LD2981 SERIES ULTRA LOW DROP VOLTAGE REGULATORS WITH INHIBIT LOW ESR OUTPUT CAPACITORS COMPATIBLE ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ STABLE WITH LOW ESR CERAMIC CAPACITORS ULTRA LOW DROPOUT VOLTAGE (0.17V TYP. AT 100mA LOAD, 7mV TYP. AT 1mA LOAD) VERY LOW QUIESCENT CURRENT (80µA TYP. AT NO LOAD IN ON MODE; MAX 1µA IN OFF MODE) GUARANTEED OUTPUT CURRENT UP TO 100mA LOGIC-CONTROLLED ELECTRONIC SHUTDOWN OUTPUT VOLTAGE OF 1.5; 1.8; 2.5; 2.85; 3.0; 3.2; 3.3; 3.6; 3.8; 4.0; 4.7; 4.85; 5.0V INTERNAL CURRENT AND THERMAL LIMIT ± 0.75% TOLERANCE OUTPUT VOLTAGE AVAILABLE (A VERSION) OUTPUT LOW NOISE VOLTAGE 160µVRMS TEMPERATURE RANGE: -40 TO 125°C SMALLEST PACKAGE SOT23-5L AND SOT-89 FAST DYNAMIC RESPONSE TO LINE AND LOAD CHANGES DESCRIPTION The LD2981 series are 100mA fixed-output voltage regulator. The low drop-voltage and the SOT23-5L SOT-89 ultra low quiescent current make them suitable for low noise, low power applications and in battery powered systems. The quiescent current in sleep mode is less than 1µA when INHIBIT pin is pulled low. Shutdown Logic Control function is available on pin n.3 (TTL compatible). This means that when the device is used as local regulator, it is possible to put a part of the board in standby, decreasing the total power consumption. The LD2981 is designed to work with low ESR ceramic capacitor. Typical applications are in cellular phone, palmtop/laptop computer, personal digital assistant (PDA), personal stereo, camcorder and camera. SCHEMATIC DIAGRAM September 2003 1/17 LD2981 SERIES ABSOLUTE MAXIMUM RATINGS Symbol Parameter VI VINH Value Unit DC Input Voltage -0.3 to 16 V INHIBIT Input Voltage -0.3 to 16 V IO Output Current Internally limited PD Power Dissipation Internally limited TSTG Storage Temperature Range -55 to 150 °C TOP Operating Junction Temperature Range -40 to 125 °C Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. THERMAL DATA Symbol Parameter Rthj-case Thermal Resistance Junction-case Rthj-amb Thermal Resistance Junction-ambient SOT23-5L SOT-89 Unit 81 15 °C/W 255 110 °C/W CONNECTION DIAGRAM (top view) SOT23-5L SOT-89 PIN DESCRIPTION Pin N° SOT23-5L Pin N° SOT-89 Symbol 1 3 VIN 2 3 2 GND INHIBIT 4 5 2/17 1 NC VOUT Name and Function Input Port Ground Pin Control switch ON/OFF. Inhibit is not internally pulled-up; it cannot be left floating. Disable the device when connected to GND or to a positive voltage less than 0.18V Not Connected Output Port LD2981 SERIES ORDERING CODES AB VERSION SOT23-5L LD2981ABM25TR LD2981ABM28TR LD2981ABM30TR LD2981ABM32TR LD2981ABM33TR LD2981ABM36TR LD2981ABM38TR LD2981ABM40TR LD2981ABM47TR LD2981ABM48TR LD2981ABM50TR C VERSION SOT-89 SOT23-5L SOT-89 OUTPUT VOLTAGES LD2981ABU25TR LD2981ABU28TR LD2981ABU30TR LD2981ABU32TR LD2981ABU33TR LD2981ABU36TR LD2981ABU38TR LD2981ABU40TR LD2981ABU47TR LD2981ABU48TR LD2981ABU50TR LD2981CM15TR LD2981CM18TR LD2981CM25TR LD2981CM28TR LD2981CM30TR LD2981CM32TR LD2981CM33TR LD2981CM36TR LD2981CM38TR LD2981CM40TR LD2981CM47TR LD2981CM48TR LD2981CM50TR LD2981CU15TR LD2981CU18TR LD2981CU25TR LD2981CU28TR LD2981CU30TR