L5991A STMicroelectronics, L5991A Datasheet
L5991A
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L5991A Summary of contents
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... August 2001 PRIMARY CONTROLLER WITH STANDBY MULTIPOWER BCD TECHNOLOGY ORDERING NUMBERS: L5991/L5991A (DIP16) line or DC-DC power supply applications using a fixed frequency current mode control. Based on a standard current mode PWM control- ler this device includes some features such as programmable soft start, IN/OUT synchronization, ...
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... L5991 - L5991A ABSOLUTE MAXIMUM RATINGS Symbol V Supply Voltage ( Output Peak Pulse Current OUT Analog Inputs & Outputs (6,7) Analog Inputs & Outputs (1,2,3,4,5,15,14, 13, 16) P Power Dissipation @ T tot T Junction Temperature, Operating Range j T Storage Temperature, Operating Range stg (*) maximum package power dissipation limits must be observed ...
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... COMP sen COMP VSS = 0. 250mA 20mA 12V 200mA 12V 5mA 20V 20V V = 24V CC C L5991 - L5991A (*) C = 1nF; T Min. Typ. Max. Unit 4.925 5.0 5.075 0.4 mV/ C 4.80 5.0 5.130 V 30 150 mA 0.2 0 100 105 kHz 93 100 107 kHz 46 ...
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... I = 2mA ST-BY V Falling comp V Rising comp Master Operation I = 0.8mA SOURCE Vclock = 3.5V Slave Operation Low Level High Level VSYNC = 3. pin14 V = 15V CC Figure 2. L5991 - Quiescent current vs. input voltage (after disable 7.6V and Y= 8.4V for L5991A µ Min. Typ. Max 100 70 1 7.8 8 ...
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... Vcc =15V, after turn-on 500KHz RT=13 CT=1nF 1 300KHz 100KHz 0.1 0.01 -50 - Figure 8. Vref vs. junction temperature. Vref [V]) 5.1 5.05 5 4.95 4 -50 -25 L5991 - L5991A and switching frequency Operating current Vcc =15V, after turn-on RT=13.3k , CT=1nF DC=75%, Co=1nF Quiescent current Start-up current Vc=Vcc= Vccon-0.5V, before turn- ...
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... L5991 - L5991A Figure 9. Vref vs. junction temperature. Vref [V] 5.1 Vcc = 15V 5.05 Iref= 20mA 5 4.95 4.9 -50 - (°C) Figure 11. Output saturation. Vsat = V [ Vcc = Vc = 15V 25° 0.2 0.4 0.6 Isource [A] Figure 13. UVLO Saturation Ipin10 [mA] 50 Vcc < Vccon 40 before turn- 200 400 600 800 Vpin10 [mV] 6/23 Figure 10 ...
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... V15 = 0V 2.5 2 V15 = Vref 1 Figure 20. E/A frequency response. G [dB] 150 100 50 PIN10 = OPEN 1V pulse 0 on PIN13 100 125 150 0.01 0.1 L5991 - L5991A Rt= 4.5Kohm 1nF Vcc = 15V, V15 100 125 Tj (°C) V15 = 0V V15 = Vref Rt = 4.5Kohm 1nF 100 Duty Cycle [%] 1 10 100 ...
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... L5991 - L5991A STANDBY FUNCTION The standby function, optimized for flyback topol- ogy, automatically detects a light load condition for the converter and decreases the oscillator fre- quency on that occurrence. The normal oscillation frequency is automatically resumed when the out- put load builds up and exceeds a defined thresh- old ...
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... limitation on the maximum duty cycle is re- quired (i.e. D ing. An internal pull-up (see fig. 24) holds the volt- age above 3V. Should the pin pick up noise (e.g. L5991 - L5991A SYNC 600 A CLK D97IN729A ...
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... L5991 - L5991A during ESD tests), it can be connected to VREF through a 4.7k resistor. Figure 24. Duty cycle control REF ST- RCT D97IN727A Pin 4. VREF (Reference Voltage). The device is provided with an accurate voltage reference (5V 1.5%) able to deliver some external circuit. A small film capacitor (0.1 F typ.), connected ...
