ISSUED DATE :2005/01/24 REVISED DATE : GT2123 C M O S P o s i t i v e Vo l t a g e R eg u l a t o r Description The GT2123 of positive, linear regulators feature low quiescent current (35 A typ.) with low dropout voltage, making them ideal for battery applications. This rugged device has both Thermal Shutdown, and Current Fold-back to prevent device failure under the “Worst” of operating conditions. The SOT-26 version also features a “Power Good” detector, which pulls low when the output is out of regulation. The GT2123 is stable with an output capacitance of 2.2 F or greater. Features Very Low Dropout Voltage Guaranteed 300mA output Over-Temperature Shutdown Current Limiting Short Circuit Current Fold-back Highly Accurate± 1.5% Adjustable output voltages Power-saving Shutdown Mode Power Good Detector Low Temperature coefficient Functional Block Diagram Applications Battery Powered Widgets Instrumentation Wireless Devices PC Peripherals Portable Electronics Cordless Phones Electronic Scales Package Dimensions REF. A B C D E F Millimeter Min. Max. 2.70 3.10 2.60 3.00 1.40 1.80 0.30 0.55 0 0.10 0° 10° REF. G H I J K L Dimensions Millimeter 1.90 REF. 1.20 REF. 0.12 REF. 0.37 REF. 0.60 REF. 0.95 REF. Typical Application Circuit 1/8 ISSUED DATE :2005/01/24 REVISED DATE : Absolute Maximum Ratings Parameter Symbol Ratings Unit Input Max Voltage VIN 8 V Output Current IOUT PD/( VIN- VO) mA GND-0.3 to VIN+0.3 V Input, Output Voltage Operating Ambient Temperature Junction Temperature Maximum Junction Temperature Thermal Resistance Power Dissipation( T=100 ) Topr -40 ~ +85 Tj -40 ~ +125 Tj Max 150 ja 260 /W PD 380 mW EDS Classification B Electrical Characteristics Ta=25 Parameter Output Voltage Output Current Current Limit Load Regulation Symbol VO IO ILIM REGLOAD Dropout Voltage VDROPOUT Ground Pin Current Line Regulation Input Voltage Over Temperature Shutdown Over Temperature Hysterisis Output Voltage Temperature Coefficient Short Circuit Current(Note2) Power Supply Rejection IGND REGLINE Min TYP Max Unit -1.5% - 1.5% V VIN=5V, VO>1.2 300 - - mA VIN=5V, VO>1.2 300 450 - mA VIN=5V, IO=1mA to 300mA 1.5V<VO(NOM) 2.0V IO=300mA 2.0V<VO(NOM) 2.8V VO=VO(NOM)-2% 2.8V<VO(NOM)<3.8V - 0.2 - 1 1300 400 300 % - 35 - - - 0.15 - 0.02 0.1 VIN=5V, IO=1mA~300mA IO=5mA VO V VIN=VOUT(T)+1 to VO 2.0V VOUT(T)+2 mV A % - 7 - 150 30 - TC - 30 - VIN=5V, VOUT<0.8V f=100Hz VIN=5V Io=100mA f=1kHz Co=2.2 f f=10kHz - 150 60 50 20 300 - mA f=10Hz~100kHz Io=10mA C BYP=0 F - 30 - Vrms 1.2 2.0 0 0 115 - 1 1.215 0.5 - 1.23 VIN 0.4 0.1 0.5 1 0.1 85 1 7 0.4 A ISC PSRR ADJ Input Bias Current ADJ Reference Voltage IADJ VREF VEH VEL IEH IEL ISD VO,SD VUV VOV ILC VPG VOL Shutdown Supply Current Shutdown Output Voltage Output Under Voltage Output Over Voltage PG Leakage Current PG Voltage Rating PG Voltage Low Condition VIN=5V, IO=1mA Note1 eN EN Input Bias Current unless otherwise noted VIN OTS OTH Output Voltage Noise EN Input Threshold VIN=5V, Co=2.2 F VIN=2.7V to 7V VIN=2.7V to 7V VEN=VIN, VIN=2.7V to 7V VEN= 0V, VIN=2.7V to 7V VIN=5V, VO=0V, VEN<VEL Io=35 A, VEN<VEL VPG=7V VO in regulation ISINK=0.4mA V ppm/ dB V V A A A V %Vo(NOM) %Vo(NOM) A V V Note 1: VIN (MIN) =VOUT+VDROPOUT 2: To prevent the Short Circuit Current protection feature from being prematurely activated, the input voltage must be applied before a current source load is applied. 