L5993 CONSTANT POWER CONTROLLER CURRENT-MODE CONTROL PWM MULTIPOWER BCD TECHNOLOGY SWITCHING FREQUENCY UP TO 1MHz LOW START-UP CURRENT (< 120 A) CONSTANT OUTPUT POWER VS. SWITCH- ING FREQUENCY HIGH-CURRENT OUTPUT DRIVE SUITABLE FOR POWER MOSFET (1A) FULLY LATCHED PWM LOGIC WITH DOU- DIP16 SO16N BLE PULSE SUPPRESSION PROGRAMMABLE DUTY CYCLE ORDERING NUMBERS: L5993 (DIP16) 100%AND 50% MAXIMUMDUTY CYCLELIMIT L5993D (SO16) PROGRAMMABLE SOFT START PRIMARY OVERCURRENT FAULT DETEC- line or DC-DC power supply applications using a TION WITH RE-START DELAY fixed frequency current mode control. PWM UVLO WITH HYSTERESIS Based on a standard current mode PWM control- IN/OUT SYNCHRONIZATION ler this device includes some features such as programmable soft start, IN/OUT synchronization, LATCHED DISABLE disable (to be used for over voltage protection and INTERNAL 100ns LEADING EDGE BLANK- for power management), precise maximum Duty ING OF CURRENT SENSE Cycle Control, 100ns leading edge blanking on PACKAGE: DIP16 AND SO16N current sense, pulse by pulse current limit, over- current protection with soft start intervention and constant power function for cotrolling throughput DESCRIPTION power in multisync monitor SMPS. This primary controller I.C., developed in BCD60II technology, has been designed to implement off BLOCK DIAGRAM SYNC DC-LIM V VREF CC 1 15 8 4 2 RCT TIMING 25V Vref + 3 + - DC T 15V/10V - PWM UVLO 14 9 - DIS DIS V C + 2.5V + 13V C-POWER 10 16 - OUT BLANKING SQ R PWM OVER CURRENT VREF OK 11 CLK 13 PGND FAULT DIS ISEN + SOFT-START - 1.2V SS 7 + 2.5V E/A 5 2R - VFB 1V R 12 6 D97IN765 SGND COMP July 1999 1/22L5993 ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit VCC Supply Voltage (I < 50mA) (*) selflimit V CC I Output Peak Pulse Current 1.5 A OUT Analog Inputs & Outputs (6,7) -0.3 to 8 V Analog Inputs & Outputs (1,2,3,4,5,15,14, 13, 16) -0.3 to 6 V P Power Dissipation T =70C (DIP16) 1 W tot amb T =50C (SO16) 0.83 W amb Tj Junction Temperature, Operating Range -40 to 150 C Tstg Storage Temperature, Operating Range -55 to 150 C (*) maximum package power dissipation limits must be observed PIN CONNECTION SYNC 1 16 C-POWER RCT 2 15 DC-LIM DC 3 14 DIS VREF 4 13 ISEN VFB 5 12 SGND COMP 6 11 PGND SS 7 10 OUT V8V9 CC C D97IN783 THERMAL DATA Symbol Parameter Value Unit Rth j-amb Thermal Resistance Junction -Ambient (DIP16) 80 C/W Thermal Resistance Junction -Ambient (SO16) 120 C/W PIN FUNCTIONS N. Name Function 1 SYNC Synchronization. A synchronization pulse terminates the PWM cycle and discharges Ct 2 RCT Oscillator pin for external Ct,Rt components 3 DC Duty Cycle control 4 VREF 5.0V +/-1.5% reference voltage at 25C 5 VFB Error Amplifier Inverting input 6 COMP Error Amplifier Output 7 SS Soft start pin for external capacitor Css 8VCC Supply for internal Signal circuitry 9V Supply for Power section C 10 OUT High current totem pole output 11 PGND Power ground 12 SGND Signal ground 13 ISEN Current sense 14 DIS Disable. It must never be left floating. Tie to SGND if not used. 15 DC-LIM Connecting this pin to Vref, DC is limited to 50%. If it is left floating or grounded no limitation is imposed 16 C-POWER Constant Power vs. Switching Frequency. Connect a capacitor to SGND. The pin must be connected to VREF if not used. 2/22