HA17384 HITACHI

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Technical content

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP High Speed Current Mode PWM Control IC for Switching Power Supply ADE-204-028A (Z) 2nd Edition Nov. 1999

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, high- speed, 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 MOSFETs)
  • 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: ¾ Current detection response time: 100 ns Typ ¾ Maximum oscillation frequency: 500 kHz
  • Low standby current: 170 mA 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 *1 (Output stops when FB terminal voltage is 7.0 V Typ or higher)
  • TSD function (thermal shut-down protection) is included *1 (Output stops when the temperature is 160°C Typ or higher)
  • Zener protection is included (Clamp voltage between VIN and GND is 34 V Typ)
  • Wide operating temperature range: ¾ Operating temperature: –20°C to +105°C ¾ Junction temperature: 150°C *2 Note: 1. H series only. 2. S series only.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Product Line-up Package Additional Function UVL Power Supply Threshold Voltage DILP8 (DP-8) SOP8 (FP-8DC) TSD (Thermal shut- down protection) OVP (Over voltage protection) V TH UVL (V) Typ V TL UVL (V) Typ HA17384SPS HA17384SRP — — 16.0 10.0 HA17384HPS HA17384HRP mm HA17385HPS HA17385HRP mm 8.4 7.6 Pin Arrangement COMP FB CS R T/CT Vref V IN OUT GND (Top view) Pin Function Pin No. Symbol Function Note

1 COMP Error amplifier output pin

2 FB Inverting input of error amp./OVP input pin 1

3 CS Current sensing signal input pin

4R T/CT Timing resistance, timing capacitance connect pin

5 GND Groung pin

6 OUT PWM Pulse output pin

7V IN Power supply voltage input pin

8 Vref Reference voltage 5V output pin

Note: 1. Overvoltage protection (OVP) input is usable only for the HA17384H and HA17385H.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Block Diagram Oscillator Totem pole output circuit Note: 1. Blocks with bold line are not included in HA17384SPS/SRP. 0.8mA EA OVP CS 7.0V UVL1 H L VL VH UVL2 Vref > 4.7VR Q S 6.5V

2 Vref

(2.5V) 2VF 160°C R R S Q PWM LOGIC Vref NOR 8.4 mA 1.2V OR 34V COMP FB (OVP input) CS RT/CT Vref V IN OUT

5 GND

2.8 V OUT 5V band gap reference regulator OVP latch TSD sense CS latch Latch set pulse

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Absolute Maximum Ratings Item Symbol Rating Unit Note Supply voltage V IN 30 V DC output current I O –0.1 A Peak output current I O PEAK –1.0 A Error amplifier input voltage VFB –0.3 to VIN V COMP terminal input voltage V COMP –0.3 to +7.5 V Error output sink current I OEA 10 mA Power dissipation P T 680 mW 1, 2 Operating temperature Topr –20 to +105 °C Junction temperature Tj 125 °C3 150 °C4 Storage temperature Tstg –55 to +125 °C3 –55 to +150 °C4 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) Ambient Temperature Ta (°C) 680mW 374mW 43°C 68°C 150°C 800 600 400 200 −20 0 20 40 60 80 100 120 140 160 166mW 105°C 125°C HA17384SPS HA17384HPS, HA17385HPS

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%. Power Dissipation PT (mW) Ambient Temperature Ta (°C) 374 mW 680 mW 43°C6 3 °C 150°C89°C 800 600 400 200 −20 0 20 40 60 80 100 120 140 160 166 mW 500 mW 222 mW 68°C 105°C 125°C 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%) 3. Applies to the HA17384HPS/HRP and HA17385HPS/HRP. 4. Applies to the HA17384SPS/SRP.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Electrical Characteristics

