TK11900 ADJUSTABLE LOW DROPOUT REGULATOR FEATURES APPLICATIONS ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Low Supply Current Low Power Shutdown Mode Low Noise Output Low Dropout Voltage Extremely High Stability High Speed On/Off Transient (50 µs typ.) ■ Miniature Package (SOT-23L) Portable Instrumentation Cordless Telephones Pagers Toys Cellular Telephones Test Equipment DESCRIPTION The TK11900 is a low dropout voltage regulator with external voltage adjustment. The output can be set between 1.5 V and 15 V by an external pair of resistors in a divider configuration. The device has a bypass pin for an external capacitor to reduce output noise to a typical 50 µV(rms). In addition, a control pin is provided that is active low (a low level turns on the output). In the “off” mode (control pin high) the device draws only 65 µA of quiescent current. TK11900 NOISE BYPASS 01 S The TK11900 is available in a miniature SOT-23L surface mount package. VIN CONTROL GND FEEDBACK VOUT ORDERING INFORMATION BLOCK DIAGRAM TK11900M Tape/Reel Code VIN CONTROL VOUT SHUT DOWN THERMAL PROTECTION TAPE/REEL CODE TL: Tape Left BANDGAP REFERENCE FEEDBACK NOISE BYPASS November 2000 TOKO, Inc. GND Page 1 TK11900 ABSOLUTE MAXIMUM RATINGS Supply Voltage ......................................................... 17 V Operating Voltage Range ............................... 1.8 to 16 V Power Dissipation (Note 1) ................................. 400 mW Storage Temperature Range ..................... -55 to +150 °C Operating Temperature Range ..................... -30 to +80 °C Junction Temperature .......................................... 150 °C Lead Soldering Temperature (10 s) ....................... 235 °C TK11900M ELECTRICAL CHARACTERISTICS Test conditions: VIN = VOUT(TYP) + 1 V, TA = 25 °C, unless otherwise specified. SYMBOL PARAMETER TEST CONDITIONS MIN TYP MAX UNITS VIN = VOUT(TYP) + 1 V, IOUT = 0 mA 140 300 µA VIN = VOUT(TYP) - 1 V, IOUT = 0 mA 380 900 µA 65 140 µA 15 V 350 mV 100 mA IQ Quiescent Current ISTBY Standby Current Output OFF VOUT Output Voltage (Note 2) VDROP Dropout Voltage IOUT = 30 mA IOUT Output Current Line Reg Line Regulation VOUT(TYP) + 1 V ≤ VIN ≤ VOUT(TYP) + 10 V 5 50 mV Load Reg Load Regulation 1 mA ≤ IOUT ≤ 80 mA 20 100 mV ∆VOUT /∆T Temperature Coefficient VIN = VOUT(TYP) - 1 V RR Ripple Rejection VNO Output Noise Voltage Vref Reference Voltage 1.5 160 ±0.15 mV/°C CL = 10 µF, f = 400 Hz 68 dB 10 Hz ≤ f ≤ 100 kHz, CL = 10 µF, CN = 0.01 µF 50 µVrms TA = 25 °C 1.225 1.250 1.275 V TA = -30 to 80 °C 1.210 1.250 1.290 V VCONT = 5 V 25 100 µA VCONT = 16 V 45 150 µA 0.6 V CONTROL TERMINAL SPECIFICATIONS ICONT Control Terminal Current VCONT(ON) Control Voltage (ON) Output ON VCONT(OFF) Control Voltage (OFF) Output OFF TR Output Rise Time (OFF to ON) IOUT = 30 mA, CL = 0.1 µF, CN = 0.1 µF 2.2 V 50 µs Note 1: Power dissipation is 400 mW when mounted as recommended. Derate at 3.2 mW/°C for operation above 25°C. Note 2: The output voltage can be set from 1.5 to 15 V by two external resistors. “Refer to Definition of Terms.” Page 2 November 2000 TOKO, Inc. TK11900 TEST CIRCUIT IIN VOUT VIN + + CL 10 µF 1 µF IOUT R1 Note: VOUT = 1.25 [(R1 + R2) / R2] 10 k - R2 - 60 k Connect Pin 5 to ground NOISE BYPASS CONT Note: CL is a tantalum capacitor ICONT CN 0.01 µF FEEDBACK R2 VCONT TYPICAL PERFORMANCE CHARACTERISTICS VOUT = 5 V, TA = 25 °C, unless otherwise specified. OUTPUT VOLTAGE VS. OUTPUT CURRENT QUIESCENT CURRENT VS. INPUT VOLTAGE OUTPUT VOLTAGE VS. INPUT VOLTAGE 5.1 500 5.1 5.0 4.9 IQ (mA) VOUT (V) VOUT (V) 5.0 4.8 250 4.7 4.6 4.9 0 50 100 0 0 10 0 20 10 20 IOUT (mA) VIN (V) VIN (V) OUTPUT VOLTAGE CHARACTERISTICS VS. INPUT VOLTAGE 5.5 REFERENCE VOLTAGE (FEEDBACK PIN) VS. TEMPERATURE GROUND CURRENT VS. OUTPUT CURRENT 10 5.0 IGND (mA) 1.27 IOUT = 0 mA Vref (V) VOUT (V) 1.28 1.26 1.25 30 mA 1.24 60 mA 4.5 4.5 5.0 VIN (V) November 2000 TOKO, Inc. 5 5.5 1.23 -50 0 0 50 TA (°C) 100 0 50 100 IOUT (mA) Page 3 TK11900 TYPICAL PERFORMANCE CHARACTERISTICS (CONT.) VOUT = 5 V, TA = 25 °C, unless otherwise specified. INPUT CURRENT AND CONTROL CURRENT VS. CONTROL VOLTAGE NOISE VS. BYPASS CAPACITOR VALUE 400 200 300 200 100 100 200 IIN 150 100 100 SHUTDOWN POINT 50 0 0 50 ICONT 0 1 pF 100 IOUT (mA) OUTPUT VOLTAGE VS. OUTPUT CURRENT 0 0 0 10 pF 100 pF1000 pF 0.01 µF0.1 µF CN 2.5 5.0 VCONT (V) RIPPLE REJECTION VS. FREQUENCY 0 5 VOUT VIN RR (dB) VOUT (V) 4 3 11900 CL = 0.1 µF SW CL 10 F -50 CN 0.01 F 0.1 F 2 CL = 10 µF 1 RIPPLE REJECTION CIRCUIT 0 0 100 -100 10 200 100 1k 10 k 100 k IOUT (mA) f (Hz) NOISE VS. SPECTRUM LINE VOLTAGE STEP RESPONSE LOAD CURRENT STEP RESPONSE SPECTRUM ANALYZER BACKGROUND NOISE IOUT 50 mA 0 mA VOUT VIN 6V VOUT (100 mV / DIV) -100 7V VOUT VOUT (20 mV / DIV) NOISE (dB) -50 IOUT = 25 mA CL = 0.1 µF CN = 0.1 µF CL = 3.3 µF CN = 0.1 µF -150 0 500 k f (Hz) Page 4 50 1M TIME (50 µs/DIV) TIME (50 µs/DIV) November 2000 TOKO, Inc. ICONT (µA) 300 IIN (µA) 500 NOISE (µV) VDROP (mV) DROPOUT VOLTAGE VS. OUTPUT CURRENT TK11900 TYPICAL PERFORMANCE CHARACTERISTICS (CONT.) VOUT = 5 V, TA = 25 °C, unless otherwise specified. STANDBY CURRENT (OFF MODE) VS. TEMPERATURE GROUND CURRENT (ON MODE) VS. TEMPERATURE 2.4 V 100 10 10 µF 5 ISTBY (µA) CL = .1 µF IGND (mA) 1 µF 0V VOUT VOUT (1 V / DIV) VCONT TURN-ON TIME VS. OUTPUT CAPACITOR IOUT = 60 mA 15 µF 50 IOUT = 30 mA 4.7 µF 0 -50 0 50 100 TA (°C) CONTROL CURRENT VS. TEMPERATURE CONTROL VOLTAGE (OFF POINT) VS. TEMPERATURE DROPOUT VOLTAGE VS. TEMPERATURE 2.0 500 VCONT = 5 V 30 20 VDROP (mV) VCONT (V) ICONT (µA) 50 TA (°C) 40 0 -50 0 TIME (50 µs/DIV) 50 10 0 -50 100 1.0 VCONT = 2.5 V 0 50 TA (°C) November 2000 TOKO, Inc. 400 300 IOUT = 60 mA 200 IOUT = 30 mA 100 100 0 -50 0 50 TA (°C) 100 0 -50 0 50 100 TA (°C) Page 5 TK11900 DEFINITION AND EXPLANATION OF TECHNICAL TERMS QUIESCENT CURRENT (IQ) PACKAGE POWER DISSIPATION (PD) The quiescent current is the current which flows through the ground terminal under no load (IOUT = 0 mA). This is the power dissipation level at which the thermal sensor is activated. The IC contains an internal thermal sensor which monitors the junction temperature. When the junction temperature exceeds the monitor threshold of 150 °C, the IC is shut down. The junction temperature rises as the difference between the input power (VIN x IIN) and the output power (VOUT x IOUT) increases. The rate of temperature rise is greatly affected by the mounting pad configuration on the PCB, the board material, and the ambient temperature. When the IC mounting has good thermal conductivity, the junction temperature will be low even if the power dissipation is great. When mounted on the recommended mounting pad, the power dissipation of the SOT23L is increased to 400 mW. For operation at ambient temperatures over 25 °C, the power dissipation of the SOT23L device should be derated at 3.2 mW/°C. To determine the power dissipation for shutdown when mounted, attach the device on the actual PCB and deliberately increase the output current (or raise the input voltage) until the thermal protection circuit is activated. Calculate the power dissipation of the device by subtracting the output power from the input power. These measurements should allow for the ambient temperature of the PCB. The value obtained from PD /(150 °C - TA) is the derating factor. The PCB mounting pad should provide maximum thermal conductivity in order to maintain low device temperatures. As a general rule, the lower the temperature, the better the reliability of the device. The thermal resistance when mounted is expressed as follows: GROUND CURRENT (IGND) Ground current is the current which flows through the current pin(s). It is defined as IIN - IOUT, excluding control current. Line Regulation (Line Reg) Line