RT9182 Dual, Low-Noise, 200mA LDO Regulator General Description Features The RT9182 is a dual-channel, low noise, and low dropout regulator supplying up to 200mA current at each channel. The output voltage ranges from 1.5V to 3.3V in 100mV increments and 2% accuracy by operating from a +2.7V to +5.5V input. z The RT9182 uses an internal PMOS as the pass device, which consumes 165uA supply current (both LDOs on) independent of load current and dropout conditions. The EN1 and EN2 pins control each output respectively. When both outputs shutdown simultaneously, the chip will be turn off and consumes nearly zero operation current which is suitable for battery-power devices. Other features include a current limiting, and over temperature protection. z z z z z z z Applications z z z z z Ordering Information RT9182 Package Type ES : SOT-23-6 Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) Output Voltage A : 2.8V (Output1), 2.8V (Output2) B : 3.0V (Output1), 3.0V (Output2) C : 2.8V (Output1), 3.0V (Output2) D : 2.8V (Output1), 2.5V (Output2) E : 2.8V (Output1), 1.8V (Output2) F : 2.5V (Output1), 2.5V (Output2) G : 2.5V (Output1), 1.8V (Output2) H : 3.3V (Output1), 2.5V (Output2) I : 3.3V (Output1), 1.8V (Output2) J : 3.0V (Output1), 2.5V (Output2) K : 3.0V (Output1), 1.8V (Output2) L : 2.8V (Output1), 1.85V (Output2) Up to 200mA Output Current (Each LDO) Dual Shutdown Pins Control Each Output 124uVRMS Low Noise Output Current Limiting and Thermal Protection Short Circuit Protection 120mV Dropout at 100mA Load Two LDOs in SOT-23-6 Package RoHS Compliant and 100% Lead (Pb)-Free Cellular Phones Laptop, Notebook, and Palmtop Computers Battery-powered Equipment Hand-held Equipment Wireless LAN Marking Information 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) VOUT1 VIN EN1 6 5 4 1 2 3 VOUT2 GND EN2 SOT-23-6 Note : There is no pin1 indicator on top mark for SOT-23-6 Note : type, and pin 1 will be lower left pin when reading top mark Richtek Pb-free and Green products are : from left to right. `RoHS compliant and compatible with the current require- ments of IPC/JEDEC J-STD-020. `Suitable for use in SnPb or Pb-free soldering processes. `100%matte tin (Sn) plating. DS9182-18 April 2008 www.richtek.com 1 RT9182 Typical Application Circuit Chip Enable Chip Enable 3 1 VOUT2 EN2 EN1 VOUT2 VOUT1 4 6 2.2uF VOUT1 RT9182 2.2uF VIN 5 GND VIN 2.2uF 2 Functional Pin Description Pin No. Pin Name Pin Function 1 VOUT2 Channel 2 Output Voltage 2 GND Common Ground 3 EN2 Note Chip Enable (Active High) Note Chip Enable (Active High) 4 EN1 5 VIN Supply Input 6 VOUT1 Channel 1 Output Voltage Note: If EN1 and EN2 are both low, both regulators and the reference turn off. Function Block Diagram Current Limit Thermal Protection Current Limit VIN + VREF VOUT1 + VOUT2 GND EN1 Bias EN2 www.richtek.com 2 DS9182-18 April 2008 RT9182 Absolute Maximum Ratings z z z z z z (Note 1) Supply Input Voltage -----------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C SOT-23-6 -------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 5) SOT-23-6, θJA --------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 2) HBM (Human Body Mode) ---------------------------------------------------------------------------------------------MM (Machine Mode) ------------------------------------------------------------------------------------------------------ Recommended Operating Conditions z z z 6.5V 0.4W 250°C/W 260°C −65°C to 150°C 2kV 200V (Note 3) Supply Input Voltage ------------------------------------------------------------------------------------------------------ 2.7V to 5.5V Enable Input Voltage ------------------------------------------------------------------------------------------------------ 0V to 5.5V Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C Electrical Characteristics (VIN = 3.6V, CIN = COUT = 2.2uF, EN1 = EN2 = VIN, typical values at TA = 25°C, for each LDO unless otherwise specified.) Parameter Symbol Test Conditions Min Typ Max Units -2 -- +2 % Output Voltage Accuracy (Load Regulation) ΔVOUT IL = 1mA to 200mA Maximum Output Current IMAX Continuous 200 -- -- mA Current Limit ILIM RLOAD = 1Ω 500 -- 1000 mA Quiescent Current No Load -- 165 260 IG μA IOUT = 100mA (Both LDOs) -- 165 260 μA IOUT = 1mA -- 1.2 -- mV IOUT = 100mA -- 120 -- mV IOUT = 200mA -- 255 -- mV Dropout Voltage (Note 4) VDROP Line Regulation ΔVLINE VIN = (VOUT +0.4V or 2.7V) to 5.5V IOUT = 1mA -0.2 -- +0.2 %/V EN Input High Threshold VIH VIN = 2.7V to 5.5V 1.6 -- -- V EN Input Low Threshold VIL VIN = 2.7V to 5.5V -- -- 0.4 V EN Input Bias Current ISD EN = GND or VIN -- -- 100 nA Shutdown Supply Current IGSD EN1 = EN2 = GND -- 0.01 2 μA Thermal Shutdown Temperature TSD -- 140 -- °C Thermal Shutdown Hysteresis ΔTSD -- 10 -- °C Output Voltage Noise eNO 10Hz to 100kHz, COUT = 4.7μF, ILOAD = 1mA -- 124 -- μVRMS 100Hz, COUT = 4.7μF, ILOAD = 100mA -- 62 -- dB Output Voltage AC PSRR DS9182-18 April 2008 www.richtek.com 3 RT9182 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 recommended. Note 3. The device is not guaranteed to function outside its operating conditions. Note 4. