APPLICATION MANUAL 8 string WLED DRIVER IC AP2001A CONTENTS 1 . DESCRIPTION 2 . FEATURES 3 . APPLICATIONS 4 . PIN CONFIGURATION 5. Ordering Information 5 . PACKAGE OUTLINE 6 . BLOCK DIAGRAM 7 . ABSOLUTE MAXIMUM RATINGS 8 . ELECTRICAL CHARACTERISTICS 9 . TEST CIRCUIT 10 . TYPICAL CHARACTERISTICS 11 . PIN DESCRIPTION 12 . CIRCUIT DESCRIPTION 13 . APPLICATION INFORMATION 14 . NOTES 15 . OFFICES 2 2 2 2 2 3 4 5 6 8 9 19 23 27 34 34 GC3-Q020A Page 1 AP2001A 8 string WLED DRIVER IC AP2001A 4. PIN CONFIGURATION COMP OVP CTM FAULT LX CH6 CH5 CH4 CH3 CH2 HQFN4040B-24 VIN AP2001A is a white LED driver IC for scanners and copiers. AP2001A contains a current mode PWM boost converter and 8 LED current sources. AP2001A can drive up to 8-channels of 12 white LEDs in series. The LED current accuracy is within 3.5%. The adjustable LED current, up to 33mA, is set by an external resistor. AP2001A includes a fixed frequency oscillator of 1.5MHz. Dimming is controlled directly from an external PWM signal with a frequency range of 100Hz to 20kHz. AP2001A protection circuits include LED open/short protections, CH short protection, VOUT short protection, Boost-FET over-current protection, over-temperature protection, and over-voltage protection AP2001A has a wide input voltage range from 8V to 28V. AP2001A is available in a 24-pin HQFN package. CH7 1. DESCRIPTION 2. FEATURES Drive up to 96 (12s x 8ch) LEDs LED Current Accuracy 3.5% (max.) LED Current Matching 1.5% (typ.) LED Max current: 33mA/ch Dimming by External PWM signal (20kHz Max) Switching Frequency: 1.5MHz (fixed) Wide Input Voltage Range: 8V~28V Internal Power MOS-FET, 0.6W LED open/short protection CH short protection Over-voltage / Boost-FET Over-current protection Thermal shutdown Flag output for LED open/short 24-pin HQFN with thermal pad 5. Ordering Information A P 2 0 0 1 A 4 Q 7 1 H - E 2 Version A Temperature range 4: Ta=-40 ~ 85C Package code Q7: HQFN4040 B-24 Storage direction E2: 1pin Left Upper side Environment code H: Lead free and Halogen free Grade 1: Consumer Product 3. APPLICATIONS Scanner LED light source for Multifunction Printer Lighting installation driver GC3-Q020A Page 2 AP2001A 5. PACKAGE OUTLINE HQFN4040B-24 GC3-Q020A Page 3 AP2001A 6. BLOCK DIAGRAM CH1 CH2 CH3 CH4 CH5 CH6 CH7 CH8 LX COMP 19 23 22 CURRENT SENSE PGND 1.2V 0.5V OVER VOLTAGE PROTECTION OPE TSD CURRENT SENSE VIN ALL LED OPEN/ SHORT FAULT CONTROL UVLO 8 CH2 12 CH4 LOW SIDE CURRENT SINK LED TIMER CH5 9 CH6 8 CH7 VDC 7 CH8 DIMMING CONTROL TSD 10 8 0.1V 6 LED OPEN/SHORT FLAG VDC THERMAL SHUTDOWN LDO CH3 11 DRIVER OSC VOUT CURRENT CH TSD OPE SHORT SENSE SHORT DRIVER, DIMMING 24 13 CH OPEN PROTECTION PWM COMPARATOR VOUT SHORT PROTECTION TIMER LATCH 17 LED SHORT PROTECTION 1.2V SWITCH LOGIC 16 8 DRIVER 20 VOLTAGE SELECT + - FAULT 15 CH1 ERROR AMP DRIVER, TIMER 18 EN0 EN1 EN2 OVP FLAG CONTROL FLG 3 OPE 5.0V VDC REG 1 1.5uA 0.5V 3.0V GND 5 CTM 21 GC3-Q020A 2 PWM 4 ISET 14 CLR Page 4 AP2001A 7. ABSOLUTE MAXIMUM RATINGS Ta=25C Parameter Symbol Value Units Conditions VIN, FAULT VIN,VFAULT -0.3 to +35 V *1 LX VLX -0.3 to +47 V *1 CH1-8 VCH -0.3 to +45 VDC, FLG, CLR, PWM -0.3 to +6 V *1 EN0, EN1, EN2 ISET, CTM, OVP, COMP -0.3 to (VDC+0.3) V *1 CH1-8 Drive Current ICH 40 mA Continuous Power PD 2000 mW *2, *3 Dissipation Operating Temperature Range TOP -40 ~ +85 C Storage Temperature Range TSTG -55 ~ +150 C Note: *1. All voltages are with respect to the potential at the GND pins (GND, PGND). *2. PD must be decreased at the rate of 20.0mW/C for operation above 25C. *3. AP2001A mounted on an FR-4 type evaluation board (4 layer 50 mm 40 mm, t= 1.0mm) GC3-Q020A Page 5 AP2001A 8. ELECTRICAL CHARACTERISTICS Suggested Operating Voltage Range Parameter Symbol VIN Operating Voltage Range VIN Value 8 28 Units V Conditions VIN=24V, PGND=GND=0V, PWM=5V, EN0=5V, EN1=EN2=0V, RISET=45.5k, TA=+25C, unless otherwise noted. Value Parameter Symbol Units Conditions MIN TYP MAX DC-DC CONVERTER Input Voltage Range VIN 8 28 V Operating Current IDD 6 12 mA (Boost FET ON) Shutdown Current ISD 90 180 A Standby Current ISTB 250 500 A PWM =0V UVLO Threshold VUVLO 4.5 6.0 7.5 V UVLO ON, VIN (Failing Edge) UVLO Hysteresis VHYS_UVLO 0.3 V UVLO ONOFF, VIN Source Current for CTM ICTMP 500 A VCTM=3V, PWM=5V Sink Current for CTM ICTMN 1.5 A VCTM=1V, PWM=0V CTM Pin Threshold Voltage VOPE 0.45 0.5 0.55 V IC ON, VCTM CTM Pin Hysteresis VHYS_OPE 0.1 V IC ONOFF, VCTM Internal Oscillator Operating FOSC_LX 1.1 1.5 1.9 MHz Frequency of Switching Internal Switch RDS-ON RLX 600 m ILX=+30mA Internal Switch ILEAK_LX 0.1 1.0 A VLX=45V OFF Leak Current Maximum Duty Cycle DMAX_LX 88 93 % COMP Output High Voltage VOH_COMP 4.45 4.85 V ICOMP=-10A COMP