regulation is the relationship between change in output voltage due to a change in input voltage. Load Regulation (Load Reg) Load regulation is the relationship between change in output voltage due to a change in load current. DROP OUT VOLTAGE (VDROP) This is a measure of how well the regulator performs as the input voltage decreases. The smaller the number, the further the input voltage can decrease before regulation problems occur. Nominal output voltage is first measured when VIN = VOUT(TYP) + 1 at a chosen load current. When the output voltage has dropped 100 mV from the nominal, VIN - VOUT is the dropout voltage. This voltage is affected by load current and junction temperature. OUTPUT NOISE VOLTAGE This is the effective AC voltage that occurs on the output voltage under the condition where the input noise is low and with a given load, filter capacitor, and frequency range. THERMAL PROTECTION This is an internal feature which turns the regulator off when the junction temperature rises above 150 °C. After the regulator turns off, the temperature drops and the regulator output turns back on. Under certain conditions, the output waveform may appear to be an oscillation as the output turns off and on and back again in succession. Page 6 Tj = 0jA x PD + TA For Toko ICs, the internal limit for junction temperature is 150 °C. If the ambient temperature (TA) is 25 °C, then: 150 °C = 0jA x PD + 25 °C 0jA = 125 °C / PD PD is the value when the thermal sensor is activated. A simple way to determine PD is to calculate VIN x IIN when the output side is shorted. Input current gradually falls as temperature rises. You should use the value when thermal equilibrium is reached. November 2000 TOKO, Inc. TK11900 DEFINITION AND EXPLANATION OF TECHNICAL TERMS (CONT.) The range of usable currents can also be found from the graph below. (mW) 3 PD 6 DPD 4 5 25 50 75 TA (°C) 150 Procedure: 1) 2) 3) 4) 5) 6) Find PD PD1 is taken to be PD x (~ 0.8 - 0.9) Plot PD1 against 25 °C Connect PD1 to the point corresponding to the 150 °C with a straight line. In design, take a vertical line from the maximum operating temperature (e.g., 75 °C) to the derating curve. Read off the value of PD against the point at which the vertical line intersects the derating curve. This is taken as the maximum power dissipation, DPD. The maximum operating current is: IOUT = (DPD / (VIN(MAX) - VOUT) 500 MOUNTED PD (mW) 400 300 FREE AIR 200 100 0 0 50 100 150 TA (°C) SOT-23L POWER DISSIPATION November 2000 TOKO, Inc. Page 7 TK11900 APPLICATION INFORMATION BOARD LAYOUT to consider the characteristics of the capacitor over temperature when selecting decoupling capacitors. Copper pattern should be as large as possible. Power dissipation is 400 mW for the SOT-23L package. A low Equivalent Series Resistance (ESR) capacitor is recommended. For low temperature operation, select a capacitor with a low ESR at the lowest operating temperature to prevent oscillation, degradation of ripple rejection and increase in noise. The minimum recommended capacitance is 2.2 µF. GND VIN VOUT + + NOISE BYPASS The ESR is another important parameter. The ESR will increase with temperature but low ESR capacitors are often larger and more costly. In general, tantalum capacitors offer lower ESR than aluminum electrolytic, but new low ESR aluminum electrolytic capacitors are now available from several manufacturers. Usually a bench test is sufficient to determine the minimum capacitance required for a particular application. After taking thermal characteristics and tolerance into account, the minimum capacitance value should capacitor or 3.3 µF for an aluminum electrolytic. Please note that linear regulators with a low dropout voltage have high internal loop gains which require care in guarding against oscillation caused by insufficient decoupling capacitance. The use of high quality