RT34063AGS

RT34063A DC-to-DC Converter Control Circuits General Description The RT34063A 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 specially designed to be incorporated in step-down and step-up and Voltage-inverting applications with a minimum number of external components. Features Operation from 3.0V to 30V Input Low Standby Current Current Limiting Internal Switch Current to 1.5A Output Voltage Adjustable Frequency Operation to 100kHz Precision 2% Reference RoHS Compliant and 100% Lead (Pb)-Free Applications Saver for Cellular Phones DC-DC Converter Module Ordering Information R T34063A Package Type N : DIP-8 S : SOP-8 Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) SC SE TC GND 2 3 4 Pin Configurations (TOP VIEW) 8 7 6 5 DRIVER IPK VCC COMP Note : RichTek Pb-free and Green products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. 100%matte tin (Sn) plating. DIP-8 / SOP-8 Functional Pin Description Pin Name SC SE TC GND COMP VCC IPK DRIVER Pin Function 1.5A Switch Collector Darlington Switch Emitter Oscillator Timing Capacitor Power GND Feedback Comparator Inverting Input Power Supply Input Highside Current Sense Input VCC-VIPK = 330mV Driver Collector DS34063A-13 March 2007 www.richtek.com 1 RT34063A Function Block Diagram DRIVER 8 SQ R Q1 IPK 7 100 2 SE Q2 1 SC IPK CT Oscillator VCC 6 Comparator + COMP 5 1.25V Reference Regulator 4 GND 3 TC Typical Application Circuit 170uH 8 180 S R 7 RSC 0.22 6 + L 1 Q 2 IPK OSC + COMP 1N5819 CT 1.25V Ref VIN 12V CT 3 1500pF 4 Optional Filter 100uF 5 R2 + 1.0uH VOUT 28V/175mA R1 2.2K 47K 330uF VOUT 100uF + CO Figure 1. Step-up Converter www.richtek.com 2 DS34063A-13 March 2007 RT34063A 8 1 + VOUT 7 VIN 2 6 3 5 4 (a) External NPN Switch 8 1 R + VOUT 7 VIN 2 R 0 for Constant VIN 6 3 5 4 (b) External NPN Saturated Switch (See Note) Figure 2. External Current Boost Connections for IC Peak Greater than 1.5A Note: If the output switch is driven into hard saturation (non-Darlington configuration) at low switch currents ( ≤ 300mA) and high driver currents ( 30mA), it may take up to 2.0μs to come out of saturation. This condition will shorten the off time at ≥ frequencies ≥ 30kHz, and is magnified at high temperature. 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. DS34063A-13 March 2007 www.richtek.com 3 RT34063A 8 1 S R Q1 7 RSC 0.33 6 + Q Q2 2 1N5819 VIN 25V IPK CT OSC + COMP CT 3 1.25V Ref 4 470pF L 220uH 100uF 5 Optional Filter R2 + 1.0uH VOUT 5.0V/500mA VOUT 100uF + R1 1.2K 3.6K 470uF CO Figure 3. Step-down Converter www.richtek.com 4 DS34063A-13 March 2007 RT34063A 8 1 7 VIN 2 VOUT + 6 3 5 4 (a) External NPN Switch 8 1 + VOUT 7 VIN 2 6 3 5 4 (b) External PNP Saturated Switch Figure 4. External Current Boost Connections for IC Peak Greater than 1.5A DS34063A-13 March 2007 www.richtek.com 5 RT34063A 8 180 S R Q1 7 RSC 0.24 6 + 1 Q Q2 2 IPK CT OSC + COMP 88uH 3 1.25V Ref L 1N5819 VIN 4.5V to 6.0V 100uF 5 1500pF 4 Optional Filter R2 R1 8.2K 953 1000uF + 1.0uH VOUT -12V/100mA VOUT 100uF + CO Figure 5. Voltage Inverting Converter www.richtek.com 6 DS34063A-13 March 2007 RT34063A 8 1 7 2 VOUT + VIN 6 3 5 4 (a) External NPN Switch 8 1 VOUT 7 VIN 2 + 6 3 5 4 (b) External PNP Saturated Switch Figure 6. External Current Boost Connections for Peak Greater than 1.5A DS34063A-13 March 2007 www.richtek.com 7 RT34063A Design Formula Table Calculation ton/toff Step-up Step-down Voltage-Inverting VOUT + VF − VIN (MIN) VIN (MIN) − VSAT VOUT + VF VIN (MIN) − VSAT − VOUT 1 f ton + toff ton +1 toff V OUT + V F V IN − V SAT 1 f ton + toff ton +1 toff (ton + toff) 1 f ton + toff ton +1 toff