2/8 ISSUED DATE :2005/01/24 REVISED DATE : Ordering Information ( contd. ) Part Number GT2123-AD Marking 3BAD2 XXXX Output Voltage Part Number Marking Output Voltage Adjustable Detailed Description The GT2123 of COMS regulators contain a PMOS pass transistor, voltage reference, error amplifier, over-current protection, thermal shutdown and Power Good detection circuitry. The P-channel pass transistor receives data from the error amplifier, over-current shutdown, and thermal protection circuits. During normal operation, the error amplifier compares the output voltage to a precision reference. Over-current and Thermal shutdown circuits become active when the junction temperature exceeds 150 , or the current exceeds 300mA. During thermal shutdown, the output voltage remains low. Normal operation is restored when the junction temperature drops below 120 . The GT2123 switches from voltage mode to current mode when the load exceeds the rated output current. This prevents over-stress. The GT2123 also incorporates current fold-back to reduce power dissipation when the output is short circuited. This feature becomes active when the output drops below 0.8 volts, and reduces the current flow by 65%. Full current is restored when the voltage exceeds 0.8 volts. External Capacitors The GT2123 is stable with an output capacitance to ground of 2.2 F or greater. Ceramic capacitors have the lowest ESR, and will offer the best AC performance. Conversely, Aluminum Electrolytic capacitors exhibit the highest ESR, resulting in the poorest AC response. Unfortunately, large value ceramic capacitors are comparatively expensive. One option is to parallel a 0.1 F ceramic capacitor with a 10 F Aluminum Electrolytic. The benefit is low ESR, high capacitance, and low overall cost. A second capacitor is recommended between the input and ground to stabilize Vin. The input capacitor should be at least 0.1 F to have a beneficial effect. All capacitors should be placed in close proximity to the pins. A “Quiet” ground termination is desirable. This can be achieved with a “Star” connection. Enable The Enable pin normally floats high. When actively, pulled low, the PMOS pass transistor shuts off, and all internal circuits are powered down. In this state, the quiescent current is less than 1 A. This pin behaves much like an electronic switch. Power Good The GT2123 includes the Power Good feature. When the output is not within 10% of the specified voltage, it pulls low. This can occur under the following conditions: 1) Input Voltage too low. 2) During Over-Temperature. 3) During Over-Current. 