LESHAN RADIO COMPANY, LTD. DC-DC Converter Control Circuits LR34063 DESCRIPTION: The LR34063 Series 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. DIP-8 SOP-8 FEATURE:: z Operation from 3.0 V to 40 V Input z Low Standby Current z Current Limiting z Output Switch Current to 1.5 A z Output Voltage Adjustable z Frequency Operation to 100 kHz z Precision 2% Reference ORDERING INFORMATION Device 1 Ipk Sense Q1 R 7 Switch Collector Q2 S Q 100 LR34063 DIP-8 LR34063D SOP-8 PIN CONNECTIONS BLOCK DIAGRAM Drive 8 Collector Package 2 Switch Emitter Switch Collector 1 8 Driver Collector Switch Emitter 2 7 Ipk Sense Timing Capacitor 3 6 VCC Gnd 4 5 Comparator Inverting Input Ipk Oscillator CT 6 VCC 3 Comparator + – (Top View) Timing Capacitor 1.25 V Reference Regulator Comparator 5 Inverting Input 4 Gnd (Bottom View) LR34063-1/12 LESHAN RADIO COMPANY, LTD. LR34063 MAXIMUM RATINGS Rating Power Supply Voltage Comparator Input Voltage Range Symbol Value Unit VCC 40 Vdc VIR – 0.3 to + 40 Vdc Switch Collector Voltage VC(switch) 40 Vdc Switch Emitter Voltage (VPin 1 = 40 V) VE(switch) 40 Vdc Switch Collector to Emitter Voltage VCE(switch) 40 Vdc Driver Collector Voltage VC(driver) 40 Vdc Driver Collector Current (Note 1) IC(driver) 100 mA Switch Current ISW 1.5 A Power Dissipation and Thermal Characteristics DIP-8 Package, TA = 25°C Thermal Resistance SOP-8 Package, D Suffix TA = 25°C Thermal Resistance PD RθJA 1.25 100 W °C/W PD RθJA TJ 625 160 mW °C/W +150 °C 0 to +70 °C Operating Junction Temperature Operating Ambient Temperature Range TA Storage Temperature Range Tstg °C – 65 to +150 NOTES: 1. Maximum package power dissipation limits must be observed. ELECTRICAL CHARACTERISTICS (VCC = 5.0 V, TA = Tlow to Thigh [Note 2], unless otherwise specified.) Characteristics Symbol Min Typ Max Unit Frequency (VPin 5 = 0 V, CT = 1.0 nF, TA = 25°C) fosc 24 33 42 kHz Charge Current (VCC = 5.0 V to 40 V, TA = 25°C) Ichg 24 35 42 µA OSCILLATOR Idischg 140 220 260 µA Discharge to Charge Current Ratio (Pin 7 to VCC, TA = 25°C) Idischg/Ichg 5.2 6.5 7.5 – Current Limit Sense Voltage (Ichg = Idischg, TA = 25°C) Vipk(sense) 250 300 350 mV Saturation Voltage, Darlington Connection (Note 4) ( ISW = 1.0 A, Pins 1, 8 connected) VCE(sat) – 1.0 1.3 V Saturation Voltage, Darlington Connection (ISW = 1.0 A, RPin 8 = 82 Ω to VCC, Forced β VCE(sat) – 0.45 0.7 V hFE 50 75 – – IC(off) – 0.01 100 µA Discharge Current (VCC = 5.0 V to 40 V, TA = 25°C) OUTPUT SWITCH (Note 3) ] 20) DC Current Gain (ISW = 1.0 A, VCE = 5.0 V, TA = 25°C) Collector Off–State Current (VCE = 40 V) NOTES: 2. Tlow = 0°C ,Thigh = +70°C 3. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient temperature as possible. 4. 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 for it 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: IC output Forced b of output switch : 10 IC driver – 7.0 mA * *The 100 Ω resistor in the emitter of the driver device requires about 7.0 mA before the output switch conducts. w LR34063-2/12 LESHAN RADIO COMPANY, LTD. LR34063 ELECTRICAL CHARACTERISTICS (continued) (VCC = 5.0 V, TA = Tlow to Thigh [Note 2], unless otherwise specified.) Characteristics Symbol Min Typ Max 1.23 1.21 1.25 – 1.27 1.29 Unit COMPARATOR Threshold Voltage TA = 25°C TA = Tlow to Thigh Vth Threshold Voltage Line Regulation (VCC = 3.0 V to 40 V) Input Bias Current (Vin = 0 V) V Regline – 1.4 5.0 mV IIB – – 20 – 400 nA ICC – – 4.0 mA TOTAL DEVICE Supply Current (VCC = 5.0 V to 40 V, CT = 1.0 nF, Pin 7 = VCC, VPin 5 > Vth, Pin 2 = Gnd, remaining pins open) NOTES: 2. Tlow = 0°C , Thigh = +70°C 3. