UC3845G-S08-R

UNISONIC TECHNOLOGIES CO., LTD UC3844/45 LINEAR INTEGRATED CIRCUIT HIGH PERFORMANCE CURRENT MODE PWM CONTROLLERS  DESCRIPTION The UTC UC3844/3845 are high performance fixed frequency current mode controllers that specifically designed for Off-Line and DC to DC converter applications with minimal external parts count. The differences between UC3844 and UC3845 are the maximum duty cycle ranges and under-voltage lockout thresholds. The UC3844 ideally suited to off-line applications with UVLO thresholds of 16V(ON) and 10V(OFF), and UC3845 has UVLO thresholds of 8.5V(ON) and 7.6V(OFF) for lower voltage applications.  FEATURES * Operation output switching frequency up to 500 kHz * Automatic feed forward compensation * Latching PWM for cycle-by-cycle current limiting * High current totem pole output * Internally trimmed reference with under voltage lockout * UVLO with hysteresis * Low startup and operating current  ORDERING INFORMATION Ordering Number Lead Free Halogen Free UC3844L-D08-T UC3844G-D08-T UC3844G-S08-R UC3845L-D08-T UC3845G-D08-T UC3845G-S08-R www.unisonic.com.tw Copyright © 2015 Unisonic Technologies Co., Ltd Package Packing DIP-8 SOP-8 DIP-8 SOP-8 Tube Tape Reel Tube Tape Reel 1 of 7 QW-R103-010.H UC3844/45 LINEAR INTEGRATED CIRCUIT MARKING  UC3844 UC3845 DIP-8 SOP-8 PIN CONFIGURATION  PIN DESCRIPTION  PIN NO 1 2 3 4 5 6 7 8 PIN NAME FUNCTION Compensation Error amplifier output, this pin is made available for loop compensation. Voltage Feedback, the inverting input of the Error Amplifier. It is normally connected to the VFB switching power supply output through a resistor divider. A voltage proportional to inductor current is connected to this input. The PWM uses this ISENSE information to terminate the output switch conduction. The Oscillator frequency and maximum output duty cycle are programmed by connecting RT/CT resistor RT to Vref and capacitor CT to ground. Operation to 1 MHz is possible. GND Power ground. This output directly drives the gate of a power MOSFET. Peak currents up to 1A are Output sourced and sunk by this pin. The output switches at one-half the oscillator frequency. VCC Positive supply. VREF Reference output, provides charging current for capacitor CT though resistor RT. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 7 QW-R103-010.H UC3844/45  LINEAR INTEGRATED CIRCUIT BLOCK DIAGRAM UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 7 QW-R103-010.H UC3844/45  LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS (TA=25°C) PARAMETER SYMBOL RATINGS UNIT Current Sense and Voltage feedback Inputs VIN -0.3 ~ +5.5 V Total Power Supply and Zener Current (ICC+IZ) 30 mA Error Amp Output Sink Current ISINK 10 mA Output Current, Source or Sink (Note 2) IOUT 1.0 A Output Energy (Capacitive Load per cycle) W 5.0 μJ DIP-8 1250 Power Dissipation PD mW SOP-8 800 Junction Temperature TJ +150 °C Operation Temperature TOPR 0 ~ 70 °C Storage Temperature TSTG -65 ~ +150 °C Note: 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. Maxmum package power dissipation limits must be observed.  