UNISONIC TECHNOLOGIES CO., LTD UMC33167 Advance LINEAR INTEGRATED CIRCUIT 5.0A, STEP-UP/DOWN/ INVERTING SWITCHING REGULATORS DESCRIPTION The UTC UMC33167 series are high performance fixed frequency power switching regulators that contain the primary functions required for dc-to-dc converters. This series was specifically designed to be incorporated in step-down and voltage-inverting configurations with a minimum number of external components and can also be used cost effectively in step-up applications. These devices consist of an internal temperature compensated reference, fixed frequency oscillator with on-chip timing components, latching pulse width modulator for single pulse metering, high gain error amplifier, and a high current output switch. Protective features consist of cycle-by-cycle current limiting, undervoltage lockout, and thermal shutdown. Also included is a low power standby mode that reduces power supply current to 36μA. FEATURES * Output Switch Current in Excess of 5.0A * Fixed Frequency Oscillator (72kHz) with On-Chip Timing * Provides 5.05V Output without External Resistor Divider * Precision 2% Reference * 0% ~ 95% Output Duty Cycle * Cycle-by-Cycle Current Limiting * Undervoltage Lockout with Hysteresis * Internal Thermal Shutdown * Operation from 7.5V ~ 40V * Standby Mode Reduces Power Supply Current to 36μA ORDERING INFORMATION Ordering Number Lead Free Halogen Free UMC33167L-TA5-T UMC33167G-TA5-T UMC33167L-TB5-T UMC33167G-TB5-T Package Packing TO-220-5 TO-220B Tube Tube MC33167L-TA5-T (1) Packing Type (1) T: Tube (2) Package Type (2) TA5: TO-220-5, TB5: TO-220B (3) Green Package (3) L: Lead Free, G: Halogen Free and Lead Free www.unisonic.com.tw Copyright © 2015 Unisonic Technologies Co., Ltd 1 of 6 QW-R103-070.c UMC33167 Advance MARKING PIN CONFIGURATION PIN DESCRIPTION PIN NO. 1 2 3 4 5 PIN NAME FB SW GND VCC COMP LINEAR INTEGRATED CIRCUIT FUNCTION Output voltage feedback control Switch Output Gnd pin IC power supply pin Compensation pin UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 8 QW-R103-070.c UMC33167 Advance LINEAR INTEGRATED CIRCUIT BLOCK DIAGRAM ILIMIT + + 4 VCC Oscillator S Q + - R PWM 2 SW PWM Latch + UVLO - Thermal Shutdown 5.50V Reference + + 100μA EA + - 1 FB 120 3 GND 5 COMP Figure 1 Simplified Block Diagram (Step Down Application) UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 8 QW-R103-070.c UMC33167 Advance LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATING (Note 2) PARAMETER SYMBOL RATINGS UNIT Power Supply Input Voltage VCC 40 V Switch Output Voltage Range VO(switch) -2.0 ~ +VIN V Voltage Feedback and Compensation Input Voltage Range VFB,VCOMP -1.0 ~ +7.0 V Power Dissipation (TA=+25°C) PD Internally Limited W Operating Junction Temperature TJ +150 °C Operating Ambient Temperature TA -40 ~ +85 °C Storage Temperature TSTG -65 ~ 150 °C Notes: 1. Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. 2. Maximum package power dissipation limits must be observed to prevent thermal shutdown activation. 3. This device series contains ESD protection and exceeds the following tests: Human Body Model 2000 V per MIL-STD-883, Method 3015. Machine Model Method 200 V. THERMAL DATA PARAMETER Junction to Ambient Junction to Case UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw SYMBOL θJA θJC RATINGS 65 5.0 UNIT °C/W °C/W 4 of 8 QW-R103-070.c UMC33167 Advance LINEAR INTEGRATED CIRCUIT ELECTRICAL CHARACTERISTICS (VCC=12V, for typical values TA=+25°C, for min/max values TA is the operating ambient temperature range that applies (Notes 4), unless otherwise noted.) PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT OSCILLATOR TA=+25°C 65 72 79 KHZ Frequency (VCC=7.5V ~ 40V) fOSC TJ=TLOW ~THIGH 62 81 KHZ ERROR AMPLIFIER 4.95 5.05 5.15 V TA=+25°C Voltage Feedback Input Threshold VFB(th) TJ=TLOW ~THIGH 4.85 5.20 V Line Regulation RegLINE