NJW4615AF1-TE1

NJW4615A Constant Current LED Driver with PWM Dimming Control ■ GENERAL DESCRIPTION The NJW4615A is a constant current LED driver with PWM dimming control. The output current can be set by external sensing resister, and the NJW4615A can set up to 100mA. Because the withstand voltage of the output (LED) pin is 35V, it can series-connect the LED depending on forward voltage of the LED. The LED dimming control can be regulated via PWM duty cycle. It is suitable for back light, light source and so on. ■ PACKAGE OUTLINE NJW4615AF1 (SOT-23-6-1) ■ FEATURES ▪ Supply Voltage Range 2.5V to 35V ▪ Output Voltage VLED = 35V max. ▪ Output Current ILED = 5mA to 100mA ▪ Output Current Accuracy 1.2% ▪ To 10 of White LED can be operated. (at LED Vf=3.2V) ▪ Quiescent Current 370µA max. ▪ PWM Dimming Control ▪ Enable Function ▪ Over Current Protection (with Hysteresis) ▪ Thermal Shutdown Protection ▪ LED Short Protection ▪ Package SOT-23-6-1 ■ BLOCK DIAGRAM VDD LED VREF ( 0.2V ) RS Current Limit Thermal Shut Down LED Short Protection GND Ver.2017-06-14 Control Logic EN PWM -1- NJW4615A ■ PIN CONFIGURATION PWM 1 6 VDD GND 2 5 EN RS 3 4 LED ■ PIN DESCRIPTIONS Pin No. Pin Name I/O 1 PWM I 2 GND - 3 RS O 4 LED O 5 EN I 6 VDD - -2- Function PWM signal input pin for dimming control. The LED dimming control can be regulated by PWM duty cycle. When this pin is open or input High level, ILED becomes set current by an external resistor (RS). Ground pin Resistor connect pin of ILED setting. The LED current can be set with connected resistor (RS) between RS pin and GND pin. RS [Ω] = 0.2 [V] / ILED [A] Constant current circuit output pin Connect cathode pin of LED. Standby control pin Normal operation: High Level. Standby mode: Low Level. Power supply pin Ver.2017-06-14 NJW4615A ■ ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL Supply Voltage VDD Output Voltage VLED EN Pin Voltage VEN PWM Pin Voltage VPWM Power Dissipation PD Junction Temperature Range Operating Temperature Range Storage Temperature Range Tj Topr Tstg RATINGS -0.3 to +40 -0.3 to +40 -0.3 to +40 -0.3 to +6 510 (*1) 710 (*2) -40 to +150 -40 to +125 -50 to +150 (Ta=25 C) UNIT V V V V mW C C C (*1) Mounted on glass epoxy board based on EIA/JEDEC. (76.2 × 114.3 × 1.6mm: 2Layers FR-4) (*2) Mounted on glass epoxy board based on EIA/JEDEC. (76.2 × 114.3 × 1.6mm: 4Layers FR-4), Internal Cu area: 74.2 × 74.2mm ■ RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL Supply Voltage VDD Output Current ILED Output Voltage VLED TEST CONDITIONS MIN. 2.5 5 - TYP. - MAX. 35 100 35 UNIT V mA V ■ ELECTRICAL CHARACTERISTICS (Unless otherwise noted, VDD= VEN=12V, VLED=1V, RS=10Ω, VPWM=OPEN, Ta=25 C) PARAMETER SYMBOL TEST CONDITIONS MIN. TYP. MAX. UNIT Quiescent Current IDD 260 370 µA Quiescent Current at OFF State IDD_OFF VEN = GND 0.1 µA Output Current Accuracy -1.2 +1.2 % ILED Output (LED) Pin ILEAK1 VEN = GND, VDD = 35V, VLED = 35V 0.1 µA Leak Current 1 Output (LED) Pin ILEAK2 VPWM = GND VDD = 35V, VLED = 35V 0.1 µA Leak Current 2 V EN Pin ON Voltage VEN_ON 1.6 VDD ILED = OFF ON V EN Pin OFF Voltage VEN_OFF 0 0.3 ILED = ON OFF V PWM Pin ON Voltage 1 VPWM_ON 1 VDD < 5V, ILED = OFF ON 0.7VDD VDD V PWM Pin OFF Voltage 1 VPWM_OFF 1 VDD < 5V, ILED = ON OFF 0 0.3VDD V PWM Pin ON Voltage 2 VPWM_ON 2 VDD 5V, ILED = OFF ON 3.5 5.5 V PWM Pin OFF