HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP High Speed Current Mode PWM Control IC for Switching Power Supply ADE-204-028B (Z) Rev.2 Jul. 2002 Description The HA17384S/H and HA17385H are PWM control switching regulator IC series suitable for highspeed, current-mode switching power supplies. With ICs from this series and a few external parts, a small, low cost flyback-transformer switching power supply can be constructed, which facilitates good line regulation by current mode control. Synchronous operation driven after an external signal can also be easily obtained which offers various applications such as a power supply for monitors small multi-output power supply. The IC series are composed of circuits required for a switching regulator IC. That is a under-voltage lockout (UVL), a high precision reference voltage regulator (5.0 V ± 2%), a triangular wave oscillator for timing generation, a high-gain error amplifier, and as totem pole output driver circuit which directly drives the gate of power MOSFETs found in main switching devices. In addition, a pulse-by-pulse type, highspeed, current-detection comparator circuit with variable detection level is incorporated which is required for current mode control. The HA17384SPS includes the above basic function circuits. In addition to these basic functions, the H Series incorporates thermal shut-down protection (TSD) and overvoltage protection (OVP) functions, for configuration of switching power supplies that meet the demand for high safety levels. Between the HA17384 and HA17385, only the UVL threshold voltages differ as shown in the product lineup table.(See next page.) This IC is pin compatible with the “3842 family” ICs made by other companies in the electronics industry. However, due to the characteristics of linear ICs, it is not possible to achieve ICs that offer full compatibility in every detail. Therefore, when using one of these ICs to replace another manufacturer’s IC, it must be recognized that it has different electrical characteristics, and it is necessary to confirm that there is no problem with the power supply (mounting) set used. HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Functions • Under-voltage lockout system • Reference voltage regulator of 5.0 V ± 2% • Triangular wave (sawtooth) oscillator • Error amplifier • Totem pole output driver circuit (direct driving for power MOS FETs) • Current-detection comparator circuit for current mode • OVP function (over voltage protection) * 1 • TSD function (thermal shut-down protection) * 1 • Protect function by zener diode (between power input and GND) Note: 1. H series only. Features • High-safety UVL circuit is used (Both VIN and Vref are monitored) • High speed operation: Current detection response time: 100 ns Typ Maximum oscillation frequency: 500 kHz • Low standby current: 170 µA Typ • Wide range dead band time (Discharge current of timing capacitance is constant 8.4 mA Typ) • Able to drive power MOSFET directly (Absolute maximum rating of output current is ±1 A peak) • OVP function (over voltage protection) is included * (Output stops when FB terminal voltage is 7.0 V Typ or higher) 1 • TSD function (thermal shut-down protection) is included * (Output stops when the temperature is 160°C Typ or higher) 1 • Zener protection is included (Clamp voltage between VIN and GND is 34 V Typ) • Wide operating temperature range: Operating temperature: –20°C to +105°C Junction temperature: 150°C * Notes: 1. H series only. 2. S series only. Rev.2, Jul. 2002, page 2 of 30 2 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Product Line-up UVL Power Supply Threshold Voltage Package Additional Function DILP8 (DP-8) SOP8 (FP-8DC) TSD (Thermal shutdown protection) OVP (Over voltage protection) VTH UVL (V) Typ VTL UVL (V) Typ HA17384SPS HA17384SRP — — 16.0 10.0 HA17384HPS HA17384HRP ❍ ❍ HA17385HPS HA17385HRP ❍ ❍ 8.4 7.6 Pin Arrangement COMP 1 8 Vref FB 2 7 VIN CS 3 6 OUT RT/CT 4 5 GND (Top view) Pin Function Pin No. Symbol Function 1 COMP Error amplifier output pin 2 FB Inverting input of error amp./OVP input pin 3 CS Current sensing signal input pin 4 RT/CT Timing resistance, timing capacitance connect pin 5 GND Groung pin 6 OUT PWM Pulse output pin 7 VIN Power supply voltage input pin 8 Vref Reference voltage 5V output pin Note: Note 1 1. Overvoltage protection (OVP) input is usable only for the HA17384H and HA17385H. Rev.2, Jul. 2002, page 3 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Block Diagram 0.8mA UVL1 COMP 1 L − + EA VL VH OVP latch R Q − OVP + 7.0V Vref 7 VIN 6 OUT 5 GND Vref > 4.7V S *1 2 8 UVL2 6.5V 1 2 Vref (2.5V) FB (OVP input) 5V band gap reference regulator H 2VF TSD sense OR 34V 2R R 160°C 1V CS latch − CS + 3 NOR R CS Q S OUT PWM LOGIC Totem pole output circuit Vref Oscillator + RT/CT − 4 2.8 V Latch set pulse 1.2V 8.4 mA Note: 1. Blocks with bold line are not included in HA17384SPS/SRP. Rev.2, Jul. 2002, page 4 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Absolute