SN8500D

Semiconductor http:// www.auk.co.kr SN8500D Switching Type (Buck) LED Driver IC ◈ Description The SN8500D is a high power PWM LED driver IC using a buck converter topology that is capable of driving up to 1.5A of output current. it operates from an input voltage range of current to single LED or a LED string. 3Vdc to 40Vdc and generates a regulated programmable constant output current for high power LEDs. external resistor controlled the maximum output ◈ Features • Operation from 3.0V to 40V input. • Low Standby Current • High efficiency • Output Switch Current to 1.5A • Halogen-Free Package is Available ◈ Application • Automotive and Marine Lighting • High Power LED Driver • Constant Current Source ◈ Pin Assignment & Description (Top View) OSC OUT GND CS VCC Package : TO-252-5L 5 4 3 2 1 Pin 1 2 3 4 5 Symbol VCC CS GND OUT OSC Description Input Voltage Peak Current Sense Pin Ground Output Pin Oscillator Timing pin ◈ Ordering Information Package Type TO-252-5L (1) Device Code, (2) Year & Week Code Device Name SN8500D Marking SN8500---(1) YYWW---(2) KSD-I6T002-000 1 SN8500D ◈ Absolute maximum ratings Characteristic Power Supply Voltage Output Current Thermal Resistance Junction-Ambient Power Dissipation Operating Temperature Range Storage Temperature Range [Ta=25℃] Symbol VCC(MAX) IOUT(MAX) Rth(j-a)* PD* Topr Tstg Rating 40 1.5 96.1 1.3 -40 ~ +85 -55 ~ +150 Unit V A ℃/W W ℃ ℃ * Mounted on a glass epoxy circuit board of 30x30mm Pad dimension of 50mm2 ◈ Recommended operating conditions Characteristic Power Supply Voltage Output Current Dimming Frequency Symbol VCC IOUT FDIM Rating Min 7 - Max 40 1.5 10 Unit V A kHz ◈ Electrical Characteristics (Ta=25℃, unless otherwise noted.) Characteristic Supply Current 1 Supply Current 2 Dropout Voltage Current Sense Voltage Maximum duty cycle Current Sense Off Current OSC ON Voltage OSC OFF Voltage OSC Charge Current OSC Discharge Current Symbol ICC1 ICC2 Vdrop VCS TDC ICS(OFF) VOSC(on) VOSC(off) ICH IDCH Condition VCC=4V, Out=open VCC=40V, Out=open VCC=10V, Iout=1A VCC=10V, Rout=820kΩ VCC=40V, VOSC=1.5V VCC=4V~40V VCC=4V~40V Vcc=5V, VOSC=0.5V Vcc=5V, VOSC=1.5V Min. Typ. Max. Unit 270 1.5 24 140 2.0 2.0 1 300 85 200 35 180 4.0 4.0 1.3 330 1000 0.5 42 260 mA mA V mV % µA V V µA µA KSD-I6T002-000 2 S8500D ◈ Functional block diagram OUT CS + 0.3V VCC CONTROL Driver OSC OSC SN8500 GND ◈ Typical Application L CS RSENSE OUT Supply Voltage 7~40V SN8500 VCC DF Power LED OSC CIN GND + CT KSD-I6T002-000 3 SN8500D ◈ Application Information 1) Input Capacitor The input capacitor (CIN) reduces the ripple of the input current drawn from the input supply and reduces noise injection into the IC. The reflected ripple voltage will be smaller when an input capacitor with larger capacitance is used. The capacitors should be placed close to the VCC and GND. 2) Current-Sense Resistor The snese resistor Rsense can be obtained as follows Rsense = 300mV / (IAVG + 0.5 x IRIPPLE) Thus target average LED current 700mA and ripple current 100mA then the result Rsense= 300mV/ (700mA + 0.5 x 100mA) = 0.4Ω When selecting the sense resistor, low–inductance resistors, such as surface–mount metal film resistors, are preferred. 