RT9186A/B Low Profile 500mA LDO with Enable and Power Good/Reset General Description Features The RT9186 is a low-dropout linear regulator providing up to 500mA load current with 160mV dropout. It is especially designed for the application of portable and smart handheld device. l The RT9186 operates from 2.5V to 5.5V supply. The internal P-MOSFET pass transistor allows the regulator to work with 190µA low quiescent current. Its preset output voltage version covers the most frequently used values, including 1.8V/2.5V/3.3V. Output voltage can also be adjusted via the ADJ pin for those other than the preset values. With only 0.1µA required in the shut down mode, one enable pin is able to control output on/off. RT9186A contains PGOOD function. On the other hand, RT9186B contains RST function with 6ms (typ.) time delay. Ordering Information RT9186A/B − l l l l l l l l l 2.5V to 5.5V Wide Input Range Guaranteed 500mA Output Current Low 160mV Dropout at 500mA 1.8V/2.5V/3.3V Preset Output Voltage Version with Adjustable Range from 0.8V to 4.5V. Reset Output with 6ms (typ.) Delay Time Power Good Output Low 190µA Ground Pin Current 0.1µA Shutdown Current Thermal and Over Current Protection RoHS Compliant and 100% Lead (Pb)-Free Applications l l l l Notebook Computer PDAs/SHDs PCMCIA/Cardbus Card Product Mobile Phone Marking Information Package Type F : MSOP-8 QV : VDFN-8L 3x3 (V-Type) Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) Output Voltage Default : Adjustable 18 : 1.8V 25 : 2.5V 33 : 3.3V A : Power Good Function B : Reset Function For marking information, contact our sales representative directly or through a Richtek distributor located in your area, otherwise visit our website for detail. Pin Configurations (TOP VIEW) VIN VIN PGOOD EN 8 2 7 3 6 4 5 VOUT VOUT ADJ GND VIN VIN PGOOG EN 2 3 4 VOUT VOUT ADJ GND 8 7 6 1 9 5 VDFN-8L 3x3 MSOP-8 RT9186A Note : Richtek Pb-free and Green products are : }RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. }Suitable for use in SnPb or Pb-free soldering processes. }100%matte tin (Sn) plating. VIN VIN RST EN 8 2 7 3 6 4 5 VOUT VOUT ADJ GND MSOP-8 VIN VIN RST EN 1 2 3 4 9 8 7 6 5 VOUT VOUT ADJ GND VDFN-8L 3x3 RT9186B DS9186AB-10 August 2007 www.richtek.com 1 RT9186A/B Pin Description Pin Name Pin Function VIN Power Input Voltage. VOUT Output Voltage. GND Ground. EN Chip Enable (Active-High). There should be a pull low resistor 100kΩ connected to GND when the control signal is floating. PGOOD Power Good Indicator. (RT9186A). RST ADJ Open-Drain Active-Low Reset Output. Connect a 100kΩ to VOUT to obtain output voltage. In shutdown the RST output is low. (RT9186B). Output Voltage Setting. Connect to GND for Fixed output voltage model. Typical Application Circuit VIN VIN CIN 1uF VOUT RT9186A/B RPGOOD/RST 100k PGOOD/ EN RST ADJ GND Chip Enable VOUT COUT 10uF TO µC Figure 1. Fixed Voltage Regulator VIN CIN 1uF Chip Enable VIN VOUT RT9186A/B EN GND 10uF PGOOD/ RST 100k TO µC ADJ V OUT = 0.8 (1 + VOUT COUT R1 ) R1 R2 R2 Figure 2. Adjustable Voltage Regulator Note1 : R2 should be less than 80k to ensure regulation. Note2 : X5R or X7R input capacitor ≧1µF is recommended for output stability. www.richtek.com 2 DS9186AB-10 August 2007 RT9186A/B Function Block Diagram VIN Current Limit Sensor + 0.8V Reference Error Amplifier - + VOUT Shutdown Logic EN Thermal Shutdown ADJ PGOOD - - + + 80% Reference 100mV Output Mode Comparator GND -RT9186A- VIN Current Limit Sensor + Error Amplifier 0.8V Reference - + VOUT Shutdown Logic EN Thermal Shutdown ADJ RST - - + + Delay Timer 80% Reference Output Mode Comparator 100mV GND -RT9186B- DS9186AB-10 August 2007 www.richtek.com 3 RT9186A/B Timing Diagram VIN 80% of VOUT (Normal) VOUT PGOOD Function (RT9186A) Reset function (RT9186B) Delay Time (typ.) 6ms Absolute Maximum Ratings l l l l l l l (Note 1) Input Voltage ---------------------------------------------------------------------------------------------------------- 7V Storage Temperature Range --------------------------------------------------------------------------------------- −65°C to 150°C Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------- 260°C Power Dissipation, PD @ TA = 25°C MSOP-8 ---------------------------------------------------------------------------------------------------------------- 0.625W VDFN-8L 3x3 ---------------------------------------------------------------------------------------------------------- 