VCC=7.5V~ 40V, TA=+25°C 0.03 0.078 %/V Input Bias Current IIB VFB=VFB(th)+0.15V 0.15 1.0 μA Power Supply Rejection Ratio PSRR VCC=7.5V~ 40V, f=120HZ 60 80 dB VOH ISOURCE=75μA, VFB=4.5V 4.2 4.9 V Output Voltage High State Swing Low State VOL ISINK=0.4mA, VFB=5.5V 1.6 1.9 V PWM COMPARATOR 92 95 100 % DC(max) Maximum (VFB=0V) Duty Cycle (VCC=20V) DC(min) Minimum (VFB=0V) 0 0 0 % SWITCH OUTPUT Output Voltage Source Saturation VSAT VCC=7.5V, ISOURCE=5.0A VCC-1.5 VCC-1.8 V Off-State Leakage ISW(off) VCC=40V, Pin 2 = GND 0 100 A Current Limit Threshold IPK(switch) VCC=7.5V 5.5 6.5 8.0 A Output Voltage Rise tR 100 200 ns Time VCC=40V,IPK=5.0A, Switching Times L=225μH, TA=+25°C Output Voltage Fall tF 50 100 ns Time UNDERVOLTAGE LOCKOUT Startup Threshold Vth(UVLO) VCC Increasing, TA=+25°C 5.5 5.9 6.3 V Hysteresis VH(UVLO) (VCC Decreasing, TA=+25°C 0.6 0.9 1.2 V TOTAL DEVICE VCC=12V, VComp<0.15V 36 100 μA Standby Power Supply Current ICC VCC=40V, Pin 1=GND for 40 60 mA Operating (TA=+25°C) maximum duty cycle Note 4: Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 8 QW-R103-070.c UMC33167 Advance LINEAR INTEGRATED CIRCUIT TYPICAL APPLICATION CURRENT ILIMIT + VCC 4 + + - Oscillator VIN 12V CIN 330μF S Q + - R PWM 2 PWM Latch + UVLO SW D1 1N5825 - Thermal Shutdown L 190uH 5.50V Reference + + 100μA EA + - 1 120 3 GND 5 COMP CF + 0.1uF FB R2 6.8K + VO 5.05V/5.0A CO 4700uF RF 68K R1 The Step-Down Converter application is shown in Figure 3. The output switch transistor Q1 interrupts the input voltage, generating a squarewave at the LCO filter input. The filter averages the squarewaves, producing a dc output voltage that can be set to any level between VIN and VREF by controlling the percent conduction time of Q1 to that of the total oscillator cycle time. If the converter design requires an output voltage greater than 5.05V, resistor R1 must be added to form a divider network at the feedback input. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 8 QW-R103-070.c UMC33167 Advance LINEAR INTEGRATED CIRCUIT APPLICATION INFORMATION The UTC UMC33167 series are monolithic power switching regulators that are optimized for dc-to-dc converter applications. These devices operate as fixed frequency, voltage mode regulators containing all the active functions required to directly implement step-down and voltage-inverting converters with a minimum number of external components. They can also be used cost effectively in step-up converter applications. Potential markets include automotive, computer, industrial, and cost sensitive consumer products. A description of each section of the device is given below with the representative block diagram shown in Figure 1. Oscillator The oscillator frequency is internally programmed to 72kHz by capacitor CT and a trimmed current source. The charge to discharge ratio is controlled to yield a 95% maximum duty cycle at the Switch Output. During the discharge of CT, the oscillator generates an internal blanking pulse that holds the inverting input of the AND gate high, disabling the output switch transistor. The nominal oscillator peak and valley thresholds are 4.1V and 2.3V respectively. Pulse Width Modulator The Pulse Width Modulator consists of a comparator with the oscillator ramp voltage applied to the noninverting input, while the error amplifier output is applied into the inverting input. Output switch conduction is initiated when CT is discharged to the oscillator valley voltage. As CT charges to a voltage that exceeds the error amplifier output, the latch resets, terminating output transistor conduction for the duration of the oscillator ramp-up period. This PWM/Latch combination prevents multiple output pulses during a given oscillator clock cycle. Figures 2 illustrate the switch output duty cycle versus the compensation voltage. Error Amplifier and Reference A high gain Error