SC1457EVB

150mA Ultra Low Dropout Regulator with Undervoltage Flag POWER MANAGEMENT Description The SC1457 is a low dropout linear regulator that operates from a +2.25V to +6.5V input range and delivers up to 150mA. A PMOS pass transistor allows the low 75µA supply current to remain independent of load, making these devices ideal for battery operated portable equipment such as cellular phones, cordless phones and personal digital assistants. The SC1457 has very low dropout voltage (typically 1.1mV at light loads and 150mV at 150mA) with better than 1.5% initial output voltage accuracy. It has a logic compatible enable control input and an internal output undervoltage monitor. Designed especially for hand held, battery powered devices, the SC1457 can be switched by a CMOS or TTL compatible logic signal. When disabled, power consumption drops nearly to zero. Other features include short circuit protection, thermal shutdown protection and reverse battery protection. The SC1457 is available in several fixed voltages in the tiny 5 lead SOT-23 package and the ultra low profile 5 lead TSOT-23. SC1457 Features Guaranteed 150mA output current Error flag indicates output undervoltage fault 2% output accuracy guaranteed over line, load and temperature Very small external components - designed to work with ceramic capacitors Low 110µVRMS output noise Very low supply current Thermal overload protection Reverse battery protection Low power shutdown Full industrial temperature range Very low profile packaging available (1mm max. height) Surface mount packaging (SOT-23-5 and TSOT-23-5) Applications Battery Powered Systems Cellular Telephones Cordless Telephones Personal Digital Assistants Portable Instrumentation Modems PCMCIA cards Typical Application Circuit U1 VIN C1 1uF 1 3 IN EN SC1457 OUT GND 2 FLG 5 4 R1 100k C2 1uF UNDERVOLTAGE FLAG VO Revision: November 10, 2004 1 www.semtech.com SC1457 POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Exposure to Absolute Maximum rated conditions for extended periods of time may affect device reliability. Parameter Input Supply Voltage I/O Pin Voltages Thermal Resistance Junction to Ambient Thermal Resistance Junction to Case Operating Ambient Temperature Range Operating Junction Temperature Range Storage Temperature Range Lead Temperature (Soldering) 10 seconds ESD Rating (Human Body Model) Symbol VIN VEN, VFLG θJ A θJ C TA TJ TSTG TLEAD V ESD Maximum -0.6 to +7 -0.6 to VIN 256 81 -40 to +85 -40 to +125 -60 to +150 300 2 Units V V °C/W °C/W °C °C °C °C kV Electrical Characteristics Unless specified: VIN = VOUT + 1V, VEN = VIN, IOUT = 100µA, TA = 25°C. Values in bold apply over full operating ambient temperature range. Parameter IN Supply Voltage Range Supply Current Symbol Conditions Min Typ Max Units VIN IQ IOUT = 0mA to150mA 2.25 75 6.50 130 160 V µA VIN = 6.5V, VEN = 0V 0.1 1.0 1.5 µA OUT Output Voltage (1) VOUT IOUT = 1mA 0mA ≤ IOUT ≤ 150mA, VOUT +1V ≤ VIN ≤ 5.5V Line Regulation (1)(2) REG(LINE) (VOUT(NOM) + 0.1V) ≤ VIN ≤ 5.5V, IOUT = 1mA -1.5% -2.0% 2.5 VOUT +1.5% +2.0% 10 12 Load Regulation (1) REG(LOAD) IOUT = 0.1mA to 150mA -3 -10 -20 mV mV V  2004 Semtech Corp. 2 www.semtech.com SC1457 POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified: