KTD3112 KINETIC | Alldatasheet
Document overview
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Technical content
Features
Drive up to 6 LEDs per string KTD3112: 2 strings, 12 LEDs total KTD3113: 3 strings, 18 LEDs total High efficiency: up to 90% High frequency step-up converter (800kHz) Wide input range: 2.7V to 5.5V Integrated 30V Power MOSFET Internal compensation and soft start Integrated 2- or 3-channel current sink Preset max. 20mA/25mA current per channel 1.5% Typ. current matching PWM dimming with < 0.3µs rise/fall time Low quiescent current LED open/short protection 25V LED open-circuit (OVP) threshold Cycle-by-cycle inductor current limit < 1µA shutdown current Pb-free Packages: TQFN33-16, WLCSP-9 1.2mm x 1.2mm -40°C to +85°C Temperature Range
Applications
Smartphone PDA GPS Portable media players Other 1-cell Li Ion LED applications Brief Description KTD3112/KTD3113 is the ideal power solution for white LED backlighting used with medium to small size LCD panels. It is a highly integrated step up DC-DC converter with input voltage range from 2.7V to 5.5V, accommodating 1-cell lithium ion battery or 5V regulated supply. KTD3112/3 integrates a 30V Power MOSFET as well as compensation and soft start circuitry, which results in a simpler and smaller solution with much fewer external components. High switching frequency ( 800kHz) allows the use of a smaller sized inductor and capacitor. Two regulated current sinks in KTD3112 and three sinks in KTD3113 provide per channel 20mA/25mA (max.) factory programmed current . With a 25V OVP, each string can connect up to six LEDs in series, for a total of 12 or 18 LEDs in KTD3112 and KTD3113 respectively. A PWM dimming control is included for wide output dimming range. The device has an EN pin which enables the IC. Various protection features are built into KTD3112/3, including cycle -by-cycle input current limit protection, output over -voltage protection, LED fault ( open or short) protection and thermal shutdown protection. The leakage current in shutdown mode is less than 1µA. KTD3112/3 is available in a RoHS compliant and Green 16-lead 3mm x 3mm x 0.75mm ThinQFN or 9-lead 1.2mm x 1.2mm WLCSP package. Typical Application VIN LX Up to 6 in series VIN 2.7V to 5.5V ENEnable PWM GND PGNDMC CIN COUT L White LEDs PWM Dimming Control S3* *S3 output available on KTD3113 only KTD3112/3 10µH 1µF10µF CVIN 1µF High Efficiency Boost 2P6S/3P6S LED Driver
October 2015 – Revision 04a Page 2 Company Confidential Pin Descriptions Pin # Name Function KTD3112 KTD3113 TQFN33-16 WLCSP-9 TQFN33-16 WLCSP-9 1, 2 B1 1, 2 B1 LX Switching node of the step-up converter
3 A2 3 A2 PWM
Pulse width controlled dimming input. Connect this pin to VIN when not used. There is an internal 400kΩ pull-down resistor at this pin. 4, 5, 8, 11, 12, 13 C3 4, 5, 11, 12, 13 C3 NC Not internally connected 6 A1 6 A1 EN IC enable pin. There is an internal 400kΩ pull- down resistor at this pin. 7 B2, C1 7 C1 GND Analog Ground pin. All GND pins must be connected in the PCB for proper operation. N/A N/A 8 B2 S3 Regulated output current sink #3
9 B3 9 B3 S2 Regulated output current sink #2
10 A3 10 A3 S1 Regulated output current sink #1
14 C2 14 C2 VIN Input supply pin for the IC
15, 16 N/A 15, 16 N/A PGND Power Ground pin MC MC Metal chassis. Connect to ground for electrical and thermal usage. MC is internally connected to Analog Ground pin. KTD3112 TQFN33-16 - Top View KTD3113 TQFN33-16 - Top View KTD3112 WLCSP-9, 1.2mm x 1.2mm - Top View KTD3113 WLCSP-9, 1.2mm x 1.2mm - Top View 121 112 103 LX LX PWM NC NC 94NC S2 MC
