TS5215CS

TS5215 300mA Low Noise LDO Voltage Regulator with Enable Low Power Consumption Low Drop Out Voltage 0.35V Fixed and Adjustable Output Enable Shutdown General Description The TS5215 series is an efficient linear voltage regulator with ultra low noise output, very low dropout voltage (typically 17mV at light loads and 350mV at 300mA), and very low power consumption (125uA at 100uA), providing high output current even when the application requires very low dropout voltage. The Chip Enable (CE) includes a CMOS or TTL compatible input allows the output to be turned off to prolong battery life. When shutdown, power consumption drops nearly to zero. The TS5215 series is included a precision voltage reference, error correction circuit, a current limited output driver, over temperature shutdown, revered battery protection and a reference bypass pin to improve its already excellent low-noise performance. The TS5215 series is available in fixed and adjustable output voltage version in SOT-25, SOT-89-5L and SOP-8 package. Features Ultra low noise output. Low dropout voltage Low power consumption “Zero” off-mode current Logic controlled electronic enable Internal current limit and Thermal shutdown protection Ordering Information Part No. TS5215CSxx TS5215CY5xx TS5215CX5xx Operating Temp. -40 ~ +125 C o Package SOP-8 SOT-89-5L SOT-25 Applications Cellular telephones Palmtops, notebook computers Battery powered equipment Consumer and personal electronics SMPS post regulator and DC to DC modules High-efficiency linear power supplies Note: Where xx denotes voltage option, available are 50= 5.0V 33= 3.3V 30= 3.0V 25= 2.5V. Leave blank for adjustable version. Contact factory for additional voltage options. Pin Assignment SOT-25 3 1 2 5 SOT-89-5L 3 4 2 5 SOP-8 1 2 5,6,7,8 3 Pin Configuration Enable Input Ground Output By Pass (fixed voltage) Feed Back (adjustable) Pin Description TTL/COMS compatible input. Logic high is enable; logic low or open is shutdown Unregulated input: +16V maximum supply Ground: Ground pin and TAB/heatsink are internally connected. Regulator output A 470uF capacitor (Cbypass) connected from Bypass to Ground quiets this reference Adjustment input: Feedback input. Connect to resistive voltage-divider network. (Vout2V) enable (EN) input that allows ON/OFF control of the regulator. Current drain reduces to “zero” when the device is shutdown, with only micro-amperes of leakage current. The EN is compatible with CMOS logic interfacing. EN may be directly tied to Vin and pulled up to the maximum supply voltage. Most of tantalum or aluminum electrolytic capacitors are adequate; film types will work. Since many aluminum electrolytic have electrolytes that freeze at about –30oC, solid tantalums are recommended for operation below –25oC. At lower values of output current, less output capacitance is required for output stability. The capacitor can be reduced to 0.47uF for current below 10mA or 0.33uF for currents below 1mA. Input Capacitor Requirement An input capacitor of 1uF or greater is recommended when the device is more than 10” away from the bulk AC supply capacitance or when the supply is a battery. No Load Stability The TS5215 series will remain stable and in regulation with no load, unlike many other voltage regulators. This is especially important in CMOS RAM keep alive applications. Reference Bypass Capacitor Bypass is connected to the internal voltage reference. A 470uF capacitor (Cbypass) connected from Bypass to Ground quiets this reference, providing a significant reduction in output noise. Cbypass reduces the regulator phase margin; when using Cbypass, output capacitors of 2.2uF or greater are generally required to maintain stability. The star up speed of the TS5215 is inversely proportional to the size of the reference bypass capacitor. Applications requiring a slow ramp up of output voltage should consider larger values of Cbypass. Likewise, if rapid turn on is necessary, consider omitting Cbypass. If output noise is not a major concern, omitted Cbypass and leave Bypass open. Adjustable Regulator Design The adjustable regulator versions can be adjusted to a specific output voltage by using two external resistors to programming the output voltage anywhere between 1.25 and the 8V maximum operating rating of the family. Two resistors are used. Resistors can be quite large up to 470kΩ, because of the