BCT2028EUK33-TR

BCT2028 500mA, Low Dropout, Linear Regulators BCT2028 500mA Low Dropout Linear Regulators GENERAL DESCRIPTION FEATURES The BCT2028 series low-power, low-noise, low-dropout, CMOS linear voltage regulators operate from a 2.5V to 5.5V input voltage. They are the perfect choice for low voltage, low power applications. A low ground current makes this part attractive for battery operated power systems. The BCT2028 series also offer ultra-low dropout voltage to prolong battery life in portable electronics. Output current minimum limit is 500mA, and over-current protection limit is set at 700mA typical. An external noise bypass capacitor connected to the device’s BP pin can further reduce the noise level.         These devices feature a shutdown function and are offered in active low with auto discharge. The output voltage is preset to voltages in the range of 1.2V to 3.3V. Other features include a low shutdown current, fold-back current limit and thermal shutdown protection. The BCT2028 is available in Green SOT23-5 packages. It operates over an ambient temperature range of -40°C to +85°C.     Low Output Noise Low Dropout Voltage Thermal-Overload Protection Output Current Limit High PSRR(74dB at 1kHz) 500mA Current Rating Available in Multiple output Voltage Versions Fixed Outputs of 1.2V, 1.5V, 1.8V, 2.5V, 2.8V, 2.85V, 3.0V and 3.3V Adjustable Output from 1.2V to 3.3V Quick output discharge -40°C to 85°C Operating Temperature Range Available in Green SOT23-5 Packages APPLICATIONS Cellular Telephones Cordless Telephones PCMCIA Cards Modems MP3 Player Hand-Held Instruments Portable/Battery-Powered Equipment REV1.7 www.broadchip.com Copyright © BROADCHIP TECHNOLOGY CO., LTD 1 BCT2028 500mA, Low Dropout, Linear Regulators ORDERING INFORMATION Order Number VOUT(V) Package Type Temperature Range Marking QTY/Reel BCT2028EUK12-TR 1.2 SOT23-5 -40°C to +85°C F2ZZ 3000 BCT2028EUK15-TR 1.5 SOT23-5 -40°C to +85°C F5ZZ 3000 BCT2028EUK18-TR 1.8 SOT23-5 -40°C to +85°C F8ZZ 3000 BCT2028EUK25-TR 2.5 SOT23-5 -40°C to +85°C F5ZZ BCT2028EUK28-TR 2.8 SOT23-5 -40°C to +85°C F8ZZ BCT2028EUK29-TR 2.85 SOT23-5 -40°C to +85°C F9ZZ 3000 BCT2028EUK30-TR 3 SOT23-5 -40°C to +85°C F0ZZ 3000 BCT2028EUK33-TR 3.3 SOT23-5 -40°C to +85°C F3ZZ 3000 BCT2028EUKAJ-TR ADJ SOT23-5 -40°C to +85°C FJZZ 3000 — 3000 — 3000 — ORDER NUMBER BCT2028 X XX XX -TR Tape and Reel Output Voltages: 12: 1.2V 15: 1.5V 18:1.8V 25:2.5V 28:2.8V 29:2.85V 30:3.0V 33:3.3V AJ:ADJ Package Type: UK: SOT23-5 Operating Temperature Range: E: -40℃ to +85℃ REV1.7 www.broadchip.com Copyright © BROADCHIP TECHNOLOGY CO., LTD 2 BCT2028 500mA, Low Dropout, Linear Regulators MARKING DESCRIPTION F：Product Code X: Output Voltage Code VOUT(V) Code 1.2 2 1.5 5 1.8 8 2.5 5 2.8 8 2.85 3.0 9 0 3.3 3 ADJ J — — — Z: The year of manufacturing, “1” stands for year 2011, “2” stands for year 2012, “7” stands for year 2017 and “8” stands for year 2018. _ _ Z: The week of manufacturing. “A” stands for week 1, “Z” stands for week 26, “A” stands for week 27, “Z” stands for week 52. REV1.7 www.broadchip.com Copyright © BROADCHIP TECHNOLOGY CO., LTD 3 BCT2028 500mA, Low Dropout, Linear Regulators ABSOLUTE MAXIMUM RATINGS CAUTION IN to GND.......................................................-0.3V to 6V This integrated circuit can be damaged by ESD if you don’t EN to GND……………....................................-0.3V to VIN pay attention to ESD protection. Broadchip recommends OUT, BP/FB to GND...........................