Philips Semiconductors Product specification Switched-mode power supply controller DESCRIPTION NE5568 PIN CONFIGURATION The NE5568 is a control circuit for use in switched mode power supplies. It contains an internal temperature-compensated supply, PWM, sawtooth oscillator, over-current sense latch, and output stage. The device is intended for low cost SMPS applications where extensive housekeeping functions are not required. The NE5568 is a selected version of the NE5561. FE, N Packages VCC 1 8 GND VZ 2 7 OUTPUT 3 6 CURRENT SENSE 4 5 FEEDBACK GAIN FEATURES • Micro-miniature (D) package • Pulse width modulator • Current limiting (cycle by cycle) • Sawtooth generator • Stabilized power supply • Double-pulse protection • Internal temperature-compensated reference RT, CT TOP VIEW SL00437 Figure 1. Pin Configuration APPLICATIONS • Switch mode power supplies • DC motor controller inverter • DC/DC converter ORDERING INFORMATION TEMPERATURE RANGE ORDER CODE DWG # 8-Pin Plastic Dual In-Line Package (DIP) DESCRIPTION 0 to +70°C NE5568N SOT97-1 8-Pin Cerdip Dual In-Line Package (CERDIP) 0 to +70°C NE5568FE 0580A BLOCK DIAGRAM RT, CT 5 REF VOLTAGE VCC SAWTOOTH GENERATOR + ERROR AMP FEEDBACK GAIN 3 7 S – OUTPUT LATCH PWM R 4 0.5V – 1 CURRENT 6 SENSE 8.2V STABILIZED SUPPLY + VCC 2 VZ 8 GND SL00438 Figure 2. Block Diagram ABSOLUTE MAXIMUM RATINGS SYMBOL PARAMETER RATING UNIT VCC Supply voltage 18 V IOUT Output current 40 mA Output duty cycle PD Max total power dissipation TA Operating temperature range 1994 Aug 31 1 98 % 0.75 W 0 to 70 °C 853-0890 13721 Philips Semiconductors Product specification Switched-mode power supply controller NE5568 DC ELECTRICAL CHARACTERISTICS VCC=12V, TA=25°C, unless otherwise specified. SYMBOL PARAMETER NE5568 TEST CONDITIONS UNIT Min Typ Max TA=25°C 3.69 3.75 3.84 V Over temperature 3.66 3.87 V Reference section VREF VZ Internal reference voltage Internal zener ref 7.8 Temperature coefficient of VREF IL=7mA Temperature coefficient of VZ 8.2 8.8 V ± 100 ppm/°C ± 200 ppm/°C Oscillator section f Frequency range Initial accuracy Over temperature 50 RT and CT Constant Duty cycle range 100k 5 fo=20kHz 0 Hz % 98 % -10 µA -20 µA 1.10 µs 0.7 0.8 µs 0.500 0.600 V Current limiting IIN Input current Pin 6=250mV TA=25°C -2 Over temp. Single pulse inhibit delay Inhibit delay time for 20% overdrive at IOUT=20mA 0.88 IOUT=40mA Current limit trip level 0.400 Error amplifier Open-loop gain 60 Feedback resistor BW Small-signal bandwidth VOH Output voltage swing VOL Output voltage swing dB Ω 10k 3 MHz 6.2 V 0.7 V Output stage IOUT Output current VCE Saturation Over temperature 20 mA IC=20mA, over temperature 0.4 V IC=40mA, over temperature 0.5 V 10.0 mA 13.0 mA 24.0 V 30.0 V 10.5 V Supply voltage/current ICC Supply current VCC Supply voltage IZ=0, voltage-fed TA=25°C Over temp. IS=10mA, current-fed 19.0 ICC=30mA, current-fed 20.0 21.0 Low supply protection Pin 1 threshold 8.0 NOTES: All curves and applications of NE5561 apply exactly 1994 Aug 31 2 9.0