(The condition is: Ta = 25°C, VIN = 15 V, CT = 3300 pF, RT = 10 kW without notice) Reference Part Item Symbol Min Typ Max Unit Test Condition Note 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 D Vref — 80 — ppm/ °C Io = –1 mA, –20°C £ Ta £ 105°C Output noise voltage V N — 100 — mV 10 Hz £ fnoise £ 10 kHz 1 Notes: 1. Reference value for design. Triangular Wave Oscillator Part Item Symbol Min Typ Max Unit Test Condition Note Typical oscillating frequency fosc Typ 47 52 57 kHz C T = 3300 pF, R T = 10 kW Maximum oscillating frequency fosc Max 500 — — kHz Supply voltage dependency of oscillating frequency D fosc 1 — –0.5 –2.0 % 12 V £ VIN £ 25 V Temperature dependency of oscillating frequency D fosc 2 — –5.0 — % –20 °C £ Ta £ 105°C1 Discharge current of CT IsinkCT 7.5 8.4 9.3 mA V CT = 2.0 V Low level threshold voltage VTLCT — 1.2 — V 1 High level threshold voltage VTHCT — 2.8 — V 1 Triangular wave amplitude D VCT — 1.6 — V D VCT = VTHCT – VTLCT 1 Notes: 1. Reference value for design.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Electrical Characteristics (cont) Error Amplifire Part / OVP Part Item Symbol Min Typ Max Unit Test Condition Note Non-inverting input voltage VFB 2.42 2.50 2.58 V V COMP = 2.5 V Input bias current I IB — –0.2 –2.0 mAV FB = 5.0 V Open loop voltage gain A VOL 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 I Osink EA 3.0 9.0 — mA V FB = 2.7 V, VCOMP = 1.1 V Output source current I Osource EA –0.5 –0.8 — mA V FB = 2.3 V, VCOMP = 5.0 V High level output voltage VOH EA 5.5 6.5 7.5 V V FB = 2.3 V, R L = 15 kW (GND) Low level output voltage VOL EA — 0.7 1.1 V V FB = 2.7 V, R L = 15 kW (Vref) OVP latch threshold voltage VOVP 6.0 7.0 8.0 V Increase FB terminal voltage OVP (FB) terminal input current IFB(OVP) —3 05 0 mAV FB = 8.0 V 1 OVP latch reset VIN voltage VIN(OVP RES) 6.0 7.0 8.0 V Decreasing V IN after OVP latched Note: 1. These values are not prescribe to the HA17384SPS/SRP because OVP function is not included.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Electrical Characteristics (cont) Current Sensing Part Item Symbol Min Typ Max Unit Test Condition Note Voltage gain A VCS 2.85 3.00 3.15 V/V V FB = 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 I BCS — –2 –10 mAV CS = 2 V Current sensing response time tpd 50 100 150 ns Time from when V CS becomes 2 V to when output becomes “L” (2 V) 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. V CS VOUT (PWM) Vth tpd Figure 1 Definition of Current Sensing Response Time tpd PWM Output Part Item Symbol Min Typ Max Unit Test Condition Note 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 1 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 1 Output low voltage at standby mode VOL STB — 0.8 1.1 V V IN = 5 V, losink = 1 mA Rise time t r — 80 150 ns C L = 1000 pF Fall time t f — 70 130 ns C L = 1000 pF Maximum ON duty Du max 94 96 100 % Minimum ON duty Du min — — 0 % Notes: 1. Pulse application test

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Electrical Characteristics (cont) UVL Part Item Symbol Min Typ Max Unit Test Condition Note Threshold voltage for V TH UVL 14.5 16.0 17.5 V Turn-ON voltage 1 high VIN level 7.6 8.4 9.2 V when V IN is rising 2 Threshold voltage for V TL UVL 9.0 10.0 11.0 V Minimum operating 1 low VIN level 6.8 7.6 8.4 V voltage after turn-ON 2 VIN UVL hysteresis voltage V HYS UVL 5.0 6.0 7.0 V V HYS UVL = VTH UVL – VTL UVL 1 0.6 0.8 1.0 V 2 Vref UVL threshold voltage VT Vref 4.3 4.7 Vref V 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 Note Operating current I IN 7.0 10.0 13.0 mA C L = 1000 pF, VFB = VCS = 0 V Standby current I STBY 120 170 230 mA Current at start up Current of latch I LATCH 200 270 340 mAV FB = 0 V after VFB = VOVP 1, 2 Power supply zener voltage VINZ 31 34 37 V I IN + 2.5 mA Overheat protection starting temperature TjTSD — 160 — °C 3, 4 Notes: 1. These values are not prescribe to the HA17384SPS/SRP because OVP function is not included. 2. VIN = 8.5 V in case of the HA17384H. 2. These values are not prescribe to the HA17384SPS/SRP because TSD function is not included. 4. Reference value for design.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Timing Chart Waveform timing (Outline)Signal Name Input voltage VIN Pin 7 UVL1 Internal signal which cannot be externally monitored. Reference voltage Vref Pin 8 UVL2 Internal signal which cannot be externally monitored. Oscillation voltage of triangular wave R T/CT Pin 4 Start up signal Internal signal which cannot be externally monitored. PWM latch setting signal internal signal which cannot be externally monitored. Error amplifier input signal V FB Pin 2 Error amplifier output signal VCOMP Pin 1 ID *1 OVP latch signal Internal signal which cannot be externally monitored. Power ON IC turn ON Stationary operation OVP input OVP latched condition Power OFF Reset of OVP latch Start up latch release ( ) shows the case using HA17385H PWM output voltage V OUT Pin 6 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. 10 V (7.6 V) 7.0 V 2 V 16 V (8.4 V)2 V 5 V 4.7 V 2.8 V 1.2 V

