REGULATING PULSE WIDTH MODULATOR

SG1526/SG2526/SG3526 REGULATING PULSE WIDTH MODULATOR DESCRIPTION The SG1526 is a high performance monolithic pulse width modulator circuit designed for fixed-frequency switching regulators and other power control applications. Included in an 18-pin dual-in-line package are a temperature compensated voltage reference, sawtooth oscillator, error amplifier, pulse width modulator, pulse metering and steering logic, and two low impedance power drivers. Also included are protective features such as soft-start and undervoltage lockout, digital current limiting, double pulse inhibit, a data latch for single pulse metering, adjustable deadtime, and provision for symmetry correction inputs. For ease of interface, all digital control ports are TTL and B-series CMOS compatible. Active LOW logic design allows wired-OR connections for maximum flexibility. This versatile device can be used to implement single-ended or push-pull switching regulators of either polarity, both transformerless and transformer coupled. The SG1526 is characterized for operation over the full military ambient junction temperature range of -55°C to +150°C. The SG2526 is characterized for operation from -25°C to +150°C, and the SG3526 is characterized for operation from 0°C to +125°C. FEATURES • • • • • • • • • • • • • • 8 to 35 volt operation 5V reference trimmed to ±1% 1Hz to 350KHz oscillator range Dual 100mA source/sink outputs Digital current limiting Double pulse suppression Programmable deadtime Undervoltage lockout Single pulse metering Programmable soft-start Wide current limit common mode range TTL/CMOS compatible logic ports Symmetry correction capability Guaranteed 6 unit synchronization HIGH RELIABILITY FEATURES - SG1526 ♦ Available to MIL-STD-883B and DESC SMD ♦ Radiation data available ♦ LMI level "S"processing available BLOCK DIAGRAM VREF +VIN GROUND RD RT CT Reference Regulator Undervoltage Lockout SYNC +VC To Internal Circuitry Oscillator OUTPUT A RESET CSOFTSTART COMPENSATION + ERROR Soft Start +VIN S Amp D Q METERING F/F Q S T R Q Q Q TOGGLE F/F OUTPUT B MEMORY F/F — ERROR + C.S. — C.S. SHUTDOWN 4/90 Rev 1.1 2/94 Copyright © 1994 1 11861 Western Avenue ∞ Garden Grove, CA 92841 (714) 898-8121 ∞ FAX: (714) 893-2570 LINFINITY Microelectronics Inc. SG1526/SG2526/SG3526 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Voltage (VIN ) ............................................................... 40V Collector Supply Voltage (VC) ............................................. 40V Logic Inputs ......................................................... -0.3V to 5.5V Analog Inputs .......................................................... -0.3V to V IN Source/Sink Load Current (each output) ....................... 200mA Reference Load Current .................................................. 50mA Note 1. Exceeding these ratings could cause damage to the device. Logic Sink Current ............................................................ 15mA Operating Junction Temperature Hermetic (J, L Packages) ............................................ 150°C Plastic (N, DW Packages) ........................................... 150°C Storage Temperature Range ............................ -65°C to 150°C Lead Temperature (Soldering, 10 Seconds) ................... 300°C THERMAL DATA J Package: Thermal Resistance-Junction to Case, θ JC .................. 25°C/W Thermal Resistance-Junction to Ambient, θ JA .............. 70°C/W N Package: Thermal Resistance-Junction to Case, θ JC .................. 30°C/W Thermal Resistance-Junction to Ambient, θ JA ............. 60°C/W DW Package: Thermal Resistance-Junction to Case, θ JC .................. 35°C/W Thermal Resistance-Junction to Ambient, θ JA ............. 90°C/W L Package: Thermal Resistance-Junction to Case, θ JC ................... 35°C/W Thermal Resistance-Junction to Ambient, θ JA ........... 120°C/W Note A. Junction Temperature Calculation: TJ = TA + (PD x θJA). Note B. The above numbers for θ JC are maximums for the limiting thermal resistance of the package in a standard mounting configuration. The θ JA numbers are meant to be guidelines for the thermal performance of the device/pcboard system. All of the above assume no ambient airflow. RECOMMENDED OPERATING CONDITIONS (Note 2) Input Voltage ............................................................. 8V to 35V Collector Supply Voltage ........................................ 4.5V to 35V Sink/Source Load Current (each output) ................ 0 to 100mA Reference Load Current ........................................... 0 to 20mA Oscillator Frequency Range .............................. 1Hz to 350KHz Oscillator Timing Resistor .................................. 2KΩ to 150KΩ Note 2. Range over which the device is functional. Oscillator Timing Capacitor .................................... 1nF to 20µF Available Deadtime Range at 40KHz ...................... 3% to 50% Operating Ambient Temperature Range: SG1526 ......................................................... -55°C to 125°C SG2526 ........................................................... -25°C to 85°C SG3526 ............................................................... 0°C to 70°C ELECTRICAL CHARACTERISTICS (Unless otherwise specified, these specifications apply over the operating ambient temperatures for SG1526 with -55°C ≤ T A ≤ 125°C, SG2526 with -25°C ≤ TA ≤ 85°C, SG3526 with 0°C ≤ TA ≤ 70°C, and VIN = 15V. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature.) Parameter Reference Section (Note 3) Output Voltage Line Regulation Load Regulation Temperature Stability (Note 9) Total Output Voltage Range (Note 9) Short Circuit Current Undervoltage Lockout Section RESET Output Voltage RESET Output Voltage Test Conditions TJ = 25°C VIN = 8 to 35V IL = 0 to 20mA Over Operating TJ Over Recommended Operating Conditions VREF = 0V VREF = 3.8V VREF = 4.8V SG1526/2526 SG3526 Units Min. Typ. Max. Min. Typ. Max. 4.95 5.00 5.05 4.90 5.00 5.10 10 30 10 30 30 10 50 10 15 50 15 50 4.90 5.00 5.10 4.85 5.00 5.15 50 125 50 125 0.2 4.8 0.4 2.4 0.2 4.8 0.4 V mV mV mV V mA V V 2.4 4/90 Rev 1.1 2/94 Copyright © 1994 2 11861 Western Avenue ∞ Garden Grove, CA 92841 (714) 898-8121 ∞ FAX: (714) 893-2570 LINFINITY Microelectronics Inc. SG1526/SG2526/SG3526 ELECTRICAL CHARACTERISTICS (continued) Parameter Oscillator Section (Note 4) Initial Accuracy Voltage Stability Temperature Stability (Note 9) Minimum Frequency (Note 