UNISONIC TECHNOLOGIES CO., LTD L2800 LINEAR INTEGRATED CIRCUIT SWITCHING REGULATOR CONTROLLER(LOW VOLTAGE) SOP-8 DESCRIPTION The UTC L2800 which is incorporating a soft start function and short circuit detection function is a single-channel switching regulator control IC and is made for low voltage applications. Because the device has a low minimum operating voltage of 1.8V, so it is ideal for the power supply of battery-operated electronic equipment. TSSOP-8 FEATURES *Wide supply voltage operating range: 1.8V~15V *Low current consumption: Typically 5.5mA in operation,1μA or less in stand-by *High speed operation is possible: Maximum 1MHz *The error amplifier gain is set inside the IC, so peripheral components are minimized. *Incorporates a soft start circuit. *Incorporates a timer-latch type short circuit detection circuit (SCP). *Totem-pole type output with adjustable on/off current (for NPN transistors) *Incorporates a stand-by function. ORDERING INFORMATION Ordering Number Lead Free Halogen Free L2800L-S08-T L2800G-S08-T L2800L-S08-R L2800G-S08-R L2800L-P08-T L2800G-P08-T L2800L-P08-R L2800G-P08-R www.unisonic.com.tw Copyright © 2013 Unisonic Technologies Co., Ltd Package Packing SOP-8 SOP-8 TSSOP-8 TSSOP-8 Tube Tape Reel Tube Tape Reel 1 of 7 QW-R103-030.C L2800 LINEAR INTEGRATED CIRCUIT PIN CONFIGURATION PIN DESCRIPTION PIN NO. 1 2 3 4 5 6 7 8 SYMBOL -IN SCP VCC BR/CTL OUT GND OSC FB I/O I I O O DESCRIPTION Error amplifier inverting input pin Soft start and SCP setting capacitor connection pin Power supply pin Output current setting and control pin Totem-pole type output pin Ground pin Capacitor and resistor connection pin for setting the oscillation frequency Error amplifier output pin BLOCK DIAGRAM UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 7 QW-R103-030.C L2800 LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS (TA=25C) PARAMETER Power Supply Voltage Output Source Current Output Sink Current RATINGS UNIT 16 V -50 mA 50 mA SOP-8 570 Power Dissipation (Note2) PD mW TSSOP-8 580 Storage Temperature TSTG -55 ~ +125 C Operating Temperature TOPR -30 ~ +85 C Notes: 1. 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. 2. When mounted on a 10cm square double-sided epoxy board. SYMBOL VCC IO+ IO- RECOMMENDED OPERATING CONDITIONS (TA=25C) PARAMETER Power Supply Voltage Error Amplifier Input Voltage BR/CTL Pin Input Voltage Output Source Current Output Sink Current SCP Pin Capacitance Phase Compensation Capacitance Output Current Setting Resistance Timing Resistance Timing Capacitance Oscillation Frequency Operating Temperature SYMBOL VCC VI VBR IO + IOCPE CP RB RT CT fOSC TOPR UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN 1.8 -0.2 -0.2 -40 TYP MAX 15 1.0 VCC 40 150 1.0 100 10 -30 0.1 0.1 390 3.0 270 500 +25 5000 10.0 10000 1000 +85 UNIT V V V mA mA μF μF Ω kΩ pF kHz C 3 of 7 QW-R103-030.C L2800 LINEAR INTEGRATED CIRCUIT ELECTRICAL CHARACTERISTICS (TA=25C, VCC=+2V) PARAMETER SYMBOL TEST CONDITIONS CIRCUIT TO PREVENT MALFUNCITION AT LOW INPUT OLTAGE (U.V.L.O) Reset Voltage VR Threshold Voltage VTH Soft Start Charging Current ICS VSCP=0V Voltage at soft start completion VTS Short Circuit