4) If output is pulled up. (Note: PG pin is an open-drain output.) 3/8 ISSUED DATE :2005/01/24 REVISED DATE : Characteristics Curve 4/8 ISSUED DATE :2005/01/24 REVISED DATE : 5/8 ISSUED DATE :2005/01/24 REVISED DATE : 6/8 ISSUED DATE :2005/01/24 REVISED DATE : External Resistor Divider Table R1(K Ohm) 1 2 Vout 5 10 20 50 100 200 500 1000 R2(K Ohm)=(1.215*R1(K Ohm))/(VOUT-1.215) 1.30 14.29 28.59 71.47 142.94 285.88 714.71 1.35 9.00 18.00 45.00 90.00 180.00 450.00 1.40 6.57 13.14 32.84 65.68 131.35 328.38 1.45 5.17 10.34 25.85 51.70 103.40 258.51 517.02 1.50 4.26 8.53 21.32 42.63 85.26 213.16 426.32 852.63 1.55 3.63 7.25 18.13 36.27 72.54 181.34 362.69 725.37 1.60 3.16 6.31 15.78 31.56 63.12 157.79 315.58 631.17 1.65 2.79 5.59 13.97 27.93 55.86 139.66 279.31 558.62 1.70 2.51 5.01 12.53 25.05 50.10 125.26 250.52 501.03 1.75 2.27 4.54 11.36 22.71 45.42 113.55 227.10 454.21 1.80 2.08 4.15 10.38 20.77 41.54 103.85 207.69 415.38 1.85 1.91 3.83 9.57 19.13 38.27 95.67 191.34 382.68 1.90 1.77 3.55 8.87 17.74 35.47 88.69 177.37 354.74 1.95 1.65 3.31 8.27 16.53 33.06 82.65 165.33 330.61 826.53 2.00 1.55 3.10 7.74 15.48 30.96 77.39 154.78 309.55 773.89 2.05 1.46 2.91 7.28 14.55 29.10 72.75 145.51 291.02 727.54 2.10 1.37 2.75 6.86 13.73 27.46 68.64 137.29 274.58 686.44 2.15 1.30 2.60 6.50 12.99 25.99 64.97 129.95 259.89 649.73 2.20 1.23 2.47 6.17 12.34 24.67 61.68 123.35 246.70 616.75 2.25 1.71 2.35 5.87 11.74 23.48 58.70 117.39 234.78 586.96 2.30 1.12 2.24 5.60 11.20 22.40 55.99 111.98 223.96 559.91 2.35 1.07 2.14 5.35 10.70 21.41 53.52 107.05 214.10 535.24 2.40 1.03 2.05 5.13 10.25 20.51 51.27 102.53 205.06 512.66 2.45 0.98 1.97 4.92 9.84 19.68 49.19 98.38 196.76 491.90 2.50 0.95 1.89 4.73 9.46 18.91 47.28 94.55 189.11 472.76 2.55 0.91 1.82 4.55 9.10 18.20 45.51 91.01 182.02 455.06 2.60 0.88 1.75 4.39 8.77 17.55 43.86 87.73 175.45 438.63 877.26 2.65 0.85 1.69 4.23 8.47 16.93 42.33 84.67 169.34 423.34 846.69 2.70 0.82 1.64 4.09 8.18 16.36 40.91 81.82 163.64 409.09 818.18 2.75 0.79 1.58 3.96 7.92 15.83 39.58 79.15 158.31 395.77 791.53 2.80 0.77 1.53 3.83 7.67 15.33 38.33 76.66 153.31 383.28 766.56 2.85 0.74 1.49 3.72 7.43 14.86 37.16 74.13 148.62 371.56 743.12 2.90 0.72 1.44 3.61 7.21 14.42 36.05 72.11 144.21 360.53 721.07 2.95 0.70 1.40 3.50 7.00 14.01 35.01 70.03 140.06 350.14 700.29 3.00 0.68 1.36 3.40 6.81 13.61 34.03 68.07 136.13 340.34 680.67 3.05 0.66 1.32 3.31 6.62 13.24 33.11 66.21 132.43 331.06 662.13 3.10 0.64 1.29 3.22 6.45 12.89 32.23 64.46 128.91 322.28 644.56 3.15 0.63 1.26 3.14 6.28 12.56 31.40 62.79 125.58 313.95 627.91 3.20 0.61 1.22 3.06 6.12 12.24 30.60 61.21 122.42 306.05 612.09 3.25 0.60 1.19 2.99 5.97 11.94 29.85 59.71 119.41 298.53 597.05 3.30 0.58 1.17 2.91 5.83 11.65 11.65 58.27 116.55 291.37 582.73 7/8 ISSUED DATE :2005/01/24 REVISED DATE : External Resistor Divider Table R1(K Ohm) 1 2 Vout 5 10 20 50 100 200 500 1000 R2(K Ohm)=(1.215*R1(K Ohm))/(VOUT-1.215) 3.35 0.57 1.14 2.85 5.69 11.38 28.45 56.91 113.82 