Voltage 2 VPWM_OFF 2 VDD 5V, ILED = ON OFF 0 1.5 EN Pin Input Current IEN VEN = 12V 7 µA PWM Pin Pull Up Resistance RPWM 1 MΩ RS Pin Output Current IOUT_RS LED = OPEN 2.3 µA 3 PWM Pin ON Delay Time tPWM_ON µs VPWM = L H, ILED = OFF ON 1 PWM Pin OFF Delay Time tPWM_OFF VPWM = H L, ILED = ON OFF µs LED Short Protection VLED_SHORT 17 20 23 V Detect Voltage Maximum Output Current ILED_MAX RS = 0 Ω 100 170 mA Ver.2017-06-14 -3- NJW4615A ■ TYPICAL APPLICATIONS VDD / V+ (*3) VDD ILED LED ILED VREF ( 0.2V ) 0 Output Current Wave Form at PWM Dimming RS Current Limit Thermal Shut Down LED Short Protection GND RS : Current Sense Resistor Control Logic EN PWM H : ON L : OFF The Rs Resistance Setting formula: RS ( ) 0.2(V ) ILED ( A) (*3) If the wiring from the power supply to the LED anode pin is long, the voltage may change due to the influence of the parasitic elements. As the countermeasure, it should connect a decoupling capacitor as close to the LED as possible. -4- Ver.2017-06-14 NJW4615A ■ TYPICAL CHARACTERISTICS Quiescent Current vs. Temperature Quiescent Current vs. Supply Voltage 400 350 300 250 200 150 100 -40℃ 25℃ 50 125℃ 150℃ 0 0 Quiescent Current at OFF State：IDD_OFF [nA] Quiescent Current : IDD [μA] Quiescent Current : IDD [μA] 350 10 20 30 Supply Voltage : VDD [V] 300 250 200 150 100 50 0 -50 40 -25 0 25 50 75 100 125 150 Temperature : [ºC] Quiescent Current at OFF State vs. Temperature [VEN=GND, VLED=1V, RS=10Ω, VPWM=OPEN] 100 VDD=2.5V VDD=12V 10 VDD=35V 1 0.1 -50 -25 0 25 50 75 100 125 150 Temperature : [ºC] Output Pin Leak Current 2 vs. Temperature Output Pin Leak Current 1 vs. Temperature [VDD=35V, VLED=35V, VEN=GND, RS=10Ω, VPWM=OPEN] 1000 Output Pin Leak Current 2 : ILEAK2 [nA] Output Pin Leak Current 1 : ILEAK1 [nA] [VDD=12V, VEN=VDD, VLED=1V, RS=10Ω, VPWM=OPEN] 400 [VEN=VDD, VLED=1V, RS=10Ω, VPWM=OPEN] VLED=1V VLED=5V VLED=35V 100 10 1 0.1 -50 Ver.2017-06-14 -25 0 25 50 75 100 125 150 Temperature [ºC] [VDD=35V, VEN=VDD, VLED=35V, RS=10Ω, VPWM=GND] 1000 100 10 1 0.1 -50 -25 0 25 50 75 100 125 150 Temperature : [ºC] -5- NJW4615A ■ TYPICAL CHARACTERISTICS EN Pin ON Voltage vs. Temperature EN Pin ON Voltage vs. Supply Voltage [VLED=1V, RS=10Ω, VPWM=OPEN] 1.5 [VDD=12V, VLED=1V, RS=10Ω, VPWM=OPEN] 1.4 25℃ EN Pin ON Voltage : VEN_ON [V] EN Pin ON Voltage : VEN_ON [V] -40℃ 125℃ 150℃ 1 1.2 1 0.8 0.6 0.4 0.2 0 0.5 0 10 20 30 Supply Voltage : VDD [V] -50 40 EN Pin OFF Voltage vs. Supply Voltage 0 25 50 75 100 125 150 Temperature : [ºC] EN Pin OFF Voltage vs. Temperature [VLED=1V, RS=10Ω, VPWM=OPEN] 1.5 -25 [VDD=12V, VLED=1V, RS=10Ω, VPWM=OPEN] 1.4 EN Pin OFF Voltage : VEN_OFF [V] EN Pin OFF Voltage : VEN_OFF [V] -40℃ 25℃ 125℃ 150℃ 1 1.2 1 0.8 0.6 0.4 0.2 0 0.5 0 10 20 30 Supply Voltage : VDD [V] -50 40 PWM Pin ON Voltage : VPWM_ON [V] PWM Pin ON Voltage : VPWM_ON [V] 2.5 2 1.5 1 -40℃ 25℃ 125℃ 150℃ 2.5 2 1.5 1 VDD=12V 0.5 VDD=2.5V 0 0 0 -6- 25 50 75 100 125 150 Temperature : [ºC] [VEN=VDD, VLED=1V, RS=10Ω] 3 [VEN=VDD, VLED=1V, RS=10Ω] 0.5 0 PWM Pin ON Voltage vs. Temperature PWM Pin ON Voltage vs. Supply Voltage 3 -25 10 20 30 Supply Voltage : VDD [V] 40 -50 -25 0 25 50 75 100 125 150 Temperature : [ºC] Ver.2017-06-14 NJW4615A ■ TYPICAL CHARACTERISTICS PWM Pin OFF Voltage vs. Temperature PWM Pin OFF Voltage vs. Supply Voltage PWM Pin OFF Voltage : VPWM_OFF [V] PWM Pin OFF