Detection(S.C.P.) Charging Current ICPC VSCP=0V Threshold Voltage VTPC SAWTOOTH WAVE OSCILLATOR(OSC) Oscillation Frequency fOSC RT=3.0kΩ, CT=270pF Frequency Input Stability fDV VCC=2V ~ 15V Frequency Variation With Temperature fDT TA=-30C ~ +85C ERROR AMPLIFIER Input Threshold Voltage VT VFB=450mV VT Input Stability VTDV VCC=2V ~ 15V VT Variation With Temperature VTDT TA= -30C ~ +85C Input Bias Current IB VIN=0V Voltage Gain Av Frequency Bandwidth BW AV=0dB VOM+ Maximum Output Voltage Range VOMOutput Source Current IOM+ VFB=0.45V Output Sink Current IOMIDLE PERIOD ADJUSTMENT SECTION Maximum Duty Cycle tDUTY RT=3.0kΩ, CT=270pF, VFB=0.8V OUTPUT SECTION VOH1 RB=390Ω, IO=-15mA VOH2 RB=750Ω, VCC=1.8V, Io= -10mA Output Voltage VOL1 RB=390Ω, IO=15mA VOL2 RB=750Ω, VCC=1.8V, Io=10mA Output Source Current IO + RB=390Ω, VO=0.9V Output Sink Current IORB=390Ω, VO=0.3V Pull Down Resistance RO OUTPUT CURRENT SETTING SECTION/CONTROL SECTION Pin Voltage VBR RB=390Ω Input Off Condition IOFF Input On Condition ION Pin Current Range IBR ENTIRE DEVICE Stand-by Current ICCS BR/CTL pin open or VCC Average Supply Current ICC RB=390Ω UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN TYP MAX UNIT 1.1 1.3 0.9 1.5 V V -1.5 0.7 -1.0 0.8 -0.7 0.9 μA V -1.5 0.7 -1.0 0.8 -0.7 0.9 μA V 400 500 2 5 600 10 kHz % % 480 520 20 24 500 5 1 -0.2 100 6 0.87 0.05 -40 40 mV mV % μA V/V MHz V V μA μA 65 75 1.0 0.8 1.2 1.0 0.1 0.1 -30 60 30 -1.0 70 0.78 30 20 0.2 -20 0.3 -1.8 5.5 1.0 145 0.2 -24 85 % 0.2 0.2 -20 40 V V V V mA mA kΩ 0.4 0 -45 -0.1 V μA μA mA 1 9.3 μA mA 4 of 7 QW-R103-030.C L2800 LINEAR INTEGRATED CIRCUIT DIAGRAM HOW TO SET THE TIME CONSTANT FOR SHORT CIRCUIT DETECTION AND SOFT START 1. SHORT CIRCUIT PROTECTION Te error amplifier output (FB pin) is fixed at VOM+ and capacitor CPE starts charging i the switching regulator output suddenly drops due to load effect. The output pin is set low and the SCP pin stays low when the voltage at the SCP pin reaches approximately 0.8V. As the protection circuit operates, by resetting the power supply the circuit will be restored. •Short circuit detection time tPE[S]≒0.8×CPE[μF] 2. SOFT START Once power on, the capacitor CPE which is connected to the SCP pin starts charging.The soft start setting voltage is compared by the PWM comparator as the voltage’s proportion at the SCP pin with the sawtooth waveform. The comparison controls the OUT pin’s ON duty,which is causing the soft start operation. During the time for completion of soft start operation, the SCP pin’s voltage stays low, but the soft start setting voltage stays high, and the circuit then enters the output short circuit detection wait state. Soft start time (until the output ON duty reaches approximately 50%) ts[S]≒0.35×CPE[μF] UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 7 QW-R103-030.C L2800 LINEAR INTEGRATED CIRCUIT APPLICATION EXAMPLE 22μH VO 5V 18kΩ VIN 3V -IN 0.1μF SCP 33μF Vcc 2kΩ BR/CTL 390Ω 1 2 3 4 8 FB 7 OSC 6 GND 5 OUT 10μF 0.1μF 270pF 3kΩ CTL UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 7 QW-R103-030.C L2800 LINEAR INTEGRATED CIRCUIT TYPICAL CHARACTERISTICS 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 7 of 7 QW-R103-030.C