NTE1765 Integrated Circuit Dual Channel Current Mode Controller Description: The NTE1765 is a high performance, fixed frequency, dual current mode controller in a 16–Lead DIP type package. This device is specifically designed for Off–Line and DC to DC converter applications offering the designer a cost effective solution with minimal external components. The NTE1765 features a unique oscillator for precise duty cycle limit and frequency control, a temperature compensated reference, two high gain error amplifiers, two current sensing comparators, drive output 2 enable pin, and two high current totem pole outputs ideally suited for driving power MOSFETS. Also included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cycle–by–cycle current limiting, and a latch for single pulse metering of each output. Features: D Unique Oscillator for Precise Duty Cycle Limit and Frequency Control D Current Mode Operation to 500kHz D Automatic Feed Forward Compensation D Separate Latching PWMs for Cycle–By–Cycle Current Limiting D Internally Trimmed Reference with Undervoltage Lockout D Drive Output 2 Enable Pin D Two High Current Totem Pole Outputs D Input Undervoltage Lockout with Hysteresis D Low Start–Up and Operating Current Absolute Maximum Ratings: Total Power Supply Current, ICC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA Zener Current, IZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA Output Current, Source or Sink (Note 1), IO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A Output Energy (Capacitive Load per Cycle), W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0µJ Current Sense, Enable and Voltage Feedback Inputs, Vin . . . . . . . . . . . . . . . . . . . . . . . –0.3 to +5.5V Sync Input, High State (Voltage), VIH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5V Sync Input, Low State (Reverse Current), IIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –5.0mA Error Amp Output Sink Current, IO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10mA Maximum Power Dissipation (TA = +25°C), PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.25mW Thermal Resistance, Junction–to–Ambient, RthJA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100°C/W Operating Junction Temperature, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150°C Operating Ambient Temperature Range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0° to +70°C Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65° to +150°C Note 1. Maximum package power dissipation limits must be observed. Electrical Characteristics: (VCC = 15V (Note 2), RT = 8.2kΩ, CT = 3.3nF, Note 3 unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit 4.9 5.0 5.1 V Reference Section Reference Output Voltage Vref IO = 1mA, TJ = +25°C Line Regulation Regline VCC = 11V to 15V – 2.0 20 mV Load Regulation Regload IO = 1mA to 10mA – 3.0 25 mV Total Output Variation over Line, Load and Temperature Vref 4.85 – 5.15 V Output Short Circuit Current ISC 30 100 – mA 46.5 49.0 51.5 kHz – 0.2 1.0 % DCmax 46.0 49.5 52.0 % DCmin – – 0 % Oscillator and PWM Sections Total Frequency Variation over Line and Temperature Frequency Change with Voltage Duty Cycle at each Output Maximum Minimum fOSC ∆fOSC/∆V VCC = 11V to 15V, TA = 0° to +70°C VCC = 11V to 15V Sync Input Current High State IIH Vin = 2.4V – 170 250 µA Low State IIL Vin = 0.8V – 80 160 µA VFB VO = 2.5V 2.42 2.50 2.58 V IIB VFB = 5V – –0.1 –1.0 µA VO = 2V to 4V 65 100 – dB TJ = +25°C 0.7 1.0 – MHz 60 90 – dB –0.45 2.0 – –1.0 – – mA mA – 12 – mA 5.0 6.2 – V – 0.8 1.1 V Error Amplifiers Voltage Feedback Input Input Bias Current Open–Loop Voltage Gain Unity Gain Bandwidth AVOL BW Power Supply Rejection Ratio PSRR VCC = 11V to 15V Output Current Source ISource VO = 3V, VFB = 2.3V Sink ISink VO = 1.2V, VFB = 2.7V VOH RL = 15k to GND, VFB = 2.3V VOL RL = 15k to Vref, VFB = 2.7V Current Sense Input Voltage Gain AV Note 4, Note 5 2.75 3.00 3.25 V/V Max. Current Sense Input Threshold Vth Note 4 430 480 530 mV Input Bias Current IIB – –2 –10 µA tPLN(IN/OUT) – 150 300 ns Output Voltage Swing High State Low State Current Sense Section Propagation Delay (Current Sense Input to Output Note 2. Adjust VCC above the Start–Up threshold before setting to 15V. Note 3. For typical values, TA = +25C; for Min/Max values, TA = 0° to +70°C. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible. Note 4. This parameter is measured at the latch trip point with Vfb = 0V. ∆V Compensation Note 5. Comparator gain is defined as AV = ∆V Current Sense Electrical Characteristics (Cont’d): (VCC = 15V (Note 2), RT = 8.2kΩ, CT = 3.3nF, Note 3 unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Drive Output 2 Enable Pin Enable Pin Voltage High State VIH Output 2 Enabled 3.5 – Vref V Low State VIL Output 2 Disabled 0 – 1.5 V IIB VIL = 0V 100 250 400 µA ISink = 20mA – 0.1 0.4 V ISink = 200mA – 1.6 2.5 V ISource = 20mA 13.0 13.5 – V ISource = 200mA 12.0 13.4 – V VCC = 6V, ISink = 1mA – 0.1 1.1 V Low State Input Current Drive Outputs Output Voltage Low State VOL High State VOH Output Voltage with UVLO Activated VOL(UVLO) Output Voltage Rise Time tr CL = 1nF – 28 150 ns Output Voltage Fall Time tf CL = 1nF – 25 150 ns Vth 13 14 15 V VCC(min) 9.0 10.0 11.0 V VCC = 12V – 0.6 1.0 mA Note 2 – 20 25 mA 15.5 17.0 19.0 V Undervoltage Lockout Section Start–Up Threshold Min. Operating Voltage After Turn–On Total Device Power Supply Current Start–Up ICC Operating Power Supply Zener Voltage VZ ICC = 30mA Note 2. Adjust VCC above the Start–Up threshold before setting to 15V. Note 3. For typical values, TA = +25C; for Min/Max values, TA = 0° to +70°C. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible. Pin Connection Diagram Sync Input 1 16 VCC CT 2 15 Vref RT 3 14 Drive Output 2 Enable Voltage Feedback 1 4 13 Voltage Feedback 2 Compensation 1 5 12 Compensation 2 Current Sense 1 6 11 Current Sense 2 Drive Output 1 7 GND 8 10 Drive Output 2 9 Drive GND 16 9 .260 (6.6) Max 1 8 .300 (7.62) .785 (19.9) Max .200 5.08) Max .245 (6.22) Min .100 (2.54) .700 (17.7)