Output Low Voltage VOL_COMP 0.15 0.3 V ICOMP=+10A Minimum CH Voltage VCH_MIN 1.08 1.2 1.32 V Current Sink Circuit and Brightness Control Maximum LED Current ILED_MAX 33 mA RISET= 18 k (MIN case) RISET=45.5 k ILED1 19.3 20 20.7 mA CH1~CH8 LED Drive Current RISET=30.33 k ILED2 28.95 30 31.05 mA CH1~CH8 RISET= 45.5 k, ILED1 1.5 % DI LED (%) = I CH (1-8) MAXorMIN - I LED _ AVE I LED _ AVE LED Current Difference Between Channels 100 RISET= 30.33 k, ILED2 1.5 % DI LED (%) = I CH (1-8) MAXorMIN - I LED _ AVE I LED _ AVE GC3-Q020A 100 Page 6 AP2001A Electrical Characteristics (Continued) Parameter LDO Output Voltage PROTECTION Over-Voltage Protection Threshold (OVP) Maximum Current Limit of Internal Switch FAULT Output ON-Resistance INTERFACE PWM Frequency Range of Brightness Control Input High Voltage Input Low Voltage FLG Output ON-Resistance MIN Value TYP MAX VDC 4.75 5.0 5.25 V VOVP 1.17 1.2 1.23 V ILX_LIMIT 1.5 Symbol RFAULT FPWM 0.1 VIH VIL RFLG 2.1 GC3-Q020A Units Conditions A 100 20 kHz 0.7 100 V V IFAULT=+10mA PWM, CLR, EN0,EN1,EN2 PWM, CLR, EN0,EN1,EN2 IFLG=+10mA Page 7 AP2001A 9. TEST CIRCUIT TM 24 1uF VDC 19 1 RFLG VIH VIL RISET VCH_MIN VOH_COMP VOL_COMP 18 VDC PGND PWM EN2 FLG EN1 ISET EN0 GND CLR CH8 CH1 6 VIH VIL VIH VIL VIH VIL VIH VIL 13 7 12 TM FPWM ILED_MAX ILED1 ILED2 GC3-Q020A Page 8 AP2001A 10. TYPICAL CHARACTERISTICS VIN=24V, PGND=GND=0V, PWM=5V, EN0=5V, EN1=EN2=0V, RISET=45.5kW, TA=+25C, unless otherwise noted. LED Current vs. ISET Pin Resistance LED Current Matching vs. LED Current 45 2.5 40 LED Current Matching(%). 35 LED Current(mA). 30 25 20 15 10 2.0 1.5 1.0 0.5 5 0.0 0 0 20 40 60 ISET Resistance(k) 80 0 100 10 20 30 LED Current(mA) 40 LED Current vs. PWM Duty(RISET =45.5k) 25 LED Current(mA). 20 15 10 5 0 0 10 20 30 40 50 60 70 PWM Duty(%) 80 90 100 LED Current vs. Input Voltage (RISET =45.5k) LED Current vs. Temperature (RISET =45.5k) 30 30 RISET=45.5k RISET =45.5k 28 26 26 24 24 LED Current(mA). LED Current(mA). 28 22 20 18 16 22 20 18 16 14 14 12 12 10 10 5 10 15 20 25 30 -40 Input Voltage(V) -20 0 20 40 60 80 100 120 Temperature(C) GC3-Q020A Page 9 AP2001A LED Current Matching vs. Temperature (RISET=45.5k) 3.0 LED Current Matching(%). 2.5 2.0 1.5 1.0 0.5 0.0 -40 -20 0 20 40 60 Temperature(C) 80 100 120 LED Current vs. Input Voltage (RISET=30.33k) LED Current vs. Temperature (RISET=30.33k) 40 40 RISET =30.33k 38 RISET=30.33k 36 36 34 34 LED Current(mA). LED Current(mA). 38 32 30 28 26 32 30 28 26 24 24 22 22 20 20 5 10 15 20 25 -40 30 -20 0 20 40 60 80 100 120 Temperature(C) Input Voltage(V) LED Current Matching vs. Temperature (RISET=30.33k) 3 LED Current Matching(%). 2.5 2 1.5 1 0.5 0 -40 -20 0 20 40 60 Temperature(C) 80 100 120 GC3-Q020A Page 10 AP2001A Switching Frequency vs. Temperature 2.0 2.0 1.8 1.8 1.6 1.6 Switching Frequency(MHz) . Switching Frequency(MHz) . Switching Frequency vs. Input Voltage 1.4 1.2 1.0 0.8 0.6 0.4 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.2 0.0 0.0 5 10 15 20 Input Voltage(V) 25 -40 30 Maximum Duty Cycle vs. Input Voltage 20 40 60 80 100 120 100 120 Maximum Duty Cycle vs. Temperature 98 98 Maximum Duty(%) . 100 Maximum Duty(%) . 0 Temperature(C) 100 96 94 96 94 92 92 90 90 5 10 15 20 Input Voltage(V) 25 -40 30 Operating Supply Current vs. Input Voltage -20 0 20 40 60 Temperature(C) 80 Operating Supply Current vs. Temperature 6.0 6.0 5.8 5.8 5.6 5.6 Operating Current(mA) . Operating Current(mA) . -20 5.4 5.2 5.0 4.8 4.6 5.4 5.2 5.0 4.8 4.6 4.4 4.4 4.2 4.2 4.0 4.0 5 10 15 20 Input Voltage(V) 25 -40 30 GC3-Q020A -20 0 20 40 60 Temperature(C) 80 100 120 Page 11 AP2001A Standby Current vs. Temperature 400 400 350 350 300 300 Standby Current(uA). Standby Current(uA). Standby Current vs. Input Voltage 250 200 150 200 150 100 100 50 50 0 0 5 10 15 20 Input Voltage(V) 25 200 200 180 180 160 160 140 120 100 80 60 80 100 120 80 100 120 100 120 100 80 60 20 20 0 0 15 20 Input Voltage(V) 20 40 60 Temperature(C) 120 40 10 0 140 40 5 -20 Shutdown Current vs. Temperature Shutdown Current(uA) . Shutdown Current(uA) . -40 30 Shutdown Current vs. Input Voltage 25 -40 30 VDC Output Voltage vs. Input Voltage -20 0 20 40 60 Temperature(C) VDC Output Voltage vs. Temperature 6.0 6.0 5.8 5.8 5.6 5.6 LDO Output Voltage(V) . VDC Output Voltage(V) . 250 5.4 5.2 5.0 4.8 4.6 5.4 5.2 5.0 4.8 4.6 4.4 4.4 4.2 4.2 4.0 4.0 5 10 15 20 Input Voltage(V) 25 -40 30 GC3-Q020A -20 0 20 40 60 Temperature(C) 80 Page 12 AP2001A 3.0 3.0 2.5 2.5 2.0 1.5 1.0 1.5 1.0 0.5 0.0 0.0 10 15 20 Input Voltage(V) 25 -40 30 Input Low Threshold Voltage vs. Input Voltage 3.0 3.0 2.5 2.5 2.0 1.5 1.0 0.0 25 -40 30 Minimum CH Voltage vs. Input Voltage 80 100 120 1.0 0.0 15 20 Input Voltage(V) 20 40 60 Temperature(C) 1.5 0.5 10 0 2.0 0.5 5 -20 Input Low Threshold Voltage vs. Temperature Input Low Voltage(V) . Input Low Voltage(V) . 