Voltage : VPWM_OFF [V] 3 2.5 2 1.5 1 -40℃ 25℃ 0.5 125℃ 150℃ 2.5 2 1.5 1 VDD=12V 0.5 VDD=2.5V 0 0 0 10 20 30 Supply Voltage : VDD [V] -50 40 PWM Pin Pull-up Resistance : RPWM [MΩ] [VDD=12V, VLED=1V, RS=10Ω] 60 -40℃ 25℃ 50 125℃ 150℃ 40 30 20 10 0 0 10 20 30 EN Pin Voltage : VEN [V] -25 0 25 50 75 100 125 150 Temperature : [ºC] PWM Pin Pull-up Resistance vs. Temperature EN Pin Input Current vs. EN Pin Voltage EN Pin Input Current : IEN [μA] [VEN=VDD, VLED=1V, RS=10Ω] 3 [VEN=VDD, VLED=1V, RS=10Ω] 40 [VDD=12V, VLED=1V, RS=10Ω, VPWM=OPEN] 2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 -50 -25 0 25 50 75 100 125 150 Temperature : [ºC] PWM Pin Input Current vs. Supply Voltage [VEN=VDD, VLED=1V, RS=10Ω, VPWM=GND] PWM Pin Input Current : IPWM [μA] 8 7 6 5 4 3 2 -40℃ 25℃ 1 125℃ 150℃ 0 0 Ver.2017-06-14 10 20 30 Supply Voltage : VDD [V] 40 -7- NJW4615A ■ TYPICAL CHARACTERISTICS PWM Pin OFF Delay Time vs. Temperature [VDD=12V, VEN=VDD, VLED=1V] 10 PWM Pin OFF Delay Time : tPWM_OFF [μs] PWM Pin ON Delay Time : tPWM_ON [μs] PWM Pin ON Delay Time vs. Temperature Rs=40Ω 9 Rs=10Ω 8 Rs=2Ω 7 6 5 4 3 2 1 0 -50 -25 0 RS=10Ω 0.8 RS=2Ω 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -50 -25 0 25 50 75 100 125 150 Temperature : [ºC] Output Current vs. Output Pin Voltage [VDD=12V, VEN=VDD] 120 [VDD=12V, VEN=VDD, RS=10Ω] Output Current : ILED [mA] Output Current : ILED [mA] RS=40Ω 0.9 25 50 75 100 125 150 Temperature : [ºC] Output Current vs. Output Pin Voltage 20.5 [VDD=12V, VEN=VDD, VLED=1V] 1 20 100 80 RS=40Ω 60 RS=10Ω 40 RS=2Ω 20 0 19.5 0 10 20 30 Output Pin Voltage : VLED [V] 40 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Output Pin Voltage : VLED [V] 1 Output Current vs.Temperature [VDD=12V, VEN=VDD, VLED=1V, RS=10Ω] 20.5 Output Current : ILED [mA] 20.4 20.3 20.2 20.1 20 19.9 19.8 19.7 19.6 19.5 -50 -25 -8- 0 25 50 75 100 125 150 175 200 Temperature : [ºC] Ver.2017-06-14 NJW4615A ■ TYPICAL CHARACTERISTICS LED Short Protection Voltage vs. Temperatue Maximu Output Current: ILED_MAX [mA] LED Short Protection Voltage : VLED_SHORT/OFF [V] Maximum Output Current vs. Output Pin Voltage [VDD=12V, VEN=VDD, RS=0Ω] 25 20 15 10 Detect Voltage 5 Release Voltage Release Voltage 140 Detect Voltage 120 100 80 60 40 20 0 0 -50 -25 0 0 25 50 75 100 125 150 Temperature [ºC] Maximum Output Current vs. Temperature 200 10 20 30 Output Pin Voltage: VLED [V] 40 Output Current vs. Current Sense Resistance [VDD=12V, VEN=VDD, RS=0Ω] [VDD=12V, VEN=VDD, VLED=1V] 100 180 160 140 120 100 80 60 40 VLED=1V 20 VLED=35V 0 Output Current : ILED [mA] Maximum Output Current : ILED_MAX [mA] [VDD=12V, VEN=VDD, RS=0Ω] 160 10 1 -50 Ver.2017-06-14 -25 0 25 50 75 100 125 150 Temperature : [ºC] 1 10 Current Sense Resistance : RS [Ω] 100 -9- NJW4615A Application Manual ■ The number of LED series connection It is necessary to drive LED that is the LED forward voltage (Vf) or more. When the LED was series connected, the supply voltage should be input sum of LED Vf (ΣLED Vf) the series connected or more. In NJW4615A, it is necessary as minimum V+ that is ΣLED Vf + NJW4615A output voltage (VLED = 1V). The maximum LED connected number that NJW4615A can drive is limited by the recommended output voltage maximum value (35V). Moreover, it should be used with ΣLED Vf within 34V that is subtracted the VLED = 1V. The table below shows