9) Maximum Frequency Sawtooth Peak Voltage Sawtooth Valley Voltage Error Amplifier Section (Note 5) Input Offset Voltage Input Bias Current Input Offset Current DC Open Loop Gain High Output Voltage Low Output Voltage Common Mode Rejection Supply Voltage Rejection PWM Comparator Section (Note 4) Minimum Duty Cycle Maximum Duty Cycle Test Conditions TJ = 25°C VIN = 8 to 35V Over Operating TJ RT = 150KΩ, CT = 20µF RT = 2KΩ, CT = 1.0nF VIN = 35V VIN = 8V RS ≤ 2KΩ RL ≥ 10MΩ, TJ = 25°C VPIN1 - VPIN2 ≥ 150mV, ISOURCE = 100µA VPIN2 - VPIN1 ≥ 150mV, ISINK = 100µA RS ≤ 2KΩ VIN = 8V to 35V VCOMPENSATION = 0.4V VCOMPENSATION = 3.6V 64 3.6 70 66 SG1526/2526 SG3526 Units Min. Typ. Max. Min. Typ. Max. ±3 0.5 7 350 0.5 3.0 1.0 3.5 0.5 ±8 1.0 10 1.0 350 3.0 1.0 3.5 ±3 0.5 5 ±8 1.0 10 1.0 % % % Hz KHz V V mV nA nA dB V V dB dB % % V V µA µA mV µA V µA V V V V µA µs µs mA 2 5 -350 -1000 35 100 72 60 3.6 4.2 0.2 0.4 94 70 66 80 0 10 2 -350 -2000 35 200 72 4.2 0.2 0.4 94 80 0 45 2.4 49 4 0.2 0.4 -125 -300 -225 -500 100 -3 0.1 100 110 -10 0.4 200 45 2.4 49 4 0.2 0.4 -125 -300 -225 -500 100 -3 0.1 100 120 -10 0.4 200 Digital Ports (SYNC, SHUTDOWN, and RESET) HIGH Output Voltage ISOURCE = 40µA LOW Output Voltage ISINK = 3.6mA VIH = 2.4V HIGH Input Current VIL = 0.4V LOW Input Current Current Limit Comparator Section (Note 6) RS ≤ 50Ω, TJ = 25°C Sense Voltage Input Bias Current Soft-Start Section Error Clamp Voltage RESET = 0.4V CS Charging Current RESET = 2.4V Output Drivers (each output) (Note 7) HIGH Output Voltage ISOURCE = 20mA ISOURCE = 100mA LOW Output Voltage ISINK = 20mA ISINK = 100mA Collector Leakage VC = 40V Rise Time CL = 1000pF Fall Time CL = 1000pF Power Consumption Section (Note 8) Standby Current SHUTDOWN = 0.4V Note 3. Note 4. Note 5. Note 6. IL = 0mA FOSC = 40KHz (RT = 4.12KΩ ±1%, CT = .01µF ±1%, RD = 0Ω) VCM = 0 to 5.2V VCM = 0 to 12V 90 80 50 50 12.5 13.5 12.5 13.5 12 13 12 13 0.2 0.3 0.2 0.3 2 1.2 2 1.2 50 150 50 150 0.3 0.6 0.3 0.6 0.1 0.2 0.1 0.2 18 30 18 30 Note 7. VC = 15V Note 8. VIN = 35V Note 9. These parameters, although guaranteed over the recommended operating conditions, are not tested in production. 4/90 Rev 1.1 2/94 Copyright © 1994 3 11861 Western Avenue ∞ Garden Grove, CA 92841 (714) 898-8121 ∞ FAX: (714) 893-2570 LINFINITY Microelectronics Inc. SG1526/SG2526/SG3526 CHARACTERISTIC CURVES FIGURE 1. REFERENCE VOLTAGE VS. SUPPLY VOLTAGE FIGURE 2. REFERENCE TEMPERATURE STABILITY FIGURE 3. REFERENCE SHORT CIRCUIT CURRENT FIGURE 4. REFERENCE RIPPLE REJECTION FIGURE 5. OSCILLATOR FREQUENCY TEMPERATURE STABILITY FIGURE 6. OUTPUT DRIVER DEADTIME VS. RD VALUE FIGURE 7. OSCILLATOR PERIOD VS. RT AND CT 4/90 Rev 1.1 2/94 Copyright © 1994 4 11861 Western Avenue ∞ Garden Grove, CA 92841 (714) 898-8121 ∞ FAX: (714) 893-2570 LINFINITY Microelectronics Inc. SG1526/SG2526/SG3526 CHARACTERISTIC CURVES (continued) FIGURE 8. UNDERVOLTAGE LOCKOUT CHARACTERISTIC FIGURE 9. ERROR AMPLIFIER OPEN LOOP GAIN VS. FREQUENCY FIGURE 10. SOFTSTART TIME CONSTANT VS. CS FIGURE 11. CURRENT LIMIT TRANSFER FUNCTION FIGURE 12. COMPARATOR INPUT TO DRIVER OUTPUT DELAY FIGURE 13. SHUTDOWN INPUT TO DRIVER OUTPUT DELAY FIGURE 14. OUTPUT DRIVER SATURATION VOLTAGE VS. ISINK FIGURE 15. OUTPUT SUPPLY SATURATION VOLTAGE VS.