0.952W Package Thermal Resistance (Note 4) MSOP-8, θJA ---------------------------------------------------------------------------------------------------------- 160°C/W VDFN-8L 3x3, θJA ---------------------------------------------------------------------------------------------------- 105°C/W Junction Temperature ----------------------------------------------------------------------------------------------- 150°C ESD Susceptibility (Note 2) HBM (Human Body Mode) ----------------------------------------------------------------------------------------- 2kV MM (Machine Mode) ------------------------------------------------------------------------------------------------ 200V Recommended Operating Conditions l l l (Note 3) Input Voltage ---------------------------------------------------------------------------------------------------------- 2.5V to 5.5V Junction Temperature Range -------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range -------------------------------------------------------------------------------------- −40°C to 85°C www.richtek.com 4 DS9186AB-10 August 2007 RT9186A/B Electrical Characteristics (VIN = VOUT(NOM) + 500mV or VIN = +2.5V (whichever is greater), TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Units 2.0 2.3 2.4 V −3 0 +3 % 0.8 -- 4.5 V 0.784 0.8 0.816 V -- 10 100 nA General Specification Input Under Voltage Lock-Out V UVLO Output Voltage Accuracy ∆VOUT (Preset Mode) IOUT = 1mA to 500mA Adjustable Output Voltage Range V OUT_ADJ ADJ Pin Voltage V ADJ ADJ Input Bias Current I ADJ VADJ = +0.8V Short Circuit Current Limit ILIM VOUT = 0V 0.9 1.4 2.0 A Quiescent Current IQ IOUT = 0mA -- 190 250 µA V DROP IOUT = 500mA VOUT = 2.5V -- 200 330 VOUT = 3.3V -- 160 220 -- 0.02 0.125 %/V Dropout Voltage (Note 6) (Note 5) ∆VLINE Line Regulation VOUT + 0.1V < VIN < 5.5V IOUT = 5mA mV ∆VLOAD IOUT = 1mA to 500mA -- 21 40 mV I STBY VIN = 5.5V -- 0.1 2 µA Logic-Low Voltage VENL VIN = 2.5V -- -- 0.7 Logic-High Voltage VENH VIN = 5.5V 1.6 -- -- I EN VCE = 5.5V -- 20 100 nA VOL Reset Output Sinking 2mA -- 50 100 mV Output High Leakage Current VRST = 5V -- -- 100 nA Threshold to Output Voltage Rising edge, referred to V OUT 77 80 83 % Rising edge of VOUT to VRST 0.7 6 8 ms PGOOD Output Low Voltage PGOOD Output sinking 2mA -- 50 100 mV Output High Leakage Current VPGOOD = 5V -- -- 100 nA Threshold to Output Voltage Rising edge, referred to 77 80 83 % Load Regulation (Note 7) Chip Enable Standby Current EN Threshold EN Input Bias Current V Reset Reset Output Low Voltage Reset Delay Time TDELAY Power Good VOUT Thermal Protection Thermal Shutdown Temperature T SD -- 160 -- °C Thermal Shutdown Hysteresis ∆TSD -- 30 -- °C DS9186AB-10 August 2007 www.richtek.com 5 RT9186A/B 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. Devices are ESD sensitive. Handling precaution is highly recommended. Note 3. The operating conditions beyond the recommended range is not guaranteed. Note 4. θJA is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board (single-layer, 1S) of JEDEC 51-3 thermal measurement standard. Note 5. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV. Note 6. Quiescent, or ground current, is the difference between input and output currents. It is defined by IQ = IIN - IOUT under no load condition (IOUT = 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin current. Note 7. Regulation is measured at constant junction temperature by using a 20ms current pulse. Devices are tested for load regulation in the load range from 1mA to 300mA and 500mA respectively. www.richtek.com 6 DS9186AB-10 August 2007 RT9186A/B Typical Operating Characteristics CIN = 1uF(X7R Ceramic), COUT = 10uF(Y5V Ceramic), TA = 25°C, unless otherwise specified. Input Voltage Output Voltagevs. vs.Output Input Voltage 3.5 Output Voltage vs. Temperature No Load 3.3 VOUT = 3.3V 3.1 ILOAD = 500mA Output Volatge (V) Output Voltage (V) 3 2.5 2 1.5 1 VEN = VIN = 5V RL = ∞ 2.9 2.7 VOUT = 2.5V 2.5 2.3 2.1 0.5 VOUT = 1.8V 1.9 VOUT = 3.3V 0 1.7 2 2.7 3.4 4.1 4.8 5.5 -50 -25 0 25 Quiescent Current vs. Temperature VEN = VIN = 3.3V VOUT = 1.8V RL = ∞ 210 190 170 150 130 100 125 VOUT = 2.5V TJ = 125°C 200 150 TJ = 25°C 100 TJ = −40°C 50 0 -50 -25 0 25 50 75 100 125 0 100 200 Temperature (°C) 1.5 1 0.5 0 Short Circuit Current Limit (A)1 2 400 500 Short Circuit Current Limit vs. Temperature 1.60 VEN = VIN = 3.3V VOUT = 1.8V RL = 0 