Maximum Ratings Item Symbol Rating Supply voltage VIN 30 V DC output current IO ±0.1 A Peak output current IO PEAK ±1.0 A Error amplifier input voltage VFB –0.3 to VIN V COMP terminal input voltage VCOMP –0.3 to +7.5 V Error output sink current IOEA 10 mA Power dissipation PT 680 mW Operating temperature Topr –20 to +105 °C Junction temperature Tj 125 °C 3 150 °C 4 –55 to +125 °C 3 –55 to +150 °C 4 Storage temperature Tstg Unit Note 1, 2 Notes: 1. For the HA17384HPS and HA17385HPS, This value applies up to Ta = 43°C; at temperatures above this, 8.3 mW/°C derating should be applied. For the HA17384SPS, This value applies up to Ta = 68°C; at temperatures above this, 8.3 mW/°C derating should be applied. Power Dissipation PT (mW) 800 680mW HA17384SPS 600 HA17384HPS, HA17385HPS 400 374mW 200 166mW 43°C 0 −20 0 20 68°C 40 60 80 100 Ambient Temperature Ta (°C) 105°C 120 125°C 140 150°C 160 Rev.2, Jul. 2002, page 5 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Absolute Maximum Ratings (cont.) Notes: 2. This is the value when the device is mounted on a glass-epoxy substrate (40 mm × 40 mm × 1.6 mm). However, For the HA17384HRP and HA17385HRP, Derating should be performed with 8.3 mW/°C in the Ta ≥ 43°C range if the substrate wiring density is 10%. Derating should be performed with 11.1 mW/°C in the Ta ≥ 63°C range if the substrate wiring density is 30%. For the HA17384SRP, Derating should be performed with 8.3 mW/°C in the Ta ≥ 68°C range if the substrate wiring density is 10%. Derating should be performed with 11.1 mW/°C in the Ta ≥ 89°C range if the substrate wiring density is 10%. HA17384SRP : −11.1 mW/°C (wiring density is 30%) : −8.3 mW/°C (wiring density is 10%) HA17384HRP, HA17385HRP : −11.1 mW/°C (wiring density is 30%) : −8.3 mW/°C (wiring density is 10%) Power Dissipation PT (mW) 800 680 mW 600 500 mW 374 mW 400 222 mW 200 166 mW 0 −20 0 43°C 20 63°C 68°C 89°C 40 60 80 100 Ambient Temperature Ta (°C) 3. Applies to the HA17384HPS/HRP and HA17385HPS/HRP. 4. Applies to the HA17384SPS/SRP. Rev.2, Jul. 2002, page 6 of 30 105°C 120 125°C 140 150°C 160 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Electrical Characteristics (The condition is: Ta = 25°C, VIN = 15 V, CT = 3300 pF, RT = 10 kΩ without notice) • Reference Part Item Symbol Min Typ Max Unit Test Condition Reference output voltage Vref 4.9 5.0 5.1 V Io = 1 mA Line regulation Regline — 20 50 mV 12 V ≤ VIN ≤ 25 V Load regulation Regload — 10 25 mV –1 mA ≥ Io ≥ –20 mA Output short current los –30 –100 –180 mA Vref = 0V Temperature stability ∆Vref — 80 — ppm/°C Io = –1 mA, –20°C ≤ Ta ≤ 105°C 1 Output noise voltage VN — 100 — µV 10 Hz ≤ fnoise • 10 kHz 1 Note: • Note 1. Reference value for design. Triangular Wave Oscillator Part Item Symbol Min Typ Max Unit Test Condition Typical oscillating frequency fosc Typ 47 52 57 kHz CT = 3300 pF, RT = 10 kΩ Maximum oscillating frequency fosc Max 500 — — kHz Supply voltage dependency of oscillating frequency ∆fosc 1 — ±0.5 ±2.0 % 12 V ≤ VIN ≤ 25 V Temperature dependency of oscillating frequency ∆fosc 2 — ±5.0 — % –20°C ≤ Ta ≤ 105°C Discharge current of CT IsinkCT 7.5 8.4 9.3 mA VCT = 2.0 V Low level threshold voltage VTLCT — 1.2 — V 1 High level threshold voltage VTHCT — 2.8 — V 1 Triangular wave amplitude ∆VCT — 1.6 — V Note: ∆VCT = VTHCT – VTLCT Note 1 1 1. Reference value for design. Rev.2, Jul. 2002, page 7 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Electrical Characteristics (cont.) (The condition is: Ta = 25°C, VIN = 15 V, CT = 3300 pF, RT = 10 kΩ without notice) • Error Amplifire Part / OVP Part Item Symbol Min Non-inverting input voltage VFB 2.42 2.50 2.58 V VCOMP = 2.5 V Input bias current IIB — –0.2 –2.0 µA VFB = 5.0 V Open loop voltage gain AVOL 65 90 — dB 2.0 V ≤ VO ≤ 4.0 V Unity gain bank width BW 0.7 1.0 — MHz Power supply voltage rejection ratio PSRR 60 70 — dB 12 V ≤ VIN ≤ 25 V Output sink current IOsink EA 3.0 9.0 — mA VFB = 2.7 V, VCOMP = 1.1 V Output source current IOsource EA –0.5 –0.8 — mA VFB = 2.3 V, VCOMP = 5.0 V High level output voltage VOH EA 5.5 6.5 7.5 V VFB = 2.3 V, RL = 15 kΩ(GND) Low level output voltage VOL EA — 0.7 1.1 V VFB = 2.7 V, RL = 15 kΩ(Vref) OVP latch threshold voltage VOVP 6.0 7.0 8.0 V Increase FB terminal voltage 1 OVP (FB) terminal input current IFB(OVP) — 30 50 µA VFB = 8.0 V 1 OVP latch reset VIN voltage VIN(OVP RES) 6.0 7.0 8.0 V Decreasing VIN after OVP latched 1 Note: Typ Max Unit Test Condition Note 1. These values are not prescribe to the HA17384SPS/SRP because OVP function is not included. Rev.2, Jul. 2002, page 8 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Electrical Characteristics (cont.) (The condition is: Ta = 25°C, VIN = 15 V, CT = 3300 pF, RT = 10 kΩ without notice) • Current Sensing Part Item Symbol Min Typ Max Unit Test Condition Note Voltage gain AVCS 2.85 3.00 3.15 V/V VFB = 0 V 1 Maximum sensing voltage VthCS 0.9 1.0 1.1 V Power supply voltage rejection ratio PSRR — 70 — dB 12 V ≤ VIN ≤ 25 V 2 Input bias current IBCS — –2 –10 µA VCS = 2 V Current sensing response time tpd 50 100 150 ns Time from when VCS becomes 2 V to when output becomes “L” (2 V) 3 Notes: 1. The gain this case is the ratio of error amplifier output change to the current-sensing threshold voltage change. 