16 PGND
A B C PWMEN S1 GNDLX S2 VINGND NC 1 2 3 A B C PWMEN S1 S3LX S2 VINGND NC
October 2015 – Revision 04a Page 3 Company Confidential Absolute Maximum Ratings1 (TA = 25C unless otherwise noted) Symbol Description Value Units VIN Input voltage -0.3 to 6 V LX High voltage node -0.3 to 30 V Sx High voltage node -0.3 to 22 V EN, PWM Control pins -0.3 to VIN+0.3 V TJ Operating Temperature Range -40 to 150 C Ts Storage Temperature Range -65 to 150 C TLEAD Maximum Soldering Temperature (at leads, 10 sec) 300 C Thermal Capabilities Symbol Description Value Units TQFN33-16 θJA Thermal Resistance – Junction to Ambient2 50 C/W PD Maximum Power Dissipation at TA ≤ 25C 2.0 W ΔPD/ΔT Derating Factor Above TA = 25C -20 mW/C WLCSP-9 θJA Thermal Resistance – Junction to Ambient2 100 C/W PD Maximum Power Dissipation at TA = 25C 1.1 W ΔPD/ΔT Derating Factor Above TA = 25C -10.0 mW/C
Ordering Information
Max. Sink Current (nominal) Marking3 Operating Temperature Package KTD3112EFJ-20-TR 20mA FZYYZ -40°C to +85°C TQFN33-16 KTD3112EFJ-25-TR 25mA FHYYZ -40°C to +85°C TQFN33-16 KTD3112EAA-20-TR 20mA FZYYZ -40°C to +85°C WLCSP-9 1.2x1.2mm KTD3112EAA-25-TR 25mA FHYYZ -40°C to +85°C WLCSP-9 1.2x1.2mm KTD3113EFJ-20-TR 20mA GDYYZ -40°C to +85°C TQFN33-16 KTD3113EAA-20-TR 20mA GDYYZ -40°C to +85°C WLCSP-9 1.2x1.2mm 1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum rating should be applied at any one time. 2. Junction to Ambient thermal resistance is highly dependent on PCB layout. Values are based on thermal properties of the device when soldered to an EV board. 3. “YYZ” is the date code and assembly code.
October 2015 – Revision 04a Page 4 Company Confidential Electrical Characteristics4 Unless otherwise noted , t he Min and Max specs are applied over the full operation temp erature range of –40°C to +85°C, while Typ values are specified at room temperature (25C). VIN = 3.6V, Symbol Description Conditions Min Typ Max Units IC Supply VIN Input operating range 2.7 5.5 V UVLO Input under voltage lockout Rising edge 2.5 2.65 V UVLOHYST UVLO hysteresis 0.15 V IQ IC standby current Not switching 0.65 mA IC operating current Switching 1.5 mA ISHDN VIN pin shutdown current EN = GND 1.0 A Step-Up Converter RDS(ON) NMOS on-resistance 0.35 Ω ILIM Peak NMOS current limit 1.5 A IINRUSH-SU Peak Inductor Current During Startup KTD3112, VIN = 3.6V, 2p6s LEDs, ILED = 25mA, L = 10µH, COUT = 1µF 700 mA FSW Oscillator frequency 800 kHz Dmax Maximum duty cycle 92 95 % OVP Over voltage threshold Measured at LX pin 25 V Current Sink ID Output current accuracy Current setting = 20mA/25mA, (Duty Cycle 100%) ±2 % Output current matching5 Current setting = 20mA/25mA, (Duty Cycle 100%) 1.5 % V_sov Current sink over voltage threshold 6.7 V TFAULT Current sink Fault Delay 80 ms Control VTH-L EN, PWM pin logic low threshold 0.4 V VTH-H EN, PWM pin logic high threshold 1.4 V REN EN pin pull-down resistor 400 kΩ RPWM PWM pin pull-down resistor 400 kΩ FPWM PWM dimming frequency 100 30000 Hz tPWM(ON) PWM dimming on-time 0.5 s TJ-TH IC junction thermal shutdown threshold 150 C IC junction thermal shutdown hysteresis 15 C 4. KTD3112/3 is guaranteed to meet performance specifications over the –40°C to +85°C operating temperature range by design, characterization and correlation with statistical process controls. 5. The current matching between channels is defined as |Id-Iavg|max/Iavg.