-0.3V to (VIN+0.3V) that all integrated circuits be handled with appropriate Output Short-Circuit Duration.................................Infinite precautions. Failure to observe proper handling and Power Dissipation, PD@TA=25℃ installation procedures can cause damage. ESD damage SOT-23-5..................................................................0.4W can range from subtle performance degradation to Package Thermal Resistance complete device failure. Precision integrated circuits may SOT-23-5, θJA.......................................................250℃/W be more susceptible to damage because very small Junction Temperature..............................................150℃ parametric changes could cause the device not to meet its Operating Temperature Range.................-40℃ to +85℃ published specifications. Storage Temperature Range....................-65℃ to 150℃ Lead Temperature (Soldering, 10 sec).....................260℃ Broadchip reserves the right to make any change in circuit ESD Susceptibility design, specification or other related things if necessary HBM.....................................................................4000V without notice at any time. Please contact Broadchip sales MM.........................................................................400V office to get the latest datasheet. NOTE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. REV1.7 www.broadchip.com Copyright © BROADCHIP TECHNOLOGY CO., LTD 4 BCT2028 500mA, Low Dropout, Linear Regulators PIN CONFIGURATION SOT23-5 TOP VIEW 1 GND 2 EN 3 5 OUT 4 BP/FB MARKING IN PIN DESCRIPTION PIN NAME FUNCTION 1 IN Regulator Input. Supply voltage can range from 2.5V to 5.5V. Bypass with a 1uF capacitor to GND. 2 GND 3 EN Shutdown Input. A logic low reduces the supply current to 10nA. Connect to IN for normal operation. BP Reference-Noise Bypass (fixed voltage version only). Bypass with a low-leakage 0.01uF ceramic capacitor for reduced noise at the output. FB Adjustable Voltage Version Only. This is used to set the output voltage of the device. 4 5 OUT Ground. Regulator Output. REV1.7 www.broadchip.com Copyright © BROADCHIP TECHNOLOGY CO., LTD 5 BCT2028 500mA, Low Dropout, Linear Regulators ELECTRICAL CHARACTERISTICS (VIN= VOUT(NOMINAL)+0.5V(1), TA = -40℃ to +85℃, unless otherwise specified.) PARAMETER SYM Input Voltage CONDITIONS VIN (1) Output Voltage Accuracy IOUT=0.1mA Maximum Output Current TYP MAX UNITS 2.5 5.5 V -2.5 2.5 % 500 Current Limit ILIM Ground Pin Current IQ Dropout Voltage(2) ΔVLNR Line Regulation ΔVLDR Load Regulation Output Voltage Noise en mA 700 No load, EN=2V mA 100 IOUT=1mA 0.9 IOUT=500mA 270 VIN=2.5V or (VOUT+0.5V) to 5.5V, IOUT=1mA 0.1 IOUT=0.1mA to 500mA, COUT=1uF, VOUT>2V 0.002 IOUT=0.1mA to 500mA, COUT=1uF, VOUT≤2V 0.004 200 500 uA mV %/V %/mA f=10Hz to 100kHz, CBP=0.01uF, COUT=10uF 50 f= CBP=0.1uF, PSRR ILOAD=50mA, COUT=1uF, 217Hz VIN=VOUT+1V f=1kHz Power Supply Rejection Ratio SHUTDWON MIN uVRMS 77 dB 74 (3) VIH EN Input Threshold VIL VIN=2.5V to 5.5V, VEN=-0.3V to VIN 1.5 0.3 EN Input Bias Current IB(SHDN) EN=0V or EN=5.5V 0.01 Shutdown Supply Current IQ(SHDN) EN=0.4V 0.01 uA 30 us TSHDN 150 °C ΔTSHDN 15 °C CBP=0.01uF, COUT=1uF, No Load Shutdown Exit Delay(4) 1 V uA THERMAL PROTECTION Thermal Shutdown Temperature Thermal Shutdown Hysteresis NOTES: 1. VIN = VOUT (NOMINAL) + 0.5V or 2.5V, whichever is greater. 