LP2985AIM5-3.3/TR

LP2985A LP2985A 150mA Low-Noise LDO Regulator Features            Ultra-low-noise output High output voltage accuracy Guaranteed 150mA output Low quiescent current Low dropout voltage Extremely tight load and line regulation Very low temperature coefficient Current and thermal limiting Reverse-battery protection “Zero” off-mode current Logic-controlled electronic enable SOT23-5 Ordering Information DEVICE Package Type MARKING Packing Packing Qty LP2985AIM5-ADJ/TR SOT23-5 LPAA,HGAA REEL 3000pcs/reel LP2985AIM5-2.5/TR SOT23-5 LPUG,LPUL,LAUA REEL 3000pcs/reel LP2985AIM5-2.8/TR SOT23-5 LPJG,LPJL,L0KA REEL 3000pcs/reel LP2985AIM5-2.9/TR SOT23-5 LPZG,LPZL,LAXA REEL 3000pcs/reel LP2985AIM5-3.0/TR SOT23-5 LRAG,LPAL,L0OA REEL 3000pcs/reel LP2985AIM5-3.3/TR SOT23-5 LPKG,LPKL,L0RA REEL 3000pcs/reel LP2985AIM5-5.0/TR SOT23-5 LR1G,LR1L,L0UA REEL 3000pcs/reel http://www.hgsemi.com.cn 1 / 12 2020 JUN LP2985A General Description The LP2985A is an efficient linear voltage regulator with ultra- low-noise output, very low dropout voltage (typically 17mV at light loads and 165mV at 150mA), and very low ground current (600µA at 100mA output). The LP2985A offers better than 1% initial accuracy. Designed especially for hand-held, battery-powered devices, the LP2985A includes a CMOS or TTL compatible enable/ shutdown control input. When shutdown, power consump- tion drops nearly to zero. Regulator ground current increases only slightly in dropout, further prolonging battery life. Key LP2985A features include a reference bypass pin to improve its already excellent low-noise performance, re- versed-battery protection, current limiting, and overtemperature shutdown. The LP2985A is available in fixed and adjustable output voltage versions in a small SOT23-5 package. Applications  Cellular telephones  Laptop, notebook, and palmtop computers  Battery-powered equipment regulation/switching  PCMCIA VCC and VPP  Consumer/personal electronics  SMPS post-regulator/dc-to-dc modules  High-efficiency linear power supplies Typical Application LP2985A-XX EN (pin 3) may be connected directly to IN (pin 1). Ultra-Low-Noise Regulator Application http://www.hgsemi.com.cn 2 / 12 2020 JUN LP2985A Pin Configuration LP2985A-XX Fixed Voltages LP2985A-ADJ Adjustable Voltage Pin Description LP2985A-x.x LP2985A (fixed) (adjustable) Pin Name 1 2 1 2 IN GND 3 3 EN 4 - BYP - 4 ADJ 5 5 OUT Pin Function Supply Input Ground Enable/Shutdown (Input): CMOS compatible input. Logic high = enable, logic low or open = shutdown. Reference Bypass: Connect external 470pF capacitor to GND to reduce output noise. May be left open. Adjust (Input): Adjustable regulator feedback input. Connect to resistor voltage divider. Regulator Output Absolute Maximum Ratings (Note 1) parameter Value Supply Input Voltage (VIN) -20V to +20V Enable Input Voltage (VEN) -20V to +20V Power Dissipation (PD) nternally Limited, Note 3 Lead Temperature (soldering, 5 sec.) 260℃ Junction Temperature (TJ) -40℃ to +85 ℃ Storage Temperature (TS) -65℃ to +150℃ Operating Ratings (Note 2) parameter Value Input Voltage (VIN) +2.5V to +16V Enable Input Voltage (VEN) 0V to VIN Junction Temperature (TJ) -40C to +85 C Thermal Resistance, SOT23-5 JA) http://www.hgsemi.com.cn Note 3 3 / 12 2020 JUN LP2985A Electrical Characteristics VIN = VOUT + 1V; IL = 100A; CL = 1.0F; VEN  2.0V; TJ = 25C, bold values indicate –40C  TJ  +125C; unless noted. Symbol Parameter Conditions Min Typical Max Units Output Voltage Accuracy variation from specified VOUT Output Voltage Temperature Coefficient Note 4 VO/VO Line Regulation VIN = VOUT + 1V to 16V 0.004 VO/VO Load Regulation IL = 0.1mA to 150mA, Note 5 0.02 VO VO/T VIN – VO IGND IGND Dropout Voltage, Note 6 Quiescent Current Ground Pin Current, Note 7 –1.0 –2.0 1.0 2.0 40 IL = 100µA 10 IL = 50mA 110 IL = 100mA 140 IL = 150mA 165 VEN ≤ 0.4V (shutdown) VEN ≤ 0.18V (shutdown) 0.01 VEN ≤ 2.0V, IL = 100µA 80 IL = 50mA 350 IL = 100mA 600 IL = 150mA 1300 % % ppm/℃ 0.012 0.05 %/V %/V 0.2 0.5 50 70 150 230 250 