MITSUBISHI SEMICONDUCTORS <Standard Linear ICs> M62212P/FP/GP GENERAL PURPOSE DC-DC CONVERTER DESCRIPTION PIN CONFIGURATION(TOP VIEW) Collector output 1 Emitter 2 output FEATURE GND 3 Cosc 4 • Wide operation power supply voltage range •••••••2.5 ~ 18V • Low power consumption••••••••••••••••••••••••1.3mA typ • High speed switching is possible.(300kHz) • Output short protection circuit and ON/OFF control are used. The dead-time control and the soft-start operation are possible • Package variation : 8pin DIP/SOP/SSOP8 M62212P / FP / GP M62212 is designed as a general purpose DC-DC converter. This small 8 pin package contains many functions allowing simpler peripheral circuits and compact set design. The output transistor is open collector and emitter follower type. This makes the control STEP-UP,STEP-DOWN and INVERTING converter. 8 VCC 7 IN 6 FB 5 DTC OUTLINE 8P2S-A (FP) 8P2X (GP) 8P4 (P) APPLICATIONS General electric products, DC-DC converter BLOCK DIAGRAM VCC 8 UVLO VTH : 2.3V PWM Comp OSC COSC 4 VCC OP Amp Short protection circuit 1.25V IN 7 VCC 1.86V 1.25V R S Q 1.15V 6 FB 5 DTC (1/8) 3 GND 0.3V 1 Collector output 2 Emitter output MITSUBISHI SEMICONDUCTORS <Standard Linear ICs> M62212P/FP/GP GENERAL PURPOSE DC-DC CONVERTER ABSOLUTE MAXIMUM RATINGS (Ta=25°C, unless otherwise noted) Symbols Items Conditions Ratings Units Vcc Power supply voltage 19 V Vo Output voltage 19 V Io Output current 150 mA Pd Power dissipation Ta=25°C 625 (P) 360(FP) 250(GP) mW Ktheta Thermal derating ratio Ta>25°C Topr Operating ambient temperature Tstg Storage temperature 5.00 (P) 2.88 (FP) 2.00(GP) mW/°C -20°C ~ +85 °C -40°C ~ +125 °C Electrical Characteristics ( Ta=25°C, Vcc =12V, Cosc=100pF unless otherwise noted ) Block Symbol All device VCC Range of power supply voltage I CC ST Standby current Output "OFF" status Std. voltage section V REF Standard voltage Voltage follower L INE Line regulation VCC=2.5 ~ 18V IB Input bias current AV Open loop gain Error amp. section GB VOM VOM - I OM + - f OSC Oscillator section UVLO section Test condition Limits Min Typ 1.19 1.3 1.8 mA 1.25 1.31 V 5 12 mV 500 nA 80 dB 0.6 MHz Output low voltage Output sink current VFB=1.86V Output source current VIN =1V 2.62 V 400 mV mA 6 -60 Oscillation frequency Units V 1.82 Output high voltage Max 18 2.5 Unity gain bandwidth + I OM Items -30 uA 110 kHz VOSCH Upper limit voltage of oscillation waveform 1.0 V VOSCL Lower limit voltage of oscillation waveform 0.45 V I OSC CH Cosc charge current -40 uA I OSC DIS1 Cosc discharge current 1 10 uA VTH ON Start-up threshold voltage VIN =1V VTH OFF Shut-down threshold voltage VIN =1V VHYS Hysteresis VHYS = VTHON - VTHOFF (2/8) 2.2 2.3 2.4 V 2.25 20 50 V 80 mV MITSUBISHI SEMICONDUCTORS <Standard Linear ICs> M62212P/FP/GP GENERAL PURPOSE DC-DC CONVERTER Electrical Characteristics ( Ta=25°C, Vcc =12V, Cosc=100pF unless otherwise noted ) Block Short protection circuit Symbol Test condition Limits Min Typ Max Units VTH FB FB threshold voltage VIN =1V,VDTC=0.7V 1.86 V VTH DTC Latch mode "H" threshold voltage VIN =1V,VFB =2.11V 1.15 V VTL DTC Latch mode "L" threshold voltage VIN =1V,VFB =2.11V 0.3 V I CH1 DTC charge current when start-up VDTC=0.7V,VFB =2.11V -45 µA I DIS1 DTC discharge current 1 VDTC=0.7V,VFB =2.11V 50 µA I CH2 DTC charge current when stable state VDTC=0.7V,VFB = 0.7V -10 µA I DIS2 DTC discharge current 2 VDTC=0.2V,VFB =2.11V 15 µA Collector output leak current VCE=18V , VCC=18V I CL Output section Items VSAT1 Collector output saturation voltage 1 VSAT2 Collector output saturation voltage 2 Emitter