2. The dropout voltage is defined as VIN - VOUT, when VOUT is 100mV below the value of VOUT for VIN = VOUT + 0.5V. (Only applicable for VOUT = +2.5V to +5.0V.) 3. VEN = -0.3V to VIN 4. Time needed for VOUT to reach 90% of final value. REV1.7 www.broadchip.com Copyright © BROADCHIP TECHNOLOGY CO., LTD 6 BCT2028 500mA, Low Dropout, Linear Regulators TYPICAL APPLICATION CIRCUIT NOTE: VOUT = (R1 + R2)/ R2 × 1.207 REV1.7 www.broadchip.com Copyright © BROADCHIP TECHNOLOGY CO., LTD 7 BCT2028 500mA, Low Dropout, Linear Regulators APPLICATION NOTE Bypass Capacitor and Low Noise Connecting a 10nF between the BP pin and GND pin significantly reduces noise on the regulator output, it is critical that the capacitor connection between the BP pin and GND pin be direct and PCB traces should be as short as possible. There is a relationship between the bypass capacitor value and the LDO regulator turn on time. DC leakage on this pin can affect the LDO regulator output noise and voltage regulation performance. Enable Function The BCT2028 features an LDO regulator enable/disable function. To assure the LDO regulator will switch on; the EN turn on control level must be greater than 1.5 volts. The LDO regulator will go into the shutdown mode when the voltage on the EN pin falls below 0.3 volts. For to protect the system, the BCT2028 have a quick discharge function. If the enable function is not needed in a specific application, it may be tied to VIN to keep the LDO regulator in a continuously on state. Programming the BCT2028 Adjustable LDO regulator The output voltage of the BCT2028 adjustable regulator is programmed using an external resistor divider as show in Figure as below. The output voltage is calculated using equation as below: R1   VOUT  VREF  1    R2  Where: VREF=1.207V typ (the internal reference voltage) Resistors R1 and R2 should be chosen for approximately 50uA divider current. Lower value resistors can be used for improved noise performance, but the solution consumes more power. Higher resistor values should be avoided as leakage current into/out of FB across R1/R2 creates an offset voltage that artificially increases/decreases the feedback voltage and thus erroneously decrease/increases VOUT. Thermal Considerations Thermal protection limits power dissipation in BCT2028. When the operation junction temperature exceeds 150°C, the OTP circuit starts the thermal shutdown function turn the pass element off. The pass element turns on again after the junction temperature cools by 15°C. REV1.7 www.broadchip.com Copyright © BROADCHIP TECHNOLOGY CO., LTD 8 BCT2028 500mA, Low Dropout, Linear Regulators For continue operation, do not exceed absolute maximum operation junction temperature 125°C. The power dissipation definition in device is: PD = (VIN−VOUT) ×IOUT + VIN×IQ The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junction to ambient. The maximum power dissipation can be calculated by following formula： PD(MAX) = ( TJ(MAX) − TA ) /θJA Where TJ(MAX) is the maximum operation junction temperature 125°C, TA is the ambient temperature and the θJA is the junction to ambient thermal resistance. For recommended operating conditions specification of BCT2028, where TJ(MAX) is the maximum junction temperature of the die (125°C) and TA is the maximum ambient temperature. The junction to ambient thermal resistance (θ JA is layout dependent) for SOT-23-5 package is 250°C/W, on standard JEDEC 51-3 thermal test board. The maximum power dissipation at TA= 25°C can be calculated by following formula: PD(MAX) = (125°C−25°C)/250 = 400mW (SOT-23-5) The maximum power dissipation depends on operating ambient temperature for fixed TJ(MAX) and thermal resistance θJA. It is also useful to calculate the junction of temperature of the BCT2028 under a set of specific conditions. In this example let the Input voltage VIN=3.3V, the output current Io=500mA and the case temperature TA=40°C measured by a thermal couple during operation. The power dissipation for the Vo=2.8V version of the BCT2028 can be calculated as: PD = (3.3V−2.8V) ×500mA+3.6V×100uA =250mW And the junction temperature, TJ, can be calculated as follows: TJ=TA+PD×θJA=40°C+0.25W×250°C/W =40°C+62.5°C=102.5°C