October 2015 – Revision 04a Page 5 Company Confidential Typical Characteristics VIN = 3.6V, L = 10H, CIN = 10F, CVIN = 1F, COUT = 1F with 2P6S LEDs in series at 25mA, TAMB = 25°C unless otherwise specified. Efficiency vs. Input Voltage Efficiency vs. LED Current Operating Current (non-switching) Operating Current (switching) Switching Frequency EN Logic Threshold Voltage Efficiency (%) Input Voltage (V) 20mA 25mA 100 0 10 20 30 40 50 Efficiency (%) LED Current (mA) 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Quiescent Current (mA) Input Voltage (V) 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Quiescent Current (mA) Input Voltage (V) 650 700 750 800 850 900 950 Frequency (KHz) Input Voltage (V) 0.6 0.7 0.8 0.9 1.0 1.1 Vth (V) Input Voltage (V) Vth-high Vth-low
October 2015 – Revision 04a Page 6 Company Confidential Typical Characteristics (continued) VIN = 3.6V, L = 10H, CIN = 10F, CVIN = 1F, COUT = 1F with 2P6S LEDs in series at 25mA, TAMB = 25°C unless otherwise noted. Soft-Start Turn On Turn Off Steady State Switching Turn On with LED Open (OVP) PWM Dimming at 20kHz 100 0 25 50 75 100 LED Current Ratio (%) PWM Duty Cycle (%) LED Current 20mA / div EN VOUT 10V / div Inductor Current 200mA / div 200µs / div LED Current 20mA / div EN 200µs / div VOUT 10V / div EN VOUT 10V / div Input Current 200mA / div 500µs / div
October 2015 – Revision 04a Page 7 Company Confidential Typical Characteristics (continued) VIN = 3.6V, L = 10H, CIN = 10F, COUT = 1F with 2P6S LEDs in series at 25mA, TAMB = 25°C unless otherwise specified. PWM Dimming at 200Hz PWM Dimming at 20kHz PWM PWM
October 2015 – Revision 04a Page 8 Company Confidential Functional Block Diagram Functional Description The KTD3112/KTD3113 are current regulated step-up (boost) converter s which respectively can drive two or three strings of LEDs. Unused channels, if any, need to be connected to ground (GND). The voltage step-up is accomplished by a boost topology, using an inductor-based DC-DC switching converter, in which the inductor serves as an energy storage device in the system. By integrating a high voltage optimized MOSFET, KTD3112/3 internal switching frequency is 800kHz while still maintaining high power efficiency. Unlike a tradition al DC-DC boost converter with a fixed output voltage , KTD3112/3 dynamically changes its output voltage regulation parameters depending on the load . The use of u nique control schemes maintains accurate current regulation in each of the current sinks while leaving the output voltage at a minimum, increasing the overall conversion efficiency. The internal step-up converter dynamically controls the voltage at the output high enough to drive the LED string with the highest total forward voltage. PWM pulses provided at PWM pin program the sink’s on and off, so that the average LED current is proportional to the PWM duty cycle. Asserting a logic high on EN pin turns e ach output sink on to maximum LED current . LED dimming is based on the popular PWM dimming scheme which is supported via the PWM pin. VIN PWM brightness control Over voltage protection Converter control Voltage Optimizing control Logic Backlight Unit Constant Current control LX VIN EN PWM GND PGND UVLO Up to 6 LEDs in series S3* *S3 output available on KTD3113 only Enable
October 2015 – Revision 04a Page 9 Company Confidential
Application Information
