Advanced Monolithic Systems AMS34063 DC-TO-DC CONVERTER CONTROL CIRCUIT FEATURES APPLICATIONS • Wide Input Voltage Operating Range from 2.5V to 40V • Low Standby Current • Current Limiting • Output Switch Current of 1.5A • Output Voltage Adjustable from 1.25 to 40V • Frequency of Operation to 100kHz • Step-Up Converter • Step-Down Converter • Voltage Inverting Application GENERAL DESCRIPTION The AMS34063 series is a control circuit containing the basic functions required for DC-to-DC converters. The device consists of an internal temperature compensated reference, a comparator, a controlled duty cycle oscillator with an active current limit circuit, a driver and a high current output switch. Designed specifically to be incorporated in Step-Up, Step-Down and Voltage -Inverting applications, the AMS34063 requires a minimum number of external components. The AMS34063 is available in the 8-lead plastic SOIC and 8-lead plastic DIP packages. ORDERING INFORMATION PACKAGE TYPE 8 LEAD PDIP AMS34063P OPER. TEMP 8 LEAD SOIC AMS34063S RANGE -40°C to +85°C PIN CONNECTIONS 8 LEAD SOIC/ 8 LEAD PDIP SWITCH COLLECTOR SWITCH EMITTER TIMING CAPACITOR GND DRIVER COLLECTOR IPK SENSE 1 8 2 7 3 6 VCC 4 5 COMPARATOR INVERTING INPUT Top View Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS34063 ABSOLUTE MAXIMUM RATINGS (Note 1) Power Supply Voltage, VCC 40V Comparator Input Voltage Range, VIR -0.3V to +40V Switch Collector Voltage, VC(switch) 40V Switch Emitter Voltage, VE(switch) 40V Switch Collector to Emitter Voltage, VCE(switch) 40V Driver Collector Voltage, VC(driver) Switch Current, ISW Power Dissipation Maximum Junction Temperature Storage Temperature 40V 1.5A (Note 3) +125°C -65°C to +150°C ELECTRICAL CHARACTERISTICS Electrical Characteristics at VCC = 5.0V, -40°C ≤TA ≤+85°C, unless otherwise noted. PARAMETER Min. AMS34063 Typ. Max. CONDITIONS Units Oscillator Charging Current 5.0V ≤ VCC ≤ 40V, TA= 25°C 20 35 50 µA Discharge Current 5.0V ≤ VCC ≤ 40V, TA= 25°C 150 200 250 µA Voltage Swing TA= 25°C 0.5 VP-P Discharge to Charge Current Ratio IPK(sense) = VCC, TA= 25°C 6.0 _ Current Limit Sense Voltage ICHG = IDISCHG, TA= 25°C 250 300 350 mV Output Switch (Note 2) Saturation Voltage, Darlington Connection ISW = 1.0A, VC(driver) = VC(switch) 1.0 1.3 V Saturation Voltage ISW = 1.0A, IC(driver) = 50mA, (Forced β ≈ 20) 0.45 0.7 V DC Current Gain ISW = 1.0A, VCE = 5.0V, TA= 25°C 35 120 Collector Off-State Current VCE = 40V, TA= 25°C 10 nA Comparator Threshold Voltage 1.18 Threshold Voltage Line Regulation 3.0V ≤ VCC ≤ 40V Input Bias Current VIN = 0V 1.25 1.32 V 0.04 0.2 mV/V 40 400 nA Total Device 5.0V ≤ VCC ≤ 40V, IPK(sense) = VCC , 2.4 3.5 mA CT = 0.001µF, V pin 5 > Vth, Pin 2 = Gnd, Remaining pins open Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. For guaranteed performance limits and associated test conditions, see the Electrical Characteristics tables. Note 2: To minimize power dissipation, low duty cycle pulse testing is used. Note 3: Power dissipation at TA = 25°C is equal to 1.0W for the 8 lead P DIP package and 625mW for the SO-8 package. For operation at temperatures above TA = 25°C derate the power dissipation at 10mW/°C. Supply Current Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS34063 FUNCTIONAL BLOCK DIAGRAM 1 8 DRIVE COLLECTOR S Q SWITCH COLLECTOR Q2 Q1 R 170 7 IPK SENSE IPK OSC VCC SWITCH EMITTER 3 TIMING CAPACITOR CT 6 + COMP. - COMPARATOR INVERTING INPUT 2 1.25V REF REG 5 4 GND TYPICAL PERFORMANCE CHARACTERISTICS Standby Supply Current vs Supply Voltage 1000 3.2 VCC = 5.0V IPK(sense) = VCC Pin 5 = GND SUPPLY CURRENT (mA) OUTPUT SWITCH ON-OFF TIME (µs) Output Switch On-Off Time vs Oscillator Timing Capacitor 100 10 1.0 CT= 0.001µF IPK(sense) = VCC Pin 2 = GND 2.4 1.6 0.8 0 100 0.1 1.0 10 OSCILLATOR TIMING CAPACITOR 0 Common-Emitter Configuration Output Switch Saturation Voltage vs Collector Current Emitter-Follower Configuration Output Switch Saturation Voltage vs Emitter Current 1.6 1.2 VCC = 5.0V Pins 1,7,8 = VCC Pin 3,5 = GND 1.5 SATURATION VOLTAGE (V) SATURATION VOLTAGE (V) 5.0 10 15 20 25 30 35 40 SUPPLY VOLTAGE (V) 1.4 1.3 1.2 1.1 VCC = 5.0V Pin 7 = VCC Pin 2,3,5 = GND 1.0 Darlington Connection 0.8 0.6 Forced Beta ≈20 0.4 0.2 1.0 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 EMITTER CURRENT (A) Advanced Monolithic Systems, Inc. www.advanced-monolithic.com 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 COLLECTOR CURRENT (A) Phone (925) 443-0722 Fax (925) 443-0723 AMS34063 TYPICAL APPLICATIONS Step-Down Converter 1 8 S Q Q2 R Q1 2 7 IPK RSC 0.33 VIN 25V OSC CT 1N5822 3 6 CT 470 pF + 100 µF + COMP. - 1.25V REF REG 5 L 220µH 4 R2 R1 1.2 k 470 µF 3.6 k Test + CO VOUT 5.0V/500mA Conditions Results Line Regulation VIN = 15 to 25V, IO = 500mA 15mV Load Regulation VIN = 25V, IO = 50 to 500mA 5.0mV Output Ripple VIN = 25V, IO = 500mA 40 mVP-P Short Circuit Current VIN = 25V, RL = 0.1Ω 2.3A Efficiency VIN = 25V, IO = 500mA 84.7% External Current Boost Connections for IC Peak Greater than 1.5A a. External NPN Switch 8 b. External PNP Saturated Switch 1 1 8 VOUT 7 2 7 2 VOUT RSC RSC VIN 6 Advanced Monolithic Systems, Inc. VIN www.advanced-monolithic.com 6 Phone (925) 443-0722 Fax (925) 443-0723 AMS34063 TYPICAL APPLICATIONS (Continued) Step-Up Converter 170µH L 1 8 180 S Q Q2 R Q1 7 2 IPK RSC 0.22 VIN 12V OSC CT 1N5819 6 100 µF 3 + + COMP. - 1.25V REF REG 5 CT 1500 pF 4 R2 R1 2.2 k 150 µF 47 k Test + CO VOUT 28V/175mA Conditions Results Line Regulation VIN = 8 to 16V, IO = 175 mA 12 mV Load Regulation VIN = 12V, IO = 75 to 175 mA 5.0 mV Output Ripple VIN = 12V, IO = 175 mA 40 mVP-P Short Circuit Current VIN = 12V, RL = 0.1Ω 2.3A Efficiency VIN = 12V, IO = 175 mA 84.7% External Current Boost Connections for IC Peak Greater than 1.5A a. External NPN Switch 18 0 8 7 b. External NPN Saturated Switch 1 VOUT 2 RSC VIN 8 1 7 2 VOUT 180 RSC 6 Advanced Monolithic Systems, Inc. VIN www.advanced-monolithic.com 6 Phone (925) 443-0722 R 0 for constant VIN Fax (925) 443-0723 AMS34063 APPLICATION HINTS Design Formula Table Calculation Step-Down Step-Up tON tOFF VOUT + VF VIN(MIN) - VSAT - VOUT VOUT + VF - VIN(MIN) VIN(MIN) - VSAT (tON + tOFF) MAX 1 fMIN 1 fMIN CT 4 x 10-5tON 4 x 10-5tON IPK(switch) 2IOUT(MAX) tON + tOFF 2IOUT ( MAX ) tOFF RSC 0.33/IPK(switch) 0.33/IPK(switch) VIN(MIN) − VSAT − VOUT tON(MAX ) IPK(switch) IPK(switch) (tON + tOFF) 8Vripple(P − P) VIN(MIN) − VSAT tON(MAX ) IPK(switch) IOUT tON ≈ Vripple L(MIN) CO VSAT = Saturation voltage of the output switch. VF = Forward voltage drop of the ringback rectifier. Notes The following power supply characteristics must be chosen: VIN – Nominal input voltage. If this voltage is not constant, then use VIN(MAX) for step-down and VIN(MIN) for step-up converter. R2 VOUT – Desired output voltage, VOUT = 1.25 1 + . R1 IOUT - Desired output current. fMIN - Minimum desired output switching frequency at the selected values for VIN and IO. Vripple(P-P) – 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. Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS34063 PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted. 8 LEAD SOIC PLASTIC PACKAGE (S) 0.189-0.197* (4.801-5.004) 8 7 6 5 0.228-0.244 (5.791-6.197) 0.150-0.157** (3.810-3.988) 1 2 3 4 0.010-0.020 x 45° (0.254-0.508) 0.053-0.069 (1.346-1.752) 0.004-0.010 (0.101-0.254) 0.014-0.019 (0.355-0.483) 0.008-0.010 (0.203-0.254) 0.050 (1.270) TYP 0°-8° TYP 0.016-0.050 (0.406-1.270) S (SO-8 ) AMS DRW# 042293 *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 8 LEAD PLASTIC DIP PACKAGE (P) 0.400* (10.160) MAX 8 7 6 5 1 2 3 4 0.255±0.015* (6.477±0.381) 0.045-0.065 (1.143-1.651) 0.300-0.325 (7.620-8.255) 0.130±0.005 (3.302±0.127) 0.065 (1.651) TYP 0.005 (0.127) MIN 0.100±0.010 (2.540±0.254) 0.125 (3.175) MIN 0.009-0.015 (0.229-0.381) 0.015 (0.380) MIN 0.018±0.003 (0.457±0.076) 0.325 +0.025 -0.015 (8.255 +0.635 -0.381 ) P (8L PDIP ) AMS DRW# 042294 *DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTUSIONS. MOLD FLASH OR PROTUSIONS SHALL NOT EXCEED 0.010" (0.254mm) Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723