RT9168/A 200mA/500mA Fixed Output Voltage LDO Regulator General Description Features The RT9168/A is a 200mA/500mA low dropout and z Stable with Low-ESR Output Capacitor micropower portable z Low Dropout Voltage (220mV at 200mA) applications. The output voltages range from 1.5V to z Low Operation Current - 80µ µA Typical 5.0V in 100mV increments and 2% accuracy. The z Shutdown Function RT9168/A is designed for use with very low ESR z Low Temperature Coefficient capacitors. The output remains stable even with a z Current and Thermal Limiting 1µF ceramic output capacitor. z Custom Voltage Available z SOT-25 and SOP-8 Packages regulator suitable for The RT9168/A uses an internal PMOS as the pass device, which does not cause extra GND current in heavy load and dropout conditions. The shutdown mode of nearly zero operation current makes the IC Pin Configurations Part Number Pin Configurations suitable for battery-powered devices. Other features RT9168/A- CBR include current limiting and over temperature (Plastic SOT-25) TOP VIEW 5 4 1. 2. 3. 4. 5. protection. The SOP-8 and SOT-25 packages are also available for larger power dissipation and 1 2 3 design flexibility. TOP VIEW RT9168/A- CS Applications z Cellular Telephones z Laptop, Notebook, and Palmtop Computers z Battery-powered Equipment z Hand-held Equipment RT9168/A- CSH OUT 1 8 IN (Plastic SOP-8) GND 2 7 GND GND 3 6 GND NC 4 Ordering Information RT9168/A- Operating temperature range C: Commercial standard Output voltage 5 SHDN/SHDN Typical Application Circuit Package type BR : SOT-25 S : SOP-8 SH : SOP-8, High shutdown OUT GND IN SHDN NC RT9168 VIN IN CIN 1µF COUT 1µF GND SHDN SHDN VOUT OUT NC 15 : 1.5V 16 : 1.6V : : 49 : 4.9V 50 : 5.0V 500mA Output current 200mA Output current DS9168/A-03 May 2001 www.richtek-ic.com.tw 1 RT9168/A Marking Information Part Number Part Number Marking RT9168-15CBR L0 RT9168A-15CBR M0 RT9168-16CBR L1 RT9168A-16CBR M1 RT9168-17CBR L2 RT9168A-17CBR M2 RT9168-18CBR L3 RT9168A-18CBR M3 RT9168-19CBR L4 RT9168A-19CBR M4 RT9168-20CBR L5 RT9168A-20CBR M5 RT9168-21CBR L6 RT9168A-21CBR M6 RT9168-22CBR L7 RT9168A-22CBR M7 RT9168-23CBR L8 RT9168A-23CBR M8 RT9168-24CBR L9 RT9168A-24CBR M9 RT9168-25CBR LA RT9168A-25CBR MA RT9168-26CBR LB RT9168A-26CBR MB RT9168-27CBR LC RT9168A-27CBR MC RT9168-28CBR LD RT9168A-28CBR MD RT9168-29CBR LE RT9168A-29CBR ME RT9168-30CBR LF RT9168A-30CBR MF RT9168-31CBR LG RT9168A-31CBR MG RT9168-32CBR LH RT9168A-32CBR MH RT9168-33CBR LJ RT9168A-33CBR MJ RT9168-34CBR LK RT9168A-34CBR MK RT9168-35CBR LL RT9168A-35CBR ML RT9168-36CBR LM RT9168A-36CBR MM RT9168-37CBR LN RT9168A-37CBR MN RT9168-38CBR LP RT9168A-38CBR MP RT9168-39CBR LQ RT9168A-39CBR MQ RT9168-40CBR LR RT9168A-40CBR MR RT9168-41CBR LS RT9168A-41CBR MS RT9168-42CBR LT RT9168A-42CBR MT RT9168-43CBR LU RT9168A-43CBR MU RT9168-44CBR LV RT9168A-44CBR MV RT9168-45CBR LW RT9168A-45CBR MW RT9168-46CBR LX RT9168A-46CBR MX RT9168-47CBR LY RT9168A-47CBR MY RT9168-48CBR LZ RT9168A-48CBR MZ RT9168-49CBR CL RT9168A-49CBR CN RT9168-50CBR CM RT9168A-50CBR CP www.richtek-ic.com.tw 2 Marking DS9168/A-03 May 2001 RT9168/A Pin Description Pin Name Pin Function IN Input GND Ground SHDN (SHDN) Active Low (High) Shutdown Input NC No Connection OUT Output Function Block Diagram SHDN or SHDN Shutdown and Logic Control IN VREF + _ Error Amp MOS Driver Current-Limit and OUT Thermal Protection GND DS9168/A-03 May 2001 www.richtek-ic.com.tw 3 