7.0 V typ

(OVP input) V COMP ID VIN 4.7 V IC operates and PWM output stops. This voltage is determined by the transformer

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 through bleeder resistor RB . At this time, when the power voltage is in the range of 2 V to 16 V*1. The low-voltage, lock out UVL1 operates and accordingly the OUT voltage, that is, the gate voltage of the power MOSFET, is fixed at 1.3 V or a lower value, resulting in the power MOSFET 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 R T/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 R B 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 MOSFET), 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 R CS . 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 kW ). 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.

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 according to the input voltage. When VIN becomes lower than 10 V*2 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 Power switch Line filter Rectifier bridge diode DC output Floating ground Power MOSFET ex. 2SK1567 SBD ex. HRP24 OVP input (Ex: from photocoupler) 20k 3.6k 100µ 200V 1000µ 10V R T 10k VCS R B 220k 1/4W C B 10µ 50V VIN 0.1µ B P S HRP32 Vref VIN OUT GND COMP FB HA17384H, HA17385H CS R T/CT R CS 100p150k 330p C T 3300p Figure 2 Mounting Circut Diagram for Operation Expression

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 MOSFET) using source resistor R CS . 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. TransformarAC input Current sense comparator Error amplifier DC output RS R R S IS VCOMP Vref OSC Flip flop Figure 5 Block Diagram of Current Mode Switching Power Spply

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP A. Control in the case of heavy load B. Control in the case of light load VCS IS 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)

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Main Characteristics Operating Current IIN (mA) Operating Current IIN (mA) Operating Current IIN (mA) Power supply voltage VIN (V) Ambient temperature Ta (°C) Operating Current vs. Ambient Temperature Standby Current/Latch Current vs. Supply Voltage Exploded diagram of the small current part from the above figure (HA17384S/H) Power supply voltage VIN (V) Standby Current/Latch Current vs. Supply Voltage Exploded diagram of the small current part from the above figure (HA17385H) Power supply voltage VIN (V) Power supply voltage VIN (V) Ambient temperature Ta (°C) 001 0 2 0 3 0 4 0 2.0 1.5 1.0 0.5 Ta = 25°C Ta = 25°C fosc = 52kHz C T = 3300pF R T = 10kΩ Ta = 25°C fosc = 52kHz C T = 3300pF R T = 10kΩ 001 0 2 0 3 0 4 0 Ta = 25°C 01 0 2 0 3 0 4 0 2.0 1.5 1.0 0.5 001 0 2 0 3 0 4 0 400 300 200 100 Supply Current vs. Supply Voltage (HA17384S/H) Supply Current vs. Supply Voltage (HA17385H)Operating Current IIN (mA) Operating Current IIN (mA)Standby ⋅ Latch Current (µA) Standby Current/Latch Current vs. Ambient Temperature Latch current (HA17384H) Latch current (HA17384H) Latch current Stanby current −20 105 806040200 −20 105 806040200 VIN = 15V fosc = 52kHz C T = 3300pF R T = 10kΩ Latch current VIN = 15V (HA17384H) VIN = 8.5V (HA17385H) Latch current

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Ambient temperature Ta (°C) Ambient temperature Ta (°C) Ambient temperature Ta (°C) Supply voltage VIN (V) Output current of Vref terminal (mA) R T/CT terminal voltage VCT (V) UVL Threshold Voltage vs. Ambient Temperature Line Regulation Characteristics of Reference Voltage Load Regulation Characteristics of Reference Voltage Reference Voltage vs. Ambient Temperature C T Discharge Current vs. RT/CT Terminal Voltage C T Discharge Current vs. Ambient Temperature UVL voltage (V) Reference voltage Vref (V) Reference voltage Vref (V) Reference voltage Vref (V) C T discharge current ICT (mA) 20 5.2 5.1 5.0 4.9 4.8 6.0 5.5 5.0 4.5 4.0 0 20 40 80 60 100 Ta = 25°C VIN = 15V C T = 3300pF R T = 10kΩ 9.5 9.0 8.5 8.0 7.5 0 1 23 5.2 5.1 5.0 4.9 4.8 Ta = 25°C VIN = 15V 9.5 9.0 8.5 8.0 7.5 C T discharge current IsinkCT (mA) 0 10 20 30 VTL VTH −20 85 6040200 −20 105 60 8040200 −20 105 60 8040200 HA17385HVTH HA17384S/H VTL C T = 3300pF R T = 10kΩ C T = 3300pF R T = 10kΩ VIN = 15V VIN=15 V Ta = 25°C VIN = 10V or more (HA17384S/H) VIN = 7.6V or more (HA17385H) Vref short protection operates Measured when R T/CT terminal voltage is externally supplied Minimum voltage of triangular wave Maximum voltage of triangular wave Measured when RT/CT terminal voltage of 2 V is externally supplied