2. Reference value for design. 3. Current sensing response time tpd is definded a shown in the figure 1. Vth VCS VOUT (PWM) tpd Figure 1 Definition of Current Sensing Response Time tpd • PWM Output Part Item Symbol Min Typ Max Unit Test Condition Output low voltage 1 VOL1 — 0.7 1.5 V losink = 20 mA Output low voltage 2 VOL2 — 1.5 2.2 V losink = 200 mA Output high voltage 1 VOH1 13.0 13.5 — V losource = –20 mA Output high voltage 2 VOH2 12.0 13.3 — V losource = –200 mA Output low voltage at standby mode VOL STB — 0.8 1.1 V VIN = 5 V, losink = 1 mA Rise time tr — 80 150 ns CL = 1000 pF Fall time tf — 70 130 ns CL = 1000 pF Maximum ON duty Du max 94 96 100 % Minimum ON duty Du min — — 0 % Note: Note 1 1 1. Pulse application test Rev.2, Jul. 2002, page 9 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Electrical Characteristics (cont.) (The condition is: Ta = 25°C, VIN = 15 V, CT = 3300 pF, RT = 10 kΩ without notice) • UVL Part Item Symbol Threshold voltage for high VIN level VTH UVL Threshold voltage for low VIN level VTL UVL VIN UVL hysteresis voltage VHYS UVL Vref UVL threshold voltage VT Vref Min Typ Max Unit Test Condition Note 14.5 16.0 17.5 V 8.4 9.2 V Turn-ON voltage when VIN is rising 1 7.6 9.0 10.0 11.0 V Minimum operating 1 6.8 7.6 8.4 V voltage after turn-ON 2 5.0 6.0 7.0 V VHYS UVL = VTH UVL – VTL UVL 1 0.6 0.8 1.0 V 4.3 4.7 Vref V 2 2 Voltage is forced toVref terminal Notes: 1. For the HA17384S/H. 2. For the HA17385H. • Total Characteristics Item Symbol Min Typ Max Unit Test Condition Operating current IIN 7.0 10.0 13.0 mA CL = 1000 pF, VFB = VCS = 0 V Standby current ISTBY 120 170 230 µA Current at start up Current of latch ILATCH 200 270 340 µA VFB = 0 V after VFB = VOVP Power supply zener voltage VINZ 31 34 37 V IIN + 2.5 mA Overheat protection starting temperature TjTSD — 160 — °C Notes: 1. 2. 2. 4. Note 1, 2 3, 4 These values are not prescribe to the HA17384SPS/SRP because OVP function is not included. VIN = 8.5 V in case of the HA17384H. These values are not prescribe to the HA17384SPS/SRP because TSD function is not included. Reference value for design. Rev.2, Jul. 2002, page 10 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Timing Chart Signal Name Waveform timing (Outline) Power ON IC turn ON OVP input Stationary operation Input voltage VIN Pin 7 2V 16 V (8.4 V) OVP latched condition Reset of OVP latch 10 V (7.6 V) This voltage is determined by the transformer 0V UVL1 Internal signal which cannot be externally monitored. Power OFF 7.0 V 2V ( ) shows the case using HA17385H 0V 5V Reference voltage Vref Pin 8 0V UVL2 Internal signal which cannot be externally monitored. 0V Oscillation voltage of triangular wave RT/CT Pin 4 Start up signal Internal signal which cannot be externally monitored. PWM latch setting signal internal signal which cannot be externally monitored. 4.7 V 4.7 V 2.8 V 1.2 V 0V IC operates and PWM output stops. 0V Start up latch release 0V 7.0 V typ (OVP input) Error amplifier input signal VFB Pin 2 0V VCOMP Error amplifier output signal 0V VCOMP Pin 1 ID *1 OVP latch signal Internal signal which cannot be externally monitored. PWM output voltage VOUT Pin 6 ID 0V VIN 0V Note: 1. ID indicates the power MOSFET drain current; it is actually observed as voltage VS generated by power MOSFET current detection source resistance RS. VCOMP indicates the error amp output voltage waveform. Current mode operation is performed so that a voltage 1/3 that of VCOMP is the current limiter level. Rev.2, Jul. 2002, page 11 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Operation (Description of Timing Chart) From Power ON to Turn On After the power is switched ON, the power supply terminal voltage (VIN) of this IC rises by charging 1 through bleeder resistor RB. At this time, when the power voltage is in the range of 2 V to 16 V* . The low-voltage, lock out UVL1 operates and accordingly the OUT voltage, that is, the gate voltage of the power MOS FET, is fixed at 1.3 V or a lower value, resulting in the power MOS FET remaining in the OFF state. When the power supply voltage reaches 16 V, UVL1 of this IC is reset and the reference voltage (Vref) generating part turns ON. However, until Vref becomes 4.7 V, the low-voltage, lock out UVL2 operates to keep the OUT terminal voltage low. After Vref terminal voltage becomes 4.7 V or higher, OUT terminal outputs a PWM pulse. Note: 1. The value is for the HA17384S/H. The value is 8.4 V for the HA17385H. Generation of Triangular Wave and PWM Pulse After the output of the Vref, each blocks begins to operate. The triangular wave is generated on the RT/CT terminal. For PWM pulses, the triangular wave rise time is taken as the variable on-duty on-time. The