UNISONIC TECHNOLOGIES CO., LTD LD1985 LINEAR INTEGRATED CIRCUIT VERY LOW DROP AND LOW NOISE VOLTAGE REGULATOR LOW ESR CAP. COMPATIBLE, WITH INHIBIT FUNCTION DESCRIPTION The UTC LD1985 is a 150mA fixed output voltage regulator. The ultra low drop voltage and the low quiescent current make them particularly suitable for low noise, low power applications, and in battery powered systems. In sleep mode quiescent current is less than 1μA when INHIBIT pin is pulled low. Shutdown Logic Control Function is available on pin 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. An external capacitor, CBYP=10nF, connected between bypass pin and GND reduce the noise to 30μVrms. Typical application is in cellular phone, palmtop laptop computer, personal digital assistant (PDA), personal stereo, camcorder and camera. FEATURES * Very Low Dropout Voltage (280mV at 150mA and 7mV at 1mA Load) * Very Low Quiescent Current * Output Current up to 150mA * Logic Controlled Electronic Shutdown * Output Voltage of 1.5, 1.8, 2.5, 2.8, 2.85, 3, 3.1, 3.2, 3.3, 3.5, 3.6, 3.8, 4, 4.7, 5V * Internal Current and Thermal Limit * Low Output Noise Voltage 30μVrms ORDERING INFORMATION Ordering Number LD1985G-xx-AF5-R Note: xx: Output Voltage, refer to Marking Information. www.unisonic.com.tw Copyright © 2015 Unisonic Technologies Co., Ltd Package SOT-25 Packing Tape Reel 1 of 9 QW-R102-021.I LD1985 LINEAR INTEGRATED CIRCUIT MARKING INFORMATION PACKAGE VOLTAGE CODE 15:1.5V 18:1.8V 25:2.5V 28:2.8V 2J:2.85V 30:3.0V 31:3.1V 32:3.2V 33:3.3V 35:3.5V 36:3.6V 38:3.8V 40:4.0V 47:4.7V 50:5.0V SOT-25 PIN CONFIGURATION PIN DESCRIPTION PIN NO. 1 2 PIN NAME VIN GND 3 INHIBIT 4 Bypass 5 VOUT MARKING DESCRIPTION Input port Ground Pin Control switches 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 Bypass pin: capacitor to be connected to GND in order to improve the thermal noise performances. Output port BLOCK DIAGRAM VOUT VIN CURRENT LIMIT INHIBIT START-UP SHUTDOWN REFERENCE VOLTAGE ERROR AMPLIFIER DRIVER BYPASS TERM. PROTEC. GND UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 9 QW-R102-021.I LD1985 LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS (TA=25°C) PARAMETER SYMBOL RATINGS UNIT DC Input Voltage VIN 7 V INHIBIT Input Voltage VINH 7 V Output Current IOUT Internally limited Power Dissipation PD Internally limited Operating Junction Temperature TOPR -40 ~ +85 °C Storage Temperature TSTG -40 ~ +150 °C Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. THERMAL DATA PARAMETER Junction to Case SYMBOL θJC RATINGS 81 UNIT °C/W ELECTRICAL CHARACTRISTICS (TJ=25°C, VIN=VOUT+1V, IOUT=1mA, VSHDN=2V, CI=1μF, CO=1μF, unless otherwise specified) PARAMETER SYMBOL TEST CONDITIONS MIN TYP Operating Input Voltage VI(OPR) 2.5 VIN=2.5V 1.470 1.5 IOUT=1 ~ 150mA 1.455 VIN =2.8V 1.764 1.8 IOUT =1 ~ 150mA 1.746 VIN =3.5V 2.450 2.5 IOUT =1 ~ 150mA 2.425 VIN =3.8V 2.744 2.8 IOUT =1 ~ 150mA 2.716 VIN =3.85V 2.793 2.85 IOUT =1 ~ 150mA 2.764 VIN =4.0V 2.940 3.0 IOUT =1 ~ 150mA 2.910 VIN =4.1V 3.038 3.1 IOUT =1 ~ 150mA 3.007 VIN =4.2V 3.136 3.2 Output Voltage VOUT IOUT =1 ~ 150mA 3.104 VIN =4.3V 3.234 3.3 IOUT =1 ~ 150mA 3.201 VIN =4.5V 3.430 3.5 IOUT =1 ~ 150mA 3.395 VIN =4.6V 3.528 3.6 IOUT =1 ~ 150mA 3.492 VIN =4.8V 3.724 3.8 IOUT =1 ~ 150mA 3.686 VIN =5.0V 3.920 4 IOUT =1 ~ 150mA 3.880 VIN =5.7V 4.606 4.7 IOUT =1 ~ 150mA 4.559 VIN =6.0V 4.900 5 IOUT =1 ~ 150mA 4.850 UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MAX 7 1.530 1.545 1.836 1.854 2.550 2.575 2.856 2.884 2.907 2.936 3.060 3.090 3.162 3.193 3.264 3.296 3.366 3.399 3.570 3.605 3.672 3.708 3.876 3.914 4.080 4.120 4.794 4.841 5.100 5.150 UNIT V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V 3 of 9 QW-R102-021.I LD1985 LINEAR INTEGRATED CIRCUIT ELECTRICAL CHARACTRISTICS(Cont.) PARAMETER Short Circuit Current Line Regulation SYMBOL ISC △VOUT Dropout Voltage VD Quiescent Current IQ Supply Voltage Rejection Control Input Logic Low Control Input Logic High SVR VIL VIH Control Input Current IINH Output Noise Voltage eN TEST CONDITIONS RL=0 VIN = VOUT +1V ~ 7V, IOUT =1mA IOUT =0 IOUT =1mA IOUT =10mA IOUT =50mA IOUT =150mA IOUT =0 IOUT =1mA IOUT =10mA IOUT =50mA IOUT =150mA OFF MODE VINH<0.18V CBYP=0.01μF, Co=10μF, f=1KHz TJ=-20 ~ 125°C TJ=-20 ~ 125°C TJ=-20 ~ 125°C, VSHDN=5V TJ=-20 ~ 125°C, VSHDN=0V B=300Hz ~ 50KHz CBYP=0.01μF, Co=10μF UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN TYP 600 1 7 40 120 280 80 100 280 1050 2900 1.5 45 MAX 30 3 10 60 150 350 100 150 330 1300 3300 0.15 2 5 0 30 15 -1 UNIT mA mV mV mV mV mV mV µA µA µA µA µA µA dB V V µA µA µV 4 of 9 QW-R102-021.I LD1985 LINEAR INTEGRATED CIRCUIT REVERSE CURRENT TEST CIRCUIT UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 9 QW-R102-021.I LD1985 LINEAR INTEGRATED CIRCUIT APPLICATION INFORMATION EXTERNAL CAPACITORS Like any low-dropout regulator, the UTC LD1985 requires external capacitors for regulator stability. This capacitor must be selected to meet the requirements of minimum capacitance and equivalent series resistance. We suggest soldering input and outputting capacitors as close as possible to the relative pins. INPUT CAPACITOR An input capacitor whose value is 1μF is required with the UTC LD1985 (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 UTC LD1985 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 E.S.R. (equivalent series resistance) value. Due to the different loop gain, the stability improves for higher output versions and so the suggested minimum output capacitor value, if low E.S.R. ceramic type is used, is 1μF for output voltages equal or major than 3.8V, 2.2μF for VOUT going from 1.8 ~ 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. 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 VIN 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 UTC LD1985 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 flows to the GND across the two feedback resistors. This current typical value is 160μA. R1 and R2 resistors are implanted type; typical values are, respectively, 42.6 KΩ and 51.150 KΩ. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 9 QW-R102-021.I LD1985 LINEAR INTEGRATED CIRCUIT TYPICAL CHARACTERISTICS (TJ=25°C, CIN=1μF, COUT=2.2μF, CBYP=100nF) Output Voltage vs Temperature 2.60 Quiescent Current vs Load Current 3000 VIN=3.5V IOUT=1mA 2.58 VOUT=2.5V CBY=10nF 2500 2.56 2000 2.52 IQ (μA) VOUT (V) 2.54 2.50 1500 2.48 1000 2.46 2.44 500 2.42 2.40 -50 0 -25 50 25 Tc ( ) 75 100 0 125 0 50 25 Dropout Voltage vs Temperature 100 75 IOUT (mA) 175 Quiescent Current vs Temperature 0.4 IOUT=150mA VOUT=2.5V CBY=10nF 150 125 VOUT=2.5V CBY=10nF 3.5 IOUT=150mA 3.0 0.3 0.2 IQ (mA) VD (V) 2.5 IOUT=50mA 2.0 1.5 0.1 1.0 IOUT=10mA 0.5 IOUT=1mA 0 -50 -25 0 50 25 TC ( ) 75 100 0 -50 125 -25 0 25 50 TC ( ) 75 Supply Voltage Rejection vs Temperature Dropout Voltage vs Output Current 90 250 fOSC=1KHz VIN=3.5 ~ 6.5V IOUT=10mA 80 SVR (dB) VD (mV) 200 150 COUT=10μF 70 COUT=1μF 60 50 100 40 VOUT=2.5V 50 0 125 100 30 0 25 50 75 100 125 150 175 IOUT (mA) UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 20 -50 -25 0 25 50 75 100 125 TC ( ) 7 of 9 QW-R102-021.I LD1985 LINEAR INTEGRATED CIRCUIT TYPICAL CHARACTERISTICS(Cont.) Supply Voltage Rejection vs Output Current Supply Voltage Rejection vs Frequency 80 100 70 80 50 60 SVR (dB) SVR (dB) 60 40 40 30 20 20 0 VIN=3.5 ~ 6.5V COUT=10μF fOSC=1KHz 0 25 50 10 100 75 IOUT (mA) 125 150 VIN=3.5 ~ 6.5V IOUT=10mA VOUT=2.5V COUT=1μF 0 101 175 102 103 f (KHz) 104 105 Line Transient Supply Voltage Rejection vs Output Current 100 Tek Run:5.00MS/s SVR (dB) 80 60 VIN 1 40 1 20 0 VOUT VIN=3.5 ~ 6.5V COUT=1μF fOSC=1KHz 0 25 50 100 75 125 150 Ch1 500mV Ch2 20.0mV M 10.0μs Ch1 3.96V CH2 VOUT=2.5V, IOUT=50mA, no CIN, COUT=4.7μF, tR=tF=20ns 175 IOUT (mA) Line Transient Supply Voltage Rejection vs Frequency 70 Tek Run:5.00MS/s 60 VIN SVR (dB) 50 1 40 30 VOUT 20 10 2 VIN=2.8 ~ 5.8V IOUT=10mA VOUT=1.8V COUT=10μF 0 101 102 103 104 105 f (KHz) UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw CH220.0mV M 10.0μs Ch1 Ch1 500mV Ch2 3.96V VOUT=2.5V, IOUT=50mA, no CIN, COUT=4.7μF, tR=tF=1μs 8 of 9 QW-R102-021.I LD1985 LINEAR INTEGRATED CIRCUIT TYPICAL CHARACTERISTICS(Cont.) UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 9 of 9 QW-R102-021.I