LD2981CU32TR LD2981CU33TR LD2981CU36TR LD2981CU38TR LD2981CU40TR LD2981CU47TR LD2981CU48TR LD2981CU50TR 1.5 V 1.8 V 2.5 V 2.85 V 3.0 V 3.2 V 3.3 V 3.6 V 3.8 V 4.0 V 4.7 V 4.85 V 5.0 V TYPICAL APPLICATION CIRCUIT (*) Inhibit Pin is not internally pulled-up then it must not be left floating. Disable the device when connected to GND or to a positive voltage less than 0.18V. 3/17 LD2981 SERIES ELECTRICAL CHARACTERISTICS FOR LD2981AB (Tj = 25°C, VI = VO(NOM) +1V, C I = 1µF(X7R), CO = 2.2µF(X7R), IO = 1mA, VINH = 2V, unless otherwise specified) Symbol Parameter VOP Operating Input Voltage VO Output Voltage Test Conditions IO = 1 to 100 mA Output Voltage 2.481 TJ= -40 to 125°C IO = 1 mA IO = 1 to 100 mA Output Voltage TJ= -40 to 125°C IO = 1 mA IO = 1 to 100 mA Output Voltage Output Voltage Output Voltage TJ= -40 to 125°C Output Voltage Output Voltage Output Voltage TJ= -40 to 125°C 3.267 TJ= -40 to 125°C IO = 1 mA TJ= -40 to 125°C 4/17 3.3 3.224 3.325 3.627 3.564 3.636 3.690 3.8 3.829 3.762 3.838 3.705 3.895 IO = 1 mA 3.97 3.96 4.04 3.9 4.1 IO = 1 mA 4.664 IO = 1 to 100 mA 4.653 TJ= -40 to 125°C 4.813 IO = 1 to 100 mA 4.801 TJ= -40 to 125°C IO = 1 mA TJ= -40 to 125°C 4.7 V V V 4.03 4.735 V V V V 4.747 4.817 4.85 4.887 V 4.899 4.729 4.962 VO(NOM) + 1 < VIN < 16 V IO = 1 mA TJ= -40 to 125°C 4 4.582 IO = 1 mA V 3.383 3.6 IO = 1 to 100 mA TJ= -40 to 125°C Unit 3.333 3.510 3.771 TJ= -40 to 125°C 3.2 3.217 3.573 IO = 1 mA IO = 1 to 100 mA Line Regulation 3.030 3.075 3.275 IO = 1 to 100 mA ∆VO 3.023 2.970 IO = 1 mA IO = 1 to 100 mA VO 3 2.925 IO = 1 to 100 mA IO = 1 to 100 mA VO 2.878 2.921 3.28 IO = 1 to 100 mA VO 2.822 2.779 3.12 IO = 1 to 100 mA Output Voltage 2.872 3.232 IO = 1 to 100 mA VO 2.85 3.168 IO = 1 to 100 mA Output Voltage 2.525 2.562 3.176 IO = 1 to 100 mA VO V IO = 1 mA IO = 1 to 100 mA VO V 2.518 IO = 1 to 100 mA IO = 1 to 100 mA VO 16 2.5 2.475 2.977 IO = 1 to 100 mA VO Max. 2.437 2.828 IO = 1 to 100 mA VO Typ. 2.5 IO = 1 mA IO = 1 to 100 mA VO Min. 4.971 5 5.038 4.950 5.050 4.875 5.125 0.003 0.014 0.032 V %/V LD2981 SERIES Symbol IQ Parameter Quiescent Current ON MODE Test Conditions Min. IO = 0 80 100 IO = 25 mA Dropout Voltage (NOTE 1) 0.8 2 TJ= -40 to 125°C IO = 0 1 TJ= -40 to 125°C 70 100 150 180 Short Circuit Current RL = 0 SVR Supply Voltage Rejection CO = 10µF VINH Inhibit Input Logic Low LOW = Output OFF TJ= -40 to 125°C VINL Inhibit Input Logic High HIGH = Output ON TJ= -40 to 125°C IINH Inhibit Input Current 250 375 TJ= -40 to 125°C IO = 100mA f = 1KHz 150 mA 63 dB 0.18 1.6 VINH = 0V TJ= -40 to 125°C 0 -1 TJ= -40 to 125°C 5 15 CO = 10 µF V V VINH = 5V BW = 300 Hz to 50 KHz mV 15 IO = 100mA Thermal Shutdown 10 TJ= -40 to 125°C IO = 25mA Output Noise Voltage 7 TJ= -40 to 125°C IO = 1mA 3 5 IO = 25mA eN 1300 VINH < 0.3 V IO = 0 TSHDN 1000 2600 IO = 1mA ISC 150 400 TJ= -40 to 125°C VINH < 0.15 V VDROP µA 800 IO = 100 mA IO = 100 mA 100 250 TJ= -40 to 125°C IO = 25 mA Unit 200 TJ= -40 to 125°C IO = 1 mA Max. 150 TJ= -40 to 125°C IO = 0 IO = 1 mA OFF MODE Typ. µA 160 µVRMS 170 °C (NOTE 1): For Vo < 2.5V dropout voltage can be calculated according to the minimum input voltage in full temperature range. 