Order this document µA78S40/D µ The µA78S40 is a switching regulator subsystem, consisting of a temperature compensated voltage reference, controlled–duty cycle oscillator with an active current limit circuit, comparator, high–current and high–voltage output switch, capable of 1.5 A and 40 V, pinned–out power diode and an uncommitted operational amplifier, which can be powered up or down independent of the IC supply. The switching output can drive external NPN or PNP transistors when voltages greater the 40 V, or currents in excess of 1.5 A, are required. Some of the features are wide–supply voltage range, low standby current, high efficiency and low drift. The µA78S40 is available in commercial (0° to + 70°C), and automotive (–40° to + 85°C) temperature ranges. Some of the applications include use in step–up, step–down, and inverting regulators, with extremely good results obtained in battery– operated systems. • Output Adjustable from 1.25 V to 40 V • • • • • UNIVERSAL SWITCHING REGULATOR SUBSYSTEM SEMICONDUCTOR TECHNICAL DATA Peak Output Current of 1.5 A Without External Transistor 80 dB Line and Load Regulation Operation from 2.5 V to 40 V Supply P SUFFIX PLASTIC PACKAGE CASE 648 Low Standby Current Drain High Gain, High Output Current, Uncommitted Op Amp PIN CONNECTIONS Simplified Block Diagram Noninv. Input Inv. Input Gnd Timing Capacitor 9 10 11 12 VCC 13 Diode Cathode 1 16 Switch Collector Diode Anode 2 15 Driver Collector Ipk Sense Driver Collector Switch Collector Switch Emitter 3 14 15 16 Op Amp Output 4 14 Ipk Sense 13 VCC 12 Timing Capacitor VCC Op Amp 5 Op Amp CT Ipk Oscilator S 11 Ground Comparator 10 Inv. Input 9 Comparator Noninv. Input Inv. Input 7 Reference 8 (Top View) – Comp. + 1.25V Reference Q Noninv. 6 R 170 – Op Amp + D1 ORDERING INFORMATION 8 Ref Output 7 Inv Input 6 Noninv Input 5 VCC Op Amp 4 Output (Bottom View) 3 Switch Emitter 2 Diode Anode 1 Diode Cathode Temperature Range Package µA78S40PC TA = 0° to +70°C Plastic µA78S40PV TA = – 40° to +85°C Plastic Device Motorola, Inc. 1996 MOTOROLA ANALOG IC DEVICE DATA Rev 1 1 µA78S40 MAXIMUM RATINGS Rating Power Supply Voltage Op Amp Power Supply Voltage Common Mode Input Range (Comparator and Op Amp) Symbol Value Unit VCC 40 V VCC (Op Amp) 40 V VICR –0.3 to VCC V ± 30 V Continuous – 10 mA Voltage from Switch Collectors to Gnd 40 V Voltage from Switch Emitters to Gnd 40 V Voltage from Switch Collectors to Emitter 40 V Differential Input Voltage (Note 2) VID Output Short Circuit Duration (Op Amp) Reference Output Current Iref Voltage from Power Diode to Gnd 40 V Reverse–Power Diode Voltage VDR 40 V Current through Power Switch ISW 1.5 A Current through Power Diode ID 1.5 A PD 1/RθJA 1500 14 mW mW/°C Tstg –65 to + 150 °C Power Dissipation and Thermal Characteristics: Plastic Package (TA = + 25°C) Derate above + 25°C (Note 1) Storage Temperature Range Operating Temperature Range µA78S40V µA78S40C °C TA –40 to +85 0 to +70 NOTES: 1. Tlow = –40° for µA78S40PV Thigh = +85° for µA78S40PV = 0° for µA78S40PC = +70° for µA78S40PC 2. For supply voltages less than 30 V the maximum differential input voltage (Error Amp and Op Amp) is equal to the supply voltage. ELECTRICAL CHARACTERISTICS (VCC = VCC (Op Amp) 5.0 V, TA = Tlow to Thigh, unless otherwise noted.) Characteristic Symbol Min Typ Max Unit Supply Voltage VCC 2.5 – 40 V Supply Current (Op Amp VCC, disconnected) (VCC = 5.0 V) (VCC = 40 V) ICC – – 1.8 2.3 3.5 5.0 Supply Current (Op Amp VCC, connected) (VCC = 5.0 V) (VCC = 40 V) ICC – – – – 4.0 5.5 Vref 1.180 1.245 1.310 V Reference