toff ton CT Ipk (SWITCH) (ton + toff ) − toff 4.0 × 10−5 ton (ton + toff ) − toff 4.0 × 10−5 ton 2 IOUT (MAX) (ton + toff ) − toff 4.0 × 10−5 ton ⎛ ton ⎞ 2 IOUT (MAX) ⎜ + 1⎟ toff ⎝ ⎠ 0.3/Ipk (SWITCH) ⎛ (VIN(MIN) − VSAT ) ⎞ ⎟ ⎜ ⎜ Ipk(SWITCH) ⎟ ton(MAX ) ⎠ ⎝ ⎛ ton ⎞ 2 IOUT(MAX) ⎜ + 1⎟ toff ⎝ ⎠ 0.3/Ipk (SWITCH) ⎛ (VIN(MIN) − VSAT ) ⎞ ⎟ ⎜ ⎜ Ipk(SWITCH ) ⎟ ton(MAX ) ⎠ ⎝ RSC 0.3/Ipk (SWITCH) ⎛ (VIN(MIN) − VSAT ) ⎞ ⎟ ⎜ ⎜ Ipk(SWITCH ) ⎟ ton(MAX ) ⎠ ⎝ L (min) CO 9 IOUT ton Vripple (pp) Ipk(SWITCH )( ton + toff ) 8 Vripple(pp) 9 IOUT ton Vripple (pp) VSAT VF : Saturation voltage of the output switch. : Forward voltage drop of the output rectifier. The following power supply characteristics must be chosen: VIN VOUT IOUT f Vripple(pp) : Nominal input voltage. : Desired output voltage VOUT = 1.25(1+ : Desired output current. : Minimum desired output switching frequency at the selected values of Vin and IO. : Desired peak-to-peak output ripple voltage. In practice, the calculated capacitor value needs to be increased due to its equivalent series resistance and board layout. The ripple voltage should be kept to a low value since it directly affects the line and load regulation. R2 R1 ) www.richtek.com 8 DS34063A-13 March 2007 RT34063A Absolute Maximum Ratings Power Supply Voltage ------------------------------------------------------------------------------------------------ 30V Feedback Input Voltage Range ------------------------------------------------------------------------------------- −0.3 to +30V Switch Collector Voltage --------------------------------------------------------------------------------------------- 30V Switch Emitter Voltage ----------------------------------------------------------------------------------------------- 30V Switch Collector to Emitter Voltage ------------------------------------------------------------------------------- 30V Driver Collector Voltage ---------------------------------------------------------------------------------------------- 30V Driver Collector Current (see Note) -------------------------------------------------------------------------------- 100mA Switch Current --------------------------------------------------------------------------------------------------------- 1.5A Power Dissipation, PD @ TA = 25°C DIP-8 --------------------------------------------------------------------------------------------------------------------- 1.25W SOP-8 -------------------------------------------------------------------------------------------------------------------- 0.625W Package Thermal Resistance DIP-8, θJA --------------------------------------------------------------------------------------------------------------- 100°C/W SOP-8, θJA -------------------------------------------------------------------------------------------------------------- 160°C/W Operating Junction Temperature ----------------------------------------------------------------------------------- +125°C Storage Temperature Range ---------------------------------------------------------------------------------------- 65 to +150°C Note:Maximum package power dissipation limits must be observed. Electrical Characteristics (VCC = 5V, TA = 25°C, unless otherwise specified) Parameter Oscillator Frequency Charge Current Discharge Current Discharge to Charge Current Ratio Current Limit Sense Voltage Output Switch Saturation Voltage, Darlington Connection Saturation Voltage, Darlington Connection DC Current Gain Collector Off-state Current Comparator Threshold Voltage Threshold Voltage Line Regulation Input Bias Current Total Device Supply Current