Current Dimming using PWM Pin KTD3112/3 allows maximum flexibility with a PWM signal control input which can be used for dimming. The IC must remain Enabled at EN pin during PWM dimming. Each LED channel can typically recover from no current within 0.3s. This allows very short PWM on-time or a duty-cycle with fine resolution. Assume a 50s minimum on-time for a 100Hz PWM signal, a 200:1 ratio can be achieved by PWM . In order to guarantee a soft -start during start-up, the EN input should always transition from low to high during power-up. If the EN input is kept high while PWM operates in burst mode, the soft -start is no longer supported resulting in some inrush current during subsequent power-ups. Fault Protection Each current sink is protected against LED short or open conditions. If an LED short circuit condition arises, the current sink continues to regulate until V SINK > VSOV. When any sink node voltage goes above VSOV (6.7V) for more than 80ms (while PWM dimming signal remains high), that channel’s current sin k will be turned off , and other channels will still work if they don’t trigger this fault condition. For example, if one or more LEDs on a channel are shorted, that channel’s sink voltage will increase. If the voltage goes above 6.7V for more than 80ms, the Current Sink Fault Protection will be triggered and only this faulty string will be disabled by shutting off this current sink. All other channels will continue normal operation if they don’t have a fault condition . When PWM dimming control is used, the 80ms fault delay is accumulated only when PWM signal is high; the PWM low time is not counted into the fault delay , so the delay time will be 80ms/DPWM (DPWM is the duty cycle of the PWM signal). In case of an LED failing open, the current sink voltage of the failed string will go close to ground and dominate the boost converter control loop. As a result the output voltage will move up to the over -voltage threshold. KTD3112/3 uses LX pin to sense the output over voltage. Once the over-voltage incident is flagged internally, the faulty channel(s) will be disabled. Then the output voltage of the boost converter will go back to normal level. During the entire process, the rest of the LED strings (healthy LED strings) would continue normal operation. The fault conditions are reset by toggling EN pin or power on reset. Thermal Shutdown Thermal shutdown feature is included in the KTD3112/3. When the IC’s junction temperature (TJ) reaches 150C, the IC will immediately enter shutdown mode. Once T J drops 15C to approximately 135C, the IC will resume normal operation. Inductor Selection A 10µH inductor is recommended for all application s. If high efficiency is a critical requirement, a low DCR inductor should be selected. The inductor’s saturation current rating should also exceed the peak input current. Table 1. Recommended Inductors
Table 2. Recommended Ceramic Capacitor Vendors Using a Schottky diode is recommended because of its low forward voltage drop and fast reverse recovery time. rating should also exceed the OVP value. Schottky diodes with 30V voltage rating (or higher) are recommended. Table 3. Recommended Schottky Diodes
October 2015 – Revision 04a Page 12 Company Confidential Packaging Information TQFN33-16 Recommended Footprint D E Pin 1 Dot By Marking 912 Detail “A” L 129 Detail “B” b e Detail “B” S C A1 A2 A Detail “A” R 0.3 (4x) max Round Corner Pin 1 Identification Top View Bottom View Side View 0.50 0.8 0.8 0.23 1.7 1.7 2.1 2.1 0.23 0.50 * Dimensions are in millimeters. Dimension mm Min. Typ. Max. A 0.65 0.75 0.85 A1 0.000 0.025 0.050 A2 0.154 0.203 0.280 b 0.18 0.23 0.30 C 0.3REF D 2.95 3.00 3.05 D1 1.7REF E 2.95 3.00 3.05 E1 1.7REF e 0.45 0.50 0.55 L 0.30 0.40 0.50 S 0.25REF
October 2015 – Revision 04a Page 13 Company Confidential WLCSP-9 1.2mm x 1.2mm Recommended Footprint Kinetic Technologies cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Kinetic Technologies product. No intellectual property or circuit patent licenses are implied. Kinetic Technologies reserves the right to change the circuitry and specifications without notice at any time. 1.2mm 0.62+/-0.035mm 2 X 0.40mm A1 Corner Top Side Die Coating 1.2mm
9 X Ø
0.25+/-0.025mm 0.025mm 2 X 0.40mm Top View Side View Bottom View WLCSP Landing * Dimensions are in millimeters. 0.40mm 0.40mm 0.21mm Copper Pad Diameter (NSMD Pad Type) 0.31mm Solder Mask Opening 0.80mm 0.80mm