LD6801 LEADTREND | Alldatasheet
Document overview
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Technical content
Features
Controller for adaptive 100Hz/120Hz current ripple remover Built-in Zener diode for input voltage clamping 10V Output Voltage for MOSFET control Programmable amplitude of LED current ripple Programmable maximum cathode voltage of LED Programmable maximum LED current Output Short protection Over temperature protection SOT23-6L Package
Applications
LED Driver Application for Non-Ripple Current LED lighting Typical Application LD6801 OUT OVP OCP GND REF VIN ROVP CREF RIN CIN LED Lighting Driver RKROCP Q1Rg Cf
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016 Pin Configuration SOT-26 (TOP VIEW) YY, Y : Year code (D: 2004, E: 2005…..) WW, W : Week code PP : Production code I01 : LD6801 1 2 3 4 5 6 VIN GND REF OVP OUT OCP YWI 01 pp
Ordering Information
Part number Package Top Mark Shipping LD6801 GL SOT-26 LD6801 GL 3000 /tape & reel The LD6801 is ROHS compliant/Green packaged. Protection Mode LED Short Protection LED Open Protection Internal OTP Auto recovery Auto recovery Auto recovery Pin Descriptions Pin NAME FUNCTION
1 VIN
Power Supply for the device. Internal Zener Clamp for wide range LED light bar voltage. Connecting a RIN to LED anode for current limit and a capacitor to GND for filter out noise
2 GND Ground
3 REF
LED Reference Voltage, It’s essential to connect REF pin with a SMD ceramic capacitor to filter the 100/120Hz ripple. 4 OCP LED current feedback and maximum LED current limit. 5 OUT This pin connects the MOSFET gate to regulate LED current ripple.
6 OVP Over voltage Protection for Short LED protection
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016 Block Diagram OUT UVLO On/Off UVLO Comparator internal bias & Vref All Block VIN GND OVP REF LED Short LED Open LED SP LED OP OCP Fault Signal Fault Table OTP K gm
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016 Absolute Maximum Ratings VIN, OVP -0.3V ~ 30V OCP, OUT -0.3V ~ 18V REF -0.3V ~ 6V Maximum Junction Temperature 150C Storage Temperature Range -65C ~ 150C VIN Clamp Zener maximum current 2.4mA Package Thermal Resistance (SOT-26, JA) 200C/W Power Dissipation (SOT-26, Tj=125oC, Ta=85C) 200mW Lead temperature (Soldering, 10sec) 260C ESD Voltage Protection, Human Body Model 2.5KV ESD Voltage Protection, Machine Model 250 V Caution: Stress exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stress above Recommended Operating Conditions may affect device reliability. Recommended Operating Conditions Item Min. Max. Unit Operating Junction Temperature -40 125 C VIN Operation Range 10 30 V VIN Sink Current 0.5 2 mA VIN pin Filter Capacitor 22 220 nF REF pin Capacitor to GND 0.1 1 F Note: 1. It’s essential to connect VCC pin with a SMD ceramic capacitor (22nF~220nF) to filter out the undesired switching noise for stable operation. This capacitor should be placed close to IC pin as possible 2. The input resistor is limit VIN sink current under 2mA. 3. The REF pin capacitor should be placed close to IC pin as possible.
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016
Electrical Characteristics
(VIN=18V, TA = 25C unless otherwise specified.) PARAMETER CONDITIONS SYMBOL MIN TYP MAX UNITS Supply Voltage (VIN Pin) VIN Clamp Voltage * IIN_CLAMP=2mA; VIN_CLAMP 29 33 V Operating Current IVIN 500 A UVLO(OFF) VUV_OFF 7 8 9 V UVLO(ON) VUV_ON 15.5 16.5 17.5 V Gate Drive Output (OUT Pin) Maximum Output voltage VOUT 10 11 13 V LED REFERENCE FILTER (REF Pin) VREF Clamp Voltage Start Up and Protection mode VREF_CLAMP 3.2 3.6 3.9 V VREF Maximum operation Voltage Normal operation mode VREF_MAX 2.8 3 3.2 V LED Reference Voltage to LED Current rate Over Voltage Protection (OVP pin) OVP Pin Clamp Voltage VOVP_CLAMP 4 V Short LED Protection Sink Current IOVP 35 40 45 A Short LED Protection Delay Time * TON_SHORT 150 S Short LED Protection Reset Time * TOFF_SHORT 40 mS LED Open Protection Threshold Voltage VOVP_LOW 100 mV Internal OTP OTP Trip level * 110 130 150 C OTP Hysteresis * 30 C *: Guaranteed by Design.