VIN = VOUT + 1V, VEN = VIN, IOUT = 100µA, TA = 25°C. Values in bold apply over full operating ambient temperature range. Parameter Out (Cont.) Current Limit Dropout Voltage(1)(3) Symbol Conditions Min Typ Max Units ILIM VD IOUT = 1mA IOUT = 50mA 400 1 50 65 75 IOUT = 100mA 100 125 155 IOUT = 150mA 150 190 230 mA mV mV mV mV Output Voltage Noise en 10Hz to 100kHz, IOUT = 50mA, COUT = 1µF 10Hz to 100kHz, IOUT = 50mA, COUT = 100µF 135 110 60 µVRMS Power Supply Rejection Ratio EN Enable Input Threshold PSRR f = 120Hz dB VIH VIL 2.25V ≤ VIN ≤ 6.5V 2.25V ≤ VIN ≤ 6.5V 0V ≤ VEN ≤ VIN 1.6 0.4 -0.5 0 +0.5 V Enable Input Bias Current(4) FLG Flag Threshold IEN µA VTH(FLG) Under voltage condition (below nominal) -4 -4 -6 -8 -12 0.4 % Output Logic Low Voltage Flag Leakage Current Over Temperature Protection High Trip Level Hysteresis V F LG IFLG IFLG = 1mA, undervoltage condition Flag OFF, VFLG = 0V to 6.5V -1 0.1 V µA +1 THI THYST 150 20 °C °C NOTES: (1) Low duty cycle pulse testing with Kelvin connections required. (2) VIN(MIN) = 2.25V. (3) Defined as the input to output differential at which the output voltage drops 100mV below the value measured at a differential of 1V. Not measurable on 1.5V and 1.8V parts due to minimum VIN constraints. (4) Guaranteed by design.  2004 Semtech Corp. 3 www.semtech.com SC1457 POWER MANAGEMENT Pin Configuration Top View Ordering Information Part Number SC1457ISK-X.XTR(1) SC1457ISKX.XTRT(1)(4) SC1457ITSK-XXTR(1) SC1457ITSKXXTRT(1)(4) SC1457EVB(3) TSOT-23-5(2) N/A SOT-23-5(2) P ackag e (SOT-23-5 & TSOT-23-5) Block Diagram Notes: (1) Where X.X or XX denotes voltage options. Available voltages are: 1.5V (1.5 or 15), 1.8V (1.8 or 18), 2.5V (2.5 or 25), 2.7V (2.7 or 27), 2.8V (2.8 or 28), 2.9V (2.9 or 29), 3.0V (3.0 or 30), 3.1V (3.1 or 31), 3.2V (3.2 or 32) and 3.3V (3.3 or 33). (2) Only available in tape and reel packaging. A reel contains 3000 devices. (3) Evaluation board for SC1457. Specify output voltage option when ordering. (4) Lead free product. This product is fully WEEE and RoHS compliant. Pin Descriptions Pin 1 2 3 4 5 Pin Name IN GND EN F LG OUT Pin Function Input pin Ground pin. Can be used for heatsinking if needed. Active high enable pin. Connect VIN if not being used. Error Flag. Open drain output. Active low indicates an output undervoltage condition. Regulator output sourcing up to 150mA. 4 www.semtech.com  2004 Semtech Corp. SC1457 POWER MANAGEMENT Marking Information Top Mark Bottom Mark x7XX x = package (5 for SOT-23-5, T for TSOT-23-5) 7 = SC1457 XX = voltage option (examples: 5731 for 3.1V option in SOT-23-5, T728 for 2.8V option in TSOT-23-5) yyww yyww = Date code (example: 0008 for week 8 of 2000) Applications Information Theory Of Operation The SC1457 is intended for applications where very low dropout voltage, low supply current and output voltage monitoring are critical. It provides a very simple, low cost solution that uses very little pcb real estate. Only two external capacitors and one resistor are required for operation. The SC1457 contains a bandgap reference trimmed for optimal temperature coefficient which is fed into the inverting input of an error amplifier. The output voltage of the regulator is divided down