5/17 LD2981 SERIES ELECTRICAL CHARACTERISTICS FOR LD2981C (Tj = 25°C, VI = VO(NOM) +1V, C I = 1µF(X7R), CO = 2.2µF(X7R), IO = 1mA, VINH = 2V, unless otherwise specified) Symbol Parameter VOP Operating Input Voltage VO Output Voltage Test Conditions IO = 1 to 100 mA Output Voltage 1.478 TJ= -40 to 125°C IO = 1 mA IO = 1 to 100 mA Output Voltage TJ= -40 to 125°C IO = 1 mA IO = 1 to 100 mA Output Voltage Output Voltage Output Voltage TJ= -40 to 125°C Output Voltage Output Voltage Output Voltage TJ= -40 to 125°C 2.94 TJ= -40 to 125°C IO = 1 mA TJ= -40 to 125°C 3.264 3.312 3.3 3.341 3.234 3.366 3.184 3.415 3.528 3.672 3.474 3.726 IO = 1 mA 3.752 3.724 TJ= -40 to 125°C 3.95 IO = 1 to 100 mA 3.92 TJ= -40 to 125°C IO = 1 mA TJ= -40 to 125°C IO = 1 mA IO = 1 to 100 mA V V V 3.847 V V V V 3.876 3.933 4 4.05 V 4.08 4.14 4.7 4.758 4.606 4.794 4.864 4.85 4.91 4.753 4.947 4.68 5.019 4.937 TJ= -40 to 125°C 3.645 4.535 4.789 TJ= -40 to 125°C 3.8 3.86 4.641 IO = 1 mA 3.6 3.667 IO = 1 mA IO = 1 to 100 mA 6/17 3.24 3.136 IO = 1 to 100 mA V 3.105 3.2 3.555 TJ= -40 to 125°C Unit 3.06 IO = 1 mA IO = 1 to 100 mA Output Voltage 3.037 IO = 1 to 100 mA IO = 1 to 100 mA VO 3 2.885 3.088 3.258 TJ= -40 to 125°C 2.85 2.895 3.16 IO = 1 mA IO = 1 to 100 mA Output Voltage 2.55 2.587 2.962 IO = 1 to 100 mA VO 2.531 2.45 IO = 1 mA IO = 1 to 100 mA VO 2.5 2.412 IO = 1 to 100 mA IO = 1 to 100 mA VO 1.836 1.863 2.949 IO = 1 to 100 mA VO 1.764 1.737 2.75 IO = 1 to 100 mA Output Voltage 1.822 2.907 IO = 1 to 100 mA VO 1.8 2.793 IO = 1 to 100 mA Output Voltage 1.530 1.555 2.814 IO = 1 to 100 mA VO V IO = 1 mA IO = 1 to 100 mA VO V 1.522 IO = 1 to 100 mA IO = 1 to 100 mA VO 16 1.5 1.470 2.468 IO = 1 to 100 mA VO Max. 1.445 1.777 IO = 1 to 100 mA VO Typ. 2.5 IO = 1 mA IO = 1 to 100 mA VO Min. 5 5.062 4.9 5.1 4.825 5.175 V V V LD2981 SERIES Symbol ∆VO Parameter Line Regulation Test Conditions Min. VO(NOM) + 1 < VIN < 16 V IO = 1 mA Typ. 0.003 Quiescent Current ON MODE IO = 0 80 IO = 1 mA 100 IO = 25 mA 250 IO = 100 mA 1000 OFF MODE VINH < 0.3 V Dropout Voltage (NOTE 1) 400 1300 2 TJ= -40 to 125°C IO = 0 1 3 7 10 15 TJ= -40 to 125°C IO = 1mA IO = 25mA 70 IO = 100mA 180 250 375 TJ= -40 to 125°C IO = 100mA 100 150 TJ= -40 to 125°C IO = 25mA Short Circuit Current RL = 0 SVR Supply Voltage Rejection CO = 10µF VINH Inhibit Input Logic Low LOW = Output OFF TJ= -40 to 125°C VINL Inhibit Input Logic High HIGH = Output ON TJ= -40 to 125°C IINH Inhibit Input Current VINH = 0V TJ= -40 to 125°C 0 -1 VINH = 5V TJ= -40 to 125°C 5 15 eN TSHDN Output Noise Voltage Thermal Shutdown 150 f = 1KHz BW = 300 Hz to 50 KHz CO = 10 µF mV 5 TJ= -40 to 125°C IO = 0 IO = 1mA ISC 150 0.8 VINH < 0.15 V VDROP µA 2600 TJ= -40 to 125°C IO = 100 mA 100 800 TJ= -40 to 125°C IO = 25 mA %/V 200 TJ= -40 to 125°C IO = 1 mA 0.014 150 TJ= -40 to 125°C IO = 0 Unit 0.032 TJ= -40 to 125°C IQ Max. mA 63 dB 0.18 1.6 V V µA 160 µVRMS 170 °C (NOTE 1): For Vo < 2.5V dropout voltage can be calculated according to the minimum input voltage in full temperature range. 