2.0 0.5 5 -20 0 20 40 60 80 Tepemerature(C) 100 120 Minimum CH Voltage vs. Temperature 1.40 1.40 1.35 1.35 Minimum CH Voltage(V) . Minimum CH Voltage(V) . Input High Threshold Voltage vs. Temperature Input High Voltage(V) . Input High Voltage(V) . Input High Threshold Voltage vs. Input Voltage 1.30 1.25 1.20 1.15 1.10 1.30 1.25 1.20 1.15 1.10 1.05 1.05 1.00 1.00 5 10 15 20 Input Voltage(V) 25 -40 30 GC3-Q020A -20 0 20 40 60 Temperature(C) 80 100 120 Page 13 AP2001A UVLO Threshold Voltage vs. Temperature UVLO Hysteresis Range vs. Temperature 7.0 0.5 UVLO ON UVLO OFF 6.6 UVLO Hysteresis Range(V). UVLO Threshold Voltage(V) . 6.8 6.4 6.2 6.0 5.8 5.6 5.4 0.4 0.3 0.2 0.1 5.2 5.0 -40 -20 0 20 40 60 80 100 0 120 -40 Temperature(C) 1.40 1.40 1.35 1.35 1.30 1.25 1.20 1.15 1.10 1.05 20 40 60 Temperature(C) 80 100 120 1.30 1.25 1.20 1.15 1.10 1.05 1.00 1.00 5 10 15 20 Input Voltage(V) 25 30 -40 Over Current Protection Threshold vs. Input Voltage -20 0 20 40 60 Temperature(C) 80 100 120 Over Current Protection Threshold vs. Temperature 3.0 3.0 2.5 2.5 LX Current Limit(A). LX Current Limit(A). 0 OVP Reference Voltage vs. Temperature OVP Reference Voltage(V). OVP Reference Voltage(V). OVP Reference Voltage vs. Input Voltage -20 2.0 1.5 1.0 0.5 2.0 1.5 1.0 0.5 0.0 0.0 5 10 15 20 Input Voltage(V) 25 30 -40 GC3-Q020A -20 0 20 40 60 Temperature(C) 80 100 120 Page 14 AP2001A LED Short Threshold Voltage vs. Temperature 14.0 14.0 13.5 13.5 13.0 13.0 LED Short Voltage(V). LED Short Voltage(V). LED Short Threshold Voltage vs. Input Voltage 12.5 12.0 11.5 11.0 10.5 12.5 12.0 11.5 11.0 10.5 10.0 10.0 5 10 15 20 Input Voltage(V) 25 30 25 30 -40 -20 0 20 40 60 80 Temperateure(C) 100 120 100 120 Thermal Shutdown vs. Input Voltage 170 Temperature(C) 160 150 140 130 5 10 15 20 Input Voltage(V) FAULT RDS-ON vs. Input Voltage FAULT RDS-ON vs. Temperature 120 120 100 100 FAULT Rds-ON(W) 140 FAULT Rds-ON(W) 140 80 60 40 20 80 60 40 20 0 0 5 10 15 20 Input Voltage(V) 25 30 -40 GC3-Q020A -20 0 20 40 60 Temperature(C) 80 Page 15 AP2001A FLG RDS-ON vs. Input Voltage FLG RDS-ON vs. Temperature 80 80 FLG Rds-ON(W ) 100 FLG Rds-ON(W ) 100 60 40 60 40 20 20 0 0 5 10 15 20 Input Voltage(V) 25 -40 30 GC3-Q020A -20 0 20 40 60 Temperature(C) 80 100 120 Page 16 AP2001A VIN-EN-PWM Start up waveform VIN=24V 1CH(Blue) 2CH(Light Blue) 3CH(Purple) 4CH(Green) Inductor Current VOUT PWM EN 500mA/DIV 10V/DIV 2V/DIV 5V/DIV Inductor Current VOUT PWM EN 500mA/DIV 10V/DIV 2V/DIV 5V/DIV PWM FLG VOUT Inductor Current 5V/DIV 5V/DIV 20V/DIV 500mA/DIV 1ms/DIV VIN-PWM-EN Start up wave form VIN=24V 1CH(Blue) 2CH(Light Blue) 3CH(Purple) 4CH(Green) 1ms/DIV At the start, CH1 LED open state VIN=24V 1CH(Blue) 2CH(Light Blue) 3CH(Purple) 4CH(Green) 2ms/DIV GC3-Q020A Page 17 AP2001A CH1-VOUT short state VIN=24V 1CH(Blue) 2CH(Light Blue) 3CH(Purple) 4CH(Green) FLG CH1 VOUT CH1 Current 5V/DIV 20V/DIV 20V/DIV 20mA/DIV FAULT CH1 VOUT CH1 Current 5V/DIV 1V/DIV 20V/DIV 50mA/DIV PWM VIN VOUT Inductor Current 5V/DIV 20V/DIV 20V/DIV 500mA/DIV 2ms/DIV CH1-GND short state VIN=24V 1CH(Blue) 2CH(Light Blue) 3CH(Purple) 4CH(Green) 2ms/DIV At the start, all CH open VIN=24V 1CH(Blue) 2CH(Light Blue) 3CH(Purple) 4CH(Green) 1ms/DIV GC3-Q020A Page 18 AP2001A 11. PIN DESCRIPTION No. Name 1 VDC Equivalent Circuit Description LDO output. The LDO supplies power to internal circuits with regulated 5.0V. The LDO always operates when there is an input at VIN. If this pin is shorted to GND, the IC limits the load current to approximately 40mA (typ.). Connect a 1.0uF ceramic capacitor between this pin and GND. Active-high PWM control input and IC enable. PWM pin has internal 200k pull-down resistor. 2 PWM 3 FLG 4 ISET 5 GND Error flag output, N-channel open drain output. This pin is "OFF" during the IC in normal operation. When one or more of the LED channel is in open or short condition, this pin turns "ON". IC condition can be observed by pull-up resistor to VDC pin. Error flag can be reset by using CLR pin. If this function is not used, connect this pin to GND. LED current setting pin. Connect a resistor between this pin and GND to program the LED current. If this pin shorts to GND, the boost converter and the CH pin turn off. VDC 6 6 CH8 VDC 7 CH7 7 Ground. White LED current stabilizer pin. CH8 pin sinks constant current from the LED string. Connect the cathode of the LED string to this pin. When CH8 pin voltage falls to 0.2V or lower, fault timer protection circuit starts the count. If not used, leave it unconnected. White LED current stabilizer pin. CH7 pin sinks constant