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient temperature as possible. 4. 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 for it 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: IC output Forced b of output switch : 10 IC driver – 7.0 mA * *The 100 Ω resistor in the emitter of the driver device requires about 7.0 mA before the output switch conducts. w LR34063-3/12 LESHAN RADIO COMPANY, LTD. LR34063 Figure 2. Timing Capacitor Waveform 1000 VCC = 5.0 V Pin 7 = VCC Pin 5 = Gnd TA = 25°C 200 100 50 ton 20 10 5.0 toff 2.0 200 mV/DIV 500 V OSC , OSCILLATOR VOLTAGE (V) t on–off , OUTPUT SWITCH ON-OFF TIME ( µs) Figure 1. Output Switch On–Off Time versus Oscillator Timing Capacitor 1.0 0.01 0.02 0.05 0.1 0.2 0.5 1.0 2.0 CT, OSCILLATOR TIMING CAPACITOR (nF) 5.0 10 10 µs/DIV Figure 4. Common Emitter Configuration Output Switch Saturation Voltage versus Collector Current Figure 3. Emitter Follower Configuration Output Saturation Voltage versus Emitter Current VCE(sat), SATURATION VOLTAGE (V) VCE(sat), SATURATION VOLTAGE (V) 1.8 1.7 1.6 1.5 1.4 1.3 VCC = 5.0 V Pins 1, 7, 8 = VCC Pins 3, 5 = Gnd TA = 25°C (See Note 4) 1.2 1.1 1.0 0 0.2 0.4 0.6 0.8 1.0 1.2 IE, EMITTER CURRENT (A) 1.4 1.1 1.0 0.9 Darlington Connection 0.8 0.7 0.6 VCC = 5.0 V Pin 7 = VCC Pins 2, 3, 5 = Gnd TA = 25°C (See Note 5) 0.5 0.4 0.3 0.2 0 Figure 5. Current Limit Sense Voltage versus Temperature 0.2 0.4 0.6 0.8 1.0 1.2 IC, COLLECTOR CURRENT(A) 1.4 1.6 Figure 6. Standby Supply Current versus Supply Voltage 3.6 400 380 3.2 VCC = 5.0 V Ichg = Idischg 360 340 320 300 280 260 240 220 200 –55 NOTE: Forced β = 20 0.1 0 1.6 I CC , SUPPLY CURRENT (mA) V IPK(sense), CURRENT LIMIT SENSE VOLTAGE (V) Pins 1, 5, 8 = Open CT = 1.0 nF TA = 25°C VCC = 5.0 V Pin 7 = VCC Pin 2 = Gnd 2.8 2.4 2.0 1.6 1.2 CT = 1.0 nF Pin 7 = VCC Pin 2 = Gnd 0.8 0.4 0 –25 0 25 50 75 TA, AMBIENT TEMPERATURE (°C) 100 125 0 5.0 10 15 20 25 30 VCC, SUPPLY VOLTAGE (V) 35 40 5. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient temperature as possible. LR34063-4/12 LESHAN RADIO COMPANY, LTD. LR34063 170 mH L 1 8 180 S Q Q2 R Q1 7 2 1N5819 Ipk Rsc 0.22 Vin 12 V OSC 6 + CT 3 CT VCC 100 + − Comp. 5 1.25 V Ref Reg 1500 pF 4 1.0 mH R2 R1 Vout 28 V/175 mA 47 k 2.2 k Vout + 330 + CO 100 Optional Filter Test Conditions Results Line Regulation Vin = 8.0 V to 16 V, IO = 175 mA 30 mV = ±0.05% Load Regulation Vin = 12 V, IO = 75 mA to 175 mA 10 mV = ±0.017% Output Ripple Vin = 12 V, IO = 175 mA 400 mVpp Efficiency Vin = 12 V, IO = 175 mA 87.7% Output Ripple With Optional Filter Vin = 12 V, IO = 175 mA 40 mVpp Figure 7. Step−Up Converter LR34063-5/12 LESHAN RADIO COMPANY, LTD. LR34063 8 1 7 R Vout 8 7 2 Rsc Vin 1 Vout 2 Rsc Vin 6 6 R ³ 0 for constant Vin Figure 8. External Current Boost Connections for IC Peak Greater than 1.5 A 8a. External NPN Switch 8b. External NPN Saturated Switch (See Note 6) 6. 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 ms 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. LR34063-6/12 LESHAN RADIO COMPANY, LTD. LR34063 1 8 S Q Q2 Q1 R 7 2 Ipk Rsc 0.33 Vin 25 V OSC 6 100 + CT VCC + − 1.25 V Ref Reg Comp. 5 1N5819 3 L CT 220 mH 470 pF 4 3.6 k R1 1.0 mH Vout 5.0 V/500 mA R2 + 1.2 k 470 + CO Vout 100 Optional Filter Test Conditions Results Line Regulation Vin = 15 V to 25 V, IO = 500 mA 12 mV = ±0.12% Load Regulation Vin = 25 V, IO = 50 mA to 500 mA 3.0 mV = ±0.03% Output Ripple Vin = 25 V, IO = 500 mA 120 mVpp