decoupling capacitors suited for your application will guarantee proper operation of the circuit. NOISE BYPASS CAPACITOR SECTION GND FEEDBACK CONTROL SOT-23L BOARD LAYOUT INPUT/OUTPUT DECOUPLING CAPACITOR CONSIDERATIONS Voltage regulators require input and output decoupling capacitors. The required values of these capacitors vary with application. Capacitors made by different manufacturers can have different characteristics, particularly with regard to high frequencies and ESR over temperature. The type of capacitor is also important. For example, a 4.7 µF aluminum electrolytic may be required for a certain application. If a tantalum capacitor is used, a lower value of 2.2 µF would be adequate. It is important to consider the temperature characteristics of the decoupling capacitors. While Toko regulators are designed to operate as low as -30 °C, many capacitors will not operate properly at this temperature. The capacitance of aluminum electrolytic capacitors may decrease to 0 at low temperatures. This may cause oscillation on the output of the regulator since some capacitance is required to guarantee stability. Thus, it is important The noise bypass capacitor (CN) should be connected as close as possible to pin 1 and ground. The recommended value for CN is 0.01 mF. The noise bypass terminal has a high impedance and care should be taken if the noise bypass capacitor is not used. This terminal is susceptible to external noise, and oscillation can occur when CN is not used and the solder pad for this pin is too large. OUTPUT VOLTAGE SETTING The output voltage can be set from 1.5 to 15 V by two external resistors according to the following equation: VOUT = 1.25 V x [(R1 + R2) / R2] VOUT R1 FEEDBACK R2 where 10 kΩ - R2 - 60 k Page 8 November 2000 TOKO, Inc. TK11900 APPLICATION INFORMATION (CONT.) CURRENT BOOST VIN VOUT + CL 10 µF RE 1 µF R1 Note: VOUT = 1.25 [(R1 + R2) / R2] 10 k - R2 - 60 k NOISE BYPASS CONT CN 0.1 µF FEEDBACK CONTROL R2 The output current can be increased by connecting an external NPN transistor as shown above. The output current capability depends on the Hfe of the external transistor. Note: The TK11900 internal short circuit protection and the thermal sensor do not protect the external transistor. November 2000 TOKO, Inc. Page 9 TK11900 PACKAGE OUTLINE Marking Information SOT-23L (SOT-23L-6) Marking TK11900 G0 0.6 6 5 4 e1 3.0 1.0 Marking 1 2 3 0.32 e +0.15 - 0.05 0.1 e 0.95 M e 0.95 e 0.95 3.5 0.95 Recommended Mount Pad +0.3 - 0.1 2.2 max 15 1.2 +0.15 - 0.05 0.4 0.15 0.1 0 - 0.1 1.4 max 0.3 (3.4) + 0.3 3.3 Dimensions are shown in millimeters Tolerance: x.x = ± 0.2 mm (unless otherwise specified) Toko America, Inc. Headquarters 1250 Feehanville Drive, Mount Prospect, Illinois 60056 Tel: (847) 297-0070 Fax: (847) 699-7864 TOKO AMERICA REGIONAL OFFICES Midwest Regional Office Toko America, Inc. 1250 Feehanville Drive Mount Prospect, IL 60056 Tel: (847) 297-0070 Fax: (847) 699-7864 Western Regional Office Toko America, Inc. 2480 North First Street , Suite 260 San Jose, CA 95131 Tel: (408) 432-8281 Fax: (408) 943-9790 Semiconductor Technical Support Toko Design Center 4755 Forge Road Colorado Springs, CO 80907 Tel: (719) 528-2200 Fax: (719) 528-2375 Visit our Internet site at http://www.tokoam.com The information furnished by TOKO, Inc. is believed to be accurate and reliable. However, TOKO reserves the right to make changes or improvements in the design, specification or manufacture of its products without further notice. TOKO does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infringements of patents or other rights of third parties which may result from the use of its products. No license is granted by implication or otherwise under any patent or patent rights of TOKO, Inc. Page 10 © 1999 Toko, Inc. All Rights Reserved November 2000 TOKO, Inc. IC-118-TK11900 0798O0.0K Printed in the USA