RT9176 1.5A Fixed and Adjustable Low Dropout Positive Voltage Regulators General Description Features The RT9176 series of high performance positive voltage regulators is designed for applications requiring low dropout performance at fully rated current. Additionally, the RT9176 series provides excellent regulation over variations in line and load. Outstanding features include low dropout performance at rated current, fast transient response, internal current-limiting, and thermal-shutdown protection of the output device. The RT9176 series of three terminal regulators offers fixed and adjustable voltage options available in space-saving SOT-223, TO-252, and TO-263 packages. z z z z z z z Applications z z Ordering Information RT9176Package Type G : SOT-223 L: TO-252 M : TO-263 Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) Output Voltage Default : Adjustable 15 : 1.5V 18 : 1.8V 25 : 2.5V 28 : 2.85V 33 : 3.3V 35 : 3.5V Low Dropout Performance, 1.5V Max. Full Current Rating Over Line and Temperature Fast Transient Response ± 2% Output Voltage Accuracy 1.5V, 1.8V, 2.5V, 2.85V, 3.3V, and 3.5V Fixed and Adjustable Output Voltage SOT-223, TO-252, and TO-263 Packages RoHS Compliant and 100% Lead (Pb)-Free z Active SCSI Termination Low Voltage Microcontrollers Switching Power Supply Post-Regulator Pin ConFigurations (TOP VIEW) 3 VIN 2 VOUT (TAB) 1 ADJ/GND SOT-223 VIN 2 VOUT (TAB) 1 Note : RichTek Pb-free and Green products are : 3 ADJ/GND TO-252 `RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. `Suitable for use in SnPb or Pb-free soldering processes. 3 VIN `100%matte tin (Sn) plating. 2 VOUT (TAB) 1 ADJ/GND TO-263 DS9176-11 March 2007 www.richtek.com 1 RT9176 Typical Application Circuit RT9176 VIN VIN = 5V VOUT = 3.45V VOUT ADJ C1 10uF IADJ R1 133 1% + + VREF C2 10uF R2 232 1% Tantalum V OUT = V REF (1+ R2 R1 ) + I ADJ R 2 (1) C1 needed if device is far from filter capacitors. (2) C2 required for stability. Figure 1. Adjustable Voltage Regulator VIN VIN = 5V RT9176-33 VOUT VOUT 3.3V GND + + C1 10uF IQ C2 10uF Tantalum (1) C1 needed if device is far from filter capacitors. (2) C2 required for stability. Figure 2. Active SCSI Bus Terminator RT9176-28 VIN VOUT 18 - 27 Lines GND + + 10uF 22uF IQ Figure 3. Fixed Voltage Regulator www.richtek.com 2 DS9176-11 March 2007 RT9176 Function Block Diagram VIN S.O.A. Current Limiting Amplifier LIMIT VOUT SENSE Thermal Overload Voltage Regulation Amplifer VREF ADJ/GND Functional Pin Description Pin Name Pin Function ADJ/GND Adjust Output Voltage or GND VOUT Output Voltage VIN Power Input DS9176-11 March 2007 www.richtek.com 3 RT9176 Absolute Maximum Ratings z z z z z z z (Note 1) Supply Input Voltage -------------------------------------------------------------------------------------------------- 15V Power Dissipation, PD @ TA = 25°C SOT-223 ----------------------------------------------------------------------------------------------------------------- 0.740W TO-252 ------------------------------------------------------------------------------------------------------------------- 1.471W TO-263 ------------------------------------------------------------------------------------------------------------------- 2.222W Package Thermal Resistance (Note 6) SOT-223, θJA ------------------------------------------------------------------------------------------------------------ 