34063AD

34063A DC-TO-DC CONVERTER CONTROL CIRCUITS The 34063A 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 Symbol VCC VIR VC(switch) VE(switch) VCE(switch) IC(driver) IC(driver) ISW PD RθJA PD RθJA PD RθJA TJ Value 40 -0.3 to +40 40 40 40 40 100 1.5 1.25 100 1.25 100 625 160 +150 0 to +70 -65to+150 Unit Vdc Vdc Vdc Vdc Vdc Vdc mA A W °C/W W °C/W mW °C/W °C °C °C TA Tstg ORDERING INFORMATION Device Temperature Range 34063AD 0° to +70°C 34063AP1 Package SO-8 Plastic DIP Pin connection ELECTRICAL CHARACTERICISTICS (VCC = 5.0 V, TA= 0 to +70 C unless otherwise specified.) Characteristics Symbol OSCILLATOR Frequency (VPin 5 = 0 V, CT = 1.0 nF, TA = 25°C) fosc Charge Current (VCC = 5.0 V to 40 V, TA = 25°C) Ichg Discharge Current (VCC = 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) Pins 1, 8 connected) o Min 24 24 140 5.2 250 — — 50 — 1.225 1.21 1.2375 — Typ 33 33 200 6.2 300 1.0 0.45 120 0.01 1.25 — 1.25 1.4 -40 2.5 Max 42 42 260 7.5 350 1.3 0.7 — 100 1.275 1.29 1.2625 5.0 -400 4.0 Unit kHz µA µA — mV V V — µA V V mV nA mA VCE(sat) Saturation Voltage (ISW = 1.0 A, RPin 8 = 82 Ω to VCC. Forced β = 20) = DC Current Gain (ISW = 1.0 A, VCE 5.0 V, TA = 25°C) hFE Collector Off-State Current (VCE = 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 V REG line IIB TOTAL DEVICE Supply Current (VCC = 5 0 V to 40 V, CT = 1 0 nF, Vpin7 = ICC VCC. 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 Darlington 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 of the driver device requires about 7.0 mA before the output switch conducts **Possible version for shipment