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV. Note 5. θJA is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board of JEDEC 51-3 thermal measurement standard. www.richtek.com 4 DS9182-18 April 2008 RT9182 Typical Operating Characteristics Output Voltage Accuracy vs. Temperature Quiescent Current vs. Supply Voltage 1.0 0.8 No Load 200 Output Voltage (%)1 Quiescent Current (uA)1 240 ILOAD = 100mA,both outputs 160 120 80 40 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 0 2.5 3.5 4.5 5.5 -40 6.5 -15 10 60 85 Temperature (°C) Supply Voltage (V) Dropout Voltage vs. Temperature Quiescent Current vs. Load Current 300 180 Both outputs loaded 150 250 Dropout Voltage (mV) Quiescent Current (uA)1 35 120 90 60 200 150 100 30 50 0 0 ILOAD = 200mA 0 40 80 120 160 -40 200 -15 10 60 85 Channel-to-Channel Isolation vs. Frequency Quiescent Current vs. Temperature 300 120 250 100 Channel Isolation (dB) 1 Quiescent Current (uA) 35 Temperature (°C) Load Current (mA) 200 150 100 50 80 60 40 20 RLOAD = 100Ω VIN = 3.6V 0 0 -45 -25 -5 15 35 Temperature (°C) DS9182-18 April 2008 55 75 95 100 1K 10K 100K 1M Frequency (Hz) www.richtek.com 5 ≈ 4.5 3.5 EN Pin Voltage (5V/Div) Load Current (100mA/Div) ≈ Load Transient Response COUT = 2.2uF ≈ ILOAD = 0 to 80mA Peak value depends on COUT ESR Time (50us/Div) Time (10us/Div) EN Pin Shutdown Response Noise RT9182AxES ILOAD = 50mA ≈ ≈ ILOAD = 100mA both output VIN = 4.5V CIN = COUT = 2.2uF Time (1ms/Div) ≈ Noise (200μV/Div) Output Voltage Deviation (20mV/Div) Line Transient Response Output Voltage (1V/Div) Input Voltage Deviation Output Voltage Deviation (50mV/Div) RT9182 f = 10Hz to 100kHz Time (10ms/Div) Noise Noise (200μV/Div) RT9182AxES No load both output VIN = 4.5V CIN = COUT = 2.2uF f = 10Hz to 100kHz Time (10ms/Div) www.richtek.com 6 DS9182-18 April 2008 RT9182 Applications Information The RT9182 is integrated with two low noise, low dropout, and low quiescent current linear regulators designed primarily for battery-powered applications. Output voltages are optional ranging from 1.5V to 3.3V, and each channel can supply current up to 200mA. Shutdown The RT9182 is shutdown by pulling the EN input low, and turned on by driving the input high. If this feature is not to be used, the EN input should be tied to VIN to keep the regulator on at all times (the EN input must not be floating). Internal P-Channel Pass Transistor The RT9182 features double typical 1.5Ω P-Channel MOSFET pass transistors. It provides several advantages over similar designs using PNP pass transistors, including longer battery life. The P-Channel MOSFET requires no base drive, which reduces quiescent current considerably. PNP-based regulators waste considerable current in dropout when the pass transistor saturates. They also use high base-drive currents under large loads. The RT9182 does not suffer from these problems and consume only 165μA of quiescent current whether in dropout, light-load, or heavy-load applications. Current Limit and Thermal Protection The RT9182 includes two independent current limit structure which monitor and control each pass transistor's gate voltage limiting the guaranteed maximum output current to 200mA. Thermal-overload protection limits total power dissipation in the RT9182. When the junction temperature exceeds TJ = +140°C, the thermal sensor signals the shutdown logic turning off the pass transistor and allowing the IC to cool. The thermal sensor will turn the pass transistor on again after the IC's junction temperature cools by 10°C, resulting in a pulsed output during continuous thermaloverload conditions. Thermal-overloaded protection is designed to protect the RT9182 in the event of fault conditions. Do not exceed the absolute maximum junction temperature rating of TJ = + 125°C for continuous operation. The output can be shorted to ground for an indefinite amount DS9182-18 April 2008 of time without damaging the part by cooperation of current limit and thermal protection. Operating Region and Power Dissipation The maximum power dissipation of RT9182 depends on the thermal resistance of the case and circuit board, the temperature difference between the die junction and ambient air, and the rate of airflow. The power dissipation across the device is P = IOUT (VIN - VOUT). The maximum power dissipation is : P(MAX) = (TJ - TA) / θJA where TJ - TA is the temperature difference between the RT9182 die junction and the