Short Circuit Current Vin = 25 V, RL = 0.1 W 1.1 A Efficiency Vin = 25 V, IO = 500 mA 83.7% Output Ripple With Optional Filter Vin = 25 V, IO = 500 mA 40 mVpp Figure 9. Step−Down Converter 8 1 1 V 8 7 Vout Rsc Vin 7 2 6 2 Rsc Vin 6 Figure 10. External Current Boost Connections for IC Peak Greater than 1.5 A 10a. External NPN Switch 10b. External PNP Saturated Switch LR34063-7/12 LESHAN RADIO COMPANY, LTD. LR34063 1 8 S Q Q2 R Q1 7 2 Ipk Rsc 0.24 OSC 6 Vin 4.5 V to 6.0 V 88 mH L CT VCC 3 + 100 + − Comp. + 1.25 V Ref Reg 5 1500 pF 1N5819 4 1.0 mH R1 Vout −12 V/100 mA 953 R2 1000 mf 8.2 k + Vout CO + 100 Optional Filter Test Conditions Results Line Regulation Vin = 4.5 V to 6.0 V, IO = 100 mA 3.0 mV = ± 0.012% Load Regulation Vin = 5.0 V, IO = 10 mA to 100 mA 0.022 V = ± 0.09% Output Ripple Vin = 5.0 V, IO = 100 mA 500 mVpp Short Circuit Current Vin = 5.0 V, RL = 0.1 W 910 mA Efficiency Vin = 5.0 V, IO = 100 mA 62.2% Output Ripple With Optional Filter Vin = 5.0 V, IO = 100 mA 70 mVpp Figure 11. Voltage Inverting Converter 8 1 1 Vout 8 7 2 7 Vout Vin 6 Vin 2 6 Figure 12. External Current Boost Connections for IC Peak Greater than 1.5 A 12a. External NPN Switch 12b. External PNP Saturated Switch LR34063-8/12 LESHAN RADIO COMPANY, LTD. LR34063 5.45′′ 2.500′′ (Top view, copper foil as seen through the board from the component side) LR34063 LR34063 LR34063 (Top View, Component Side) *Optional Filter. Figure 13. Printed Circuit Board and Component Layout (Circuits of Figures 7, 9, 11) INDUCTOR DATA Converter Inductance (mH) Turns/Wire Step−Up 170 38 Turns of #22 AWG Step−Down 220 48 Turns of #22 AWG Voltage−Inverting 88 28 Turns of #22 AWG All inductors are wound on Magnetics Inc. 55117 toroidal core. LR34063-9/12 LESHAN RADIO COMPANY, LTD. LR34063 Calculation Step−Up V out ) V ton/toff V F * V in(min) * V sat in(min) (ton + toff) V Step−Down Voltage−Inverting V out ) V |V out| ) V F * V sat * V out in(min) 1 f in F * V sat 1 f t on ) t toff V 1 f t on ) t off ton ) 1 t off t on ) t off ton ) 1 t off off ton ) 1 t off ton (ton + toff) − toff (ton + toff) − toff (ton + toff) − toff CT 4.0 x 10−5 ton 4.0 x 10−5 ton 4.0 x 10−5 ton Ipk(switch) 2I Rsc L(min) CO ǒ out(max) ǒ Ǔ t on ) 1 t off 2I 0.3/Ipk(switch) (V Ǔ * V sat) in(min) I pk(switch) 9 ǒ (V t on(max) 0.3/Ipk(switch) in(min) I I I outt on V ripple(pp) 2I out(max) * V sat * V out) pk(switch) Ǔ t (t ) t ) pk(switch) on off 8V ripple(pp) on(max) ǒ out(max) ǒ Ǔ t on ) 1 t off 0.3/Ipk(switch) (V * V sat) in(min) I pk(switch) 9 Ǔ t on(max) I outt on V ripple(pp) Vsat = Saturation voltage of the output switch. VF = Forward voltage drop of the output rectifier. The following power supply characteristics must be chosen: ǒ Ǔ Vin − Nominal input voltage. Vout − Desired output voltage, |V out| + 1.25 1 ) R2 R1 Iout − Desired output current. fmin − Minimum desired output switching frequency at the selected values of Vin and IO. Vripple(pp) − Desired peak−to−peak output ripple voltage. In practice, the calculated capacitor value will need to be increased due to its equivalent series resistance and board layout. The ripple voltage should be kept to a low value since it will directly affect the line and load regulation. Figure 14. Design Formula Table LR34063-10/12 LESHAN RADIO COMPANY, LTD. LR34063 Mechanical Dimensions Unit: mm f e f f e f f SOP-8 e e ' f f ¶ ' e fe 5 5 f e fe LR34063-11/12 LESHAN RADIO COMPANY, LTD. LR34063 Mechanical Dimensions (Continued) DIP-8 Unit: mm f e f e e e f f e ¶hf f 0$; 5 f 0,1 LR34063-12/12