300 275 350 % % mV mV mV mV mV mV mV mV 1 5 µA µA 125 150 600 800 1000 1500 1900 2500 µA µA µA µA µA µA µA µA PSRR Ripple Rejection frequency = 100Hz, IL = 100µA 75 ILIMIT Current Limit VOUT = 0V 320 Note 8 0.05 %/W IL = 50mA, CL = 2.2µF, 470pF from BYP to GND 260 nV/ Hz VO/PD Thermal Regulation eno Output Noise dB 500 mA ENABLE Input regulator shutdown VIL Enable Input Logic-Low Voltage VIH Enable Input Logic-High Voltage regulator enabled Enable Input Current VIL ≤ 0.4V VIL 0.18V ≤ VIH 2.0V ≤ VIH 2.0V ≤ IIL IIH 0.4 0.18 2.0 V 0.01 2 V V 5 –1 –2 20 25 µA µA µA µA Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3: The maximum allowable power dissipation at any TA (ambient temperature) is PD(max) = (TJ(max) – TA)÷θJA. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The θJA of the LP2985A-xx (all versions) is 220℃/W mounted on a PC board (see “Thermal Considerations” section for further details). http://www.hgsemi.com.cn 4 / 12 2020 JUN LP2985A Note 4: Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range. Note 5: Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification. Note 6: Dropout Voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V differential. Note 7: Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of the load current plus the ground pin current. Note 8: Thermal regulation is defined as the change in output voltage at a time “t” after a change in power dissipation is applied, excluding load or line regulation effects. Specifications are for a 150mA load pulse at VIN = 16V for t = 10ms. Typical Characteristics http://www.hgsemi.com.cn 5 / 12 2020 JUN LP2985A Typical Characteristics http://www.hgsemi.com.cn 6 / 12 2020 JUN LP2985A Block Diagrams LP2985A-XX Ultra-Low-Noise Fixed Regulator LP2985A Ultra-Low-Noise Adjustable Regulator http://www.hgsemi.com.cn 7 / 12 2020 JUN LP2985A Applications Information Enable/Shutdown Forcing EN (enable/shutdown) high (> 2V) enables the regu- lator. EN is compatible with CMOS logic gates. If the enable/shutdown feature is not required, connect EN (pin 3) to IN (supply input, pin 1). See Figure 1. Input Capacitor A 1µF capacitor should be placed from IN to GND if there is more than 10 inches of wire between the input and the ac filter capacitor or if a battery is used as the input. Reference Bypass Capacitor BYP (reference bypass) is connected to the internal voltage reference. A 470pF capacitor (CBYP) connected from BYP to GND quiets this reference, providing a significant reduction in output noise. CBYP reduces the regulator phase margin; when using CBYP, output capacitors of 2.2µF or greater are generally required to maintain stability. The start-up speed of the LP2985A 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 CBYP. Likewise, if rapid turn-on is necessary, consider omitting CBYP. If output noise is not a major concern, omit CBYP and leave BYP open. Output Capacitor An output capacitor is required between OUT and GND to prevent oscillation. The minimum size of the output capacitor is dependent upon whether a reference bypass capacitor is used. 1.0µF minimum is recommended when CBYP is not used (see Figure 2). 2.2µF minimum is recommended when CBYP is 470pF (see Figure 1). 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) of about 5Ωor less and a resonant frequency above 1MHz. Ultra-low-ESR capacitors can cause a low amplitude oscillation on the output and/or underdamped transient response. Most tantalum or aluminum electrolytic capacitors are adequate; film types will work, but are more expensive. Since many aluminum electrolytics have electro- lytes that freeze at about –30℃, solid tantalums are recom- mended for operation below –25℃. At lower values of output current, less output capacitance is required for output stability. The capacitor can be reduced to 0.47µF for current below 10mA or 0.33µF for currents below 1mA. No-Load Stability The LP2985A will remain stable and in regulation with no load (other than the internal voltage divider) unlike many other voltage