maximum LED number at each Vf. (All LED Vf assumes ideally same) LED Vf is up to 3.0V ▪▪▪ up to 11 lights LED Vf is up to 3.2V ▪▪▪ up to 10 lights LED Vf is up to 3.7V ▪▪▪ up to 9 lights LED Vf is up to 4.2V ▪▪▪ up to 8 lights VDD V+ (*4) 35V (*3) Vf n pcs. = LEDVf 34V VDD LED + VREF (0.2V) RS Current Limit Thermal Shut Down LED Short Protection GND Control Logic EN PWM (*4) If the wiring from the power supply to the VDD pin is long, the voltage may change due to the influence of the parasitic elements. As the countermeasure, it should connect a decoupling capacitor as close to the VDD pin as possible. - 10 - Ver.2017-06-14 NJW4615A Application Manual ■ PWM input pulse and PWM dimming accuracy The ILED transient behavior corresponding to PWM input pulse has some delay at rise/fall time. PWM Input Pulse Output Current Pulse tPWM_ON tPWM_OFF Output Current PWM ON/OFF Propagation Delay ( Output Current Pulse Width Error : εt = tPWM_ON - tPWM_OFF) If enter a PWM signal with short pulse width, for the output current pulse width error becomes larger against the PWM input pulse width, it is incapable of accurate PWM dimming. The Output current pulse width error rate (εt) becomes the following value. ( εt=tPWM_ON –tPWM_OFF ) εt = approx. 2µs (Output Current: ILED=20mA,Ta=25 C typ. ) The actual value of the output current pulse width error rate can calculate by above error rate (εt) and the frequency and Duty of the PWM input pulse. (fPWM: PWM input pulse frequency, D: PWM input pulse Duty) Based on the allowable value of the output current pulse width error rate, you should determine the frequency and Duty of the PWM input pulse. PWM Input pulse width = D / 100 × ( 1 / fPWM ) Output Current pulse width = PWM Input pulse width - εt Output Current pulse width error rate = (Output Current pulse width - PWM Input pulse width) / PWM Input pulse width × 100 = -εt / PWM Input pulse width × 100 [%] 【 Output current pulse width error rate calculation example: operation with PWM input pulse frequency 200Hz and Duty1% 】 PWM Input pulse width = 1 [%] / 100 × ( 1 / 200[Hz] ) = 50 [µs] Output Current pulse width error rate = -2 [µs] / 50 [µs] × 100 = -4 [%] Output Current Duty vs. PWM Input Pulse Duty 【 Measurement Conditions 】 100 ILED=5mA Output Current (ILED) ILED=20mA Output Current Duty [%] 10 ILED=100mA 1 20mA (RS = 10Ω) 100mA (RS = 2Ω) Supply Voltage 12V Output (LED) pin Input Voltage at 1V PWM Input Pulse 200Hz, 0 to 5V Ambient Temperature Ver.2017-06-14 (RS = 40Ω) Output Current ILED Pulse Width The time is more than 90% of set current. 0.1 0.01 0.01 5mA 0.1 1 10 PWM Input Pulse Duty [%] Ta=25ºC 100 - 11 - NJW4615A Application Manual ■ Protection Circuit ▪ Over Current Protection (Refer to Maximum Output Current vs. Output Pin Voltage) This protection function limits the output current, when the RS pin and GND pin was shorted. The limited current is dependence on output (LED) pin voltage. When the output (LED) pin voltage is less than "LED Short Protection Detect Voltage", maximum output current is limited to approx. 170mA (output (LED) pin voltage=1V, Ta=25 C). The output current returns to set current, when the short status is release. ▪ LED Short Protection (Refer to Maximum Output Current vs. Output Pin Voltage) This protection function limits the output current, when the output (LED) pin rises as in LED shorten at output FET ON. The output current is limited to approx. 