current from the LED string. Connect the cathode of the LED string to this pin. When CH7 pin voltage falls to 0.2V or lower, fault timer protection circuit starts the count. If not used, leave it unconnected. GC3-Q020A Page 19 AP2001A No. Name Equivalent Circuit VDC 8 8 CH6 VDC 9 9 CH5 VDC 10 10 CH4 VDC 11 11 CH3 VDC 12 12 CH2 VDC 13 CH1 13 Description White LED current stabilizer pin. CH6 pin sinks constant current from the LED string. Connect the cathode of the LED string to this pin. When CH6 pin voltage falls to 0.2V or lower, fault timer protection circuit starts the count. If not used, leave it unconnected. White LED current stabilizer pin. CH5 pin sinks constant current from the LED string. Connect the cathode of the LED string to this pin. When CH5 pin voltage falls to 0.2V or lower, fault timer protection circuit starts the count. If not used, leave it unconnected. White LED current stabilizer pin. CH4 pin sinks constant current from the LED string. Connect the cathode of the LED string to this pin. When CH4 pin voltage falls to 0.2V or lower, fault timer protection circuit starts the count. If not used, leave it unconnected. White LED current stabilizer pin. CH3 pin sinks constant current from the LED string. Connect the cathode of the LED string to this pin. When CH3 pin voltage falls to 0.2V or lower, fault timer protection circuit starts the count. If not used, leave it unconnected. White LED current stabilizer pin. CH2 pin sinks constant current from the LED string. Connect the cathode of the LED string to this pin. When CH2 pin voltage falls to 0.2V or lower, fault timer protection circuit starts the count. If not used, leave it unconnected. White LED current stabilizer pin. CH1 pin sinks constant current from the LED string. Connect the cathode of the LED string to this pin. When CH1 pin voltage falls to 0.2V or lower, fault timer protection circuit starts the count. If not used, leave it unconnected. GC3-Q020A Page 20 AP2001A No. Name 14 CLR Description The error flag clear pin. When this pin is pulled to a high level, the LED open or short flag will be cleared. During high level, the IC stops operation. CLR pin has an internal 200k pull-down resistor. EN0 IC enable and channel select pin. The channel preferred to be used can be selected by the combination of EN0, EN1, and EN2. EN0 pin has an internal 200k pull-down resistor. EN1 IC enable and channel select pin. The channel preferred to be used can be selected by the combination of EN0, EN1, and EN2. EN1 pin has an internal 200k pull-down resistor. 17 EN2 IC enable and channel select pin. The channel preferred to be used can be selected by the combination of EN0, EN1, and EN2. EN2 pin has an internal 200k pull-down resistor. 18 PGND 15 16 Equivalent Circuit Power ground for internal switching FET. Internal power MOS-FET pin, N-channel open drain output. 19 19 LX PGND 20 20 FAULT N-channel MOS-FET open drain output pin. Internal MOSFET is "ON" during the IC in normal operation. MOS-FET turns "OFF" when: -Fault timer protection stops the operation of the IC -IC detects the OVP pin short condition -All 8 channel pins are in open or short condition. When the number of operating channels is selected to 7 or less by the enable pin, this pin will not turn "OFF". By connecting a P-channel FET, this pin can be used as on/off switch for VIN power line, and also as a protection to abnormal operation. If not used, connect to GND. GC3-Q020A Page 21 AP2001A No. Name Equivalent Circuit VDC 21 CTM 21 VDC 22 OVP 22 Description PWM signal buffer output. Connect a 0.1uF ceramic capacitor between this pin and GND. When PWM signal is "HIGH" level, CTM pin is pulled up to VDC and the capacitor will be charged. When PWM signal is "LOW" level, IC will sink and discharge the capacitor. In standby mode, IC will start operation when CTM pin voltage is more than 0.5V. When CTM pin voltage falls to less than 0.4V, IC will enter standby mode. Over-voltage protection pin. The resistor divided output voltage is applied to this pin. IC will limit the output voltage rise when the OVP pin voltage rises to 1.2V. When the OVP pin voltage falls to less than 0.1V, such as an output short, boost converter, CH1-8 pin and FAULT pin turns off. Error amplifier output pin Connect a resistor and a capacitor between this pin and ground for phase compensation. 