135°C/W SOT-223, θJC ----------------------------------------------------------------------------------------------------------- 19°C/W TO-252, θJA ------------------------------------------------------------------------------------------------------------- 68° C/W TO-252, θJC ------------------------------------------------------------------------------------------------------------- 7.5° C/W TO-263, θJA ------------------------------------------------------------------------------------------------------------- 45° C/W TO-263, θJC ------------------------------------------------------------------------------------------------------------- 7.8° C/W Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260° C Junction Temperature ------------------------------------------------------------------------------------------------- 150°C Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C ESD Susceptibility (Note 2) HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 8kV MM (Machine Mode) -------------------------------------------------------------------------------------------------- 750V Recommended Operating Conditions z z (Note 3) Supply Input Voltage -------------------------------------------------------------------------------------------------- 3V to 12V Junction Temperature Range ---------------------------------------------------------------------------------------- −40°C to 125°C Electrical Characteristics (TA = 25° C, unless otherwise specified) Parameter Symbol Test Conditions IOUT = 10mA, (VIN−VOUT) = 2V, Reference Voltage (Note 4) RT9176 VREF RT9176-15 RT9176-18 RT9176-25 Output Voltage (Note 4) VOUT RT9176-28 RT9176-33 RT9176-35 www.richtek.com 4 Min Typ Max Units 1.243 1.256 1.281 V 10mA < IOUT < 1.5A, 1.5V < VIN-VOUT < 10V 1.231 1.256 1.294 V IOUT = 10mA, VIN = 3.3V, TJ = 25°C 1.485 1.5 1.53 0 < IOUT < 1.5A, 3.3V < VIN < 10V 1.470 1.5 1.55 IOUT = 10mA, VIN = 3.3V, TJ = 25°C 1.797 1.815 1.85 0 < IOUT < 1.5A, 3.3V < VIN < 10V 1.779 1.815 1.87 IOUT = 10mA, VIN = 4.0V, TJ = 25°C 2.460 2.500 2.544 0 < IOUT < 1.5A, 4.0V < VIN < 10V 2.450 2.500 2.550 IOUT= 10mA, VIN= 4.25V, TJ = 25°C 2.822 2.850 2.910 0 < IOUT < 1.5A, 4.25V < VIN < 10V 2.793 2.850 2.936 TA = 25°C V IOUT = 10mA, VIN = 4.75V, TJ = 25°C 3.267 3.300 3.365 0 < IOUT< 1.5A, 4.75V < VIN < 10V 3.234 3.300 3.400 IOUT = 10mA, VIN= 5V, TJ = 25°C 3.465 3.500 3.570 0 < IOUT < 1.5A, 5.0V < VIN < 10V 3.430 3.500 3.605 DS9176-11 March 2007 RT9176 Parameter Symbol Test Conditions Min Typ Max Units RT9176 IOUT = 10mA, 1.5V ≤ VIN−V OUT ≤ 10V -- 0.1 0.3 % RT9176-15 I OUT = 0mA, 3.3V ≤ VIN ≤ 15V -- 1 6 mV I OUT = 0mA, 3.3V ≤ VIN ≤ 15V -- 1 6 mV I OUT = 0mA, 4.0V ≤ VIN ≤ 15V -- 1 6 mV RT9176-28 I OUT = 0mA, 4.25V ≤ VIN ≤ 15V -- 1 6 mV RT9176-33 I OUT = 0mA, 4.75V ≤ VIN ≤ 15V -- 1 6 mV RT9176-35 I OUT = 0mA, 5.0V ≤ VIN ≤ 15V -- 1 6 mV RT9176 (VIN−VOUT) = 3V, 0mA ≤ I OUT ≤ 1.5A -- 0.2 0.4 % RT9176-15 VIN = 3.3V, 0 ≤ I OUT ≤ 1.5A -- 1 10 mV RT9176-18 VIN = 3.3V, 0 ≤ I OUT ≤ 1.5A -- 1 10 mV VIN = 4.0V, 0 ≤ I OUT ≤ 1.5A -- 1 10 mV RT9176-28 VIN = 4.25V, 0 ≤ I OUT ≤ 1.5A -- 1 10 mV RT9176-33 VIN = 4.75V, 0 ≤ I OUT ≤ 1.5A -- 1 12 mV RT9176-35 VIN = 5.0V, 0 ≤ I OUT ≤ 1.5A -- 1 15 mV I OUT = 500mA -- 1.15 1.25 V I OUT = 1.5A -- 1.3 1.5 V 1.5 1.75 -- A (VIN−VOUT) = 2V -- 5 10 mA IQ VIN = 5V -- 5 10 mA Ripple Rejection PSRR fRIPPLE = 120Hz , (VIN − VOUT) = 2V, VRIPPLE = 1VP-P -- 72 -- dB Adjust Pin Current IADJ -- 65 120 μA Adjust Pin Current Change ΔIADJ -- 0.2 5 μA Line Regulation (Note 4) Load Regulation (Note 4) Dropout Voltage RT9176-18 RT9176-25 RT9176-25 (Note 5) Current Limit ΔVLINE ΔVLOAD VDROP ILIM Minimum Load Current RT9176 Quiescent Current RT9176-XX VIN = 5V 10mA ≤ IOUT ≤ 1.5A, VIN = 5V 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 recommended. Note 3. The device is not guaranteed to function outside its operating conditions. Note 4. Low duty cycle pulse testing with Kelvin connections. Note 5. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV. Note 6. θJA is measured in the natural convection at T A = 25°C on a low effective thermal conductivity test board of JEDEC 51-3 thermal measurement standard. The pad size is 6mm2 on SOT-223 packages, 100mm2 on TO-252 packages, 125mm2 on TO-263 packages. DS9176-11 March 2007 www.richtek.com 5 RT9176 Typical Operating Characteristics Output Voltage vs. Temperature Reference Voltage vs. Temperature 1.27 3.4 Output Voltage (V) 3 2.6 VOUT = 2.5V 2.2 VIN = 5V CIN = 10uF Electrolytic CO = 10uF Tantalum RL = ∞ 1.8 VOUT = 1.5V 1.4 Reference Voltage (V) VOUT = 3.3V 1.26 1.25 VIN = 5V CIN = 10uF Electrolytic CO = 10uF Tantalum R1 = R2 = 100Ω RL = ∞ 1.24 1.23 -50 -25 0 25 50 75 100 125 -50 Temperature (° C) 0 50 75 100 125 Quiescent Current vs. Temperature ADJ Pin Current vs. Temperature 70 60 VIN = 5V CIN = 10uF Electrolytic CO = 10uF Tantalum R1 = R2 = 100Ω RL = ∞ 50 Quiescent Current (mA) 7 6 5 VOUT = 2.5V 4 3 2 VIN = 5V CIN = 10uF Electrolytic CO = 10uF Tantalum RL = ∞ 1 40 0 -50 -25 0 25 50 75 100 125 -50 -25 0 Temperature (° C) 25 50 75 Temperature(° C) 100 125 Current Limit vs. Temperature Current Limit vs. Input Voltage 2 3 2.5 1.9 VOUT = 2.5V, RL = 1Ω 2 1.5 1 Current Limit (A)1 Current Limit (A) 25 Temperature (° C) 80 ADJ Pin Current (uA) -25 1.8 VOUT = 2.5V, RL = 1Ω 1.7 VIN = 5V CIN = 10uF Electrolytic CO = 10uF Tantalum 1.6 0.5 CIN = 10uF Electrolytic CO = 10uF Tantalum 0 2 4 6 8 10 Input Voltage (V) www.richtek.com 6 12 14 1.5 -50 -25 0 25 50 75 100 125 Temperature (° C) DS9176-11 March 2007 RT9176 Current Limit Dropout Voltage vs. Load Current 3.5 VOUT = 2.5V -40°C 3 1.2 25°C 1.1 1.0 125°C Current Limit (A) Dropout Voltage (V) 1 1.3 CIN = 10uF Electrolytic CO = 10uF Tantalum 0 0.3 0.6 0.9 1.2 2 1.5 1 VIN = 5V, VOUT = 2.5V CIN = 10uF Electrolytic CO = 10uF Tantalum RL = 1Ω 0.5 0.9 0.8 2.5 0 Time (2.5ms/Div) 1.5 Load Current (A) VOUT = 1.5V CO = 10uF Tantalum ILOAD = 100mA 20 10 0 Line Transient Response Output Voltage Deviation (mV) Output Voltage Deviation (mV) Line Transient Response 30 Input Voltage Deviation (V) 7 6 5 30 20 0 7 6 5 Time (10us/Div) Time (10us/Div) Line Transient Response Load Transient Response 40 30 VOUT = 3.3V CO = 10uF Tantalum ILOAD = 100mA 20 0 Output Voltage Deviation (mV) Input Voltage Deviation (V) Output Voltage Deviation (mV) VOUT = 2.5V CO = 10uF Tantalum ILOAD = 100mA -20 -10 7 6 5 Time (10us/Div) DS9176-11 March 2007 300 200 VIN = 3.3V, VOUT = 1.5V CIN = CO = 10uF Tantalum Preload = 0.1A 100 0 -100 Load Current (A) -20 Input Voltage Deviation (V) 40 1 0.5 0 Time (10us/Div) www.richtek.com 7 RT9176 200 100 VIN = 3.3V, VOUT = 1.5V