MITSUBISHI SEMICONDUCTORS <Standard-Linear> M62211P/FP GENERAL PURPOSE MULTI FUNCTION DC-DC CONVERTER Notice: This is not a final specification. Some parametric limits are subject to change. DESCRIPTION M62211FP is designed as a general purpose multi-function DC-DC converter. This small 10 pin package contains many functions allowing simpler peripheral circuits and compact set design. The output circuit is designed OPEN-COLLECTOR output. This makes the application for STEP-UP, STEP-DOWN and INVERTING. The input of this unit has two channels containing priority control circuit. This makes the control a simple matter when the back-light is on and during the stable state. PIN CONFIGURATION(TOP VIEW) Collector output 1 Emitter output 2 GND 3 10 Vcc 9 IN1 8 IN2 Cosc 4 7 FB TIN 5 6 DTC OUTLINE 10P2N-A FEATURE • Wide operation power supply voltage range•••••••2.5~35V • Operation can be synchronized by the external sync signal • Operation can be controlled using two prioritized systems. (High input has priority) • High speed switching is possible.(500kHzmax) • Output short protection circuit and ON/OFF control are used. The dead-time control and the soft-start operation are possible • Small size 10-pin SOP package. Collector output 1 Emitter 2 output GND 3 14 Vcc Cosc 4 11 FB 13 IN1 12 IN2 TIN 5 10 DTC NC 6 9 NC NC 7 8 NC OUTLINE 14P4 APPLICATIONS Back-light control of personal computers and word processors General electric products NC: NO CONNECTION BLOCK DIAGRAM VCC 10 TIN 5 OSC & sync ckt UVLO VTH : 2.3V COSC 4 VCC PWM Comp OP Amp1 1 Collector output 2 Emitter output IN1 9 Std. voltage 1.25V Short protection circuit 1.25V VCC 1.86V IN2 8 R OP Amp2 S Q 1.15V 7 FB 0.3V 6 3 DTC GND (1/9) MITSUBISHI SEMICONDUCTORS <Standard-Linear> M62211P/FP GENERAL PURPOSE MULTI FUNCTION DC-DC CONVERTER ABSOLUTE MAXIMUM RATINGS (Ta=25°C, unless otherwise noted) Symbols Items Conditions Ratings Units Vcc Power supply voltage 36 V Vo Output voltage 36 V Io Output current 150 mA Pd Power dissipation Ta=25°C 1500 (P) 450 (FP) mW K theta Thermal derating ratio Ta>25°C 1.2 (P) 3.6 (FP) mW/°C Topr Operating ambient temperature -20 ~ +85 °C Tstg Storage temperature -40 ~ +150 °C Electrical Characteristics ( Ta=25°C, Vcc =12V, Cosc=390pF unless otherwise noted ) Block Symbol Items Test condition Power supply voltage range Circuit current No load Std. VREF voltage section LINE Standard voltage Voltage follower Line regulation Vcc=2.5 ~ 3.5V Input bias current AV Open loop gain GB Error VOM+ amp. section VOM- Min Typ 1.19 Units V 2.4 3.5 mA 1.25 1.31 V 12 mV 500 nA 5 Unity gain bandwidth Max 35 2.5 Vcc All device Icc IB Limits 80 dB 0.6 MHz 1.7 2.5 V 400 mV Output high voltage VFB=1.86V Output low voltage VFB=1.86V IOM+ Output sink current VFB=1.86V IOM- Output source current VIN1=1V, VIN2=1V fosc Oscillation frequency 110 kHz VOSCH Upper limit voltage of oscillation waveform 1.0 V Lower limit voltage of oscillation waveform mA 6 -100 -50 uA VOSCL Oscil- IOSC CH Cosc charge current lator section IOSC DIS1 Cosc discharge current 1 0.45 V -120 uA 30 uA IOSC DIS2 Cosc discharge current 2 120 uA VTINH TIN "H" level VTINL TIN "L" level 2.2 (2/9) Vcc V 1.0 V MITSUBISHI SEMICONDUCTORS <Standard-Linear> M62211P/FP GENERAL PURPOSE MULTI FUNCTION DC-DC CONVERTER Electrical Characteristics ( Ta=25°C, Vcc =12V, Cosc=390pF unless otherwise noted ) Block Symbol VTH ON UVLO section VTH OFF Short protec tion circuit Items Test condition Start-up theshould voltage Limits Min Typ Max 2.2 2.3 2.4 2.25 Shut-down theshould voltage 20 50 Units V V 80 mV VHYS Hysteresis VTH FB FB threshold voltage VIN1=1V, VIN2=1V, VDTC=0.7V 1.86 V VTH DTC Latch mode "H" threshold voltage VIN1=1V, VIN2=1V, VFB=2.11V 1.15 V VTL DTC Latch mode "L" threshold voltage VIN1=1V, VIN2=1V, VFB=2.11V 0.3 V ICH1 DTC charge current when start-up VDTC=0.7V, VFB=2.11V -35 µA IDIS1 DTC discharge current 1 VDTC=0.7V, VFB=2.11V 45 µA ICH2 DTC charge ccurrent when stable state VDTC=0.7V, VFB=0.7V -15 µA IDIS2 DTC discharge current 2 VDTC=0.2V, VFB=2.11V 20 µA Collector