284.54 569.09 3.40 0.56 1.11 2.78 5.56 11.12 27.80 55.61 111.21 278.03 556.06 3.45 0.54 1.09 2.72 5.44 10.87 27.18 54.36 108.72 271.81 543.62 3.50 0.53 1.06 2.66 5.32 10.63 26.59 53.17 106.35 265.86 531.73 3.55 0.52 1.04 2.60 5.20 10.41 26.02 52.03 104.07 260.17 520.34 3.60 0.51 1.02 2.55 5.09 10.19 25.47 50.94 101.89 254.72 509.43 3.65 0.50 1.00 2.49 4.99 9.98 24.95 49.90 99.79 249.49 498.97 3.70 0.49 0.98 2.44 4.89 9.78 24.45 48.89 97.79 244.47 488.93 3.75 0.48 0.96 2.40 4.79 9.59 23.96 47.93 95.86 239.64 479.29 3.80 0.47 0.94 2.35 4.70 9.40 23.50 47.00 94.00 235.01 470.02 3.85 0.46 0.92 2.31 4.61 9.22 23.06 46.11 92.22 230.55 461.10 3.90 0.45 0.91 2.26 4.53 90.5 22.63 45.25 90.50 226.26 452.51 3.95 0.44 0.89 2.22 4.44 8.88 22.21 44.42 88.85 222.12 444.24 4.00 0.44 0.87 2.18 4.36 8.73 21.81 43.63 87.25 218.13 436.27 4.05 0.43 0.86 2.14 4.29 8.57 21.43 42.86 85.71 214.29 428.57 4.10 0.42 0.84 2.11 4.21 8.42 21.06 42.11 84.23 210.57 421.14 4.15 0.41 0.83 2.07 4.14 8.28 20.70 41.40 82.79 206.98 413.97 4.20 0.41 0.81 2.04 4.07 8.14 20.35 40.70 81.41 203.52 407.04 4.25 0.40 0.80 2.00 4.00 8.01 20.02 40.03 80.07 200.16 400.33 4.30 0.39 0.79 1.97 3.94 7.88 19.69 39.38 78.77 196.92 393.84 4.35 0.39 0.78 1.97 3.88 7.75 19.38 38.76 77.51 193.78 387.56 4.40 0.38 0.76 1.91 3.81 7.63 19.07 38.15 76.30 190.74 381.48 4.45 0.38 0.75 1.88 3.76 7.51 18.78 37.56 75.12 187.79 375.58 4.50 0.37 0.74 1.85 3.70 7.40 18.49 36.99 73.97 184.93 369.86 4.55 0.36 0.73 1.82 3.64 7.29 18.22 36.43 72.86 182.16 364.32 4.60 0.36 0.72 1.79 3.59 7.18 17.95 35.89 71.79 179.47 358.94 4.65 0.35 0.71 1.77 3.54 7.07 17.69 35.37 70.74 176.86 353.71 4.70 0.35 0.70 1.74 3.49 6.97 17.43 34.86 69.73 174.32 348.64 4.75 0.34 0.69 1.72 3.44 6.87 17.19 34.37 68.74 171.85 343.71 4.80 0.34 0.68 1.69 3.39 6.78 16.95 33.89 67.78 169.46 338.91 4.85 0.33 0.67 1.67 3.34 6.69 16.71 33.43 66.85 167.13 334.25 4.90 0.33 0.66 1.65 3.30 6.59 16.49 32.97 65.94 164.86 329.72 4.95 0.33 0.65 1.63 3.25 6.51 16.27 32.53 65.06 162.65 325.30 5.00 0.32 0.64 1.61 3.21 6.42 16.05 32.10 64.02 160.50 321.00 Note: Small load (greater than 2mA) is necessary as R1 or R2 is large than 50Kohm. Otherwise, output voltage probably cannot be pulled down to 0V on disable mode Important Notice: All rights are reserved. Reproduction in whole or in part is prohibited without the prior written approval of GTM. GTM reserves the right to make changes to its products without notice. GTM semiconductor products are not warranted to be suitable for use in life-support Applications, or systems. GTM assumes no liability for any consequence of customer product design, infringement of patents, or application assistance. Head Office And Factory: Taiwan: No. 17-1 Tatung Rd. Fu Kou Hsin-Chu Industrial Park, Hsin-Chu, Taiwan, R. O. C. TEL : 886-3-597-7061 FAX : 886-3-597-9220, 597-0785 China: (201203) No.255, Jang-Jiang Tsai-Lueng RD. , Pu-Dung-Hsin District, Shang-Hai City, China TEL : 86-21-5895-7671 ~ 4 FAX : 86-21-38950165 8/8