3) Output inductor The value of the inductor is not fixed and can be adjusted freely in order to make tradeoffs among size, cost, and efficiency. Although lower inductor values will minimize size and cost, they will also reduce efficiency due to higher peak currents. On the other hand, higher inductor values will increase efficiency, but at some point the resistive losses due to the extra turns of wire will exceed the benefit gained from lower AC current levels. Also, high inductor values can affect the load–transient response of the converter. 4) Freewheeling diode The schottky barrier diode SDB30A40(40V, 3A) was recommended for freewheeling diode KSD-I6T002-000 4 SN8500D ◈ Application Guide L=220uH CS RSENSE OUT Supply Voltage 7~40V SN8500 VCC OSC DF (SDB30A40) Power LED x n CIN=47uF GND + CT=470pF L=220uH CS RSENSE OUT Supply Voltage 7~40V SN8500 VCC OSC DF (SDB30A40) Power LED x n CIN=47uF GND + CT=470pF KSD-I6T002-000 5 SN8500D ◈ Application Guide L=220uH CS RSENSE Supply Voltage 7~40V OUT SN8500 VCC Power LED ENABLE SDS511 OSC GND + CT=470pF CIN=47uF DF (SDB30A40) IPK SDB30A40 Supply Voltage 12Vac RSENSE OUT SN8500 VCC DF (SDB30A40) CIN=47uF L=220uH + CT GND CT=470pF Power LED (MR16) KSD-I6T002-000 6 SN8500D ◈ Electrical Characteristic Curves Fig.1 VCS vs TA Current Sense Voltage Change – VCS [%] 20 16 12 8 4 0 -4 -8 -12 -16 -20 -50 -25 0 25 50 75 5 V C C =10V Fig.2 ICC vs TA Supply Current – ICC [mA] 4 3 2 1 0 V C C =5V 100 125 150 -50 -25 0 25 50 75 100 125 150 Ambient Temperature - TA [℃] Ambient Temperature - TA [℃] Fig.3 Dropout Voltage vs TA Fig.4 LED Current vs PWM Duty 350 3.0 Dropout Voltage- VDROP[V] LED Current- ILED[mA] 2.5 2.0 1.5 1.0 0.5 0.0 -50 -25 0 25 50 75 V C C =10V I O U T =1A 300 250 200 150 100 50 0 Vc c =1 5 V fD I M =1 KH z CT=4 7 0 pF L= 2 2 0 u H R s = 0 .9 9 Ω 100 125 150 0 20 40 60 80 100 Ambient Temperature - TA [℃] PWM Duty Cycle [%] KSD-I6T002-000 7 SN8500D ◈ Electrical Characteristic Curves Fig.5 Start-up Waveform VCC=15V Ch1► Ch1► Fig.6 Normal Operating Waveform VCC=15V Ch2► Ch3► Ch4► Ch1 : OSC, 2V/Div Ch2 : IIN, 80mA/Div Ch3 : VOUT, 10V/Div Ch4 : IOUT, 200mA/Div Ch2► Ch3► Ch4► Ch1 : OSC, 2V/Div Ch2 : IIN, 50mA/Div Ch3 : VOUT, 10V/Div Ch4 : IOUT, 200mA/Div Fig.7 Dimming Waveform fosc=100Hz Ch1► Ch2► Ch3► Ch4► Ch1 : OSC, 5V/Div Ch2 : IIN, 80mA/Div Ch3 : VLED, 3V/Div Ch4 : ILED, 200mA/Div KSD-I6T002-000 8 SN8500D ◈ TO-252-5L Outline Dimension (Unit : mm) θ θ ※ Recommend PCB solder land 5.60 [Unit: mm] 11.00 5.60 2.00 1.27 0.60 KSD-I6T002-000 7.20 9 SN8500D The AUK Corp. products are intended for the use as components in general electronic equipment (Office and communication equipment, measuring equipment, home appliance, etc.). Please make sure that you consult with us before you use these AUK Corp. products in equipments which require high quality and / or reliability, and in equipments which could have major impact to the welfare of human life(atomic energy control, airplane, spaceship, transportation, combustion control, all types of safety device, etc.). AUK Corp. cannot accept liability to any damage which may occur in case these AUK Corp. products were used in the mentioned equipments without prior consultation with AUK Corp.. Specifications mentioned in this publication are subject to change without notice. KSD-I6T002-000 10