SL34063A DC-TO-DC CONVERTER CONTROL CIRCUITS The SL34063A is a monolithic control circuit containing the primary functions required for DC-to-DC converters. These devices consist of an internal temperature compensated reference, comparator, controlled duty cycle oscillator with an active current limit circuit, driver and high current output switch. This series was specifically designed to be incorporated in Step-Down and Step-Up and Voltage-Inverting applications with a minimum number of external components. FEATURES FUNCTIONAL BLOCK DIAGRAM • • • • • • • Operation from 3.0 V to 40 V Input Low Standby Current Current Limiting Output Switch Current to 1.5 A Output Voltage Adjustable Frequency Operation to 100 kHz Precision 2% Reference MAXIMUM RATINGS Rating Power Supply Voltage Comparator Input Voltage Range Switch Collector Voltage Switch Emitter Voltage (Vpin 1 = 40 V) Switch Collector to Emitter Voltage Driver Collector Voltage Driver Collector Current (Note 1) Switch Current Power Dissipation and Thermal Characteristics Ceramic Package, U Suffix TA = +25°C Thermal Resistance Plastic Package, P Suffix TA = +25°C Thermal Resistance SOIC Package, D Suffix TA = +25°C Thermal Resistance Operating Junction Temperature Operating Ambient Temperature Range Storage Temperature Range SLS Symbol VCC VIR VC(switch) VE(switch) VCE(switch) IC(driver) IC(driver) ISW Value Unit 40 Vdc -0.3 to +40 Vdc 40 Vdc 40 Vdc 40 Vdc 40 Vdc 100 mA 1.5 A PD RθJA PD RθJA PD RθJA 1.25 100 1.25 100 625 160 +150 0 to +70 -65to+150 TJ TA Tstg W °C/W W °C/W mW °C/ W °C °C °C System Logic Semiconductor 1 SL34063A ORDERING INFORMATION Device Temperature Range Package 34063AD 0° to +70°C SO-8 34063AP1 Plastic DIP Pin connection ELECTRICAL CHARACTERICISTICS (V CC = 5.0 V, TA= 0 to +70oC unless otherwise specified.) Characteristics Symbol OSCILLATOR Frequency (V Pin 5 = 0 V, CT = 1.0 nF, TA = 25°C) fosc Charge Current (V CC = 5.0 V to 40 V, TA = 25°C) Ichg Discharge Current (V CC = 5.0 V to 40 V, TA = 25°C) Idischg Discharge to Charge Current Ratio (Pin7 to Vcc, TA=25°C) Idischg/Ichg Current Limit Sense Voltage (Ichg = Idischg, TA = 25°C) Vlpk(sense) OUTPUT SWITCH (Note 3) Saturation Voltage, Darlington Connection (ISW = 1.0 A, VCE(sat) Min Typ Max Unit 24 24 140 5.2 250 33 33 200 6.2 300 42 42 260 7.5 350 kHz µA µA — mV — 1.0 1.3 V — 0.45 0.7 V 50 — 120 0.01 — 100 — µA 1.225 1.21 1.2375 1.25 — 1.25 1.275 1.29 1.2625 V — 1.4 -40 5.0 -400 mV nA 2.5 4.0 mA Pins 1, 8 connected) Saturation Voltage (ISW = 1.0 A, RPin 8 = 82 Ω to VCC. VCE(sat) Forced β = 20) DC Current Gain (ISW = 1.0 A, VCE = 5.0 V, TA = 25°C) hFE Collector Off-State Current (V CE = 40V) IC(off) COMPARATOR Threshold Voltage (TA = 25°C) Vth (TA = TLOW to THIGH) Threshold Voltage (TA = 25°C) ** Threshold Voltage Line Regulation (VCC = 3 0 V to 40 V) Input Bias Current (Vin=0V) Vth Regime IIB TOTAL DEVICE Supply Current (VCC = 5 0 V to 40 V, C T = 1 0 nF, Vpin7 = VCC. ICC V VPin5 > Vth, Pin 2 = Gnd, Remaining pins open) NOTES: 1. Maximum package power dissipation limits must be observed. 2.Low duty cycle pulse techniques are used during test to maintain Junction temperature as close to ambient temperature as possible 3.If the output switch is driven into hard saturation (non Darlington configuration) at low switch currents (< 300 mA) and high driver currents (>30 mA), it may take up to 2.0 µs to come out of saturation This condition will shorten the off' time at frequencies > 30 kHz, and is magnified at high temperatures This condition does not occur with a Darlingto n configuration, since the output switch cannot saturate If a non Darlington configuration is used, the following output drive condition is recommended Forced β of output switch = IC, output/(Ic, driver -7.0 mA*) > 10 *The 100 Ω. resistor in the emitter o f the driver device requires about 7.0 mA before the output switch conducts **Possible version for shipment SLS System Logic Semiconductor 2