regulators. This is especially important in CMOS RAM keep-alive applications. http://www.hgsemi.com.cn 8 / 12 2020 JUN LP2985A Thermal Considerations The LP2985A is designed to provide 150mA 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-to-ambient ther- mal resistance of the device and the following basic equation: TJ(max) − TA θJA PD(max) TJ(max) is the maximum junction temperature of the die, 125℃, and TA is the ambient operating temperature. θJA is layout dependent; Table 1 shows examples of junction-to-ambient thermal resistance for the LP2985A. Package SOT-23-5 (M5) θ θ JA Recommended Minimum Footprint JA 1" Square Copper Clad 220°C/W 170℃/W θJC 130℃/W Table 1. SOT-23-5 Thermal Resistance The actual power dissipation of the regulator circuit can be determined using the equation: �� = (��� − ����)���� + ��� ���� 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 LP2985AM5-3.3 at room temperature with a minimum footprint layout, the maximum input voltage for a set output current can be determined as follows: PD(max) = (125℃ − 25℃) 220℃/W PD(max) = 455mW The junction-to-ambient thermal resistance for the minimum footprint is 220°C/W, from Table 1. The maximum power dissipation must not be exceeded for proper operation. Using the output voltage of 3.3V and an output current of 150mA, the maximum input voltage can be determined. From the Electrical Characteristics table, the maximum ground current for 150mA output current is 2500µA or 2.5mA. 455mW = (VIN – 3.3V) 150mA + VIN ·2.5mA 455mW = VIN·150mA – 495mW + VIN·2.5mA 950mW = VIN·152.5mA VIN(max) = 6.23V Therefore, a 3.3V application at 150mA of output current can accept a maximum input voltage of 6.2V in a SOT23-5 package. For a full discussion of heat sinking and thermal effects on voltage regulators, refer to the Regulator Thermals section of Micrel’s Designing with Low-Dropout Voltage Regu- lators handbook. http://www.hgsemi.com.cn 9 / 12 2020 JUN LP2985A Fixed Regulator Applications LP2985A-XX Figure 1. Ultra-Low-Noise Fixed Voltage Application Figure 1 includes a 470pF capacitor for low-noise operation and shows EN (pin 3) connected to IN (pin 1) for an applica- tion where enable/shutdown is not required. COUT = 2.2µFminimum. LP2985A-XX Figure 2. Low-Noise Fixed Voltage Application Figure 2 is an example of a low-noise configuration where CBYP is not required. COUT = 1µF minimum. Adjustable Regulator Applications The LP2985AM5 can be adjusted to a specific output voltage by using two external resistors (Figure 3). The resis- tors set the output voltage based on the following equation: VOUT = 1.242V × R2 +1 R1 This equation is correct due to the configuration of the bandgap reference. The bandgap voltage is relative to the output, as seen in the block diagram. Traditional regulators normally have the reference voltage relative to ground and have a different VOUT equation. Resistor values are not critical because ADJ (adjust) has a high input impedance, but for best results use resistors of 470kΩ or less. A capacitor from ADJ to ground provides greatly improved noise performance. LP2985A Figure 3. Ultra-Low-Noise Adjustable Voltage Application Figure 3 includes the optional 470pF noise bypass capacitor from ADJ to GND to reduce output noise. 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. http://www.hgsemi.com.cn 10 / 12 2020 JUN LP2985A Physical Dimensions SOT23-5 Dimensions In Millimeters(SOT23-5) A A1 B C C1 D Min： 1.05 0.00 2.82 2.65 1.50 0.30 0° 0.30 Max： 1.15 0.15 3.02 2.95 1.70 0.60 8° 0.40 Symbol： http://www.hgsemi.com.cn 11 / 12 Q a b e 0.95 BSC 1.90 BSC 2020 JUN LP2985A IMPORTANT STATEMENT: Huaguan Semiconductor reserves the right to change its products and services without notice. Before ordering, the customer shall obtain the latest relevant information and verify whether the information is up to date and complete. Huaguan Semiconductor does not assume any responsibility or obligation for the altered documents. 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