GND, IC=150mA,VE=0V Emitter follower, IE=50mA,VC=12V (3/8) -1 0.3 1.6 1 µA 1.1 V V MITSUBISHI SEMICONDUCTORS <Standard Linear ICs> M62212P/FP/GP GENERAL PURPOSE DC-DC CONVERTER 1. Application Circuit (STEP-DOWN converter with current buffer transistor) L VIN VOUT D CIN R1 8 1 R2 4 COSC M62212 2 7 6 5 3 (4/8) COUT MITSUBISHI SEMICONDUCTORS <Standard Linear ICs> M62212P/FP/GP GENERAL PURPOSE DC-DC CONVERTER 2. FUNCTION DESCRIPION 1) Soft Start (The peripheral circuit is shown in Fig.1) When the power is turned ON, input terminal IN is at 0V level. Therefore, the FB terminal is fixed to High level. The DTC terminal goes up gradually starting from 0V due to the internal charge current and the external CDTC. When the level of DTC terminal reaches the lower limit of the triangular wave of the oscillator, PWM comparator and the output circuit go into operation causing the output voltage, "Vo" of the DC-DC converter to rise. The charge current is designed to be approximately 45µA. FB DTC 1.0V OSC 0.45V OFF External Tr collector ON Fig.2 2) DTC The dead time control is set by installing a resistor between the DTC terminal and GND. However, the DTC terminal serves as the short protection circuit also. Therefore, its set up depends on whether the short protection circuit is used and not. (When the short protection circuit is used) At this time, the charge current for DTC is approximately 10µA . Therefore, RDTC should be set to 40KΩ ~ 110KΩ. (When the short protection circuit is not used) At this time, the charge current for DTC is approximately 45µA. Therefore, RDTC is set to 12KΩÅ`25KΩ. (5/8) MITSUBISHI SEMICONDUCTORS <Standard Linear ICs> M62212P/FP/GP GENERAL PURPOSE DC-DC CONVERTER 3) Short Protection Circuit The Short Protection Circuit used the timer latch system. It is determined by setting the capacity used for the soft start connected to the DTC terminal. Fig.3 shows the short protection circuit and the timing chart for various modes. When the power is turned on, the FB terminal goes high (approx. 2.3V) and the DTC terminal goes low (goes up slowly from 0V). Thus, approximately 45µA current will flow when SW1:ON and SW2:OFF. The potential, namely the potential of the FB terminal is in the amplitude of the triangular wave, SW1 will be OFF and SW2 will be ON and approximately 50µA will flow into the DTC terminal. This discharge current will cause the DTC terminal to drop from 1.15V. At this time, if the potential of the FB terminal goes to the control potential before the potential at the DTC terminal goes lower than 0.45V which is the lower limit value of the triangular wave and if the potential of the FB terminal is lower than the potential of the DTC terminal, then the system is activated. When the output is shorted, the system is either activated or latched depending on whether the time for the high potential of the FB terminal reaches the potential of the control state is long or short. (For detail, see [II] and [IV] of the Mode) There are two ways to go back to operation after the latch to shut off output. Either method can restart with soft start. 