surrounding environment, θJA is the thermal resistance from the junction to the surrounding environment. The GND pin of the RT9182 performs the dual function of providing an electrical connection to ground and channeling heat away. Connect the GND pin to ground using a large pad or ground plane. Capacitor Selection and Regulator Stability Like any low-dropout regulator, the external capacitors used with the RT9182 must be carefully selected for regulator stability and performance. Using a capacitor whose value is > 1uF on the RT9182 input and the amount of capacitance can be increased without limit. The input capacitor must be located a distance of not more than 0.5" from the input pin of the IC and returned to a clean analog ground. Any good quality ceramic or tantalum can be used for this capacitor. The capacitor with larger value and lower ESR (equivalent series resistance) provides better PSRR and linetransient response. The output capacitor must meet both requirements for minimum amount of capacitance and ESR in all LDO applications (see Figure1). The RT9182 is designed specifically to work with low ESR ceramic output capacitor in space-saving and performance consideration. Using a ceramic capacitor whose value is at least 1uF with ESR is > 5mΩ on the RT9182 output ensures stability. The RT9182 still works well with output capacitor of other types due to the wide stable ESR range. Output capacitor www.richtek.com 7 RT9182 Note that some ceramic dielectrics exhibit large capacitance and ESR variation with temperature. It may be necessary to use 2.2μF or more to ensure stability at temperatures below -10°C in this case. Also, tantalum capacitors, 2.2μF or more may be needed to maintain capacitance and ESR in the stable region for strict application environment. Tantalum capacitors maybe suffer failure due to surge current when it is connected to a low-impedance source of power (like a battery or very large capacitor). If a tantalum capacitor is used at the input, it must be guaranteed to have a surge current rating sufficient for the application by the manufacture. Load-Transient Considerations The RT9182 load-transient response graphs show two components of the output response: a DC shift from the output impedance due to the load current change, and the transient response. The DC shift is quite small due to the excellent load regulation of the IC. Typical output voltage transient spike for a step change in the load current from 0mA to 50mA is tens mV, depending on the ESR of the output capacitor. Increasing the output capacitor's value and decreasing the ESR attenuates the overshoot. more than a diode-drop, this diode will become forward biased and current will flow from the VOUT terminal to VIN. This diode will also be turned on by abruptly stepping the input voltage to a value below the output voltage. To prevent regulator mis-operation, a Schottky diode could be used in the applications where input/output voltage conditions can cause the internal diode to be turned on (see Figure3). As shown, the Schottky diode is connected in parallel with the internal parasitic diode and prevents it from being turned on by limiting the voltage drop across it to about 0.3V < 100mA to prevent damage to the part. Region of Stable Cout ESR v.s Load Current 100 COUT = 4.7uF Instable 10 COUT = 1uF Cout COUT ESR ((Ω) )1 of larger capacitance can reduce noise and improve loadtransient response, stability, and PSRR. The output capacitor should be located not more than 0.5" from the VOUT pin of the RT9182 and returned to a clean analog ground. 1 Stable 0.1 0.01 Instable 0.001 0 40 80 120 160 200 Load Current (mA) Figure 1 VIN VOUT Input-Output (Dropout) Voltage A regulator's minimum input-output voltage differential (or dropout voltage) determines the lowest usable supply voltage. In battery-powered systems, this will determine the useful end-of-life battery voltage. Because the RT9182 uses a P-Channel MOSFET pass transistor, the dropout voltage is a function of drain-to-source onresistance [RDS(ON)] multiplied by the load current. Figure 2 VIN VOUT Reverse Current Path The power transistor used in the RT9182 has an inherent diode connected between each regulator input and output (see Figure2). If the output is forced above the input by www.richtek.com 8 Figure 3 DS9182-18 April 2008 RT9182 Outline Dimension H D L C B b A A1 e Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.889 1.295 0.031 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.250 0.560 0.010 0.022 C 2.591 2.997 0.102 0.118 D 2.692 3.099 0.106 0.122 e 0.838 1.041 0.033 0.041 H 0.080 0.254 0.003 0.010 L 0.300 0.610 0.012 0.024 SOT-23-6 Surface Mount 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] DS9182-18 April 2008 www.richtek.com 9