60mA when the output (LED) pin voltage rose to approx. 20V. ▪ Thermal Shutdown Function (Refer to Output Current vs. Temperature) When junction temperature of the NJW4615A exceeds the 170°C*, internal thermal shutdown circuit function stops the device function. When junction temperature decreases to 150°C* or less, the device operation returns to normal operation. The purpose of this function is to prevent malfunctioning of IC at the high junction temperature. Therefore it is not something that urges positive use. It should make sure to operate within the junction temperature range rated ( +150°C). *) Design value - 12 - Ver.2017-06-14 NJW4615A Application Manual ■ The Loss of Constant Current Driver The power consumption of the LED lighting circuit is classified as "the power consumption of the constant current driver" "the power consumption of the LED" and "the power consumption of the current sense resistor (RS)". The loss of constant current driver is caused mainly by quiescent current (IDD) and output current (ILED). The power dissipation of the device can calculate by follow equation. V+ VDD (*4) PD ≈ VDD IDD + (VLED - VRS) ILED = VDD IDD + (V+ - LED Vf - 0.2) ILED [W] (*3) LEDVf VDD Rs pin voltage (VRS): 0.2V ΣLED Vf represents the sum of the LED Vf of use. IDD LED + VREF (0.2V) VLED - VRS RS Current Limit Thermal Shut Down LED Short Protection Control Logic EN GND ILED e.g.) VDD = V+ = 12[V], IDD=260[µA], LED Vf = 9[V], ILED = 100[mA] PD ≈ 12[V] 260[µA] + (12[V] - 9[V] -0.2[V]) 100[mA] ≈ 283[mW] PWM As shown in the above equation, the loss of constant current driver will increase in proportion to the voltage difference between the LED driving voltage V+ and ΣLED Vf. It should set the LED operating Voltage (V+) and output current (ILED) with consideration of PD. NJW4615AF1 (SOT-23-6) Power Dissipation (Topr=-40ºC to +125ºC, Tj=150ºC) The device power dissipation must be below the power dissipation rate of the device package including thermal derating to ensure correct operation. 800 (*2) on 4 Layers Board 700 Package Power : Pd [mW] 600 (*1) on 2 Layers Board 500 400 (*1) Mounted on glass epoxy board based on EIA/JEDEC. (76.2×114.3×1.6mm: 2Layers FR-4) 300 (*2) Mounted on glass epoxy board based on EIA/JEDEC. 200 (76.2×114.3×1.6mm: 4Layers FR-4), Internal Cu area: 74.2×74.2mm 100 0 -50 -25 Ver.2017-06-14 0 25 50 75 100 Ambient Temperature : Ta [ºC] 125 150 - 13 - NJW4615A Application Manual ■ Parallel Drive of NJW4615A For applications that require more than 100mA, it can correspond by parallel connecting two or more NJW4615A. The LED current becomes sum of LED current of each NJW4615A. Each device accepts different set current. ILED [A] = ILED1 + ILED2 = 0.2 / RS1 [Ω] + 0.2 / RS2 [Ω] (e.g. ILED = 150 [mA] setting: RS1 = 4[Ω], RS2 = 2 [Ω] ） V+ (*3) ILED VDD (*4) ILED1 VDD ILED2 VDD LED VREF (0.2V) Control Logic EN PWM + VREF (0.2V) RS Current Limit Thermal Shut Down LED Short Protection GND LED + RS1 RS Current Limit Thermal Shut Down LED Short Protection GND Control Logic EN RS2 PWM PWM - 14 - Ver.2017-06-14 NJW4615A MEMO [CAUTION] The specifications on this databook are only given for information, without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. Ver.2017-06-14 - 15 -