Voltage Line Regulation (3.0 V ≤ VCC ≤ 40 V, Iref = 1.0 mA, TA = 25°C) Regline – 0.04 0.2 mV/V Reference Voltage Load Regulation (1.0 mA ≤ Iref ≤ 10 mA, TA = 25°C) Regload – 0.2 0.5 mV/mA GENERAL mA mA REFERENCE Reference Voltage (Iref = 1.0 mA) 2 MOTOROLA ANALOG IC DEVICE DATA µA78S40 ELECTRICAL CHARACTERISTICS (VCC = VCC (Op Amp) 5.0 V, TA = Tlow to Thigh, unless otherwise noted.) Characteristic Symbol Min Typ Max 20 20 – – 50 70 150 150 – – 250 350 Unit OSCILLATOR µA Charging Current (TA = 25°C) (VCC = 5.0 V) (VCC = 40 V) Discharging Current (TA = 25°C) (VCC = 5.0 V) (VCC = 40 V) Ichg Oscillator Voltage Swing (TA = 25°C) (VCC = 5.0 V) Vosc – 0.5 – V tchg/tdis – 6.0 – – VCLS 250 – 350 mV Output Saturation Voltage 1 (ISW = 1.0 A, Pin 15 tied to Pin 16) Vsat1 – 0.93 1.3 V Output Saturation Voltage 2 (ISW = 1.0 A, I15 = 50 mA) Vsat2 – 0.5 0.7 V hFE – 70 – – IC(off) – 10 – nA VD IDR – 1.25 1.5 V – 10 – nA VIO IIB – 1.5 15 mV – 35 200 nA IIO VICR PSRR – 5.0 75 nA 0 – 70 96 VCC – 2.0 – dB – 4.0 15 mV – 30 200 nA Ratio of Charge/Discharge Time µA Idis CURRENT LIMIT Current–Limit Sense Voltage (TA = 25°C) (VCC – Vlpk Sense) OUTPUT SWITCH Output Transistor Current Gain (TA = 25°C) (IC = 1.0 A, VCE = 5.0 V) Output Leakage Current (TA = 25°C) (VCE = 40 V) POWER DIODE Forward Voltage Drop (ID = 1.0 A) Diode Leakage Current (TA = 25°C) (VDR = 40 V) COMPARATOR Input Offset Voltage (VCM = Vref) Input Bias Current (VCM = Vref) Input Offset Current (VCM = Vref) Common Mode Voltage Range (TA = 25°C) Power–Supply Rejection Ratio (TA = 25°C) (3.0 ≤ VCC ≤ 40 V) V OUTPUT OPERATION AMPLIFIER Input Offset Voltage (VCM = 2.5 V) Input Bias Current (VCM = 2.5 V) Input Offset Current (VCM = 2.5 V) VIO IIB IIO AVOL+ – 5.0 75 nA 25 250 – V/mV Voltage Gain – (TA = 25°C) (RL = 2.0 kΩ to VCC (Op Amp), 1.0 V ≤ VO ≤ 2.5 V) AVOL– 25 250 – V/mV Common Mode Voltage Range (TA = 25°C) VICR CMRR 0 – 76 100 VCC – 2.0 – dB PSRR 76 100 – dB ISource ISink 75 150 – mA 10 35 – mA SR – 0.6 – V/µs – – 1.0 V VCC(Op Amp) – 3.0 – – V Voltage Gain + (TA = 25°C) (RL = 2.0 kΩ to Gnd, 1.0 V ≤ VO ≤ 2.5 V) Common Mode Rejection Ratio (TA = 25°C) (VCM = 0 V to 3.0 V) Power–Supply Rejection Ratio (TA = 25°C) (3.0 V ≤ VCC (Op Amp) ≤ 40 V) Output Source Current (TA = 25°C) Output Sink Current (TA = 25°C) Slew Rate (TA = 25°C) Output Low Voltage (TA = 25°C, IL = –5.0 mA) Output High Voltage (TA = 25°C, IL = 50 mA) MOTOROLA ANALOG IC DEVICE DATA VOL VOH V 3 Figure 1. Output Switch On/Off Time versus Oscillator Timing Capacitor 1000 Figure 2. Standby Supply Current versus Supply Voltage 3.2 100 I CC , SUPPLY CURRENT (mA) VCC = 5.0 V Ipk(sense) = VCC Pin 10 = Gnd Pin 9 = Vref ton toff 10 1.0 0.1 1.0 10 5.0 10 15 20 25 30 35 40 Figure 4. Common–Emitter Configuration Output Switch Saturation Voltage versus Collector Current 1.2 1.1 1.0 0.2 0.4 0.6 0.8 1.0 IE, EMITTER CURRENT (A) 4 0 Figure 3. Emitter–Follower Configuration Output Switch Saturation Voltage versus Emitter Current 1.3 0 0.8 VCC, SUPPLY VOLTAGE (V) VCC = 5.0 V Pins 14, 15, 16 = VCC Pins 10, 12 = Gnd Pin 9 = Vref 1.4 1.6 CT, OSCILLATOR TIMING CAPACITOR (nF) 1.6 1.5 CT = 0.001 µF Ipk(sense) = VCC Pin 3 = Gnd 2.4 0 100 V CE(sat) , SATURATION VOLTAGE (V) V CE(sat) , SATURATION VOLTAGE (V) t on-off , OUTPUT SWITCH ON-OFF TIME ( µ s) µA78S40 1.2 1.4 1.2 VCC = 5.0 V Pin 14 = VCC Pins 3, 10, 12 = Gnd Pin 9 = Vref 1.0 0.8 Darlington Connection 0.6 Forced Beta = 20 0.4 0.2 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 IC, COLLECTOR CURRENT (A) MOTOROLA ANALOG IC DEVICE DATA µA78S40 Figure 