THERMAL DATA PARAMETER Junction to Ambient SYMBOL SOP-8 DIP-8 θJA RATINGS 156 100 UNIT °C/W ELECTRICAL CHARACTERISTICS (TA=25°C, VCC=15V, RT=10k, CT=3.3nF, 0°C ≤ TA ≤ 70°C, unless otherwise specified)  PARAMETER REFERENCE SECTION Reference Output Voltage Line Regulation Load Regulation Temperature Stability Total Output Variation over Line, Load, Temperature Output Noise Voltage Long Term Stability Output Short Circuit Current OSCILLATOR SECTION Oscillator Voltage Swing Discharge Current Frequency SYMBOL VREF △VOUT △VOUT IOUT=1.0mA,TJ=25°C VCC=12V ~ 25V IOUT=1.0mA ~ 20mA VREF TYP MAX UNIT 4.9 5.0 2.0 3.0 0.2 5.1 20 25 V mV mV mV/°C 5.18 V eN S ISC -180 μV mV mA VOSC IDSG fOSC/V fOSC/T VFB VOH VOL ISINK ISOURCE II(BIAS) GVO PSRR GBW 4.82 f=10Hz ~ kHz, TJ=25°C TA=125°C for 1000 Hours -30 VOSC=2.0V, TJ=25°C TJ=25°C 0°C ≤ TA ≤ 70°C VCC=12V ~ 25V 0°C ≤ TA ≤ 70°C VOUT=2.5V RL=15k to ground, VFB=2.3V RL=15k to VREF, VFB=2.7V VOUT=1.1V, VFB=2.7V VOUT=5.0V, VFB=2.3V VFB=2.7V VOUT=2.0V ~ 4.0V VCC=12V ~ 25V TJ=25°C UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN tS fOSC Frequency Change with Voltage Frequency Change with Temperature ERROR AMPLIFIER SECTION Voltage Feedback Input High Output Voltage Swing Low Sink Output Current Source Input Bias Current Open Loop Voltage Gain Power Supply Rejection Ratio Unity Gain Bandwidth TEST CONDITIONS 47 46 50 5 -85 1.6 10.8 52 0.2 5.0 2.42 5.0 2.0 -0.5 65 60 0.7 2.50 6.2 0.8 12 -1.0 -0.1 90 70 1.0 V mA 57 60 1.0 2.58 1.1 kHz % % V V mA -2.0 μA dB dB MHz 4 of 7 QW-R103-010.H UC3844/45  LINEAR INTEGRATED CIRCUIT ELECTRICAL CHARACTERISTICS(Cont.) PARAMETER CURRENT SENSE SECTION Current Sense Input Voltage Gain (Note 2, 3) Maximum Current Sense Input Threshold (Note 2) Input Bias Current Power Supply Rejection Ratio Propagation Delay OUTPUT SECTION SYMBOL MIN TYP MAX UNIT GV 2.85 3.0 3.15 V/V VI(THR) 0.9 1.0 1.1 V -2.0 70 150 -10 μA dB ns II(BIAS) PSRR TEST CONDITIONS VCC=12V ~ 25V (Note 4) tPLH(IN/OUT) Low VOL High VOH Output Voltage ISINK=20mA ISINK=200mA ISINK=20mA ISINK=200mA VCC=6.0V, ISINK=1.0mA CL=1.0nF,TJ=25°C CL=1.0nF,TJ=25°C 13 12 0.1 1.6 13.5 13.4 0.1 50 50 300 0.4 2.2 V V Output Voltage with UVLO Activated VOL(UVLO) 1.1 V Output Voltage Rise Time tR 150 ns Output Voltage Fall Time tF 150 ns UNDERVOLTAGE LOCKOUT SECTION UC3844 14.5 16.0 17.5 Startup Threshold VTHR V UC3845 7.8 8.4 9.0 UC3844 8.5 10.0 11.5 Minimum Operating VCC(MIN) V Voltage After Turn-On UC3845 7.0 7.6 8.2 PWM SECTION MAX DCMAX 47 48 50 % Duty Cycle MIN DCMIN 0 % TOTAL DEVICE Power Supply Zener Voltage VZ ICC=25mA 30 36 V VCC=6.5V UC3845 0.5 1.0 Power Supply Current ICC mA (Note 4) UC3844 VCC=14V 12 17 Startup Current ISTART-UP VCC=14V, UVLO Active 0.3 0.5 mA Notes: 1. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible. 2. This parameter is measured at the latch trip point with VFB=0V. 3. Comparator gain is defined as: V Output Compensation AV= V Current Sense Input 4. Adjust VCC above the startup threshold before setting to 15V. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 7 QW-R103-010.H UC3844/45 LINEAR INTEGRATED CIRCUIT TYPICAL CHARACTERISTICS  Current Sense Input Threshold vs. Error Amp Output Voltage 0 VCC = 15V VOUT = 2.0V ~ 4.0V RL = 100k TA = 25℃ 80 Gain 30 60 60 40 90 Phase 20 120 0 150 -20 10 100 1.0k 10k 100k 1.0M Excess Phase Degrees, φ Open Loop Voltage Gain, GV (dB) 100 180 10M Frequency, f (Hz) UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw Current Sense Input Threshold, VIN(THR) (V) Error Amp Open Loop Gain Phase vs. Frequency 1.2 1.0 TA = 125℃ 0.8 TA = 25℃ 0.6 0.4 TA = -55℃ 0.2 0 VCC = 15V 0 2.0 4.0 6.0 8.0 Error Amp Output Voltage, VOUT (V) 6 of 7 QW-R103-010.H UC3844/45 UCX844 Supply Current, ICC (mA) UCX845 TYPICAL CHARACTERISTICS(Cont.) Output Saturation Voltage, VO(SAT) (V)  LINEAR INTEGRATED CIRCUIT 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-R103-010.H