Ω 300 Load Current (mA) Short Circuit Current Limit Short Circuit Current Limit (A) 75 Dropout Voltage vs. Load Current 250 Dropout Voltage (mV) Quiescent Current (uA) 1 230 50 Temperature (°C) Input Voltage (V) VEN = VIN = 3.3V VOUT = 1.8V RL = 0 Ω 1.55 1.50 1.45 1.40 Time (1 ms/Div) -50 -25 0 25 50 75 100 125 Temperature (°C) DS9186AB-10 August 2007 www.richtek.com 7 RT9186A/B Output Voltage Deviation(mV) Load Transient Response 20 0 -20 Load Current (A) Input Voltage(V) Output Voltage Deviation(mV) Line Transient Response 4 3 ILOAD = 100mA VOUT = 1.8V Without CIN 20 0 -20 0.4 0.2 0 VOUT = 1.8V VIN = 3.3V ILOAD = 1 to 250mA Time (50us/Div) Time (50us/Div) Reset Response Reset Response VEN (2V/Div) ILOAD = 50mA VOUT = 3.3V VIN = 3.8V VIN = VEN (2V/Div) VOUT (2V/Div) VOUT (2V/Div) VRST (2V/Div) ILOAD = 50mA VOUT = 3.3V Without CIN VRST (2V/Div) Time (10ms/Div) Time (1ms/Div) PGOOD Response Shutdown Response VOUT (2V/Div) ILOAD = 50mA VOUT = 3.3V VIN = 3.8V ILOAD = 500mA, VOUT = 3.3V, VIN = 5V EN Voltage (V) VEN (2V/Div) 4 2 0 Output Voltage (V) 3 VPGOOD (2V/Div) 2 1 0 Time (1ms/Div) www.richtek.com 8 Time (100us/Div) DS9186AB-10 August 2007 RT9186A/B Application Information Capacitor Selection and Regulator Stability Input-Output (Dropout) Voltage Careful selection of the external capacitors for RT9186 is highly recommended in order to remain high stability and performance. A regulator’ s minimum input-to-output voltage differential (dropout voltage) determines the lowest usable supply voltage. In battery-powered systems, this determines the useful end-of-life battery voltage. Because the device uses a P-MOSFET, its dropout voltage is a function of drain-tosource on-resistance, RDS(ON), multiplied by the load current: Regarding the Input capacitor, connecting an X7R or X5R ceramic capacitor which is ≧1µF between input and ground is a must. Distance less than 1 cm between input pin and ground of RT9186 is recommended to avoid any unstability. With larger value of capacitor adding on lower ESR could result in better performance for both PSRR and line transient response. Regarding the output capacitor, connecting a10µF capacitor between output and ground is a must. Any capacitor is acceptable only with a highlight of relation between ESR region and Load current, shown in below. Output capacitor with larger capacitance can reduce noise and improve load transient response, stability, and PSRR. The same as Input capacitor, distance less than 1 cm between output pin and ground of RT9186 is recommended to avoid any unstability. Region of Stable COUT ESR vs. Load Current 100.00 100 VIN = 3V COUT ESR (Ω) 10.00 10 VDROPOUT = VIN -VOUT = RDS(ON) IOUT Over-Current and Short-Circuit Protection The RT9186 continuously monitors output current to provide maximum safety. In the event of output over current or short-circuit, over-current protection function will activate and override the voltage regulation function to limit output current at 1.4A typically. Large power dissipation at this condition may cause chip temperature to raise and trigger the over temperature protection if over-current or shortcircuit is not removed in a short time Power Good and Reset The power good and the reset output is an open-drain output. Connect an 100kΩ pull up resistor to VOUT to obtain an output voltage. The power good will output high immediately after the output voltage arrives 80% of normal output voltage. In the same situation, the reset will output high with 6ms delay time. See Timing Diagram and Typical Operating Characteristics. Instable 1.001 Adjustable Operation Stable The output voltage of RT9186 is adjustable from 0.8V to 0.10 0.10 4.5V by an external voltage divider as shown in Typical Application Circuit Figure 2. The value of R2 should be Instable 0.01 0.01 less than 80kΩ to ensure regulation. 