RT9172 Preliminary 3A Fixed Output Voltage LDO Regulator General Description Features The RT9172 series of low-dropout linear regulators z Low Dropout Voltage operate from a +2.25V to +6.0V input supply. A wide z Low Ground Pin Current range of preset output voltage options is available. z Load Regulation of 0.4% at 3A These low dropout linear regulators respond very z fast to step changes in load, which are suitable for z 0.5µ µA Quiescent Current in Shutdown Mode Guaranteed Output Current of 3A DC low The z Available in TO-263 and TO-220 Packages RT9172 uses an internal PMOS as the pass device, z Output Voltage Accuracy ±1.5% which does not cause extra GND current in heavy z Error Flag Indicates Output Status load and dropout condition. The shutdown mode of z Sense Option Improves Better Load Regulation low operation current makes the IC suitable for z Extremely Low Output Capacitor Requirements power-saving systems. The other features include z Over-temperature/Over-current Protection voltage microprocessor applications. current limiting and over temperature protection. Ordering Information RT9172 - Package type T5 : TO-220-5 M5 : TO-263-5 T : TO-220 M : TO-263 G : SOT-223 Operating temperature range C: Commercial standard Output voltage 15 : 1.5V 16 : 1.6V : Applications z Microprocessor Power Supplies z GTL, GTL+, BTL, and SSTL Bus Terminators z Power Supplies for DSPs z SCSI Terminator z Post Regulators z High Efficiency Linear Regulators z Battery Chargers z Other Battery Powered Applications Pin Configurations Part Number Pin Configurations TOP VIEW RT9172- CT (Plastic TO-220) 1. VIN 2. GND (TAB) 32 : 3.2V 33 : 3.3V 3. VOUT S: Pin out exchange N : Pin 5 bond sense F : Pin 5 bond flg 1 2 3 TOP VIEW RT9172- CM 1. VIN 2. GND (TAB) 3. VOUT (Plastic TO-263) 1 2 3 TOP VIEW RT9172- CG (Plastic SOT-223) 1 2 3 1. VIN 2. GND (TAB) 3. VOUT To be continued DS9172-03 April 2002 www.richtek-ic.com.tw 1 RT9172 Preliminary Part Number Pin Configurations Part Number TOP VIEW RT9172N- CT5 1. 2. 3. 4. 5. RT9172F- CT5 (Plastic TO-220-5) 12 3 4 5 1. 2. 3. 4. 5. RT9172F- CM5 (Plastic TO-263-5) 1 2 3 4 5 TOP VIEW RT9172S- CT5 EN VIN GND (TAB) VOUT SENSE/FLG (Plastic TO-220-5) 12 3 4 5 TOP VIEW RT9172N- CM5 Pin Configurations VIN EN GND (TAB) SENSE VOUT TOP VIEW RT9172S- CM5 EN VIN GND (TAB) VOUT SENSE/FLG 1. 2. 3. 4. 5. (Plastic TO-263-5) 1 2 3 4 5 1. 2. 3. 4. 5. VIN EN GND (TAB) SENSE VOUT Typical Application Circuit VIN VIN = 3.3V RT9172-25 VOUT VOUT 2.5V, 3A GND CIN 1µF COUT Fig. 1 RT9172N-25 VIN VOUT VIN = 3.3V Trace resistance = Rt VLOAD = 2.5V ILOAD CIN 10 µF EN GND SENSE L O A D COUT Fig. 2 RT9172F-25 VIN = 3.3V VIN VOUT 10K CIN 10µF Trace resistance = Rt V OUT = 2.5V 10K EN GND FLG VLOAD = 2.5V-I LOADRt ILOAD COUT L O A D Fig. 3 Recommend COUT: (1) 10µF (or larger) electrolytic or tantalum capacitance (2) 1µF or 10µF ceromic capacitor parrell with 100µF electrolytic or tantalum capacitance www.richtek-ic.com.tw 2 DS9172-03 April 2002 RT9172 Preliminary Function Block Diagram RT9172F VIN VOUT Buffer Amplifier EN _ + Thermal Current Limiting Sensor FLG + _ Vref GND RT9172N/RT9172S VIN VOUT SENSE Buffer Amplifier EN Thermal Current Limiting Sensor _ + Vref GND RT9172 VIN VOUT Buffer Amplifier Thermal Current Limiting Sensor _ + Vref GND DS9172-03 April 2002 www.richtek-ic.com.tw 3 RT9172 Preliminary Absolute Maximum Ratings z Input Voltage 6V z Power Dissipation Internally Limited z ESD Rating 3 kV z Storage Temperature Range −65°C to 150°C z Lead Temperature (Soldering, 5 sec.) 260°C z Package Thermal Resistance z TO-263, θJC 8°C/W TO-263, θJA 19.4°C/W