triangular wave fall time is taken as the dead-band time. The initial rise of the triangular wave starts from 0 V, and to prevent a large on-duty at this time, the initial PWM pulse is masked and not output. PWM pulses are outputted after the second triangular wave. The above operation is enabled by the charge energy which is charged through the bleeder resistor RB into the capacitor CB of VIN. Stationary Operation PWM pulses are outputted after the second wave of the triangular wave and stationary operation as the switching power supply starts. By switching operation from ON/OFF to OFF/ON in the switching device (power MOS FET), the transformer converts the voltage. The power supply of IC VIN is fed by the back-up winding of the transformer. In the current mode of the IC, the current in the switcing device is always monitored by a source resistor RCS. Then the current limiter level is varied according to the error voltage (COMP terminal voltage) for PWM control. One third of the error voltage level, which is divided by resistors “2R” and “R” in the IC, is used to sense the current (R = 25 kΩ). Two diodes between the error output and the 2R-R circuit act only as a DC level shifter. Actually, these diodes are connected between the 2R-R circuit and GND, and, the current sensing comparator and GND, respectively. Therefore, these blocks operate 1.4 V higher than the GND level. Accordingly, the error of the current sensing level caused by the switching noise on the GND voltage level is eliminated. The zener diode of 1 V symbolically indicates that the maximum sensing voltage level of the CS terminal is 1 V. Rev.2, Jul. 2002, page 12 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Power OFF At power OFF, the input voltage of the transformer gradually decreases and then VIN of IC also decreases 2 according to the input voltage. When VIN becomes lower than 10 V* or Vref becomes lower than 4.7 V, UVL1 (UVL2) operates again and the PWM pulse stops. Note: 2. The value is for the HA17384S/H. The value is 7.6 V for the HA17385H. Commercial AC voltage + − 100µ 200V − Power switch + Rectifier bridge diode Line filter CB 10µ 50V 3.6k OVP input (Ex: from photocoupler) SBD ex. HRP24 + HRP32 P VIN 20k RB 220k 1/4W + − S B 150k DC output 1000µ 10V 0.1µ COMP + − − Floating ground Vref 100p FB VIN CS OUT 51 RT 10k RT/CT CT 3300p Power MOSFET ex. 2SK1567 GND HA17384H, HA17385H VCS 330p 1k RCS 1 2W Figure 2 Mounting Circut Diagram for Operation Expression Rev.2, Jul. 2002, page 13 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP 2R 2VF R 1V CS latch − VCS CS terminal + VCOMP COMP terminal (Error output) R CS S Q PWM pulse Latch setting pulse (Implemented in triagular wave oscillator) Latch setting pulse VCOMP Error voltage × 1 3 VCS Current sensing level Current Sense Comparator Threshold Voltage VCS (V) Figure 3 Operation Diagram of Current Sensing Part Point: 1) At maximum rated load, the setting should be made to give approximately 90% of area A below. 2) When the OVP latch is operated, the setting should be made in area B or C. 1.0 B Heavy load 0.8 A : Stationary operation / PWM (Current-mode operation) B : Current limit operation / Max duty cycle C : No sensitivity area / No PWM output 0.6 A 0.4 Light load 1.4V 0.2 4.4V 7.5V C 0.0 0 1 2 3 4 5 6 7 Error Amplifier Output Voltage Vcomp (V) Figure 4 Current Sense Characteristics Rev.2, Jul. 2002, page 14 of 30 8 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Features and Theory of Current Mode Control Features of Current Mode Control • Switch element current detection is performed every cycle, giving a high feedback response speed. • Operation with a constant transformer winding current gives a highly stable output voltage (with excellent line regulation characteristics, in particular). • Suitable for flyback transformer use. • External synchronous operation is easily achieved. (This feature, for example, is applicable to synchronization with a forizontal synchronizing signal of CRT monitor.) Theory of Current Mode Control In current mode control, a PWM pulse is generated not by comparing an error voltage with a triangular wave voltage in the voltage mode, but by changing the current limiter level in accordance with the error voltage (COMP terminal in this IC, that is,output of the error amplifier output) which is obtained by constantly monitoring the current of the switching device (power MOS FET) using source resistor RCS. One of the features of current mode control is that the current limited operates in all cycles of PWM as described by the above theory. In voltage mode, only one feedback loop is made by an output voltage. In current mode, on the other hand, two loops are used. One is an output voltage loop and the other is a loop of the switching device current itself. The current of the switching device can be controlled switch high speed. In current mode control, the current in the transformer winding is kept constant, resulting in high