output leak current VCE=35V, Vcc=35V Collector output saturation voltage Emitter follower, IE=50mA, Vc=12V Output ICL section VSAT1 (3/9) -1 1 1.6 µA V MITSUBISHI SEMICONDUCTORS <Standard-Linear> M62211P/FP GENERAL PURPOSE MULTI FUNCTION DC-DC CONVERTER 1. Explanation of Back Light Control Circuit VCC DC/AC D1 Cl Co OSC & sync ckt UVLO V TH :2.3V FL Tube Cosc R1 OP Amp1 IN1 D2 R3 Std. voltage 1.25V VR1 IN2 R OP Amp2 RFL R2 R4 CDELAY CFL S Q Cf2 Cf1 RDTC CDTC Rl1 Rl2 Fig.1 An Application of the Back Light Control Circuit 1-1. Priority Control Operation As far as OPAmp1 and OPAmp2 are concerned, there is no problem when either IN1 or IN2 is used to control current, since the setting up to lower the output voltage of the DC-DC converter is prioritized. (The above figure uses IN1 to control current.) 1) When starting, the output voltage "Vo" is determined by the feedback to IN2 via R1 and R2 and the following equation : Vo=VREF * (R1 + R2)/R2 (VREF =1.25Vtyp) (Area of the Timing Chart 1) 2) Next, this output voltage "Vo" is used to discharge the FL tube by the inverter and causes the tube current to flow. The tube current is filtered and smoothed by RFL, D2, and CFL so that the DC voltage (VCFL) corresponding to the tube current is generated at CFL. The voltage of VCFL is divided by R3, VR1, and R4, and feedback to IN1, it can control tube current. (Area of the Timing Chart 2) 3) Here, CDELAY is inserted between R3 and VR1 + R4 in order to regulate the timing to switch from the voltage control to the current control. (Area of the Timing Chart 3) 4) When in the current control state, it is possible to adjust brightness by changing the amount of feedback of the tube current using VR1. (Area of the Timing Chart 4) 5) If the feedback used for controlling current is lost due to irregularities in the FL tube. etc.. the control returns to the voltage control mode. (Area of the Timing Chart 5) (4/9) MITSUBISHI SEMICONDUCTORS <Standard-Linear> M62211P/FP GENERAL PURPOSE MULTI FUNCTION DC-DC CONVERTER <Timing Chart> (V) (mArms) (V) (V) II I III IV (5/9) V MITSUBISHI SEMICONDUCTORS <Standard-Linear> M62211P/FP GENERAL PURPOSE MULTI FUNCTION DC-DC CONVERTER 1-2 Setting Up TIN 1) Setting Up the Level The TIN terminal is shown in Fig.a. In order for the level of TIN to satisfy the conditions shown in the table below, the external circuits shown in Fig.b or Fig.c should be used when the external voltage level of the input is high. 100KΩ TIN 5 5 5 50KΩ 3 GND Fig.b Fig.a Items Symbols min TIN "H" level VTINH 2.2 TIN "L" level VTINL Fig.c typ max Unit VCC V 1.0 V 2) Setting Up frequency The periodical change of TIN is expected to be +30% ~ -20%. The fIN is set to approximately 1.5 times fOSC fIN = 1.5 * fOSC fsoc ≈ 1 1.3µs+(23 * 10 *3Cosc ) COSC TIN (6/9) (Hz) MITSUBISHI SEMICONDUCTORS <Standard-Linear> M62211P/FP GENERAL PURPOSE MULTI FUNCTION DC-DC CONVERTER 1-3 Soft Start, DTC, and Short Protection 1) Soft Start (The peripheral circuit is shown in Fig.1) When the power is turned ON, IN1 and IN2 are 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 35µA. 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 12KΩ ~ 25KΩ. (7/9) MITSUBISHI SEMICONDUCTORS <Standard-Linear> M62211P/FP GENERAL PURPOSE MULTI FUNCTION 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. 2.4V) and the DTC terminal goes low (goes up slowly from 0V). Thus, approximately 35µA 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 45µA 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 1.25V 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. (8/9) MITSUBISHI SEMICONDUCTORS <Standard-Linear> M62211P/FP GENERAL PURPOSE MULTI FUNCTION DC-DC CONVERTER Comp1 FB (Initial RESET) 1.86V R Q Vcc 1.25V I2 25µ I1 10µ S SW1 DTC CDTC Comp2 I3 55µ 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 0.20 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 35µ 45µ Charge 10µ Discharge 45µ Charge 10µ Charge Charge Discharge 35µ 35µ 45µ Charge 10µ Discharge Discharge 45µ 20µ 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 (9/9)