TO-220, θJC 8°C/W TO-220, θJA 62°C/W SOT-223, θJC 15°C/W SOT-223, θJA 60°C/W Junction Temperature Range -40°C to +125°C Electrical Characteristics (Limits in standard typeface are for TA = 25°C, unless otherwise specified: VIN = VO(NOM) + 1.0V, IL = 10mA, COUT = 10µF (Ceramic), VEN = VIN) Parameter Symbol Test Conditions Min Typ Max Units -1.5 0 +1.5 % 2.25 -- 6 V VOUT + 0.4V < VIN < 6.0V -- 0.35 0.8 % Note 1 -- 0.4 1 Note 2 -- 0.1 0.3 IL = 300mA -- 50 70 IL = 3A -- 400 700 -- 1.2 3 mA -- 0.5 5 µA Output Voltage Tolerance Input Voltage Range VIN Line Regulation ∆VLINE Load Regulation ∆VLOAD Dropout Voltage VDROP Quiescent Current IQ Shutdown Supply Current IGSD Peak Output Current IO(PEAK) 3.5 5 -- A ILIMIT 3.5 5 -- A Guaranteed by design -- 170 -- °C Guaranteed by design -- 10 -- °C Output = High 1.2 VIN -- Output = Low -- 0 0.4 VEN = VIN -- 0.1 -- nA -- 1 -- nA 2 -- -- mA VEN = 0V % mV Short Circuit Protection Current Limit Over Temperature Protection Shutdown Threshold TSD Thermal Shutdown Hysteresis Shutdown Function EN Pin Shutdown Threshold VEN EN Input Current FLG Pin Leakage Current FLG Pin Sink Current ILEAKAGE VFLG = 0.5V V Note 1: RT9172-CX, RT9172F-XXCX5, 10mA < IL < 3A Note 2: RT9172S-XXCX5, RT9172N-XXCX5, 10mA < IL < 3A www.richtek-ic.com.tw 4 DS9172-03 April 2002 RT9172 Preliminary Pin Description Pin No. Pin Name Pin Function RT9172F RT9172N RT9172S RT9172 1 1 2 -- EN Chip Enable 2 2 1 1 VIN Power Input 3 3 3 2 GND Ground 4 4 5 3 VOUT Output Voltage 5 -- -- -- FLG ERROR Flag -- 5 4 -- SENSE Remote Sense DS9172-03 April 2002 www.richtek-ic.com.tw 5 RT9172 Preliminary Typical Operating Charateristics PSRR 0 CIN = 1nF COUT = 10µF Electrolytic Capacitor VIN = 5V VOUT = 2.5V TA = 25°C PSRR (dB) -20 -20 -30 -40 10mA -50 CIN = 1nF COUT = 68µF Tantalum Capacitor VIN = 5V VOUT = 2.5V TA = 25°C -10 PSRR (dB) -10 PSRR 0 -30 -40 10mA -50 100mA -60 -60 -70 -70 100mA 10 100 1K 10K 100K 1M 10 100 Frequency (Hz) Noise Signal & Spectrum Distribution 6 8 10 200 1500 160 500 120 -500 200 1000 CIN = 1µF COUT = 10µF Tantalum Capacitor Load = 10mA Sampling Rate = 250KHz 80 40 0 25 50 75 80 100 125 2 8 10 1600 -1000 120 ≈ CIN = 1µF COUT = 68µF Tantalum Capacitor Load = 10mA Sampling Rate = 250KHz 80 40 0 0 25 50 75 Frequency (KHz) 100 Noise Signal (uV) 6 125 4 6 8 10 0 0 25 50 75 Frequency (KHz) 100 125 Noise Signal & Spectrum Distribution Noise Level (uV) Noise Signal (uV) Noise Level (uV) 4 200 1000 www.richtek-ic.com.tw 6 Time (mS) Time (mS) CIN = 1µF COUT = 10µF Tantalum Capacitor Load = 100mA Sampling Rate = 250KHz 40 Noise Signal & Spectrum Distribution 2 1M ≈ Frequency (KHz) 0 100K 1600 -1000 120 ≈ 0 0 Noise Signal (uV) 4 Noise Level (uV) Noise Level (uV) Noise Signal (uV) 2 10K Noise Signal & Spectrum Distribution Time (mS) 0 1K Frequency (Hz) 0 2 Time (mS) 4 6 8 10 200 1000 1600 -1000 120 ≈ CIN = 1µF COUT = 68µF Tantalum Capacitor Load = 100mA Sampling Rate = 250KHz 80 40 0 0 25 50 75 100 125 Frequency (KHz) DS9172-03 April 2002 RT9172 Preliminary Output Voltage Deviation (V) VIN = 3.5V 0.2 COUT = 10µF Tantalum 0.1 TT 02 > -0.1 Load Current (A) CIN = 10µF Electrolytic Load Transient Response ≈ ≈ 1 T 0.11 > 0 10 20 30 40 50 60 70 80 90 100 0.3 CIN = 68µF Tantalum 0.1 TT 02 > ≈ ≈ 1 T 0.11 > 0 10 20 30 Time (µS) Output Voltage (mV) TT 02 > ≈ ≈ T 3.5 1↓ 0 10 20 30 40 50 60 Time (µS) DS9172-03 April 2002 70 80 90 100 Input Voltage (V) Output Voltage (mV) Input Voltage (V) COUT = 10µF 100 VOUT = 2.5V Loading = 100mA 4.5 50 60 70 80 90 100 Line Transient Response 150 -50 40 Time (µS) Line Transient Response 50 VIN = 3.5V 0.2 COUT = 10µF Tantalum -0.1 Load Current (A) Output Voltage Deviation (V) Load Transient Response 0.3 150 COUT = 68µF VOUT = 2.5V Loading = 100mA T 100 50 T 02 > -50 ≈ ≈ 4.5 T 1> 3.5 0 10 20 30 40 50 60 70 80 90 100 Time (µS) www.richtek-ic.com.tw 7 RT9172 Preliminary Functional Description Capacitor Selection Dropout Voltage The RT9172 requires a minimum input capacitance of The dropout voltage of a regulator is defined as the 1µF between the input and ground pins to prevent any minimum input-to-output differential required to stay impedance interactions with the supply. The RT9172 within 2% of the output voltage. The RT9172 uses an requires a minimum of 10µF (tantalum, or electrolytic) capacitance between the output and ground pins for internal MOS-FET with an RDS(ON) 160mΩ. For CMOS LDOs, the dropout voltage is the product of the proper operation, if used 10µF ceromic please parrell load current and the RDS(ON) of the internal MOSFET. with 100µF tantalum or electrolytic. Larger capacitance provides better load dynamics and noise performance. Maximum Output Current Capability RT9172 can deliver a continuous current of 1.5 A over Error Operation (FLG) the full operating temperature range. A heatsink may The RT9172 produces a logic low signal at the FLG pin be required depending on the maximum power when the output drops out of regulation due to low input dissipation and maximum ambient temperature of the voltage, current limiting, or thermal limiting. application. Under all possible conditions, the junction The internal error FLG comparator has an open drain output stage. Hence, the FLG pin should be pulled high through a pull up resistor. temperature must be within the range specified under operating conditions. The total power dissipation of the device is given by: PD = (VIN - VOUT) IOUT+ (VIN) IGND Sense Pin In applications where the regulator output is not very close to the load, RT9172 can provide better remote load regulation using the SENSE pin. Fig.2 and Fig.3 depict the advantage of the SENSE option. RT9172 regulates the voltage at the output pin. Hence, the voltage at the remote load will be the regulator output voltage minus the drop across the trace resistance. For example, in the case of a 3.3V output, if the trace resistance is 100mΩ, the voltage at the remote load will be 3V with 3A of load current, ILOAD. The RT9172 regulates the voltage at the sense pin. Connecting the sense pin to the remote load will provide regulation at the remote load, as shown in Fig.2 and Fig.3. where IGND is the operating ground current of the device (specified under Electrical Characteristics). The maximum allowable temperature rise (TRMAX) depends on the maximum ambient temperature (TAMAX) of the application, and the maximum allowable junction temperature (TJMAX): TRMAX = TJMAX – TAMAX The maximum allowable value for junction to ambient Thermal Resistance, θJA = TRMAX - TAMAX The maximum allowable value for junction to ambient Thermal Resistance, θJA, can be calculated using the formula: θJA = TRMAX / PD RT9172 are available in TO-220, TO-263, and SOT- Chip Enable Operation 223 packages. The thermal resistance depends in A CMOS logic level signal at the chip enable (EN) pin amount of copper area or heat sink, and on air flow. If will turn-off the regulator. Pin EN must be actively terminated through a 10kΩ pull-up resistor for a proper the maximum allowable value of θJA calculated above is ≧ 60 °C/W for TO-220 package, ≧ 60 °C/W for operation. If this pin is driven from a source that actively TO-263 package, and ≧140 pulls high and low (such as a CMOS rail to rail package, no