stability. An important consequence is that the line regulation in terms of total characteristics is better than that in voltage mode. Transformar AC input DC output OSC RS S Flip flop R Current sense comparator + − IS 2R R − VCOMP + Error amplifier Vref Figure 5 Block Diagram of Current Mode Switching Power Spply Rev.2, Jul. 2002, page 15 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP A. Control in the case of heavy load VCS IS B. Control in the case of light load VCS IS As the load becomes heavy and the DC output decreases, the current sensing level is raised as shown in A. above in order to increase the current in the switching device in each cycle. When the load decreases, inverse control is carried out as shown in B. above. Figure 6 Primary Current Control of Transformer in Current Mode (Conceptual Diagram) Rev.2, Jul. 2002, page 16 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Main Characteristics Supply Current vs. Supply Voltage (HA17384S/H) Supply Current vs. Supply Voltage (HA17385H) 20 Ta = 25°C fosc = 52kHz CT = 3300pF RT = 10kΩ Operating Current IIN (mA) Operating Current IIN (mA) 20 15 10 Latch current (HA17384H) 5 0 0 10 20 30 Power supply voltage VIN (V) CT = 3300pF RT = 10kΩ 15 10 5 0 40 Ta = 25°C fosc = 52kHz Latch current 0 10 20 30 Power supply voltage VIN (V) 40 Standby Current/Latch Current vs. Supply Voltage Standby Current/Latch Current vs. Supply Voltage Exploded diagram of the small current part from the above figure (HA17384S/H) Exploded diagram of the small current part from the above figure (HA17385H) 1.5 1.0 Latch current (HA17384H) 0.5 0 2.0 Ta = 25°C Operating Current IIN (mA) Operating Current IIN (mA) 2.0 0 10 20 30 Power supply voltage VIN (V) 1.5 1.0 Latch current 0.5 0 40 Ta = 25°C 0 10 20 30 Power supply voltage VIN (V) 40 Operating Current vs. Ambient Temperature Standby Current/Latch Current vs. Ambient Temperature 400 VIN = 15V fosc = 52kHz CT = 3300pF RT = 10kΩ Standby ⋅ Latch Current (µA) Operating Current IIN (mA) 12 11 10 9 8 −20 0 20 40 60 80 Ambient temperature Ta (°C) 105 300 Latch current VIN = 15V (HA17384H) VIN = 8.5V (HA17385H) 200 100 0 −20 Stanby current 0 20 40 60 80 Ambient temperature Ta (°C) 105 Rev.2, Jul. 2002, page 17 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP UVL Threshold Voltage vs. Ambient Temperature 20 Line Regulation Characteristics of Reference Voltage 5.2 15 VTH Reference voltage Vref (V) UVL voltage (V) HA17384S/H HA17385H VTL 10 VTH VTL 5 0 −20 Reference voltage Vref (V) 5.0 Vref short protection operates 4.5 CT discharge current ICT (mA) Ta = 25°C VIN = 15V Measured when RT/CT terminal voltage is externally supplied Minimum voltage of triangular wave Maximum voltage of triangular wave 7.5 0 1 2 3 RT/CT terminal voltage VCT (V) Rev.2, Jul. 2002, page 18 of 30 4 10 20 Supply voltage VIN (V) 30 Reference Voltage vs. Ambient Temperature 5.2 VIN = 15V CT = 3300pF RT = 10kΩ 5.1 5.0 4.9 4.8 −20 20 40 60 80 100 Output current of Vref terminal (mA) CT Discharge Current vs. RT/CT Terminal Voltage 9.5 8.0 4.9 0 CT discharge current IsinkCT (mA) Reference voltage Vref (V) 5.5 8.5 5.0 85 CT = 3300pF RT = 10kΩ Ta = 25°C VIN = 15V 9.0 5.1 4.8 0 20 40 60 Ambient temperature Ta (°C) Load Regulation Characteristics of Reference Voltage 6.0 4.0 0 Ta = 25°C CT = 3300pF VIN = 10V or more (HA17384S/H) RT = 10kΩ VIN = 7.6V or more (HA17385H) 0 20 40 60 80 Ambient temperature Ta (°C) 105 CT Discharge Current vs. Ambient Temperature 9.5 VIN=15 V 9.0 Measured when RT/CT terminal voltage of 2 V is externally supplied 8.5 8.0 7.5 −20 0 20 40 60 80 Ambient temperature Ta (°C) 105 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Ta = 25°C VIN = 15V 200 50 F 7µ 10 5 500 02 0. 20 1k 2k F 0p 47 = pF CT 00 F 10 00p F 22 00p µF 47 01 F 0. 2µ 100 04 0. Oscillation frequency fosc (kHz) 500 5k 10k 20k 50k 100k 200k Timing resistance RT (Ω) Figure 7 Oscillation Frequency vs. Timing Resistance Case 1. Setting large maximum duty cycle. Triangular wave PWM maximum ON pulse Du max = 95% fosc = 52kHz In the case of small CT and large RT (ex. CT = 3300pF, RT = 10kΩ) Case 2. Setting small maximum duty cycle. Triangular wave PWM maximum ON pulse Du max = 40% fosc = 52kHz In the case of large CT and small RT (ex. CT = 0.033µF, RT = 680Ω) Figure 8 Relationship Between Triangular Wave and Maximum ON Duty of PWM Pulse Rev.2, Jul. 2002, page 19 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Maximum ON duty Du max (%) 100 Ta = 25°C VIN = 15V 75 50 25 0 500 1k 2k 5k 10k 20k 50k 100k 200k Timing Resistance RT (Ω) Note: In the oscillation system of this IC, a constant discharging current of 8.4mA flows the timing capacitor during triangular wave fall. Therefore, note that a small maximum ON duty (large dead band) leads to a large supply current. Refer to the equations of oscillation frequency and supply current for details. Figure 9 PWM Pulse ON Duty vs. Timing Resistance Rev.2, Jul. 2002, page 20 of 30 VIN = 15V CL = 1000pF 60 CT = 3300pF Dumax = 