Amplifier is provided with access to the inverting input and output. This amplifier features a typical dc voltage gain of 80dB, and a unity gain bandwidth of 600kHz with 70 degrees of phase margin. The noninverting input is biased to the internal 5.05V reference and is not pinned out. The reference has an accuracy of ±2.0% at room temperature. To provide 5.0V at the load, the reference is programmed 50mV above 5.0V to compensate for a 1.0% voltage drop in the cable and connector from the converter output. If the converter design requires an output voltage greater than 5.05V, resistor R1 must be added to form a divider network at the feedback input as shown in Figures 1 and 3. The equation for determining the output voltage with the divider network is: VOUT=5.05(R2/R1+1) External loop compensation is required for converter stability. A simple low-pass filter is formed by connecting a resistor (R2) from the regulated output to the inverting input, and a series resistor-capacitor (RF, CF) between Pins 1 and 5. The compensation network component values shown in each of the applications circuits were selected to provide stability over the tested operating conditions. The step-down converter (Figure 3) is the easiest to compensate for stability. The simplest way to optimize the compensation network is to observe the response of the output voltage to a step load change, while adjusting RF and CF for critical damping. The final circuit should be verified for stability under four boundary conditions. These conditions are minimum and maximum input voltages, with minimum and maximum loads. By clamping the voltage on the error amplifier output (Pin 5) to less than 150mV, the internal circuitry will be placed into a low power standby mode, reducing the power supply current to 36A with a 12V supply voltage. The Error Amplifier output has a 100 A current source pull-up that can be used to implement soft-start. Switch Output The output transistor is designed to switch a maximum of 40V, with a minimum peak collector current of 5.5A. When configured for step-down or voltage-inverting applications, as in Figures 3, the inductor will forward bias the output rectifier when the switch turns off. Rectifiers with a high forward voltage drop or long turn on delay time should not be used. If the emitter is allowed to go sufficiently negative, collector current will flow, causing additional device heating and reduced conversion efficiency. shows that by clamping the emitter to 0.5V, the collector current will be in the range of 100A over temperature. A 1N5825 or equivalent Schottky barrier rectifier is recommended to fulfill these requirements. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 7 of 8 QW-R103-070.c UMC33167 Advance LINEAR INTEGRATED CIRCUIT APPLICATION INFORMATION(Cont.) Undervoltage Lockout An Undervoltage Lockout comparator has been incorporated to guarantee that the integrated circuit is fully functional before the output stage is enabled. The internal reference voltage is monitored by the comparator which enables the output stage when VCC exceeds 5.9V. To prevent erratic output switching as the threshold is crossed, 0.9V of hysteresis is provided. Thermal Protection Internal Thermal Shutdown circuitry is provided to protect the integrated circuit in the event that the maximum junction temperature is exceeded. When activated, typically at 170°C, the latch is forced into a ‘reset’ state, disabling the output switch. This feature is provided to prevent catastrophic failures from accidental device overheating. It is not intended to be used as a substitute for proper heatsinking. The UTC MC34167 is contained in a 5-lead TO-220 type package. The tab of the package is common with the center pin (Pin 3) and is normally connected to ground. UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 8 of 8 QW-R103-070.c