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 (2mA Typ. at 150mA Load and 80μA at no Load) * 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 Lead Free Halogen Free LD1985L-xx-AF5-R LD1985G-xx-AF5-R Note: xx: Output Voltage, refer to Marking Information. www.unisonic.com.tw Copyright © 2010 Unisonic Technologies Co., Ltd Package Packing SOT-25 Tape Reel 1 of 10 QW-R102-021,F LD1985 LINEAR INTEGRATED CIRCUIT MARKING INFORMATION PACKAGE VOLTAGE CODE MARKING 15:1.5V 18:1.8V 25:2.5V 28:2.8V 2J:2.85V 30:3.0V 31:3.1V 32:3.2V SOT-25 33:3.3V 35:3.5V 36:3.6V 38:3.8V 40:4.0V 47:4.7V 50:5.0V PIN CONFIGURATION PIN DESCRIPTION PIN NO. 1 2 PIN NAME VIN GND 3 INHIBIT 4 Bypass 5 VOUT 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 UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 10 QW-R102-021,F LD1985 LINEAR INTEGRATED CIRCUIT 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 3 of 10 QW-R102-021,F 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 -20 ~ +125 °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 Output Voltage VOUT IOUT=1 ~ 150mA 1.455 VIN =2.8V 1.764 1.8 Output Voltage VOUT IOUT =1 ~ 150mA 1.746 VIN =3.5V 2.450 2.5 Output Voltage VOUT IOUT =1 ~ 150mA 2.425 VIN =3.8V 2.744 2.8 Output Voltage VOUT IOUT =1 ~ 150mA 2.716 VIN =3.85V 2.793 2.85 Output Voltage VOUT IOUT =1 ~ 150mA 2.764 VIN =4.0V 2.940 3.0 Output Voltage VOUT IOUT =1 ~ 150mA 2.910 VIN =4.1V 3.038 3.1 Output Voltage VOUT 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 Output Voltage VOUT IOUT =1 ~ 150mA 3.201 VIN =4.5V 3.430 3.5 Output Voltage VOUT IOUT =1 ~ 150mA 3.395 VIN =4.6V 3.528 3.6 Output Voltage VOUT IOUT =1 ~ 150mA 3.492 VIN =4.8V 3.724 3.8 Output Voltage VOUT IOUT =1 ~ 150mA 3.686 VIN =5.0V 3.920 4 Output Voltage VOUT IOUT =1 ~ 150mA 3.880 VIN =5.7V 4.606 4.7 Output Voltage VOUT IOUT =1 ~ 150mA 4.559 VIN =6.0V 4.900 5 Output Voltage VOUT IOUT =1 ~ 150mA 4.850 Short Circuit Current Isc RL=0 400 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 mA 4 of 10 QW-R102-021,F LD1985 LINEAR INTEGRATED CIRCUIT ELECTRICAL CHARACTRISTICS(Cont.) PARAMETER Line Regulation Dropout Voltage Quiescent Current Supply Voltage Rejection Control Input Logic Low Control Input Logic High SYMBOL △VOUT VD IQ SVR VIL VIH Control Input Current IINH Output Noise Voltage eN TEST CONDITIONS VIN = VOUT +1V ~ 7V, IOUT =1mA IOUT =0 TJ=-20 ~ 125°C, IOUT=0 IOUT =1mA IOUT =1mA, TJ=-20 ~ 125°C IOUT =10mA IOUT =10mA, TJ=-20 ~ 125°C IOUT =50mA IOUT =50mA, TJ=-20 ~ 125°C IOUT =150mA IOUT =150mA, TJ=-20 ~ 125°C IOUT =0 TJ=-20 ~ 125°C, IOUT=0 IOUT =1mA IOUT =1mA, TJ=-20 ~ 125°C IOUT =10mA IOUT =10mA, TJ=-20 ~ 125°C IOUT =50mA IOUT =50mA, TJ=-20 ~ 125°C IOUT =150mA IOUT =150mA, TJ=-20 ~ 125°C OFF MODE VINH<0.18V OFF MODE VINH<0.18V TJ=-20 ~ 125°C 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 1 7 40 120 280 80 100 200 600 2000 MAX 30 3 5 10 15 60 90 150 225 350 575 100 150 150 200 300 400 1050 1200 3000 4000 UNIT mV mV mV mV mV mV mV mV mV mV mV µA µA µA µA µA µA µA µA µA µA µA 2 µA 0 45 0.15 2 5 0 30 15 -1 dB V V µA µA µV 5 of 10 QW-R102-021,F LD1985 LINEAR INTEGRATED CIRCUIT REVERSE CURRENT TEST CIRCUIT UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 10 QW-R102-021,F 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 7 of 10 QW-R102-021,F 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 VIN=3.5V IOUT=1mA 2.58 VOUT=2.5V Cby=10nF 2000 2.56 1600 2.52 IQ (μA) VOUT (V) 2.54 2.50 1200 2.48 800 2.46 2.44 400 2.42 2.40 -50 0 -25 50 25 Tc (℃) 75 100 0 125 0 25 Dropout Voltage vs Temperature 50 100 75 IoUT (mA) 150 125 175 Quiescent Current vs Temperature 0.4 VOUT=2.5V Cby=10nF VOUT=2.5V Cby=10nF 3.5 IOUT=150mA 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 (℃) 8 of 10 QW-R102-021,F 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) 150 125 VIN=3.5 ~ 6.5V IOUT=10mA VOUT=2.5V COUT=1μF 0 1 10 175 2 3 10 10 f (KHz) 10 4 10 5 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 75 150 125 Ch1 500mV Ch2 CH2 20.0mV M 10.0μs Ch1 175 3.96V VOUT=2.5V, IOUT=50mA, no CIN, COUT=4.7μF, tr=tf=20ns 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 1 10 10 2 10 3 10 4 10 5 f (KHz) UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw CH2 20.0mV M 10.0μs Ch1 Ch1 500mV Ch2 3.96V VOUT=2.5V, IOUT=50mA, no CIN, COUT=4.7μF, tr=tf=1μs 9 of 10 QW-R102-021,F 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 10 of 10 QW-R102-021,F