95% RT = 10kΩ 55 50 Dumax = 40% 45 40 −20 CT = 0.033µF RT = 680Ω 0 20 40 60 80 Ambient Temperature Ta (°C) Rise/Fall Time (ns) Ta = 25°C CT = 3300pF RT = 10kΩ 150 Rise tr time 100 tf ime lT Fal 50 0 0 1000 4000 2000 3000 Output load capacitance CL (pF) Current sensing level VCS (V) Current Sensing Level vs. Ambient Temperature 1.25 1.00 VIN = 15V Measured when COMP terminal VFB = 0V voltage is externally supplied 0.75 0.50 CL = 1000pF 20 VCS = 0V fos VFB = 0V c=3 00 kH z fos c=5 0kH z 15 10 5 25 50 75 100 Maximum ON Duty Du max (%) Rise/Fall Time of Output Pulse vs. Ambient Temperature 250 VIN = 15V VCS = 0V 200 VFB = 0V CL = 1000pF CT = 3300pF RT = 10kΩ 150 Rise time tr 100 Fall Time tf 50 0 −20 0 20 40 60 80 Ambient temperature Ta (°C) 105 Relationship Between Low Voltage Malfunction Protection and PWM Output VIN (UVL1) L H H L Vref (UVL2) L L H H PWM OUTPUT L L Available to output L IC is in the ON Condition Standby state and Operation Standby description state state output is state fixed to LO. 0.25 0 −20 Operating Current vs. Maximum ON Duty 25 VIN = 15V Ta=25°C 0 0 105 Rise/Fall Time of Output Pulse vs. Load Capacitance 250 VIN = 15V VCS = 0V 200 VFB = 0V Operating Current IIN (mA) Oscillation Frequency vs. Ambient Temperature 65 Rise/Fall Time (ns) Oscillation Frequency fosc (kHz) HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP 0 20 40 60 80 Ambient temperature Ta (°C) 105 Rev.2, Jul. 2002, page 21 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP 100 VIN = 15V, Ta = 25°C 50 Gain AVO 25 Unit gain frequency fT = 1MHz Typ 0 60 Phase Φ Phase margin at fT ΦO = 60° Typ −25 10 0 100 1k 10k 100k 1M 120 180 10M Error Amplifier Input Signal Frequency f (Hz) Figure 10 Open Loop Gain Characterisrics of Error Amplifier Rev.2, Jul. 2002, page 22 of 30 Phase Φ (deg) Gain AVO (dB) 75 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP •Calculation of operation parameters 1. Maximum ON duty Du max (Refer to the right figure.) 1 Du max = 190Ω 1 + 1.78 × In 1 + RT − 440Ω Triangular wave 2. Oscillation frequency fosc PWM maximum ON pulse ( ) 1 fosc = CT × RT × { 0.56 + In (1 + R 190Ω − 440Ω )} T From the above two equations, the following two equations are obtained. 3. Equalization to device RT from Du max RT = e 190Ω 0.56 (1/Du max − 1) Dumax is the ratio of maximum ON time of PWM to one cycle time. + 440Ω −1 (e = 2.71828.base of natural logarithm) In the above case, Dumax = 95% 4. Equation to device CT from fosc and RT Du max CT = 1.78 × fosc × RT 5. Operating current IIN IIN = IQ + IsinkCT × (1 − Du max) + Ciss × VIN × fosc providing that IQ = 8.4mA Typ (Supply current when oscillation in IC stops.) Ciss is the input gate capacitance of the power MOSFET which is connected and VIN is the supply voltage of the IC. Example 1: Calculation when RT = 10kΩ and CT = 3300pF fosc = 52kHz, Du max = 95%, IIN = 9.7mA Example 2: Calculation for 50% of Du max and 200 kHz of fosc RT = 693Ω, CT = 6360pF, IIN = 12.5mA However, Ciss = 1000pF, VIN = 18V Note that the actual value may differ from the calculated one because of the internal delay in operation and input characteristics of the POWER MOS FET. Check the value when mounting. Additionally a small Dumax leads to a large supply current, even if the frequency is not changed, and start up may become difficult. In such a case, the following measure is recommended. (1) For an AC/DC converter, a small bleeder resistance is required. (2) The large capacitance between Vref and GND is required. (3) Use a large Dumax with a triangular wave and raise the current limit of the switching device to around the maximum value (1.0V Typ). V The current limit is expressed as IDmax = THCS RCS Figure 11 Calculation of Operation Parameters Rev.2, Jul. 2002, page 23 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Application Circuit Example (1) Rectifier bridge diode + 141V − + − Commercial AC 100V Line filter 100µ 200V VIN SBD 1000µ HRP24 10V + HRP32 16.4V 20k 220k 1/4W P 10µ 50V + − S B HA17384H, HA17385H 2SA1029 0.1µ COMP 150k 10k VIN CS OUT RT/CT GND 51 RT 10k 47k Vref 100p FB HA17431 CT 3300p The circuit for output current limiter 470p 1k DC 5V, 3A OUTPUT − 3.6k 10k + − 1k Transformer specification example EI-22 type core (H7C18 × 06Z) Gap length lg = 0.3mm 2SK1567 Transformer coil example P: 0.5∅80T/570µH S: 0.5∅16T Bifiler/22µH B: 0.2∅44T/170µH 1 2W Notes: 1. : PRIMARY GND, : SECONDARY GND. 2. Check the wiring direction of the transformer coil. 3. Insert a snubber circuit if necessary. 