ZXLD1370 60V HIGH ACCURACY BUCK/BOOST/BUCK-BOOST LED DRIVER-CONTROLLER Description Pin Assignments The ZXLD1370 is an LED driver controller IC for driving external TSSOP-16EP MOSFETs to drive high current LEDs. It is a multi-topology controller that efficiently controls the current through series connected LEDs. The multi-topology enables it to operate in buck, boost and buck- boost configurations. The 60V capability, coupled with its multi-topology capability, enables it to be used in a wide range of applications and drive in excess of 15 LEDs in series. The ZXLD1370 is a modified hysteretic controller using a patent pending control scheme providing high output current accuracy in all Typical Applications Circuit three modes of operation. High accuracy dimming is achieved through DC control and high frequency PWM control. VIN 8V to 18V I LED = 1A The ZXLD1370 uses two pins for fault diagnosis. A flag output R1 highlights a fault, while the multi-level status pin gives further 0R1 LED 1 L1 to 4 information on the exact fault. 33m H VAUX VIN ISM C1 PWM 4.7F GI SD1 Features PSD3100 COUT ADJ GATE 4.7F Q1 0.5% Typical Output Current Accuracy RGI2 REF FLAG 62k DMN6068LK3 6V to 60V Operating Voltage Range R4 TADJ STATUS LED Driver Supports Buck, Boost and Buck-Boost RGI1 2k SHP SGND PGND 51k U1 Configurations ZXLD1370 C2 Wide Dynamic Range Dimming TH1 100pF 10k 20:1 DC Dimming GND Thermally connected 1000:1 Dimming Range at 500Hz Up to 1MHz Switching High Temperature Control of LED Current Using TADJ Buck-Boost Diagram Utilizing Thermistor and TADJ Available in Automotive Grade with AEC-Q100 and TS16949 Certification ILED Available in Green Molding Compound (No Br, Sb) with Lead REF Rth Free Finish/ RoHS Compliant 100% Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) An Automotive-Compliant Part is Available Under Separate TADJ TH1 Data Sheet (ZXLD1370Q) 10% 70C 85C TLED Thermal network response in Buck configuration with: Rth = 2k and TH1=10k (beta =3900) Curve Showing LED Current vs. T LED Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See ZXLD1370 Pin Descriptions Type Pin Name Pin Function (Note 4) Adjust Input (for DC Output Current Control) Connect to REF to set 100% output current. ADJ 1 I Drive with dc voltage (125mV<V < 2.5V) to adjust output current from 10% to 200% of set value. ADJ The ADJ pin has an internal clamp that limits the internal node to less than 3V. This provides some failsafe should they get overdriven. REF 2 O Internal 1.25V Reference Voltage Output Temperature Adjust Input for LED Thermal Current Control Connect thermistor/resistor network to this pin to reduce output current above a preset temperature TADJ 3 I threshold. Connect to REF to disable thermal compensation function (see section on Thermal Control). Shaping Capacitor for Feedback Control Loop SHP 4 I/O Connect 100pF 20% capacitor from this pin to ground to provide loop compensation. Operation Status Output (Analog Output) Pin is at 4.5V (nominal) during normal operation. STATUS 5 O Pin switches to a lower voltage to indicate specific operation warnings or fault conditions (see section on STATUS output). Status pin voltage is low during shutdown mode. SGND 6 P Signal Ground - Connect to 0V PGND 7 P Power Ground - Connect to 0V and pin 8 to maximize copper area. Not Connected Internally recommend connection to pin 7, (PGND), to maximize PCB copper for N/C 8 thermal dissipation. Not Connected Internally recommend connection pin 10 (GATE) to permit wide copper trace to gate N/C 9 of MOSFET. GATE 10 O Gate Drive Output to External NMOS Transistor connect to pin 9 Auxiliary Positive Supply to Internal Switch Gate Driver Connect to V , or auxiliary supply from 6V to 15V supply to reduce internal power dissipation (refer to IN V 11 P AUX Application Section for more details). Decouple to ground with capacitor close to device (refer to Applications section). Input Supply to Device (6V to 60V) V 12 P IN Decouple to ground with capacitor close to device (refer to Applications section). Current Monitor Input ISM 13 I Connect current sense resistor between this pin and V . IN The nominal voltage across the resistor is 225mV. Flag Open Drain Output FLAG 14 O Pin is high impedance during normal operation. Pin switches low to indicate a fault, or warning condition. Digital PWM Output Current Control Pin is driven either by open drain or push-pull, 3.3V or 5V logic levels. PWM 15 I Drive with frequency higher than 100Hz to gate output on and off during dimming control. The device enters standby mode when PWM pin is driven with logic low level for more than 15ms nominal (refer to Application Section for more details). Gain Setting Input Used to set the device in Buck mode, Boost or Buck-Boost modes. Connect to ADJ in Buck mode operation. GI 16 I For Boost and Buck-Boost modes, connect to resistive divider from ADJ to SGND. This defines the ratio of switch current to LED current (see Application Section). The GI pin has an internal clamp that limits the internal node to less than 3V. This provides some failsafe should they get overdriven. EP PAD P Exposed Paddle Connect to 0V plane for electrical and thermal management. Note: 4. Type refers to whether or not pin is an Input, Output, Input/Output or Power Supply pin. 2 of 39 ZXLD1370 February 2017 Diodes Incorporated www.diodes.com Document number: DS32165 Rev. 7 - 2