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... Besides, no current flows when the gate voltage is 13V, steady state. Under UVLO conditions an internal circuit (shown SHORT T hic L5991 - L5991A + R g only. g ment. Rg' V ...
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... L5991 - L5991A in fig.28) holds the pin low in order to ensure that the external MOS cannot be turned on acciden- tally. The peculiarity of this circuit is its ability to mantain the same sink capability (typically, 20mA @ 1V) from the start-up threshold. CC When the threshold is exceeded and the L5991 starts operating pulled high (refer to fig ...
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... STANDBY signal goes low the N-channel FET 11 is turned off and the pin becomes floating D97IN498 ISEN OUT DRIVER - R 10V 4 VREF STANDBY ST-BY LEVEL SHIFT RCT L5991 - L5991A (in order to get T , sets the operating frequency of the fact, as long osc is charged through R and V10 · V10 STANDBY ...
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... L5991 - L5991A now disconnected and C is charged through R T only. In this way the oscillator frequency (f be lower. Refer to pin 2 description to see how to calculate the timing components. Typical values for V and respectively. This 1.5V hysteresis is enough to prevent undesired frequency change 5 ratio. osc ...
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... APPLICATION IDEAS Here follows a series of ideas/suggestions aimed at Figure 33. Typical application circuit for computer monitors (90W). either improving performance or solving common application problems of L5991 based supplies. L5991 - L5991A 15/23 ...
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... L5991 - L5991A Figure 34. Typical application circuit for inkjet printers (40W). 16/23 ...
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... Figure 38. Bipolar transistor driver. L5991 SGND VREF ISEN R A OPTIONAL D97IN751A ISOLATION BOUNDARY OUT ISEN 13 11 SGND V IN 2.2M 33K STD1NB50 REF 4 L5991 47K 12 11 D97IN762B OUT ISEN 13 L5991 11 PGND D97IN763 L5991 - L5991A R SENSE V IN D97IN761 T SELF-SUPPLY WINDING V IN 17/23 ...
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... L5991 - L5991A Figure 39. Typical E/A compensation networks. From Error Amp compensation circuit for stabilizing any current-mode topology except for boost and flyback converters operating with continuous inductor current. From Error Amp compensation circuit for stabilizing current-mode boost and flyback topologies operating with continuous inductor current. ...
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... DC OUT L5991 11 PGND SGND Figure 46. Voltage mode operation Figure 44. Device shutdown on overcurrent L5991 11 PGND SGND D97IN755A ISEN SENSE DC 3 10K L5991 COMP SGND ISEN D97IN758A L5991 - L5991A R START DIS L5991 2.2K SGND PGND D98IN905 2 max VREF R SENSE DIS ISEN SENSE OPTIONAL D97IN756A R· ...
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... L5991 - L5991A Figure 47. Device shutdown on mains undervoltage 80÷400V Figure 48. Synchronization to flyback pulses (for monitors). 20/ VREF 4 4.7K 3 5.1 R2 10K SGND D97IN750B SYNC L5991 5.1V SGND L5991 12 11 PGND D97IN753A ...
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... DIM. MIN. TYP. MAX. MIN. a1 0.51 0.020 B 0.77 1.65 0.030 b 0 8.5 e 2.54 e3 17.78 F 7.1 I 5.1 L 3.3 Z 1.27 inch MECHANICAL DATA TYP. MAX. 0.065 0.020 0.010 0.787 0.335 0.100 0.700 0.280 0.201 0.130 0.050 L5991 - L5991A OUTLINE AND DIP16 21/23 ...
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... L5991 - L5991A mm DIM. MIN. TYP. MAX. MIN. A 1.75 a1 0.1 0.25 0.004 a2 1.6 b 0.35 0.46 0.014 b1 0.19 0.25 0.007 C 0.5 c1 45˚ (typ.) D (1) 9.8 10 0.386 E 5.8 6.2 0.228 e 1.27 e3 8.89 F (1) 3.8 4 0.150 G 4.6 5.3 0.181 L 0.4 1.27 0.016 M 0.62 8˚(max.) S (1) D and F do not include mold flash or protrusions ...
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