4. OVP function is not included in HA17384SPS/SRP. Snubber circuit example 470p 1kV FRD DFG1C8 51 P S (Opetation Theory) Because this circuit is a flyback type, the voltages in the primary (P), secondary (s) coils of the transformer and backup (B) coil are proportional to each other. Using this, the output voltage of the backup coil (VIN of IC) is controlled at constant 16.4V. (The voltage of the point divided by resistors of 20kΩ and 3.6kΩ is 2.5V). Figure 12 Primary Voltage Sensing Flyback Converter Rev.2, Jul. 2002, page 24 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Application Circuit Example (2) When the error amplifier is used − Rectifier bridge diode + 141V + − Commercial AC 100V 100µ 200V 220k 1/4W Line filter 2SA1029 10k HRP32 VIN 16.4V 10k P 10µ 50V 47k SBD HRP24 S + B − HA17431 The circuit for output current limiter Transformer specification example EI-22 type core (H7C18 × 06Z) Gap length lg = 0.3mm Transformer coil example P: 0.5∅80T/570µH S: 0.5∅16T Bifiler/22µH B: 0.2∅44T/170µH + + 1.8k − 1000µ 10V 330 3.3µ + − 3.3k DC 5V, 3A OUTPUT B 4.7k HA17431 HA17384H, HA17385H − 0.1µ Vref COMP 150k 100p RT 10k FB VIN CS OUT RT/CT GND CT 3300p 470p When the error amplifier is not used Vref COMP 2SK1567 51 Photocoupler (for output control) 1 2W 1k 1k 4.7k OVP input FB 0.8mA VIN Bleeder resistor (adjuster according to the rating of the Photocoupler) CS OUT RT/CT GND (Operation Theory) On the secondary side (S) of the flyback converter, error amplification is carried out by a shunt regulator and photocoupler. The voltage of the backup coil (B) is not monitored, which differs from the application example (1). In addition, OVP operates on the secondary side (S) using a photocoupler. Refer to the application example (1) for the other notes. Figure 13 Secondary Voltage Sensing Flyback Converter Rev.2, Jul. 2002, page 25 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Application Examples for Fuller Exploitation of Power Supply Functions A number of application examples are briefly described below. 1. Soft start A soft start is a start method in which the PWM pulse width is gradually increased when the power supply is activated. This prevents the stress on the transformer and switch element caused by a rapid increase in the PWM pulse width, and also prevents overshoot when the secondary-side output voltage rises. The circuit diagram is shown in figure 14. VIN 7 DIN IO 800µA typ Vref 5V − FB 2 + EA 8 1 (4.4V) VREF (5V) RCU COMP D1 D2 (3.7V) 2.5V CST (3V) IC internal circuit (around error amp.) 2R (1V) R 1V To power supply detection comparator External circuit (only partially shown) Figure 14 Circuit Diagram for Soft Start Operation: In this circuit, error amp output source current IO (800 µA typ.) gradually raises the switch element current detection level, using a voltage slope that charges soft start capacitance CST. When the voltage at each node is at the value shown in parentheses in the figure, the soft start ends. The soft start time is thus given by the following formula: TST = (3.7 V/800 µA) × CST ≈ 4.62 CST (ms) (CST unit: µF) External parts other than CST operate as follows: Diode D1 : Current detection level shift and current reverse-flow prevention. Diode D2 : Together with diode DIN in the IC, CST charge drawing when power supply falls. Resistance RCU : For CST charge-up at end of soft start. (Use a high resistance of the order of several hundred kΩ.) Note: During a soft start, since PWM pulses are not output for a while after the IC starts operating, there is a lack of energy during this time, and intermittent mode may be entered. In this case, the capacitance between Vref and GND should be increased to around 4.7 µF to 10 µF. Rev.2, Jul. 2002, page 26 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Notice for Use 1. OVP Latch Block • Case When DC power is applied directly as the power supply of the HA17384H, HA17385H, without using the transformer backup coil. Also, when high-frequency noise is superimposed on the VIN pin. • Problem The IC may not be turn on in the case of a circuit in which VIN rises quickly (10 V/100 µs or faster), such as that shown in figure 15. Also, the OVP latch may operate even though the FB pin is normally at VOVP or below after the IC is activated. • Reason Because of the IC circuit configuration, the timer latch block operates first. • Remedy (counter measure) Take remedial action such as configuring a time constant circuit (RB, CB) as shown in figure 16, to keep the VIN rise speed below 10 V/100 µs. Also, if there is marked high-frequency noise on the VIN pin, a noise cancellation capacitor (CN) with the best possible high-frequency characteristics (such as a ceramic capacitor) should be inserted between the VIN pin and GND, and close to the VIN pin. When configuring an IC power supply with an activation resistance and backup winding, such as an AC/DC converter, the rise of VIN will normally be around 1 V/100 µs, and there is no risk of this problem occurring, but careful attention must be paid to high-frequency noise. Also, this phenomenon is not occuring to the HA17384S, because OVP function is not built-in. Input Output VIN VIN HA17384 Series Feedback GND Figure 15 Example of Circuit with Fast VIN Rise Time Rev.2, Jul. 2002, page 27 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Input Output Time constant circuit RB 51Ω CN VIN VIN 18V CB 1µF Feedback HA17384 Series + GND Figure 16 Sample Remedial Circuit 2. Externally