7/17 LD2981 SERIES TYPICAL PERFORMANCE CHARACTERISTICS (Tj = 25°C, VI = VO(NOM) +1V, CI = 1µF(X7R), CO = 2.2µF(X7R), VINH = 2V, unless otherwise specified) Figure 1 : Output Voltage vs Temperature Figure 4 : Load Regulation vs Temperature Figure 2 : Output Voltage vs Temperature Figure 5 : Dropout Voltage vs Temperature Figure 3 : Line Regulation vs Temperature Figure 6 : Quiescent Current vs Temperature 8/17 LD2981 SERIES Figure 7 : Quiescent Current vs Output Current Figure 10 : Dropout Voltage vs Output Current Figure 8 : OFF MODE Quiescent Current vs Temperature Figure 11 : Inhibit Input Current vs Temperature Figure 9 : Quiescent Current vs Input Voltage Figure 12 : Inhibit Voltage vs Temperature 9/17 LD2981 SERIES Figure 13 : Supply Voltage Rejection vs Frequency Figure 16 : Worst Case: Lowest Output Version Figure 14 : Noise Voltage vs Frequency Figure 17 : Load Transient Response VO = 4.7V, IO = 1 to 100mA, CO = 4.7µF X7R Figure 15 : Best Case: Highest Output Version Figure 18 : Line Transient Response VI = (VO(NOM) + 1V), VO = 4.7V, IO = 100mA, CO = 4.7µF X7R 10/17 LD2981 SERIES APPLICATION NOTES EXTERNAL CAPACITORS Like any low-dropout regulator, the LD2981 requires external capacitors for regulator stability. This capacitor must be selected to meet the requirements of minimum capacitance and equivalent series resistance. We suggest to solder input and output capacitors as close as possible to the relative pins. INPUT CAPACITOR An input capacitor whose value is 1µF is required with the LD2981 (amount of capacitance can be increased without limit). This capacitor must be located a distance of not more than 0.5" from the input pin of the device and returned to a clean analog ground. Any good quality ceramic, tantalum or film capacitors can be used for this capacitor. OUTPUT CAPACITOR The LD2981 is designed specifically to work with ceramic output capacitors. It may also be possible to use Tantalum capacitors, but these are not as attractive for reasons of size and cost. By the way, the output capacitor must meet both the requirement for minimum amount of capacitance and ESR (equivalent series resistance) value. The figures 1 and 2 show the allowable ESR range as a function of the output capacitance. These curves represent the stability region over the full temperature and IO range. Due to the different loop gain, the stability improves for higher output versions and so the suggested minimum output capacitor value, if low ESR ceramic type is used, is 1µF for output voltages equal or major than 3.8V, 2.2µF for output voltages from 2.85 to 3.3V, and 3.3µF for the other versions. However, if an output capacitor lower than the suggested one is used, it’s possible to make stable the regulator adding a resistor in series to the capacitor (see Figure1 & Figure2 to choose the right value according to the used version and keeping in account that the ESR of ceramic capacitors has been measured @ 100KHz). IMPORTANT The output capacitor must maintain its ESR in the stable region over the full operating temperature