RT9168/A Absolute Maximum Ratings z Input Voltage 8V z Power Dissipation, PD @ TA = 25°C SOT-25 0.25W SOP-8 0.625W z Operating Junction Temperature Range −40°C to 125°C z Storage Temperature Range −65°C to 150°C z Package Thermal Resistance z SOT-25, θJA 250°C/W SOP-8, θJA 160°C/W Lead Temperature (Soldering, 5 sec.) 260°C Electrical Characteristics (VIN = 5.0V, CIN = 1µF, COUT = 1µF, TA = 25°C, unless otherwise specified) Parameter Symbol Input Voltage Range VIN Output Voltage Accuracy ∆VOUT Maximum Output Current Current Limit RT9168 RT9168A RT9168 RT9168A RT9168 Min Typ Max 2.9 -- 7 IL = 50mA 2.7 -- 7 IL = 1mA -2 -- +2 % 200 -- -- mA 500 -- -- mA -- 300 -- mA -- 700 -- mA No Load -- 80 150 IOUT = 200mA -- 90 150 IOUT = 500mA -- 90 150 IOUT = 1mA -- 1.1 5 mV IOUT = 50mA -- 55 100 mV IOUT = 200mA -- 220 300 mV IOUT = 500mA -- 600 750 mV -0.2 -- +0.2 %/V IOUT = 0mA to 200mA -- 0.01 0.04 IOUT = 0mA to 500mA -- 0.01 0.04 IMAX ILIMIT RT9168/A GND Pin Current Test Conditions IG RT9168A RT9168/A (Note) Dropout Voltage RT9168/A (VOUT(Nominal)≥3.0V RT9168/A Version) RT9168A VDROP Line Regulation ∆VLINE Load Regulation ∆VLOAD RLOAD = 1 Ohm VIN = (VOUT+0.15) to 7V, IOUT = 1mA Units V µA %/mA SHDN, SHDN Input High Threshold VIH VIN = 3V to 5.5V 2.2 -- -- V SHDN, SHDN Input Low Threshold VIL VIN = 3V to 5.5V -- -- 0.4 V SHDN, SHDN Bias Current ISD -- -- 100 nA Shutdown Supply Current IGSD -- 0.01 1 µA Thermal Shutdown Temperature TSD -- 155 -- °C Ripple Rejection PSRR -- 58 -- dB VOUT = 0V F = 100Hz, CBP = 10nF, COUT = 10µF Notes: Dropout voltage definition: VIN - VOUT when VOUT is 50 mV below the value of VOUT at VIN = VOUT + 0.5V www.richtek-ic.com.tw 4 DS9168/A-03 May 2001 RT9168/A Typical Operating Charateristics GND Current vs. Temp. 120 3.32 105 GND Current ( µ A) Output Voltage (V) Output Voltage vs. Temp. 3.33 3.31 3.30 3.29 3.28 90 75 60 45 30 3.27 15 3.26 VOUT = 3.3V 3.25 -50 -25 0 25 50 75 100 125 VOUT = 3.3V 0 -50 150 -25 0 Dropout Voltage vs. Output Current 75 100 125 150 Current Limit vs. Temp. 480 300 420 Current Limit (mA) 85°C 250 Dropout Voltage (mV) (V) 50 Temperature ( °C °C )) °C)) Temperature (°C 25°C 200 -40°C 150 100 360 300 240 180 120 50 RT9168 VOUT = 3.3V 60 VOUT = 3.3V 0 0 25 50 75 100 125 150 175 0 -50 200 -25 0 25 50 75 100 125 150 Temperature (°C (°C ) Output Current (mA) Current Limit vs. Temp. 900 70 800 60 700 PSRR 50 PSRR (dB) Current Limit (mA) 25 600 500 400 40 30 20 300 RT9168A VOUT = 3.3V 200 100 -50 -25 0 25 50 75 100 Temperature (°C )) DS9168/A-03 May 2001 125 ILOAD = 1mA, COUT = 4.7µF VOUT = 3.3V 10 150 0 10 10 100 100 1K 1000 10K 10000 100K 100000 1M 100000 Frequency (KHz) www.richtek-ic.com.tw 5 RT9168/A Load Transient Response Output Voltage Deviation (mV) 20 TT 02 > ≈ T 11 > -50 Time (50µS/Div) COUT = 1µF 100 VOUT = 3.0V Loading = 1mA 50 TT 02 > -50 ≈ ≈ 5 T 4 1↓ TT 02 > -20 Output Voltage (mV) Line Transient Response 150 20 ≈ 50 ≈ ≈ 50 T 11 > -50 Time (50µS/Div) Line Transient Response 150 COUT = 1µF 100 VOUT = 3.0V Loading = 50mA 50 TT 02 > -50 ≈ ≈ 5 T 4 1↓ Input Voltage (V) Output Voltage (mV) Line Transient Response COUT = 4.7µF 100 VOUT = 3.0V Loading = 1mA 50 TT 2> 0 -50 ≈ 5 ≈ T 4 1↓ Time (500µS/Div) www.richtek-ic.com.tw 6 Time (1mS/Div) Line Transient Response 60 COUT = 4.7µF 40 VOUT = 3.0V Loading = 50mA 20 TT 2> 0 -20 Input Voltage (V) Output Voltage (mV) Time (1mS/Div) 150 VOUT = 3.0V VIN = 4V COUT = 4.7µF 40 CIN = 10µF Load Current (mA) Load Current (mA) Output Voltage (mV) VOUT = 3.0V VIN = 4V COUT = 1µF 40 CIN = 10µF -20 Input Voltage (V) Load Transient Response 60 Input Voltage (V) Output Voltage Deviation (mV) 60 ≈ 5 ≈ T 4 1↓ Time (500µS/Div) DS9168/A-03 May 2001 RT9168/A Applications Guides Capacitor Selection and Regulator Stability Region of Stable COUT ESR vs. Load Current 100 Like any low-dropout regulator, the external capacitors COUT = 4.7µF used with the RT9168/A must be carefully selected for 10 Using a capacitor whose value is > 1µF on the RT9168/A input and the amount of capacitance can be increased without limit. The input capacitor must be located not more than 0.5" from the input pin of the IC and returned to a clean analog ground. Any good COUT ESR (mΩ) (Ω) Ω regulator stability and performance. COUT = 1µF 1 0.1 0.01 quality ceramic or tantalum can be used for this capacitor. The capacitor with larger value and lower ESR (equivalent series resistance) provides better 0.001 0 40 80 PSRR and line-transient response. applications. The RT9168/A is designed specifically to work with low ESR ceramic output capacitor in spacesaving and performance consideration. Using a ceramic capacitor whose value is at least 1µF with ESR is > 5mΩ on the RT9168/A output ensures stability. The RT9168/A still works well with output 160 200 Fig. 1 The output capacitor must meet both requirements for minimum amount of capacitance and ESR in all LDO 120 Load Current (mA) 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. capacitor of other types due to the wide stable ESR Load-Transient Considerations range. Fig.1 shows the curves of allowable ESR range The RT9168/A load-transient response graphs (see as a function of load current for various output voltages and capacitor values. Output capacitor of larger capacitance can reduce noise and improve load-transient response, stability, and PSRR. The output capacitor should be located not more than 0.5" from the VOUT pin of the RT9168/A and returned to a clean analog ground. 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 Typical Operating Characteristics) 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. stability at temperatures below -10°C in this case. Also, Shutdown Input Operation tantalum capacitors, 2.2µF or more may be needed to The RT9168/A is shutdown by pulling the SHDN maintain capacitance and ESR in the stable region for strict application environment. input low, and turned on by driving the input high. If this feature is not to be used, the SHDN input should be tied to VIN to keep the regulator on at all times (the SHDN input must not be left floating). DS9168/A-03 May 2001 www.richtek-ic.com.tw 7 RT9168/A To ensure proper operation, the signal source used to prevent regulator mis-operation, a Schottky diode drive the SHDN input must be able to swing above and should below the specified turn-on/turn-off voltage thresholds input/output voltage conditions can cause the which guarantee an ON or OFF state (see Electrical internal diode to be turned on (see Fig.3). As shown, Characteristics). The ON/OFF signal may come from the Schottky diode is connected in parallel with the either CMOS output, or an open-collector output with internal parasitic diode and prevents it from being pull-up resistor to the RT9168/A input voltage or turned on by limiting the voltage drop across it to another logic supply. The high-level voltage may about 