CIN = CO = 10uF Tantalum Preload = 0.1A 0 Load Transient Response 300 Output Voltage Deviation (mV) Output Voltage Deviation (mV) Load Transient Response 300 100 2 1 0 0 1 0.5 0 Time (10us/Div) Time (10us/Div) 200 100 VIN = 5V, VOUT = 2.5V CIN = CO = 10uF Tantalum Preload = 0.1A 0 Load Current (A) Load Current (A) -100 Load Transient Response 300 Output Voltage Deviation (mV) Output Voltage Deviation (mV) Load Transient Response 300 VIN = 5V, VOUT = 2.5V CIN = CO = 10uF Tantalum Preload = 0.1A -100 Load Current (A) Load Current (A) -100 200 2 1 0 Time (10us/Div) VVININ == 5V, 5V, VVOUT 3.3V OUT == 3.3V 200 CCININ==CCOO==10uF 10uFTantalum Tantalum Preload Preload==0.1A 0.1A 100 0 -100 1 0.5 0 Time (10us/Div) Output Voltage Deviation (mV) Load Transient Response 300 200 100 VIN = 5V, VOUT = 3.3V CIN = CO = 10uF Tantalum Preload = 0.1A 0 Load Current (A) -100 2 1 0 Time (10us/Div) www.richtek.com 8 DS9176-11 March 2007 RT9176 Application Information Output voltage adjustment Output Capacitor Like most regulators, the RT9176 regulates the output by comparing the output voltage to an internally generated reference voltage. On the adjustable version as shown in Figure 4, the VREF is available externally as 1.25V between VOUT and ADJ. The voltage ratio formed by R1 and R2 should be set to conduct 10mA (minimum output load). The output voltage is given by the following equation: RT9176 requires a capacitor from VOUT to GND to provide ) + IADJ R2 On fixed versions of RT9176, the voltage divider is provided internally. VIN VIN Region of Stable COUT ESR vs. Load Current RT9176 VOUT R1 COUT = 100uF 10uF + CADJ Instable + + VREF IADJ 65uA 10 VOUT ADJ 10uF The output capacitor does not have a theoretical upper limit and increasing its value will increase stability. COUT = 100μF or more is typical for high current regulator design. R2 C OUT ESR (Ω) VOUT = VREF R2 (1+ R1 compensation feedback to the internal gain stage. This is to ensure stability at the output terminal. Typically, 10μF tantalum or 50μF aluminum electrolytic is sufficient and please takes the notice of output capacitor ESR range (Figure 5). COUT = 10uF 1 Stable 0.1 Figure 4. Basic Adjustable Regulator Instable Input Bypass Capacitor An input capacitor is recommended. A 10μF tantalum on the input is a suitable input bypassing for almost all applications. 0.01 0 0.2 0.4 0.6 0.8 1 Load Current (A) Figure 5 Adjust Terminal Bypass Capacitor The adjust terminal can be bypassed to ground with a bypass capacitor (CADJ) to improve ripple rejection. This bypass capacitor prevents ripple from being amplified as the output voltage is increased. At any ripple frequency, the impedance of the CADJ should be less than R1 to prevent the ripple from being amplified: (2p * fRIPPLE * CADJ) < R1 The R1 is the resistor between the output and the adjust pin. Its value is normally in the range of 100-200Ω. For example, with R1 = 124Ω and fRIPPLE = 120Hz, the CADJ should be > 11μF. DS9176-11 March 2007 Load Regulation When the adjustable regulator is used (Figure 6), the best load regulation is accomplished when the top of the resistor divider (R1) is connected directly to the output pin of the RT9176. When so connected, RP is not multiplied by the divider ratio. For Fixed output version, the top of R1 is internally connected to the