Synchronized Operation • Case When, with a power supply using the HA17384S/H or HA17385H, externally synchronized operation is performed by applying an external syncronous signal to the RT/CT pin (pin 4). • Problem Synchronized operation may not be possible if the amplitude of the external syncronous signal is too large. • Reason The RT/CT pin falls to a potential lower than the ground. • Remedy (counter measure) In this case, clamping is necessary using a diode with as small a VF value as possible, such as a schottky barrier diode, as shown in figure 17. Vref HA17384 Series RT External synchronous signal CT 47 0.01µF Figure 17 Sample Remedial Circuit Rev.2, Jul. 2002, page 28 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Package Dimensions As of January, 2002 Unit: mm 6.3 7.4 Max 9.6 10.6 Max 8 5 1 0.89 4 1.3 7.62 0.5 Min 2.54 Min 5.06 Max 1.27 Max + 0.10 0.25 – 0.05 0.48 ± 0.10 2.54 ± 0.25 0˚ – 15˚ Hitachi Code JEDEC JEITA Mass (reference value) DP-8B Conforms Conforms 0.51 g As of January, 2002 Unit: mm 3.95 4.90 5.3 Max 5 8 *0.22 ± 0.03 0.20 ± 0.03 4 1.75 Max 1 0.75 Max + 0.10 6.10 – 0.30 1.08 1.27 *0.42 ± 0.08 0.40 ± 0.06 + 0.11 0.14 – 0.04 0˚ – 8˚ + 0.67 0.60 – 0.20 0.15 0.25 M *Dimension including the plating thickness Base material dimension Hitachi Code JEDEC JEITA Mass (reference value) FP-8DC Conforms — 0.085 g Rev.2, Jul. 2002, page 29 of 30 HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Disclaimer 1. Hitachi neither warrants nor grants licenses of any rights of Hitachi’s or any third party’s patent, copyright, trademark, or other intellectual property rights for information contained in this document. Hitachi bears no responsibility for problems that may arise with third party’s rights, including intellectual property rights, in connection with use of the information contained in this document. 2. Products and product specifications may be subject to change without notice. Confirm that you have received the latest product standards or specifications before final design, purchase or use. 3. Hitachi makes every attempt to ensure that its products are of high quality and reliability. However, contact Hitachi’s sales office before using the product in an application that demands especially high quality and reliability or where its failure or malfunction may directly threaten human life or cause risk of bodily injury, such as aerospace, aeronautics, nuclear power, combustion control, transportation, traffic, safety equipment or medical equipment for life support. 4. Design your application so that the product is used within the ranges guaranteed by Hitachi particularly for maximum rating, operating supply voltage range, heat radiation characteristics, installation conditions and other characteristics. Hitachi bears no responsibility for failure or damage when used beyond the guaranteed ranges. Even within the guaranteed ranges, consider normally foreseeable failure rates or failure modes in semiconductor devices and employ systemic measures such as failsafes, so that the equipment incorporating Hitachi product does not cause bodily injury, fire or other consequential damage due to operation of the Hitachi product. 5. This product is not designed to be radiation resistant. 6. No one is permitted to reproduce or duplicate, in any form, the whole or part of this document without written approval from Hitachi. 7. Contact Hitachi’s sales office for any questions regarding this document or Hitachi semiconductor products. Sales Offices Hitachi, Ltd. Semiconductor & Integrated Circuits Nippon Bldg., 2-6-2, Ohte-machi, Chiyoda-ku, Tokyo 100-0004, Japan Tel: (03) 3270-2111 Fax: (03) 3270-5109 URL http://www.hitachisemiconductor.com/ For further information write to: Hitachi Semiconductor (America) Inc. 179 East Tasman Drive San Jose,CA 95134 Tel: <1> (408) 433-1990 Fax: <1>(408) 433-0223 Hitachi Europe Ltd. Electronic Components Group Whitebrook Park Lower Cookham Road Maidenhead Berkshire SL6 8YA, United Kingdom Tel: <44> (1628) 585000 Fax: <44> (1628) 585200 Hitachi Asia Ltd. Hitachi Tower 16 Collyer Quay #20-00 Singapore 049318 Tel : <65>-6538-6533/6538-8577 Fax : <65>-6538-6933/6538-3877 URL : http://semiconductor.hitachi.com.sg Hitachi Europe GmbH Electronic Components Group Dornacher Straße 3 D-85622 Feldkirchen Postfach 201, D-85619 Feldkirchen Germany Tel: <49> (89) 9 9180-0 Fax: <49> (89) 9 29 30 00 Hitachi Asia Ltd. (Taipei Branch Office) 4/F, No. 167, Tun Hwa North Road Hung-Kuo Building Taipei (105), Taiwan Tel : <886>-(2)-2718-3666 Fax : <886>-(2)-2718-8180 Telex : 23222 HAS-TP URL : http://www.hitachi.com.tw Hitachi Asia (Hong Kong) Ltd. Group III (Electronic Components) 7/F., North Tower World Finance Centre, Harbour City, Canton Road Tsim Sha Tsui, Kowloon Hong Kong Tel : <852>-2735-9218 Fax : <852>-2730-0281 URL : http://semiconductor.hitachi.com.hk Copyright © Hitachi, Ltd., 2002. All rights reserved. Printed in Japan. Colophon 6.0 Rev.2, Jul. 2002, page 30 of 30