internally using a resistor divider and compared to the bandgap voltage. The error amplifier drives the gate of a low R DS(ON) P-channel MOSFET pass device. An active high enable pin (EN) allows the regulator to be shut down. Pulling this pin low causes the device to enter a very low power shutdown mode, where it will draw typically 0.1µA from the input supply. An open drain flag pin (FLG) is provided to signal whenever the output voltage is 6% (typically) below nominal. A tap is taken from the internal resistor divider and compared to the bandgap voltage to determine if the output voltage is above or below this level. The flag pin pulls low whenever the output is out of specification. An external pullup resistor is required for a high signal when the flag pin is not pulling low. Since this circuitry is powered from the input supply, the FLG pin will pull low for output voltages all the way down to zero, unlike external devices powered from the LDO output.  2004 Semtech Corp. 5 The regulator has its own current limit circuitry to ensure that the output current will not damage the device during output short, overload or start-up. The current limit is guaranteed to be greater than 400mA to allow fast charging of the output capacitor and high initial currents for DSP initialization. The SC1457 includes thermal shutdown circuitry to turn off the device if T J exceeds 150°C (typical), with the device remaining off until TJ drops by 20°C (typical). Reverse battery protection circuitry ensures that the device cannot be damaged if the input supply is accidentally reversed, limiting the reverse current to less than 1.5mA. Component Selection - General Output capacitor - Semtech recommends a minimum capacitance of 1µF at the output with an equivalent series resistance (ESR) of < 1Ω over temperature. While the SC1457 has been designed to be used with ceramic capacitors, it does not have to be used with ceramic capacitors, allowing the designer a choice. Increasing the bulk capacitance will further reduce output noise and improve the overall transient response. Input capacitor - Semtech recommends the use of a 1µF ceramic capacitor at the input. This allows for the device being some distance from any bulk capacitance on the rail. Additionally, input droop due to load transients is reduced, improving overall load transient response. Flag pullup resistor - Semtech recommends a maximum value of 100kΩ for this resistor to ensure that this pin is high even under worst-case flag pin leakage conditions of 1µA when off. www.semtech.com SC1457 POWER MANAGEMENT Applications Information (Cont.) Thermal Considerations The worst-case power dissipation for this part is given by: PD(MAX ) = (VIN(MAX) − VOUT(MIN) )• IOUT(MAX ) + VIN(MAX ) • IQ(MAX ) With the standard SOT-23-5/TSOT-23-5 Land Pattern shown at the end of this datasheet, and minimum trace widths, the thermal impedance junction to ambient for SC1457ISK is 256°C/W. Thus no additional heatsinking is required for this example. The junction temperature can be reduced further (or higher power dissipation can be allowed) by the use of larger trace widths and connecting PCB copper to the GND pin (pin 2), which connects directly to the device substrate. Adding