23 COMP IC power supply pin. This pin is the voltage input pin for the internal LDO which supplies the power to the internal circuits. Connect a 1.0uF ceramic capacitor between this pin and GND. 24 24 VIN VDC - THERMAL PAD - Ground. GC3-Q020A Page 22 AP2001A 12. CIRCUIT DESCRIPTION 12-1. PWM Boost Converter 12-6. LED Constant Current Sink AP2001A includes a current mode PWM boost converter. It contains a boost FET, 8 LED current sink channels, 1.5MHz fixed frequency switching oscillator and some protection circuits. The PWM boost converter and the LED current sinks are controlled by an input signal to the PWM pin. The fast transient response of the current mode architecture easily handles the LED load variation caused by the PWM dimming signal or a sudden input voltage change. . The boost converter continuously monitors the various CH pins' voltages and selects the CH pin (that is connected) with the maximum forward voltage of the LED strings to use as the feedback signal. The feedback reference voltage is 1.2V. The inverting amplifier creates a COMP pin signal equaling the difference between the feedback signal and the reference voltage of the error amplifier. The COMP pin signal minus the boost FET current is compared with the slope compensation signal to determine the boost FET on-time. When the load is decreased, the boost FET on-time is decreased. 12-2. 5V Low-Dropout Regulator AP2001A includes an internal low-dropout regulator (LDO) for supplying internal circuits. When VIN is higher than 8.0V, this LDO generates 5.0V supply to the VDC pin. For regulating LDO output, it should be connected to a 1.0uF bypass capacitor between the VDC pin and GND. 12-3. Enable When EN0, EN1, and EN2 are low, the IC shuts down, and consumption current is about 90mA (when VIN =24V). When EN0, EN1, or EN2 is high, the IC is in standby mode. The IC is operational when the CTM voltage is over 0.5V and the PWM pin input is high. If the CTM voltage is under 0.4V, the IC is in standby mode. 12-4. Switching Frequency AP2001A includes a 1.5MHz fixed frequency switching oscillator for the boost converter. 12-5. PWM Control AP2001A uses an external PWM signal for direct dimming. When the PWM dimming signal is high, the LED current is the value set by the RISET resistor. When the PWM dimming signal is low, the LED current is 0mA. The pulse width of the PWM dimming signal should be greater than 30ms. AP2001A includes 8 LED constant current sink channels. It can drive up to 8 channels of 12 white LEDs in series. The LED current can be set up to 33mA per channel for a maximum total LED current of 264mA. The LED current is set by the external resistor, RISET, which is connected between the ISET pin and GND. The LED current of all channels is the same value. The LED current of each string is approximately as follows; I LED (mA) = 910 RISET (kW) When RISET is 45.5k, the LED current is approximately 20mA. The LED current accuracy is 3.5% among all channels. The CH pin voltages are always monitored after standby mode. The CH pin with the lowest voltage will be the CH that has the maximum LED forward voltage of all channels. It is the CH pin used for the feedback voltage. All other CH pins' voltages are higher than the feedback pin's voltage. 12-7. Under Voltage Lockout (UVLO) If VIN falls below 6.0V, the IC will stop operation except for the LDO and UVLO circuits. When VIN comes back above 6.3V, the IC will enter standby mode. The hysteresis on UVLO is 0.3V. 12-8. Over-Voltage Protection (OVP) To maintain a safe level at the output voltage, AP2001A includes an over-voltage protection function that monitors the output of the resistive voltage divider from the output voltage. If the OVP pin voltage rises above 1.20V, the boost converter will turn off, but the LED current sources remain in the operating mode. When the OVP pin voltage falls below 1.20V, the boost converter will restart. The OVP function prevents an LED string open or a sharp increase of VIN from damaging the IC. 12-9. Fault Timer AP2001A includes a fault timer protection by timer latch circuit. When CH pin short protection, over-temperature protection, or over current protection is engaged, the counter of the timer circuit starts. The Boost converter and constant current drivers are stopped after a count of 7680 cycles of the switching frequency and the FAULT pin is turned off. If the IC is latched off by the fault timer, it can be reset by shutting down the IC via an EN0, EN1, and EN2 low level input or UVLO ON for VIN below 4.5V. GC3-Q020A Page 23 AP2001A 12-10. LED Constant Current Sink Fault protection AP2001A has fault protection functions that detect the abnormal conditions of open/short LEDs and CH pin shorts. These protections start with the operation of the boost converter and continue to be monitored after softstart. 