to assure stability. Also, capacitor tolerance and variation with temperature must be considered to assure the minimum amount of capacitance is provided at all times. This capacitor should be located not more than 0.5" from the output pin of the device and returned to a clean analog ground. INHIBIT INPUT OPERATION The inhibit pin can be used to turn OFF the regulator when pulled low, so drastically reducing the current consumption down to less than 1µA. When the inhibit feature is not used, this pin must be tied to VI to keep the regulator output ON at all times. To assure proper operation, the signal source used to drive the inhibit pin must be able to swing above and below the specified thresholds listed in the electrical characteristics section under VIH VIL. Any slew rate can be used to drive the inhibit. REVERSE CURRENT The power transistor used in the LD2981 has not an inherent diode connected between the regulator input and output. If the output is forced above the input, no current will flow from the output to the input across the series pass transistor. When a VREV voltage is applied on the output, the reverse current measured, according to the test circuit in figure 19, flows to the GND across the two feedback resistors. This current typical value is 160µA. R1 and R 2 resistors are implanted type; typical values are, respectively, 42.6 KΩ and 51.150 KΩ. 11/17 LD2981 SERIES Figure 19 : Reverse Current Test Circuit 12/17 LD2981 SERIES SOT23-5L MECHANICAL DATA mm. mils DIM. MIN. TYP MAX. MIN. TYP. MAX. A 0.90 1.45 35.4 57.1 A1 0.00 0.10 0.0 3.9 A2 0.90 1.30 35.4 51.2 b 0.35 0.50 13.7 19.7 C 0.09 0.20 3.5 7.8 D 2.80 3.00 110.2 118.1 E 1.50 1.75 59.0 68.8 e 0.95 37.4 H 2.60 3.00 102.3 118.1 L 0.10 0.60 3.9 23.6 . 7049676C 13/17 LD2981 SERIES SOT-89 MECHANICAL DATA mm. mils DIM. MIN. TYP MAX. MIN. TYP. MAX. A 1.4 1.6 55.1 63.0 B 0.44 0.56 17.3 22.0 B1 0.36 0.48 14.2 18.9 C 0.35 0.44 13.8 17.3 C1 0.35 0.44 13.8 17.3 D 4.4 4.6 173.2 181.1 D1 1.62 1.83 63.8 72.0 E 2.29 2.6 90.2 102.4 e 1.42 1.57 55.9 61.8 e1 2.92 3.07 115.0 120.9 H 3.94 4.25 155.1 167.3 L 0.89 1.2 35.0 47.2 P025H 14/17 LD2981 SERIES Tape & Reel SOT23-xL MECHANICAL DATA mm. inch DIM. MIN. TYP A MAX. MIN. TYP. 180 13.0 7.086 C 12.8 D 20.2 0.795 N 60 2.362 T 13.2 MAX. 0.504 0.512 14.4 0.519 0.567 Ao 3.13 3.23 3.33 0.123 0.127 0.131 Bo 3.07 3.17 3.27 0.120 0.124 0.128 Ko 1.27 1.37 1.47 0.050 0.054 0.0.58 Po 3.9 4.0 4.1 0.153 0.157 0.161 P 3.9 4.0 4.1 0.153 0.157 0.161 15/17 LD2981 SERIES Tape & Reel SOT89 MECHANICAL DATA mm. inch DIM. MIN. TYP A MIN. TYP. 180 13.0 13.2 MAX. 7.086 C 12.8 D 20.2 0.795 N 60 2.362 T 16/17 MAX. 0.504 0.512 14.4 0.519 0.567 Ao 4.70 4.80 4.90 0.185 0.189 0.193 Bo 4.30 4.40 4.50 0.169 0.173 0.177 Ko 1.70 1.80 1.90 0.067 0.071 0.075 Po 3.9 4.0 4.1 0.153 0.157 0.161 P 7.9 8.0 8.1 0.311 0.315 0.319 LD2981 SERIES Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics All other names are the property of their respective owners © 2003 STMicroelectronics - All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States. http://www.st.com 17/17