Symbol Test Conditions Min Typ Max Units VPIN5 = 0V, CT = 1.0nF ICHG 5.0V ≤ VCC ≤ 30V IDISCHG 5.0V ≤ VCC ≤ 30V Pin 7 to VCC VLIMIT ICHG = IDISCHG ISW = 1.0A, Pins1, 8 connected ISW = 1.0A, RPIN8 = 82Ω to VCC, Forced β ≅ 20 ISW = 1.0A, VCE = 5.0V VCE = 30V 26 25 160 5.5 280 --50 -- 38 36 250 6.9 330 1.0 0.45 75 0.01 48 43 290 7.9 380 1.3 0.7 -100 kHz μA μA -mV V V -μA V mV nA 1.225 1.25 1.275 3.0V ≤ VCC ≤ 30V IBIAS VIN = 0V VCC = 5.0V to 30V, CT = 1.0nF, Pin7 = VCC, VPIN5 > VTH, Pin2 = GND, Remaining pins open --1.4 -20 5.0 -400 ICC -- 3.0 4.5 mA DS34063A-13 March 2007 www.richtek.com 9 RT34063A Typical Operating Characteristics Output Switch On-Off Time vs. Oscillator Timing Capacitor 1000 T On-Off , Output Switch On-Off Time (us) Timing Capacitor Waveform 100 VCC = 5.0V Pin 7 = VCC Pin 5 = GND TA = 25°C 10 VOUT = 5.0V Pin 1,8 = Open, Pin 7 = VCC CT = 1.0nF ,Pin 5 = GND TA = 25°C 0.1 1 10 1 0.01 Time (10us/Div) TC, Oscilator Timing Capacitor (nF) Emitter Follower Configuration Output Saturation Voltage vs. Emiter Current A VCE, Saturation Voltage (V) 1.6 1.5 1.4 1.3 1.2 1.1 1 0 0.3 0.6 0.9 Common Emiter Configuration Output Switch Saturation Voltage vs. Collector Current A VCE, Saturation Voltage (V) 1.0 1.7 0.8 0.6 0.4 VCC = 5.0V Pin 1,7,8 = VCC Pin 3,5 = GND TA = 25°C 1.2 1.5 0.2 VCC = 5.0V Pin 7 = VCC Pin 2,3,5 = GND TA = 25°C 0 0.3 0.6 0.9 1.2 1.5 0.0 IE, Emitter Current (A) ICC, Collector Current (A) Standyby Supply Current vs. Supply Voltage 3.5 Current Limit Sense Voltage vs. Temperature 400 Current Limit Sense Voltage (mV) . ICC, Supply Current (mA) . 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0 5 10 15 20 380 360 340 320 300 280 260 240 220 200 -40 -20 0 20 40 60 80 VCC = 5.0V Pin 7 = VCC Pin 5 = 2.0V Pin 2 = GND TA = 25°C 25 30 VCC = 5.0V ICHARGE = IDISCHARGE Supply Voltage (V) www.richtek.com 10 Temperature (°C) DS34063A-13 March 2007 RT34063A IC v s. VCE(Q1) Curve 2000 IC v s. VCE(Q1) Curve 2000 TJ = -20°C Ib = 34mA 1600 TJ = -10°C Ib = 34mA 1600 I C (mA) I C (mA) 1200 Ib = 15mA 1200 Ib = 15mA 800 Ib = 8mA 800 Ib = 8mA 400 400 Ib = 2.4mA 0 0 160 320 480 640 800 Ib = 2.4mA 0 0 160 320 480 640 800 VCE (mV) VCE (mV) IC v s. VCE(Q1) Curve 2000 IC v s. VCE(Q1) Curve 2000 TJ = 0°C Ib = 34mA 1600 TJ = 25°C Ib = 34mA 1600 I C (mA) I C (mA) 1200 Ib = 15mA 1200 Ib = 15mA Ib = 8mA 800 Ib = 8mA 800 400 400 Ib= 2.4mA Ib = 2.4mA 0 0 0 160 320 480 640 800 0 160 320 480 640 800 VCE (mV) VCE (mV) IC v s. VCE(Q1) Curve 1800 1500 TJ = 70°C Ib = 34mA Ib = 15mA 1200 I C (mA) Ib = 8mA 900 600 300 0 0 160 320 480 640 800 Ib = 2.4mA VCE (mV) DS34063A-13 March 2007 www.richtek.com 11 RT34063A Outline Dimension A B E C L I D F J Dimensions In Millimeters Symbol Min A B C D E F I J L 9.068 6.198 3.556 0.356 1.397 2.337 3.048 7.366 0.381 Max 9.627 6.604 4.318 0.559 1.651 2.743 3.556 8.255 Dimensions In Inches Min 0.357 0.244 0.140 0.014 0.055 0.092 0.120 0.290 0.015 Max 0.379 0.260 0.170 0.022 0.065 0.108 0.140 0.325 8-Lead DIP Plastic Package www.richtek.com 12 DS34063A-13 March 2007 RT34063A A H M J B F C I D Dimensions In Millimeters Symbol Min A B C D F H I J M 4.801 3.810 1.346 0.330 1.194 0.170 0.050 5.791 0.400 Max 5.004 3.988 1.753 0.508 1.346 0.254 0.254 6.200 1.270 Dimensions In Inches Min 0.189 0.150 0.053 0.013 0.047 0.007 0.002 0.228 0.016 Max 0.197 0.157 0.069 0.020 0.053 0.010 0.010 0.244 0.050 8-Lead SOP Plastic Package Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Richtek Technology Corporation Taipei Office (Marketing) 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com DS34063A-13 March 2007 www.richtek.com 13