approximately one square inch of PCB copper to pin 2 will reduce θ JA t o approximately 130°C/W and T J(MAX) f or the example above to approximately 100°C for the SOT-23-5 package. The use of multi layer boards with internal ground/power planes will lower the junction temperature and improve overall output voltage accuracy. Layout Considerations While layout for linear devices is generally not as critical as for a switching application, careful attention to detail will ensure reliable operation. 1) Attaching the part to a larger copper footprint will enable better heat transfer from the device, especially on PCBs where there are internal ground and power planes. 2) Place the input, output and bypass capacitors close to the device for optimal transient response and device behaviour. 3) Connect all ground connections directly to the ground plane. If there is no ground plane, connect to a common local ground point before connecting to board ground. (1) For all practical purposes, equation (1) can be reduced to the following expression: PD(MAX) = (VIN(MAX ) − VOUT(MIN) )• IOUT(MAX ) (2) Looking at a typical application, 3.3V to 2.8V at 150mA: VIN(MAX) = 3.3 + 5% = 3.465V VOUT(MIN) = 2.8V - 2% = 2.744V IOUT = 150mA TA = 85°C Inserting these values into equation (2) gives us: PD( MAX ) = (3.465 − 2.744 ) • 0.150 = 108mW Using this figure, we can calculate the maximum thermal impedance allowable to maintain TJ ≤ 125°C: θ JA (MAX ) = (T J(MAX ) − TA (MAX ) ) PD(MAX ) = (125 − 85) = 370°C / W 0.108  2004 Semtech Corp. 6 www.semtech.com SC1457 POWER MANAGEMENT Typical Characteristics Quiescent Current vs. Junction Temperature vs. Input Voltage 120 IOUT = 150mA 100 80 IQ (µA) VIN = 3.8V 60 40 20 0 -50 -25 0 25 TJ (°C) 50 75 100 125 IQ(OFF) (nA) VIN = 6.5V 200 175 150 125 100 75 50 25 0 -50 -25 0 25 TJ (°C) 50 75 100 125 Off-State Quiescent Current vs. Junction Temperature VIN = 6.5V VEN = 0V Output Voltage vs. Junction Temperature vs. Output Current 0.00 IOUT = 1mA -0.05 VOUT Deviation (%) -0.10 -0.15 100mA ≤ IOUT ≤ 150mA -0.20 -0.25 VIN = VOUT + 1V -0.30 -50 -25 0 25 TJ (°C) 50 75 100 125 0 10 8 6 4 2 12 Line Regulation vs. Junction Temperature vs. Input Voltage Change IOUT = 1mA REGLINE (mV) IOUT = 50mA VIN = VOUT + 1V to 6.5V VIN = VOUT + 1V to 5.5V -50 -25 0 25 TJ (°C) 50 75 100 125 Load Regulation vs. Junction Temperature 10 9 8 7 REGLOAD (mV) ILIM (A) 6 5 4 3 2 1 0 -50 -25 0 25 TJ (°C) 50 75 100 125 VIN = VOUT + 1V IOUT = 0.1mA to 150mA 0.90 0.85 0.80 0.75 0.70 0.65 0.60 0.55 0.50 0.45 0.40 Current Limit vs. Junction Temperature vs. Input Voltage VIN = 6.5V VIN = 3.8V -50 -25 0 25 TJ (°C) 50 75 100 125  2004 Semtech Corp. 7 www.semtech.com SC1457 POWER MANAGEMENT Typical Characteristics (Cont.) Dropout Voltage vs. Junction Temperature vs. Output Current 200 175 150 125 VD (mV) 100 75 50 25 0 -50 -25 0 25 TJ (°C) 50 75 100 125 IOUT = 50mA VD (mV) IOUT = 150mA 200 175 150 125 100 75 50 25 0 0 25 50 75 IOUT (mA) 100 125 150 Top to bottom: TJ = 125°C TJ = 25°C TJ = -40°C Dropout Voltage vs. Output Current vs. Junction Temperature Enable Input Threshold Voltage vs. Junction Temperature vs. Input Voltage 1.6 1.4 1.2 VEN (V) 1.0 0.8 VIL @ VIN = 3.8V 0.6 0.4 -50 -25 0 25 TJ (°C) 50 75 