heatsink is needed since the package comparator), the pull-up resistor is not required. This can pin must be tied to VIN if not used. requirements. If the value for allowable θJA falls below dissipate enough °C/W for SOT-223 heat to satisfy these these limits, a heat sink is required. www.richtek-ic.com.tw 8 DS9172-03 April 2002 RT9172 Preliminary Heatsinking TO-220Packages The thermal resistance of a TO-220 package can be reduced by attaching it to a heat sink or a copper plane on a PC board. If a copper plane is to be used, the values of θJA will be same as shown in next section for TO-263 package. As shown in the figure, increasing the copper area beyond 1 square inch produces very little improvement. The minimum value for θJA for the TO263 package mounted to a PCB is 32°C/W. Heatsinking TO-263 and SOT-223 Packages The TO-263 and SOT-223 packages use the copper plane on the PCB as a heatsink. The tab of these packages are soldered to the copper plane for heat sinking. Fig.4 shows a curve for θJA of TO-263 package for different copper area sizes, using a typical PCB with 1 ounce copper and no solder mask over the copper area for heat sinking. θJA vs. Copper (1 Ounce) Area for TO-263 200 180 TRMAX = TJMAX - TAMAX 160 4W 140 120 100 2.5W 80 60 1W 40 20 0 0 0.5 1 1.5 2 2.5 3 Copper Foil Area (SQ. IN.) Fig. 4 DS9172-03 April 2002 www.richtek-ic.com.tw 9 RT9172 Preliminary Package Information D F A M C E1 E MARK L1 A1 b1 b2 b L2 e Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 4.064 4.826 0.160 0.190 A1 2.032 2.921 0.080 0.115 b 0.635 1.016 0.025 0.040 b1 1.143 1.524 0.045 0.060 b2 0.305 0.559 0.012 0.022 C 1.143 1.397 0.045 0.055 D 9.779 10.668 0.385 0.420 E 7.620 9.398 0.300 0.370 e 2.286 2.794 0.090 0.110 E1 11.176 12.954 0.440 0.510 F 2.616 2.870 0.103 0.113 L1 17.526 18.542 0.690 0.730 L2 7.544 8.636 0.297 0.340 M 3.708 3.962 0.146 0.156 3-Lead TO-220 Plastic Package www.richtek-ic.com.tw 10 DS9172-03 April 2002 RT9172 Preliminary A D C B MARK E L1 b1 b L2 b2 e U V 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 DS9172-03 April 2002 www.richtek-ic.com.tw 11 RT9172 Preliminary D D1 B C L e e A H A1 b Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A -- 1.803 -- 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 0.914 -- 0.036 -- 3-Lead SOT-223 Plastic Surface Mount www.richtek-ic.com.tw 12 DS9172-03 April 2002 RT9172 Preliminary D A M C F E1 MARK E P A1 b2 e Symbol b Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 4.064 4.826 0.160 0.190 A1 2.032 2.921 0.080 0.115 b 0.635 1.016 0.025 0.040 b2 0.305 0.559 0.012 0.022 C 1.143 1.397 0.045 0.055 c 1.524 1.829 0.060 0.072 D 9.779 10.668 0.385 0.420 E 7.620 9.398 0.300 0.370 E1 11.176 12.954 0.440 0.510 F 14.224 15.113 0.560 0.595 M 3.708 3.962 0.146 0.156 P 24.689 26.416 0.972 1.040 5-Lead TO-220 Plastic Package DS9172-03 April 2002 www.richtek-ic.com.tw 13 RT9172 Preliminary A D C B MARK E L1 L2 b2 b e U V 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 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 1.524 1.829 0.060 0.072 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. 5-Lead TO-263 Plastic Surface Mount Package www.richtek-ic.com.tw 14 DS9172-03 April 2002 Preliminary DS9172-03 April 2002 RT9172 www.richtek-ic.com.tw 15 RT9172 Preliminary RICHTEK TECHNOLOGY CORP. RICHTEK TECHNOLOGY CORP. Headquarter Taipei Office (Marketing) 6F, No. 35, Hsintai Road, Chupei City 8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5510047 Fax: (8863)5537749 Tel: (8862)89191466 Fax: (8862)89191465 Email: [email protected] www.richtek-ic.com.tw 16 DS9172-03 April 2002