very high input impedance and low bias current of the sense comparator, the resistor values are calculated by: Vout = 1.23V * (R2 / R1 + 1) Output Capacitor Requirement The TS5215 series requires an output capacitor to maintain stability and improve transient response is necessary. The value of this capacitor is dependent upon whether a reference bypass capacitor is used. 1uF minimum is recommended when Cbypass is not used. 2.2uF minimum is recommended when Cbypass is 470uF. Larger values improve the regulator’s transient response. The output capacitor value may be increased without limit. The output capacitor should have an ESR (effective series resistance) less than 5Ω and a resonant frequency above 1MHz. Ultra low ESR capacitors can cause a low amplitude oscillation on the output and/or under damped transient response. A capacitor from Adj to Ground provides greatly improved noise performance. Dual Supply Operation When used in dual supply systems where the regulator load is returned to a negative supply, the output voltage must be diode clamped to ground. TS5215 series 4-4 2006/01 rev. C Application Information (continues) Thermal Characteristics TS5215 series is designed to provide 300mA of continuous current in a very small package. Maximum power dissipation can be calculated based on the output current and the voltage drop across the part. To determine the maximum power dissipation of the package, use the junction-ambient thermal resistance of the device and the following basic equation: Pd(max) = [ Tj(max) – Ta ] /Θja Tj(max) is the maximum junction temperature of the die(125oC), and Ta is the ambient operating temperature. Θja is layout dependent, the actual power dissipation of the regulator circuit can be determined using the equation: Pd = ( Vin – Vout ) * Iout + Vin * Ignd Substituting Pd(max) for Pd and solving for the operating conditions that are critical to the application will give the maximum operating conditions for the regulator circuit. For example, when operating the TS5215CX533 at room temperature with a minimum footprint layout, the maximum input voltage for a set output current can be determined as follows: Pd(max) = (125oC – 25oC) / 220oC/W Pd(max) = 455mW The junction to ambient thermal resistance for the minimum footprint is 220 C/W, the maximum power dissipation must not be exceeded for proper operation. Using the output voltage of 3.3V and an output current of 300mA, the maximum input voltage can be determined. Form the electrical characteristics table, the maximum ground current for 300mA output current is 2.5mA. 445mW = ( Vin – 3.3V ) * 300mA + Vin * 2.5mA 445mW = Vin * 300mA – 3.3 * 300mA + Vin * 2.5mA 445mW = Vin * 300mA – 990mW + Vin * 2.5mA 1435mW = Vin * 302.5mA Vin(max) = 4.74v Therefore, a 3.3V application at 300mA of output current can accept a maximum input voltage of 4.74V in a SOT-25 package. Reference Voltage Output Application An example of reference voltage (1.23V) as the output voltage when adjustable pin connect to output. o Fixed Output Regulator Application Ultra Low Noise Fixed Voltage Application Includes a 470uF capacitor for low noise operation and shows EN connected to IN for an application where enable/shutdown minimum. is not required. Cout= 2.2uF Low Noise Fixed Voltage Application An example of a low noise configuration where Cbypass is not required. Cout= 1uF minimum TS5215 series 5-5 2006/01 rev. C SOT-25 Mechanical Drawing DIM A B C D E F H L SOT-25 DIMENSION MILLIMETERS INCHES MIN MAX MIN MAX 2.70 3.00 0.106 0.118 0.25 0.50 0.010 0.020 1.90(typ) 0.075(typ) 0.95(typ) 0.037(typ) 1.50 1.70 0.059 0.067 1.05 1.35 0.041 0.053 2.60 3.00 0.102 0.118 0.60(typ) 0.024(typ) SOT-89-5L Mechanical Drawing DIM A B C D E F G H I J SOT-89-5L DIMENSION MILLIMETERS INCHES MIN MAX MIN MAX 4.40 4.60 4.05 4.25 1.50 1.70 0.35 0.41 2.40 2.60 0.80 -3.00(typ) 1.50(typ) 0.40 0.52 1.40 1.60 0.17 0.18 0.16 0.17 0.06 0.07 0.01 0.02 0.09 0.10 0.03 -0.12(typ) 0.06(typ) 0.01 0.02 0.05 0.06 TS5215 series 6-6 2006/01 rev. C SOP-8 Mechanical Drawing A DIM 16 9 B P 1 8 G C D K M R F A B C D F G K M P R SOP-8 DIMENSION MILLIMETERS INCHES MIN MAX MIN MAX 4.80 5.00 0.189 0.196 3.80 4.00 0.150 0.157 1.35 1.75 0.054 0.068 0.35 0.49 0.014 0.019 0.40 1.25 0.016 0.049 1.27 (typ) 0.05 (typ) 0.10 0.25 0.004 0.009 0o 7o 0o 7o 5.80 6.20 0.229 0.244 0.25 0.50 0.010 0.019 TS5215 series 7-7 2006/01 rev. C