100 125 -4.0 -4.5 VTH(FLG) (% below V OUT(NOM)) VIH @ VIN = 6.5V VIH @ VIN = 3.8V -5.0 -5.5 -6.0 -6.5 -7.0 -7.5 -8.0 Flag Threshold Voltage vs. Input Voltage vs. Output Voltage VOUT = 1.5V VIL @ VIN = 6.5V VOUT = 3.3V 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 VIN (V) Flag Threshold Voltage vs. Junction Temperature vs. Output Voltage -4.0 -4.5 VTH(FLG) (% below V OUT(NOM)) -5.0 VFLG (mV) -5.5 -6.0 -6.5 -7.0 -7.5 -8.0 -50 -25 0 25 TJ (°C) 50 75 100 125 VOUT = 3.3V VOUT = 1.5V 200 175 150 125 100 75 50 Flag Voltage vs. Junction Temperature vs. Flag Current VIN = 4.3V IFLG = 10mA IFLG = 1mA 25 0 -50 -25 0 25 TJ (°C) 50 75 100 125  2004 Semtech Corp. 8 www.semtech.com SC1457 POWER MANAGEMENT Typical Characteristics (Cont.) Reverse Battery Protection vs. Junction Temperature 5.0 4.5 4.0 3.5 I(REV BAT) (mA) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 -50 -25 0 25 TJ (°C) 50 75 100 125 VIN = VEN = -6.5V  2004 Semtech Corp. 9 www.semtech.com SC1457 POWER MANAGEMENT Evaluation Board Schematic J1 RIPPLE MON J2 IN MON J3 IN 1 C1 C2 R4 3 U1 IN EN GND 2 SC1457 OUT FLG 5 R1 4 C3 C4 R2 R3 J4 OUT MON J5 EN J8 1 2 3 EN J6 1 2 IQ MON C5 J7 FLG J10 GND J11 GND J12 GND J13 GND J14 GND J15 GND J16 1 2 3 LOAD DRV EN J9 LOAD DRV 1 2 3 4 Q1 S S S G Si4410 D D D D 8 7 6 5 Evaluation Board Bill of Materials Quantity 3 2 1 3 1 1 1 2 1 6 1 1 1 1 1 1  2004 Semtech Corp. Reference C 1, C 4, C 5 C 2, C 3 J1 J2 - J4 J5 J6 J7 J8 , J1 6 J9 J1 0 - J1 5 Q1 R1 R2 R3 R4 U1 Part/Description Not placed 1µF ceramic BNC socket Test pin Test pin Header, 2 pin Test pin Header, 3 pin Test pin Test pin S i 4410 100kΩ, 1/10W Not placed See next page 10kΩ, 1/10W SC1457ISK-X.X or SC1457ITSK-XX 10 Vendor Notes Murata Various Various Various Various Various Various Various Various Vishay Various GRM42-6X7R105K10 VOUT ripple monitor Red White Yellow Orange Black Various Various Semtech www.semtech.com SC1457 POWER MANAGEMENT Evaluation Board Gerber Plots Top Copper Output Voltage Option (V) 1.5 1.8 2.5 2.7 2.8 2.9 3.0 3.1 3.2 3.3 R3 Value/Siz e 10Ω/0.5W 12Ω/0.5W 16Ω/0.5W 18Ω/0.5W 18Ω/0.5W 18Ω/0.5W 20Ω/0.5W 20Ω/0.5W 22Ω/0.5W 22Ω/0.5W Bottom Copper Top Silk Screen  2004 Semtech Corp. 11 www.semtech.com SC1457 POWER MANAGEMENT Outline Drawing - SOT-23-5 A e1 N EI DIM D A A1 A2 b c D E1 E e e1 L L1 N 01 aaa bbb ccc A DIMENSIONS MILLIMETERS INCHES MIN NOM MAX MIN NOM MAX .035 .000 .035 .010 .003 .110 .060 .045 .057 .006 .051 .020 .009 .118 .069 0.90 0.00 .90 0.25 0.08 2.80 1.50 1.15 1.45 0.15 1.30 0.50 0.22 3.00 1.75 2X E/2 E 1 ccc C 2X N/2 TIPS 2 e B D aaa C A2 SEATING PLANE .114 .063 .110 BSC .037 BSC .075 BSC .012 .018 .024 (.024) 5 0° 10° .004 .008 .008 2.90 1.60 2.80 BSC 0.95 BSC 1.90 BSC 0.30 0.45 0.60 (0.60) 5 0° 10° 0.10 0.20 0.20 C A1 bxN H bbb C A-B D GAGE PLANE 0.25 L (L1) c 01 SEE DETAIL SIDE VIEW A DETAIL A NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. Outline Drawing - TSOT-23-5  2004 Semtech Corp. 12 www.semtech.com SC1457 POWER MANAGEMENT Land Pattern - SOT-23-5 & TSOT-23-5 X DIM (C) G Y P Z C G P X Y Z DIMENSIONS MILLIMETERS INCHES (.098) .055 .037 .024 .043 .141 (2.50) 1.40 0.95 0.60 1.10 3.60 NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804  2004 Semtech Corp. 13 www.semtech.com