0 100 200 300 Load Current (mA) 400 500 Chip Enable Operation Pull the EN pin low to drive the device into shutdown mode. At the same time, pin 3 (PGOOD/RST) is pulled low. During shutdown mode, the standby current drops to 0.1µA (typ). The output voltage decay rate is determined by the external capacitor and load current. Drive the EN pin high to turn on the device again. DS9186AB-10 August 2007 www.richtek.com 9 RT9186A/B Reverse Current Path The P-MOSFET pass element of RT9186 has an inherendiode connected between the regulator input and output as shown in Figure 3. The inherent diode will be forward biased and conduct an unlimited current if VOUT is sufficiently higher than V IN . a Schottky diode is recommended connecting parallel with the inherent diode in the application where output voltage may be higher than input voltage as shown in Figure 4. This Schottkly will clamp the forward bias voltage to 0.3V and conduct the possible current to protect the RT9186 from damage by unlimited current. VIN VOUT Figure 3. Inherent Diode of P-MOSFET Pass Transistor 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 RT9186A/B, where T J(MAX) is the maximum junction temperature of the die (125°C) and TA is the maximum ambient temperature. The junction to ambient thermal resistance θJA is layout dependent. For VDFN-8L 3x3 package, the thermal resistance θJA is 105°C/W on the standard JEDEC 51-3 single-layer 1S thermal test board and 70°C/W on the standard JEDEC 51-7 4-layers 2S2P thermal test board. The maximum power dissipation at TA = 25°C can be calculated by following formula : PD(MAX) = ( 125°C - 25°C ) / 105 = 0.952W for single-layer 1S board PD(MAX) = ( 125°C - 25°C ) / 70 = 1.428W for 4-layers 2S2P board VOUT Figure 4. Schottkly Diode Parallel with The Ingerent Diode Thermal Considerations Thermal protection limi ts power dissipation in RT9186A/B. When the operation junction temperature exceeds 160°C, the OTP circuit starts the thermal shutdown function and turns the pass element off. The pass element turn on again after the junction temperature cools by 30°C. 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 www.richtek.com 10 Maximum Power Dissipation (mW) VIN The maximum power dissipation depends on operating ambient temperature for fixed T J(MAX) and thermal resistance θJA. For RT9186A/B packages, the Figure 5 of derating curves allows the designer to see the effect of rising ambient temperature on the maximum power allowed. 1500 DFN-8L at 4-Layers PCB 1250 DFN-8L at 1-Layers PCB 1000 750 500 MSOP-8 at 1-Layers PCB 250 0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 5 DS9186AB-10 August 2007 RT9186A/B PCB Layout Good board layout practices must be used or instability can be induced because of ground loops and voltage drops. The input and output capacitors MUST be directly connected to the input, output, and ground pins of the device using traces which have no other currents flowing through them. The best way to do this is to layout CIN and COUT near the device with short traces to the VIN, VOUT , and ground pins. The regulator ground pin should be connected to the external circuit ground so that the regulator and its capacitors have a “single point ground”. It should be noted that stability problems have been seen in applications where “vias” to an internal ground plane were used at the ground points of the device and the input and output capacitors. This was caused by varying ground potentials at these nodes resulting from current flowing through the ground plane. Using a single point ground technique for the regulator and it’ s capacitors fixed the problem. Since high current flows through the traces going into VIN and coming from VOUT, Kelvin connect the capacitor leads to these pins so there is no voltage drop in series with the input and output capacitors. Optimum performance can only be achieved when the device is mounted on a PC board according to the MSOP-8 Board Layout diagram. GND + SET VOUT PGOOD / RST EN VIN + GND MSOP-8 Board Layout DS9186AB-10 August 2007 www.richtek.com 11 RT9186A/B Outline Dimension D L E E1 e A2 A A1 b Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.810 1.100 0.032 0.043 A1 0.000 0.150 0.000 0.006 A2 0.750 0.950 0.030 0.037 b 0.220 0.380 0.009 0.015 D 2.900 3.100 0.114 0.122 e 0.650 0.026 E 4.800 5.000 0.189 0.197 E1 2.900 3.100 0.114 0.122 L 0.400 0.800 0.016 0.031 8-Lead MSOP Plastic Package www.richtek.com 12 DS9186AB-10 August 2007 RT9186A/B D2 D L E E2 1 e A b A3 A1 Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.800 1.000 0.031 0.039 A1 0.000 0.050 0.000 0.002 A3 0.175 0.228 0.007 0.009 b 0.200 0.300 0.008 0.012 D 2.950 3.050 0.116 0.120 D2 2.250 2.350 0.089 0.093 E 2.950 3.050 0.116 0.120 E2 1.450 1.550 0.057 0.061 e L 0.650 0.425 0.026 0.525 0.017 0.021 V-Type 8L DFN 3x3 Package Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)89191466 Fax: (8862)89191465 Email: [email protected] DS9186AB-10 August 2007 www.richtek.com 13