5. Step–Down Converter Vin 25V RSC 0.33 + 100 470 pF CT 9 10 11 12 13 14 15 16 VCC CT Ipk Oscilator – + Comp. Q R 170 1.25V Reference 8 S – Op Amp + 7 6 D1 5 4 3 2 1 1N5822 L R2 * 3.6k R1 1.2k Vout 5.0V/500mA 220µH + 470 * Use external rectifier to increase circuit efficiency CO Figure 6. Step–Up Converter L Vin 12V 170µH RSC 0.22 + 100 9 10 11 180 1500 pF CT 12 13 14 15 16 VCC CT Ipk Oscilator – + Comp. Q R 170 1.25V Reference 8 S – Op Amp + 7 6 5 D1 4 3 2 1 1N5822 * R2 47k R1 22k MOTOROLA ANALOG IC DEVICE DATA + * Use external rectifier to increase circuit efficiency 150 Vout 28V/175mA CO 5 µA78S40 Figure 7. Inverting Converter Vin 15V D45H8 RSC 0.30 + 100 50µH 100 9 10 11 12 13 14 L 100 + CO 270 1800 pF CT Vout –15V/500mA 1N5822 15 16 VCC CT Ipk Oscilator – + Comp. 8 Q R 170 1.25V Reference R1 1.5k S – Op D1 Amp + 7 6 5 4 3 2 1 R2 18k Design Formula Table Calculation ton toff (ton + toff) max CT Ipk(switch) Step–Down Vout + VF Vin(min) – Vsat – Vout I fmin 4 x 10 5 ton 2 Iout(max) RSC 0.33 Ipk(switch) L(min) Vin(min) – Vsat – Vout ton(max) Ipk(switch) CO Ipk(switch) (ton + toff) 8 Vripple(pp) Step–Up Inverting Vout – VF Vin(min) Vin(min) Vsat I fmin 4 x 10 5 ton 2 Iout(max) ton – toff toff Vout + VF Vin(min) – Vsat I fmin 4 x 10 5 ton 2 Iout(max) 0.33 Ipk(switch) Vin(min) – Vsat Ipk(switch) ≈ Iout ton Vripple ton(max) ton + toff toff 0.33 Ipk(switch) Vin(min) – Vsat Ipk(switch) ≈ ton(max) Iout ton Vripple Vsat = Saturation voltage of the output switch. VF = Forward voltage drop of the ringback rectifier. The following power supply characteristics must be chosen: ǒ) Ǔ Vin – Nominal input voltage. If this voltage is not constant, then use Vin(max) for step–down and Vin(min) for step–up and inverting convertor. R2 1.25 R2 for step–down and step–up: Vout for inverting. 1 R1 R1 Iout – Desired output current. fmin – Minimum desired output switching frequency at the selected values for Vin and IO. Vripple(pp) – Desired peak–to–peak output ripple voltage. In practice, the calculated value will need to be increased due to the capacitor’s equivalent series – resistance and board layout. The ripple voltage should be kept to a low value since it will directly effect the line and load regulation. Vout – Desired output voltage: Vout = 1.25 + See Application Note AN920 for further information 6 MOTOROLA ANALOG IC DEVICE DATA µA78S40 OUTLINE DIMENSIONS P SUFFIX PLASTIC PACKAGE CASE 648–08 ISSUE R –A– 16 9 1 8 NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. DIMENSION L TO CENTER OF LEADS WHEN FORMED PARALLEL. 4. DIMENSION B DOES NOT INCLUDE MOLD FLASH. 5. ROUNDED CORNERS OPTIONAL. B F C L S –T– SEATING PLANE K H G D J 16 PL 0.25 (0.010) M MOTOROLA ANALOG IC DEVICE DATA T A M M DIM A B C D F G H J K L M S INCHES MIN MAX 0.740 0.770 0.250 0.270 0.145 0.175 0.015 0.021 0.040 0.70 0.100 BSC 0.050 BSC 0.008 0.015 0.110 0.130 0.295 0.305 0_ 10 _ 0.020 0.040 MILLIMETERS MIN MAX 18.80 19.55 6.35 6.85 3.69 4.44 0.39 0.53 1.02 1.77 2.54 BSC 1.27 BSC 0.21 0.38 2.80 3.30 7.50 7.74 0_ 10 _ 0.51 1.01 7 µA78S40 Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; P.O. Box 20912; Phoenix, Arizona 85036. 1–800–441–2447 or 602–303–5454 JAPAN: Nippon Motorola Ltd.; Tatsumi–SPD–JLDC, 6F Seibu–Butsuryu–Center, 3–14–2 Tatsumi Koto–Ku, Tokyo 135, Japan. 03–81–3521–8315 MFAX: [email protected] – TOUCHTONE 602–244–6609 INTERNET: http://Design–NET.com ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, 51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852–26629298 8 ◊ *uA78S40/D* MOTOROLA ANALOG IC DEVICE DATA µA78S40/D