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Maximum ON duty Du max (%) 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. 100 500 1k 2k 5k 10k 20k 50k 100k 200k Ta = 25°C VIN = 15V Figure 9 PWM Pulse ON Duty vs. Timing Resistance

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Oscillation Frequency fosc (kHz) Ambient Temperature Ta (°C) Ambient temperature Ta (°C) Ambient temperature Ta (°C) Operating Current IIN (mA) Maximum ON Duty Du max (%) Output load capacitance CL (pF) Oscillation Frequency vs. Ambient Temperature Operating Current vs. Maximum ON Duty Rise/Fall Time of Output Pulse vs. Load Capacitance Rise/Fall Time of Output Pulse vs. Ambient TemperatureRise/Fall Time (ns) Rise/Fall Time (ns) Current sensing level VCS (V) VIN (UVL1) Vref (UVL2) PWM OUTPUT Condition L L L L H L H H L Standby state IC is in the ON state and output is fixed to LO. Available to output Current Sensing Level vs. Ambient Temperature Relationship Between Low Voltage Malfunction Protection and PWM Output Operation state Standby state H L 65 25 0 25 50 75 100 VIN = 15V fosc=50kHz fosc=300kHzVCS = 0V VFB = 0V 250 0 1000 2000 3000 Fall Time tf 200 150 100 VIN = 15V VCS = 0V VFB = 0V Ta = 25°C C T = 3300pF R T = 10kΩ 4000 250 200 150 100 1.25 1.00 0.75 0.50 0.25 VIN = 15V C L = 1000pF C T = 3300pF R T = 10kΩDumax = 95% VIN = 15V VCS = 0V VFB = 0V C T = 3300pF R T = 10kΩ VIN = 15V VFB = 0V Rise time tr C L = 1000pF −20 105 60 8040200 −20 105 60 8040200 −20 105 60 8040200 C T = 0.033µF R T = 680ΩDumax = 40% Ta=25°C C L = 1000pF Rise time tr Fall Time tf Measured when COMP terminal voltage is externally supplied

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Gain AVO (dB) Error Amplifier Input Signal Frequency f (Hz) Gain AVO 100 −25 Phase Φ (deg) 120 180 10 100 1k 10k 100k 1M 10M Phase Φ VIN = 15V, Ta = 25°C Φ O = 60° Typ Phase margin at fT Unit gain frequency f T = 1MHz Typ Figure 10 Open Loop Gain Characterisrics of Error Amplifier

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Triangular wave PWM maximum ON pulse Dumax is the ratio of maximum ON time of PWM to one cycle time. In the above case, Dumax = 95%

  • Calculation of operation parameters 1. Maximum ON duty Du max (Refer to the right figure.) Du max = 1 1 + 1.78 × In 1 +190Ω R T − 440Ω( ) R T = + 440 Ω190Ω 0.56 (1/Du max − 1) C T = 1.78 × Du max fosc × RT IDmax = VTHCS fosc = 1 C T × R T × 0.56 + In 1 +190Ω (){} 2. Oscillation frequency fosc From the above two equations, the following two equations are obtained. 3. Equalization to device RT from Du max e (e = 2.71828.base of natural logarithm) 4. Equation to device CT from fosc and 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. 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. Example 1: Calculation when R T = 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 R T = 693Ω , CT = 6360pF, IIN = 12.5mA (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). The current limit is expressed as R T − 440Ω However, Ciss = 1000pF, VIN = 18V R CS − 1 Figure 11 Calculation of Operation Parameters

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Application Circuit Example (1) Notes: P Snubber circuit example 51470p 1kV FRD DFG1C8 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. Commercial AC 100V Rectifier bridge diode Line filter 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 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 (V IN of IC) is controlled at constant 16.4V. (The voltage of the point divided by resistors of 20kΩ and 3.6kΩ is 2.5V). 20k 3.6k 100µ 200V 1000µ 10V R T 10k 220k 1/4W 10µ 50V VIN 16.4V 0.1µ − + B P S HRP32 DC 5V, 3A OUTPUT Vref VIN OUT GND COMP FB HA17384H, HA17385H 2SK1567 SBD HRP24 CS R T/CT 100p150k 470p C T 3300p 141V 10k 2SA1029 HA17431 10k 47k Figure 12 Primary Voltage Sensing Flyback Converter

