SGS-Thomson L4916 free download

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L4916 VOLTAGE REGULATOR PLUS FILTER . . . . . . . . PRELIMINARY DATA FIXED OUTPUT VOLTAGE 8.5 V 250 mA OUTPUT CURRENT HIGH RIPPLE REJECTION HIGH LOAD REGULATION HIGH LINE REGULATION SHORT CIRCUIT PROTECTION THERMAL SHUT DOWN WITH HYSTERESIS DUMP PROTECTION DESCRIPTION This circuit combines both a filter and a voltage regulator in order to provide a high ripple rejection over a wider input voltage range. A supervisor low-pass loop of the element prevents the output transistor from saturation at low input voltages. The non linear behaviour of this control circuitry allows a fast settling of the filter. BLOCK DIAGRAM POW ER MINIDIP (4 + 4) ORDERING NUMBER : L4916 October 1988 1/8 L4916 PIN CONNECTION (top view) ABSOLUTE MAXIMUM RATINGS Symbol Vi Vi IO Ptot Tstg, Tj Peak Input Voltage (300 ms) DC Input Voltage Output Current Power Dissipation Storage and Junction Temperature Parameter Value 40 28 Internally Limited Internally Limited ­ 40 to 150 °C Unit V V THERMAL DATA Symbol R th j-amb R th j-pins Parameter Thermal Resistance Junction-ambient Thermal Resistance Junction-pins Max Max Value 80 20 Unit °C/W °C/W 2/8 L4916 ELECTRICAL CHARACTERISTICS (Tamb =25 °C; Vi = 13.5 V, test circuit of fig. 1, unless otherwise specified) Symbol Vi VO VI/O VO VO Parameter Input Voltage Output Voltage Controlled Voltage Vi = 12 to 18 V IO = 5 to 150 mA 8.1 8.5 1.6 1 50 Test Conditions Min. Typ. Max. 20 8.9 2.1 20 100 Unit V V V mV mV Input-output Dropout Vi = 5 to 10 V IO = 5 to 150 mA Vi = 12 to 18 V IO = 10 mA IO = 5 to 250 mA ton = 30 µs toff = 1 ms Vi = 8.5 V IO = 5 to 150 mA ton = 30 µs toff = 1 ms IO = 5 mA Vi = 6 to 18 V IO = 5 to 150 mA IO = 10 mA Viac = 1 Vrms f = 100 Hz IO = 150 mA VIDC = 12 to 18 V VIDC = 6 to 11 V 250 IO = 150 mA Vi = 5 to 11 V Vi = 11 to 18 V Junction Line Regulation Load Regulation VO Load Regulation (filter mode) 150 250 mV Iq Iq VO T SVR Quiescent Current Quiescent Current Change Output Voltage Drift Supply Voltage Rejection 1 0.05 1.2 2 mA mA mV/°C 70 35(*) 300 500(*) 300 145 dB dB mA ms ms °C ISC Ton Short Circuit Current Switch On Time TJ Thermal Shutdown Temperature (*) D epending of the C FT capacitor. Figure 1 : Test and Application Circuit. 3/8 L4916 Figure 2 : P.C. Board and Component Layout of Fig. 1 (1 : 1 scale). PRINCIPLE OF OPERATION During normal operation (input voltage upper than VI MIN = VOUT NOM + VI/O). The device works as a normal voltage regulator built aroundthe OP1 of the block diagram. The series pass element use a PNP-NPN connection to reduce the dropout. The reference voltage of the OP1 is derived from a REF through the OP2 and Q3, acting as an active zener diode of value VREF. In this condition the device works in the range (1) of the characteristic of the non linear drop control unit (see fig.3). The output voltage is fixed to its nominal value: R1 VOUT NOM = VREF (1 + )= R2 VCFT (1 + R1 ) R2 R1 = INTERNALLY FIXED RATIO = 2.4 R2 The ripple rejection is quite high (70