12-10-1. LED Open Protection If LED strings are disconnected due to a damaged LED or a CH pin connection failure, the LED current through those strings will be 0mA. The boost converter will continue to operate, raising the output voltage trying to get the LED current through those strings to the proper set value. If this happens, the IC and other components will be destroyed by the boost FET's over current and/or output voltage. AP2001A has two kinds of CH pin open detection functions, which operate during startup and afterwards. When a disconnected CH pin is detected, this pin becomes a hi-impedance and the boost converter doesn't control this pin. i) In the case of one or more CH pins being open at startup: If the IC is being used with one or more CH pins disconnected, an initial diagnosis of the CH pins detects this condition during standby mode. If the output voltage is rising up to the OVP setting voltage, the LED timer circuit starts counting. After a count of 1920 cycles of the switching frequency, any CH pins that the LED current sinks are not driving to 1/5 of the LED current setting value will be disconnected, therefore, these LED current sources will be turned off. ii) If one or more CH pin's becomes open during steady state (after the initial diagnosis of CH pins at startup): If the output voltage is rising up to the OVP setting voltage, the LED timer circuit starts counting. After a count of 1920 cycles of the switching frequency, any CH pins that the LED current sinks are not driving to the LED current setting value will be disconnected, therefore, these LED current sinks will be turned off. If all CH pins are disconnected the boost converter and the LED current sources will turn off completely. This function guarantees that the LED current sinks are only used for connecting LED strings. If a high level signal is input into the CLR pin or VIN falls below 4.5V, this protection function will be reset. 12-10-2. forward voltage of the affected LED strings will be lower than the none affected strings. The output voltage is the same for all channels; therefore, the affected LED strings will have a higher CH pin voltage. If any of the CH pin voltages reach 12V above ground and the error amplifier is in a stable status, the LED timer circuit starts counting. After a count of 1920 cycles of the switching frequency, any CH pins that exhibit this LED short condition will be disconnected; therefore, these LED current sources will be turned off. If a high level signal is input into the CLR pin or VIN falls below 4.5V, this protection function will be reset. 12-10-3. CH pin Short Protection If the CH pin is connected to GND, the boost converter will operate to increase the output voltage to try to reach the LED current set value. Also, it will overdrive the remaining LEDs damaging or destroying the LEDs the IC and other components. AP2001A has the CH pin short protection function. If the CH pin voltage is below 0.2V and this condition continues, the IC will detect the CH pin short condition to GND. The boost converter and the LED current sources will immediately turn off. 12-11. Over-Temperature Protection AP2001A has the over-temperature protection function. If the IC temperature exceeds +125C, the boost converter and LED current sources will turn off completely by fault timer. 12-12. VDC Short Protection If the VDC pin is connected to GND, the load current of the internal LDO will be restricted to below 40mA preventing the IC from overheating. 12-13. Over-Current Protection AP2001A has the over-current protection function. If the IC detects that the current of the boost FET is over 1.5A, the boost FET will turn off. This monitor is reset on each cycle of the boost frequency. If it continuously detects an over current situation, the boost converter and the LED current sinks will turn off completely based on the fault timer circuit. LED Short Protection If a short circuit occurs between an LED anode an cathode due to LED damage and/or an external resistive connection, etc. in one or more of the LED strings, the GC3-Q020A Page 24 AP2001A 12-14. VOUT Short Protection 12-15. AP2001A has VOUT short protection function. If the OVP pin voltage falls below 0.1V, the IC will detect the OVP pin short condition to GND and the boost converter and the LED current sinks will immediately turn off. Then if the OVP pin voltage rises over 0.1V, the boost converter and the LED current sinks will immediately turn on. This protection internal protection does not protect the overall circuit because the over-current condition still exists through the schottky diode. To protect against this, an input voltage ON/OFF switch can be added by connecting a P-channel FET to the FAULT pin. When the disable signal of the FET for fault timer is latched, the FAULT pin becomes ON-state and the P-channel FET turns