1. Turning ON the Vcc. 2. Make the FB terminal to go to the low potential of 1.86V or less. Then, it is cancel led. [Mode Explained] [ I ] Mode •••••••••••• Activation This is used when the FB terminal goes down to the control state potential when the DTC terminal is in up slope. In order for the activation to occur when the DTC terminal is in down slope, the FB terminal potential must go below the DTC terminal before the DTC terminal goes to 0.45V. [ II ] Mode ••••••••••••• Output short --> Activation The system is activated if the FB terminal potential goes below the DTC terminal potential before the DTC terminal goes to 0.45V. If there is not enough time, the output is turned OFF (Latched) [ III ] Mode •••••••••••• ON/OFF Control --> Activation This mode turns off the output by forcing the DTC terminal to go down. (The system) returns as in the case of the activation. [ IV ] Mode •••••••••••• Output Short (Latch) The output is turned OFF when the FB terminal potential did not go down to the control state before the DTC terminal went down to 0.45V. (6/8) MITSUBISHI SEMICONDUCTORS <Standard Linear ICs> M62212P/FP/GP GENERAL PURPOSE DC-DC CONVERTER Comp1 FB (Initial RESET) 1.86V R Q Vcc 1.25V I2 35µ I1 10µ S SW1 DTC CDTC Comp2 I3 60µ RDTC 90KΩ (900mV) 1.15V 0.3V SW2 * SW1 and SW2 are turned ON by "H" signal. FB 2.0 1.15 DTC DTC set up value (Tentative) 1.0 OSC 0.45 0 I1 I2 I3 ON ON ON ON ON ON ON ON ON ON ON ON OFF OFF OFF OFF ON ON OFF OFF OFF ON OFF ON OFF ON OFF OFF OFF ON OFF ON ON Charge Discharge 45µ 50µ Charge 10µ Discharge 50µ Charge 10µ Charge Charge Discharge 45µ 45µ 50µ Charge 10µ Discharge Discharge 50µ 15µ Activate Output short ON/OFF control --> Activate Output short (Latch) [I] [ II ] [ III ] [ IV ] Fig.3 Short Protection Circuit and the Timing Chart of the Modes (7/8) MITSUBISHI SEMICONDUCTORS <Standard Linear ICs> M62212P/FP/GP GENERAL PURPOSE DC-DC CONVERTER 3.CONSTANT DEFINITION CONSTANT TON TOFF TON + TOFF TOFF (MIN) TON (MAX) D (MAX) COSC L (MIN) R1 RDTC (*1,*2) not use short protection use short protection (*4) CDTC (*4) (*1) calicurate from start-up time calicurate from shat down time Step-down converter Step-up converter VO + VF VIN - VCE(sat) - VO 1 fOSC VO + VF - VIN VIN - VCE(sat) 1 fOSC TON + TOFF TON 1+ TOFF Inverting converter |Vo| + VF VIN - VCE(sat) 1 fOSC TON + TOFF TON 1+ TOFF 1 -TOFF fOSC 1 -TOFF fOSC TON + TOFF TON 1+ TOFF 1 -TOFF fOSC TON(MAX) TON(MAX) TON(MAX) TON + TOFF TON + TOFF TON + TOFF 1 1 1 -16 * 10 -12 -16 * 10 -12 -16 * 10 -12 3 3 75 * 10 * fosc 75 * 10 * fosc 75 * 10 3 * fosc 2 2 2 2 (VIN - VCE(sat) - VO) * TON(MAX) (VIN -VCE(sat)) * TON(MAX) * fOSC (VIN -VCE(sat)) * TON(MAX) * fOSC 2 * V O * IO 2 * V O * IO ∆IO VO -1 * R2 VREF VDTC(MAX) | ICH1 | VDTC(MAX) | ICH2 | | ICH1 | * tstart VDTC(MAX) IDIS1 * tshort VDTC(MAX) -VOSCL VO -1 * R2 VREF VDTC(MAX) | ICH1 | VDTC(MAX) | ICH2 | |VO| -1 *R2 VREF VDTC(MAX) | ICH1 | VDTC(MAX) | ICH2 | | ICH1 | * tstart VDTC(MAX) IDIS1 * tshort VDTC(MAX) -VOSCL | ICH1 | * tstart VDTC(MAX) IDIS1 * tshort VDTC(MAX) -VOSCL VF : Forward Voltage of outer Diode. VCE(sat) : Saturation Voltage of M62212 or Saturation Voltage of Current buffer Transistor. Åô Please setting the Oscillation frequency first and calicurate each constant value. *1 : Please setting Å¢Io about 1/3 to 1/5 of maximum output current. R1 *2 :|Vo|= (1+ ) * VREF R2 *3 : Please settng R2 about few KÉ∂ to score of KÉ∂ because output voltage don't undergo a influence of input current (Terminla 7). *4 : Please setting VDTC(MAX) to satisfy D(MAX), fixed from caracteristics of D(MAX) - VDTC(MAX). ICH1 means DTC charge current when start-up(-45µA typ), ICH2 means DTC charge current when stable state(-10µA typ), VOSCL means lower limit vlage of oscillation waveform (0.45V typ), and IDIS1 means DTC discharge current 1(50µA typ). tstart means time internval when terminal vltage of DTC increase to VOSCL from lower voltage and to start switching at first. tshort means time interval when output is shut down after output is shorted. (8/8)