output and ground pins can be connected to low side of the load. www.richtek.com 9 RT9176 VIN RT9176 VIN VOUT GND RP Parasitic Line Resistance R1 (Connect R1 to VOUT or case) R2 RL Connect R2 to load Figure 6. Best Load Regulation Using Adjustable Output Regulator Thermal Protection RT9176 has thermal protection which limits junction temperature to 150°C. However, device functionality is only guaranteed to a maximum junction temperature of +125°C. The power dissipation and junction temperature for RT9176 are given by PD = (VIN - VOUT) x IOUT TJUNCTION = TAMBIENT + (PD x θJA) Note: TJUNCTION must not exceed 125° C Current Limit Protection RT9176 is protected against overload conditions. Current protection is triggered at typically 1.75A. Thermal Consideration The RT9176 series contain thermal limiting circuitry designed to protect itself from over-temperature conditions. Even for normal load conditions, maximum junction temperature ratings must not be exceeded. As mention in thermal protection section, we need to consider all sources of thermal resistance between junction and ambient. It includes junction-to-case, case-to-heat-sink interface, and heat sink thermal resistance itself. Junction-to-case thermal resistance is specified from the IC junction to the bottom of the case directly below the die. Proper mounting is required to ensure the best possible thermal flow from this area of the package to the heat sink. The case of all devices in this series is electrically connected to the output. Therefore, if the case of the device must be electrically isolated, a thermally conductive spacer is recommended. www.richtek.com 10 DS9176-11 March 2007 RT9176 Outline Dimension D D1 H C B L e L1 e A A1 b Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 1.450 1.803 0.057 0.071 A1 0.020 0.100 0.0008 0.0047 b 0.610 0.787 0.024 0.031 B 3.302 3.708 0.130 0.146 C 6.706 7.290 0.264 0.287 D 6.299 6.706 0.248 0.264 D1 2.896 3.150 0.114 0.124 e 2.261 2.362 0.089 0.093 H 0.229 0.330 0.009 0.013 L 1.550 1.950 0.061 0.077 L1 0.800 1.100 0.009 0.013 3-Lead SOT-223 Surface Mount Package DS9176-11 March 2007 www.richtek.com 11 RT9176 D U C D1 R B T V E S L1 L3 b1 b L2 e b2 A Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 2.184 2.388 0.086 0.094 B 0.889 2.032 0.035 0.080 b 0.508 0.889 0.020 0.035 b1 1.016 Ref. 0.040 Ref. b2 0.457 0.584 0.018 0.023 C 0.457 0.584 0.018 0.023 D 6.350 6.731 0.250 0.265 D1 5.207 5.461 0.205 0.215 E 5.334 6.223 0.210 0.245 e 2.108 2.438 0.083 0.096 L1 9.398 10.414 0.370 0.410 L2 L3 0.508 Ref. 0.635 1.016 0.020 Ref. 0.025 0.040 U 3.810 Ref. 0.150 Ref. V 3.048 Ref. 0.120 Ref. R 0.200 0.850 0.008 0.033 S 2.500 3.400 0.098 0.134 T 0.500 0.850 0.020 0.033 3-Lead TO-252 Surface Mount Package www.richtek.com 12 DS9176-11 March 2007 RT9176 C D U B V E L1 b1 L2 e b2 b A Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 4.064 4.826 0.160 0.190 B 1.143 1.676 0.045 0.066 b 0.660 0.914 0.026 0.036 b1 1.143 1.397 0.045 0.055 b2 0.305 0.584 0.012 0.023 C 1.143 1.397 0.045 0.055 D 9.652 10.668 0.380 0.420 E 8.128 9.652 0.320 0.380 e 2.286 2.794 0.090 0.110 L1 14.605 15.875 0.575 0.625 L2 2.286 2.794 0.090 0.110 U 6.223 Ref. 0.245 Ref. V 7.620 Ref. 0.300 Ref. 3-Lead TO- 263 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] DS9176-11 March 2007 www.richtek.com 13