off, the current route to GND is cut off (Fig.1). AP2001A has an ON/OFF control function of CH5, CH6, CH7, and CH8 using the pins EN0, EN1, and EN2. EN0 EN1 EN2 L H L L H H L H L L H L H L H H L L L H L H H H LX PGND OVP 19 22 18 DRIVER SWITCH LOGIC OPE TSD CURRENT SENSE FAULT 20 TIMER LATCH CURRENT CH VOUT TSD SENSE SHORT SHORT Fig. 1. Protection for short circuit of VOUT and GND Note: When the number of operating channels selected is 7 or less using the EN0, EN1, and EN2 pins, the FAULT pin will not turn "OFF", therefore this protection will not work. CH1 ~CH4 OFF ON ON ON ON ON ON ON CH5 CH6 CH7 CH8 OFF ON ON ON ON ON ON OFF OFF ON ON ON OFF OFF OFF OFF OFF ON ON OFF OFF OFF OFF OFF OFF ON OFF OFF OFF OFF OFF OFF Fig. 2. LED string selected by combination of EN CH pins that are turned off via EN0, EN1, and EN2 are not monitored by the Error Flag function. 12-16. CH1 CH2 CH3 CH4 CH5 CH6 CH7 CH8 Choose the Number of LED CH Error Flag The operating condition of AP2001A can be checked by using the FLG pin and the FAULT pin. The FLG pin and the FAULT pin are N-channel open drain outputs. . i) FLG pin When one or more of the LED strings are in open or short condition, this pin turns "ON". The operating condition of the IC can be observed by connecting a pull-up resistor to VDC. The Error flag can be reset by using the CLR pin. As noted above, CH pins that are turned off via EN0, EN1, and EN2 are not monitored by the Error Flag function. ii) FAULT pin The FAULT pin turns "OFF" when: -The fault timer function stops the operation of the IC -The IC detects the OVP pin short condition -All 8 channel pins are in open or short condition. When the number of operating channels selected is 7 or less using the EN0, EN1, and EN2 pins, this pin will not turn "OFF". This flag is cleared by the UVLO operation for input voltages lower than 4.5V or shutdown mode for EN0, EN1, and EN2 (input "LOW" level). In this case, the fault flag is reset and turned on. GC3-Q020A Page 25 AP2001A 12-17. POWER DISPATION Maximum Power Dissipation 2500 Evaluation Board FR-4 type x=50mm, y=40mm, t=1.0mm Thickness of copper foil:35mm Thickness of inner coat copper foil:25mm Pd_max (mW). 2000 1500 1000 500 0 -50 0 50 100 150 Ta () Note Please consult Maximum Power Dissipation graph above and verify your thermal design. This IC assumes that the actual maximum operating temperature is less than 125C, because even with over-temperature protection this IC has the possibility of operating over 125C. The actual maximum power dissipation of your design should be verified because this IC is not warranted if the over-temperature protection function has been used. GC3-Q020A Page 26 AP2001A 13. APPLICATION INFORMATION 13-1. Application Circuit Input Voltage LED Number LED Current Inductor Peak Current Switching Frequency OVP Setting 44.5V VIN =22~26V 12 white LEDs in series /8 parallel /96pcs (VOUT MAX: 38V) 26mA 850mA max 1500kHz CH1 CH2 CH3 CH4 CH5 CH6 CH7 CH8 CIN1 D COUT2 L ROVP1 COUT1 ROVP2 RCOMP CCOMP2 LX ROVP3 CCOMP1 19 COMP 22 CURRENT SENSE PGND 1.2V 0.5V OVER VOLTAGE PROTECTION OPE TSD CURRENT SENSE VIN ALL LED OPEN/ SHORT FAULT CONTROL LDO CH3 11 CH4 LOW SIDE CURRENT SINK LED TIMER OSC CH5 9 CH6 8 CH7 VDC 7 CH8 DIMMING CONTROL TSD 10 8 0.1V 6 LED OPEN/SHORT FLAG VDC THERMAL SHUTDOWN 24 CIN2 CH2 12 DRIVER VOUT CURRENT CH TSD OPE SHORT SENSE SHORT DRIVER, DIMMING UVLO 13 8 CH OPEN PROTECTION PWM COMPARATOR VOUT SHORT PROTECTION TIMER LATCH 17 LED SHORT PROTECTION 1.2V SWITCH LOGIC 16 8 DRIVER 20 VOLTAGE SELECT + - FAULT 15 CH1 ERROR AMP DRIVER, TIMER 18 EN0 EN1 EN2 OVP 23 FLAG CONTROL VDC RFLG FLG 3 OPE 5.0V VDC REG 1 GND CDC 1.5uA 0.5V 3.0V 5 21 CTM CCTM 2 PWM 4 14 ISET CLR RISET1 RISET2 GC3-Q020A Page 27 AP2001A 13-2. Component List Circuit Symbol RFLG ROVP1 ROVP2 ROVP3 RSET1 RSET2 RCOMP CIN1 CIN2 CDC CCTM CCOMP1 CCOMP2 COUT1 COUT2 Silk R15 R9 R10 R11 R5 R6 R12 C1 C6 C10 C9 C7 C8 C3 C4 Diode D D Inductor L L Resistor Capacitor Part Number Value 100k 510 k,0.5% 360 k,0.5% 24 k,0.5% 33k,0.5% 2.0k,0.5% Short GRM31CR71H475K 4.7uF/50V CM21X5R105K50AB 1.0uF/50V CM105X5R105K16AB 1.0uF/6.3V CM05B104K16AB 0.1uF/16V CM05B104K16AB 0.1uF/16V CM05B104K16AB 0.1uF/16V GRM31CR71H475K 4.7uF/50V GRM31CR71H475K 4.7uF/50V More than VR=60V, Io=1A #A916CY-100M D63CB 10uH GC3-Q020A Company Remark Flag pull-up OVP setting OVP setting OVP setting LED current setting 26mA Phase compensation MURATA Input bypass capacitor KYOCERA IC bypass capacitor KYOCERA VDC bypass capacitor KYOCERA KYOCERA Phase compensation KYOCERA Phase compensation MURATA Output capacitor MURATA Output capacitor - TOKO Page 28 AP2001A 13-3. Application Specification LED Current vs. Input Voltage LED Current Matching vs. Input Voltage Vin vs. ILED Vin vs. LED Current CH to CH Tolerance 5 30 4 3 LED Current CH to CH Tolerance(%). ILED(mA). 