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016 Typical Performance Characteristics IVIN (uA) Temperature (C) Fig. 1 IVIN vs. Temperature -40 0 40 80 120 125 250 300 350 400 450 200 VUV_ON (V) Temperature (C) Fig. 2 VUV_ON vs. Temperature -40 0 40 80 120 125 15.6 15.8 16.0 16.2 16.4 16.6 VUV_OFF (V) Temperature (C) Fig. 3 VUV_OFF vs. Temperature 8.1 8.5 8.7 9.1 8.3 -40 0 40 80 120 125 8.9 VREF_CLAMP (V) Fig. 4 VREF_CLAMP vs. Temperature Temperature (C) 3.1 3.3 3.5 3.7 3.9 4.1 -40 0 40 80 120 125 IOVP (uA) Temperature (C) Fig. 5 IOVP vs. Temperature -40 0 40 80 120 125 Fig. 6 VLED=36V,ILED=1000mA,W/O LD6801 ILED_AC Vout
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016 Fig. 7 VLED=36V,ILED=1000mA,With LD6801 ILED_AC Vout Fig. 8 Power On @ 90VAC,With LD6801 ILED VAC Fig. 9 LED Open Protection ILED Vout VREF Fig. 10 LED Short Protection ILED Vout VCC_PS VGATE_PS
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016
Application Information
LD6801 is an external MOSFET controller for LED lighting current ripple eliminated. The REF pin connection a filter capacitor to GND to suppressor the 100/120Hz LED current ripple. In the start -up process, the LD6801 charges the REF capacitor quickly to avoid LED voltage overshoot this time. And the device provide adjustable short LED string protection, LED string open protection and programmable over current limiting. Theory of Operation The LED light bar and LD6801 are both supplied by an AC/DC current source. The drain of external MOSFET is connected to the cathode of LED light bar . A sensing resistor R OCP is connected between the source of MOSFET and GND. The gate is connected to the OUT pin of LD6801. The LD6801 detects the OVP pin and OCP pin voltage to adjust CREF Voltage and control the external MOSFET operate in saturation region. When external MOSFET working in the saturation region, the LED current ripple transfer to LED voltage on MOSFET. If the drain Voltage of external MOSFET break away saturation region, the LED current ripple suppressor will invalid naturally. Reference Voltage to LED Current Ratio and LED Current Limit There is K value ratio of the LED current and V REF voltage. It provides stable voltage to let MOSFET be working in saturation Region and suppress LED current 100~120Hz ripple. The following table is the K value ratio setting. RK parameter (Ω) K value ratio (VREF/VOCP) < 1k 10 45~58k 13 > 75k 16 The over current protection is regulation the LED current to limit threshold. The VREF operation voltage is limited to 3V on REF pin. So that the LED limit current threshold is VOCP = ILED * ROCP = VREF / K The suggestion for normal LED operation current is 0.4~0.8 times LED limit current threshold. It avoids the larger LED current ripple to trigger over current limit protection or produce MOSFET thermal issue. LED String Open Protection When OVP pin voltage and REF Voltage is under 0.2V. The LD6801 would be go to LED open stage and OUT pin and VREF voltage pull high until the LED string reply connection. LED string Short Protection Fig. 11 is the function block of LED short protection. If OVP pin voltage larger than 4V and in condition of IOVP > 40uA and continuous 150uS around, the LD6801 would be turn off MOSFET until 40mS around. Then, the Over voltage protection state is reset. The programed over voltage protection calculated as below: VOVP_TH = 4V + (ROVP * 40A)
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016 Fig. 11 VIN Zener Clamp and RIN Selection The LD6801 support wide range LED light bar application that integrated Zener diode which is about 2mA sink current and V UV_ON is to 16V. S o the value of RIN that is connected between V LED and VIN of LD6801, we can be calculated as below: (VLED_MIN –VUV_ON) / 0.5mA > RIN And RIN > (VLED_MAX – VIN_CLAMP) / 2mA Where VLED is a terminal voltage of LED light bar Internal Thermal protection Thermal protection limits total power dissipation in this device. When the junction temperature reaches 1 30C approximately, The LD6801 would be turn off the MOSFET until the IC’s junction temperature cool s down approximately 30°C. PCB Design Guideline 1. The bypass capacitor of VIN should be placed as close as possible to the VIN and GND pin of IC. 2. LD6801 should be placed near to the external MOSFET 3. To consider temperature requirement, we need add PCB pad or heat sink be to fit system spec. 4. The area of LED current loop should be as small as possible Over Voltage 40uA IOVP OVP ROVP VOUT 4V ILED
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016
Package Information
Dimension in Millimeters Dimensions in Inches Min Max Min Max A 2.692 3.099 0.106 0.122 B 1.397 1.803 0.055 0.071 D 0.300 0.500 0.012 0.020 F 0.95 TYP 0.037 TYP H 0.080 0.254 0.003 0.010 I 0.050 0.150 0.002 0.006 J 2.600 3.000 0.102 0.118 M 0.300 0.600 0.012 0.024 Θ 0° 10° 0° 10° Important Notice Leadtrend Technology Corp. reserves the right to make changes or corrections to its products at any time without notice. Customers should verify the datasheets are current and complete before placing order
Leadtrend Technology Corporation www.leadtrend.com.tw LD6801-DS-00 July 2016
Revision History
REV. Date Change Notice 00 07/28/2016 Original Specification.