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Application Circuit Example (2) Photocoupler (for output control) Commercial AC 100V Rectifier bridge diode When the error amplifier is used Line filter 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 (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. When the error amplifier is not used Bleeder resistor (adjuster according to the rating of the Photocoupler) 100µ 200V 1000µ 10V R T 10k 220k 1/4W 10µ 50V VIN 16.4V 141V 0.1µ 4.7k − + B P S HRP32 DC 5V, 3A OUTPUTVref VIN OUT GND COMP FB HA17384H, HA17385H HA17431 2SK1567 SBD HRP24 CS R T/CT R T/CT 1.8k B 4.7k 100p150k 470p C T 3300p 330 3.3µ 3.3k Vref VIN OUT GND FB CS 0.8mA COMP OVP input 47k HA17431 2SA1029 10k 10k Figure 13 Secondary Voltage Sensing Flyback Converter

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. +EA IO 800µA typ Vref (3V) (4.4V) (3.7V) (5V) 7VIN D IN VREF R CU C ST 2.5V IC internal circuit (around error amp.) External circuit (only partially shown) FB R 1V To power supply detection comparator (1V) COMP Figure 14 Circuit Diagram for Soft Start Operation: In this circuit, error amp output source current IO (800 mA 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 mA) · CST » 4.62 CST (ms) (CST unit: mF) 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 kW .) 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 mF to 10 mF.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP 2. OVP latch output overvoltage protection (the HA17384H and HA17385H only) The OVP latch is incorporated in the error amp input pin (FB). If the FB pin is pulled up to 7.0 V typ. just once when the power supply enters any kind of error state, IC operation can be halted and held as it is (latched). To reset the latch, drop the IC’s supply voltage to 7.0 V typ. or below momentarily. An OVP latch application example is shown in figure 15. +EA VIN R 2 47k 2.5V Inside IC OVP comparator FB Error amplifier +OVP 7.0V COMP1 R 1 10k HA17431 (Vref ≈ 2.5V) 2SA1029 R 3 10k External circuit (only partially shown) Figure 15 Example of OVP Latch Application Circuit This circuit protects the system by causing latch operation in the event of an overload or load short. In the steady state, the error amp input/output pins operate at 2.5 V typ., but if the load becomes heavy the FB pin level drops and the COMP pin level rises. As shown in the figure, this is detected by the HA17431 shunt regulator, and the FB pin level is pulled up, operating the OVP latch. The operation parameters are as follows: COMP pin voltage detection level: Vth = (R1 + R2) / R2 · 2.5 V

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 ms or faster), such as that shown in figure 16. Also, the OVP latch may operate even though the FB pin is normally at V OVP 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 17, to keep the VIN rise speed below 10 V/100 ms. 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 ms, 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. OutputInput VIN VIN GND FeedbackHA17384 Series Figure 16 Example of Circuit with Fast VIN Rise Time

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Package Dimensions Hitachi Code JEDEC EIAJ Mass (reference value) DP-8 Conforms Conforms 0.54 g Unit: mm 1 4 9.6

10.6 Max

0.89 1.3 6.3 7.4 Max2.54 Min5.06 Max 7.62 0.25 + 0.10 – 0.05 0° – 15°

0.1 Min

1.27 Max

(reference value) FP-8DC Conforms 0.085 g Unit: mm *Dimension including the plating thickness Base material dimension

1.75 Max

4.90 0.25 0.15 0° – 8° M 8 5 1 4 1.27 3.95 0.40 – 0.06 *0.42 – 0.08

5.3 Max

0.75 Max

0.14+ 0.11 – 0.04 0.20 – 0.03 *0.22 – 0.03 0.60+ 0.67 – 0.20 6.10+ 0.10 – 0.30 1.08

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP Cautions 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 fail- safes, 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. Hitachi, Ltd. Semiconductor & Integrated Circuits. Nippon Bldg., 2-6-2, Ohte-machi, Chiyoda-ku, Tokyo 100-0004, Japan Tel: Tokyo (03) 3270-2111 Fax: (03) 3270-5109 Copyright © Hitachi, Ltd., 1998. All rights reserved. Printed in Japan. Hitachi Asia Pte. Ltd.

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