28 26 24 22 ILED1 ILED2 ILED3 ILED4 ILED5 ILED6 ILED7 ILED8 23 24 25 1 0 -1 -2 -3 -4 20 22 2 ILED1 ILED2 ILED3 ILED4 ILED5 ILED6 ILED7 ILED8 -5 26 22 23 24 Vin(V) 25 26 Vin(V) Efficiency vs. Input Voltage Vin vs. Efficiency 100 95 Efficiency(%) 90 85 V _ xI Efficiency = OUT LED TOTAL 100 VIN x I IN 80 75 [%] 70 65 60 22 23 24 25 26 Vin(V) LED Current vs. PWM Signal Duty LED Current Matching vs. PWM Signal Duty LED Current vs. PWM Signal Duty LED Current CH to CH Tolerance vs. PWM Signal Duty 5 30 4 3 LED Current CH to CH Tolerance(%). LED Current(mA). 25 20 15 10 5 ILED1 ILED2 ILED3 ILED4 ILED5 ILED6 ILED7 ILED8 2 1 0 -1 -2 -3 -4 0 ILED1 ILED2 ILED3 ILED4 ILED5 ILED6 ILED7 ILED8 -5 10 20 30 40 50 60 70 80 90 10 100 20 30 40 50 60 70 80 90 100 PWM Signal Duty(% ) PWM Signal Duty(% ) GC3-Q020A Page 29 AP2001A 13-4. Operating wave form VOUT=38.0V, ILED=26mA (Light Blue) VOUT (Blue) Inductor Current VIN 22V 100mV/Div (AC) 500mA/Div 24V 26V GC3-Q020A Page 30 AP2001A 13-4-1. Inductor Current waveform on start-up VOUT=38.0V, ILED=26mA (Purple) PWM (Light Blue) VOUT (Blue) Inductor Current (Green) EN VIN 22V VINENPWM 2V/Div 10V/Div 500mA/Div 5V/Div (Green) EN (Light Blue) VOUT (Blue) Inductor Current (Purple) PWM 2V/Div 10V/Div 500mA/Div 5V/Div VINPWMEN 24V 26V GC3-Q020A Page 31 AP2001A 13-4-2. LED Current waveform on state-up VOUT=38.0V, ILED=26mA (Purple) PWM (Light Blue) VOUT (Blue) LED Current (Green) EN Vin 22V VINEN0PWM 2V/Div 10V/Div 10mA/Div 5V/Div (Green) EN (Light Blue) VOUT (Blue) LED Current (Purple) PWM 2V/Div 10V/Div 10mA/Div 5V/Div VINPWMEN0 24V 26V GC3-Q020A Page 32 AP2001A 13-4-3. LED Current waveform at PWM dimming VIN =24V, VOUT=38.0V, ILED=26mA PWM Signal Duty=20, 50, 90%, PWM Frequency =3, 10kHz, EN=5V (Green) EN 2V/Div (Green) EN (Light Blue)VOUT 10V/Div (Light Blue) VOUT (Blue) LED Current 10mA/Div (Blue) LED Current (Purple) PWM 5V/Div (Purple) PWM 5V/Div PWM Duty 20% PWM Frequency=3kHz 2V/Div 10V/Div 10mA/Div PWM Frequency=10kHz 50% 90% GC3-Q020A Page 33 AP2001A 15. OFFICES 14. NOTES Please be sure that you carefully discuss your planned purchase with our office if you intend to use the products in this application manual under conditions where particularly extreme standards of reliability are required, or if you intend to use products for applications other than those listed in this application manual. Power drive products for automobile, ship or aircraft transport systems; steering and navigation systems, emergency signal communications systems, and any system other than those mentioned above which include electronic sensors, measuring, or display devices, and which could cause major damage to life, limb or property if misused or failure to function. Medical devices for measuring blood pressure, pulse, etc., treatment units such as coronary pacemakers and heat treatment units, and devices such as artificial organs and artificial limb systems which augment physiological functions. Electrical instruments, equipment or systems used in disaster or crime prevention. If you need more information on this product and other ASAHI KASEI TOKO POWER DEVICES products, please contact us. ASAHI KASEI TOKO POWER DEVICES CORPORATION 13-45, Senzui 3-chome, Asaka-shi, Saitama-ken 351-0024, Japan TEL: +81-48-460-1870 (Marketing Department) FAX: +81-48-460-1600 Semiconductors, by nature, may fail or malfunction in spite of our devotion to improve product quality and reliability. We urge you to take every possible precaution against physical injuries, fire or other damages which may cause failure of our semiconductor products by taking appropriate measures, including a reasonable safety margin, malfunction preventive practices and fire-proofing when designing your products. This application manual is effective from Sep. 2010. Note that the contents are subject to change or discontinuation without notice. When placing orders, please confirm specifications and delivery condition in writing. ASAHI KASEI TOKO POWER DEVICES is not responsible for any problems nor for any infringement of third party patents or any other intellectual property rights that may arise from the use or method of use of the products listed in this application manual. Moreover, this application manual does not signify that ASAHI KASEI TOKO POWER DEVICES agrees implicitly or explicitly to license any patent rights or other intellectual property rights which it holds. None of the ozone depleting substances (ODS) under the Montreal Protocol are used in our manufacturing process. YOUR DISTRIBUTOR GC3-Q020A Page 34