0.3V. < 100 mA to prevent damage to the part. be used in any applications where exceed the RT9168/A input voltage, but must remain within the absolute maximum ratings for the SHDN pin. Internal P-Channel Pass Transistor The RT9168/A features a typical 1.1Ω P-channel MOSFET pass transistor. It provides VIN VOUT several advantages over similar designs using PNP pass Fig. 2 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 RT9168/A does not suffer from these problems and consume only 80µA of VIN VOUT quiescent current whether in dropout, light-load, or heavy-load applications. Fig. 3 Input-Output (Dropout) Voltage A regulator’s minimum input-output voltage differential (or dropout voltage) determines the Current Limit and Thermal Protection lowest usable supply voltage. In battery-powered The RT9168 includes a current limit which monitors systems, this will determine the useful end-of-life and controls the pass transistor’s gate voltage limiting battery voltage. Because the RT9168/A uses a P- the output current to 300mA Typ. (700mA Typ. for channel MOSFET pass transistor, the dropout RT9168A). Thermal-overload protection limits total voltage is a function of drain-to-source on-resistance power dissipation in the RT9168/A. When the junction [RDS(ON)] multiplied by the load current. temperature exceeds TJ = +155°C, the thermal sensor signals the shutdown logic turning off the pass Reverse Current Path The power transistor used in the RT9168/A has an inherent diode connected between the regulator input and output (see Fig.2). If the output is forced above the input by 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 www.richtek-ic.com.tw 8 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 thermal-overload conditions. Thermal-overloaded protection is designed to protect the RT9168/A in the event of fault conditions. Do not exceed the absolute maximum junctiontemperature rating of TJ = +150°C for continuous operation. The output can be shorted to ground for an DS9168/A-03 May 2001 RT9168/A indefinite amount of time without damaging the part by cooperation of current limit and thermal protection. Operating Region and Power Dissipation The maximum power dissipation of RT9168/A 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: PMAX = (TJ - TA) /θJA where TJ - TA is the temperature difference between the RT9168/A die junction and the surrounding environment, θJA is the thermal resistance from the junction to the surrounding environment. The GND pin of the RT9168/A 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. DS9168/A-03 May 2001 www.richtek-ic.com.tw 9 RT9168/A Package Information D C B b H A e Symbol L A1 Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.889 1.295 0.035 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.356 0.559 0.014 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 0.102 0.254 0.004 0.010 L 0.356 0.610 0.014 0.024 SOT- 25 Surface Mount Package www.richtek-ic.com.tw 10 DS9168/A-03 May 2001 RT9168/A H A M J B F C D Symbol I Dimensions In Millimeters Dimensions In Inches 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 0.178 0.254 0.007 0.010 I 0.102 0.254 0.004 0.010 J 5.791 6.198 0.228 0.244 M 0.406 1.270 0.016 0.050 8–Lead SOP Plastic Package DS9168/A-03 May 2001 www.richtek-ic.com.tw 11 RT9168/A 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: marketing@richtek-ic.com.tw DS9168/A-03 May 2001 www.richtek-ic.com.tw 13