9 RT9027A/B Application Information Output Voltage Setting Thermal Shutdown Protection The output voltage of RT9027AB is adjustable from 1.6V to VIN by VSET voltage. It is set by internal voltage divider resisters shown in function block diagram. The VOUT voltage level is set as 1.6 times of VSET voltage level when VSET is higher than 1V. When VSET is less than 0.8V, the IC will be shutdown. RT9027AB over temperature protection function limits power dissipation to prevent this die from over temperature damage. When the RT9027B operation junction temperature exceeds 140°C, the over temperature protection circuit starts the thermal shutdown function and turns the pass transistor off. The pass transistor turns on again after the junction temperature cools by 30°C. For RT9027A, it lowers its OTP trip level to 110°C. It limits IC case temperature under 100°C and provides maximum safety to customer while output short circuit occurring. Fully Turn On and Enable Logic Function For RT9027A, pin1 named FON features fully turn on function. When the FON pin is in logic low level, the IC goes into fully turn on mode. During this condition, the pass transistor will be fully turned on. The FON pin is pulled to high level internally. For the enable function, it is acceptable to use the VSET pin to control the IC. When the VSET pin is in logic low level (<0.8V), the IC will be shutdown. For RT9027B, there is an EN pin for power on/off control. When the EN pin is in logic low level, the IC will be shutdown. During this condition, the pass transistor, error amplifier, and band gap are turned off, reducing the supply current to 10uA typical. The IC goes into operation mode when the EN pin is in logic high level condition. The EN pin is pulled to high level internally. Capacitor Selection Good bypassing is recommended from input to ground to improve the AC performance. A 2.2uF input ceramic capacitor or greater located as close as possible to the IC is recommended. The RT9027AB is specifically designed to use ceramic output capacitors as low as 2.2uF. The ceramic capacitors offer significant cost and space savings, along with high frequency noise filtering. Current Limit and Short Circuit Protection The RT9027A contains an independent current limit and short circuit current protection to prevent the IC from damaging in unexpected applications. The current limit monitors and controls the pass transistor’ s gate voltage, limiting the output current to a certain level (2A typ.). When the output voltage is less than 0.4V, the short circuit current protection starts the current fold back function and limits the output current at 0.8A (typ.). www.richtek.com 10 Thermal Considerations For continuous operation, do not exceed absolute maximum operation junction temperature 125°C. The power dissipation definition in device is: PD = (VIN − VOUT) x IOUT + VIN x IQ The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junction to ambient. The maximum power dissipation can be calculated by following formula : PD(MAX) = (TJ(MAX) − TA) / θJA Where T J(MAX) is the maximum operation junction temperature 125°C, TA is the ambient temperature and the θJA is the junction to ambient thermal resistance. For recommended operating conditions specification of RT9027A/B, where TJ(MAX) is the maximum junction temperature of the die (125°C) and TA is the maximum ambient temperature. Since the multiple GND pins of the SOP-8 package are internally shorted and connected to lead frame, it is efficient to dissipate the heat by adding copper area on GND footprint. Figure 1 shows the relation about thermal resistance θJA vs. copper area on a standard JEDEC 517 (4 layer, 2S2P) thermal test board at TA = 25°C. For example, with 10mm x 10mm copper area PCB, we can obtain the lower thermal resistance about 45°C/W. DS9027A/B-02 April 2011 RT9027A/B The maximum power dissipation at TA = 25°C can be calculated by following formula : PD(MAX) = (125°C − 25°C) / 45°C/W = 2.22W for SOP-8 package θJA (°C/W) Thermal Resistance θJA ( ℃ /W) 100 90 80 70 60 50 40 30 20 10 0 0 20 40 60 80 100 Copper Area (mm2) Figure 1 The maximum power dissipation depends on operating ambient temperature for fixed TJ(MAX) and thermal resistance θJA . For RT9027AB packages, the Figure 2 of de-rating curves allows the designer to see the effect of rising ambient temperature on the maximum power allowed. Maximum Power Dissipation (W) 2.4 100mm2 2.2 2 1.8 1.6 1.4 1.2 1 JEDEC 4-layers PCB 50mm2 25mm2 15mm2 min. layout 0.8 0.6 0.4 0.2 0 0 25 50 75 100 125 Ambiemt Temperature (°C) (℃ ) Figure 2. De-rating Curves for RT9027AB Package DS9027A/B-02 April 2011 www.richtek.com 11 RT9027A/B Outline Dimension H A M J B F C I D Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 4.801 5.004 0.189 0.197 B 3.810 3.988 0.150 0.157 C 1.346 1.753 0.053 0.069 D 0.330 0.508 0.013 0.020 F 1.194 1.346 0.047 0.053 H 0.170 0.254 0.007 0.010 I 0.050 0.254 0.002 0.010 J 5.791 6.200 0.228 0.244 M 0.400 1.270 0.016 0.050 8-Lead SOP Plastic Package Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 5F, No. 95, Minchiuan Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)86672399 Fax: (8862)86672377 Email: [email protected] Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek. www.richtek.com 12 DS9027A/B-02 April 2011