USERS MANUAL ISL97682IRTZEVALZ AN1662 Rev 0.00 ISL97682 LED Driver Evaluation Board User Manual October 11, 2011 Please refer to the ISL97682IRTZEVALZ Evaluation Board Introduction Schematic on page 2 for more details. The ISL97682IRTZEVALZ Evaluation Board provides a LED dimming frequency and duty cycle. complete testing platform for the ISL97682, a two channel - As mentioned in step 4 above, when the shunt on JP20 LED driver. Please refer to the product datasheet (ISL97682, is connected to the upper position, FPWM/DPWM pin is FN7689) for detailed information including pinout, pin function connected to VDC, the device enters direct PWM mode, description, electrical specifications, applications related which means both the LED dimming frequency and the information, etc. duty cycle are synchronized with the external PWM signal applied on the PWMI pin. Instructions - When the shunt on JP20 is connected to the lower Please follow the steps described below to start your position, the FPWM/DPWM pin is connected to a resistor. evaluation. Under such conditions, the LED dimming frequency of the chip is programmed by the resistance connected on the 1. For both switch 1 and 2 (SW1 and SW2 shown on the FPWM/DPWM pin as per Equation 2: board), set them to position 3 (left side). 7 10 2. For enable control jumper JP1, put the shunt to the ON FPWMHz = 12.4 ----------------------------------- (EQ. 2) R FPWM position (right side) to connect EN pin to VIN. When the shunt is set to the OFF position, it will disable the chip by The duty cycle is still modulated by the external PWM pulling the EN pin to ground. signal applied on PWMI pin. On board, potentiometer R11 3. Connect JP14 so the VIN pin is connected to PVIN. and a few other resistors are provided for easily adjusting 4. For JP20, connect the shunt to the upper position. the LED dimming frequency under such a configuration. 5. Connect WR and JP2-JP6. 6. Apply 1.5V~5.5V PWM signal between PWMI pin and AGND. 7. Apply 4V~26.5V between PVIN and PGND and the LEDs should be lit, and you can start the evaluation. NOTE: In step 1 above, the SW1, SW2 position can be adjusted to different positions for different configurations, see Table 1 for details. TABLE 1. SW1 SW2 POSITION POSITION DESCRIPTION 1 1 LX switching frequency = 600kHz, PFM CH1 and CH3 3 3 LX switching frequency = 1MHz, PFM CH1 and CH3 3 1 LX switching frequency = 600kHz, No PFM CH1 and CH3 1 3 LX switching frequency = 1MHz, No PFM CH1 and CH3 The LED maximum DC current adjustment. For each channel, the maximum DC current is set by resistance connected to RSET pin. The current for each channel can be calculated as shown in Equation 1: 402 ---------------------------- (EQ. 1) I LEDmA = RSETk On the board, a potentiometer R5 and a few other resistors are provided for easily adjust the LED maximum DC current. AN1662 Rev 0.00 Page 1 of 7 October 11, 2011ISL97682IRTZEVALZ AN1662 Rev 0.00 Page 2 of 7 October 11, 2011 ISL97682IRTZEVALZ Evaluation Board Schematic JP11 JP12 LED36 LED12 P8 AGND P7 R8 R6 LED11 LED35 AGND 5k R5 1M 0 P6 P10 TP8 RSET R7 R9 AGND PGND 10k Open P5 P9 LED10 LED34 R1 C3 C15 AGND TP9 33pF 8.2nF 150k PGND FSW/PHS R2 VDC 100k 1 3 1 3 LED9 LED33 U2 SW1 SW2 P4 5 16 NC PWMI LED8 LED32 PWMI U1 TP5 CH3 P3 6 15 EN CH3 EN ISL97682 LED7 LED31 1 3 7 14 VIN NC JP1 VDC TP3 C2 8 CH1 FPWN/DPWM 13 CH1 LED6 LED30 0.1F/50V 2 JP20 C13 R12 R11 R10 LED5 LED29 1nF/50V VDC 27k 100k 0 R4 R3 P2 C11 R13 C4 10k 1nF/50V 357k VIN 1F/16V Open C10 C9 LED4 LED28 TP1 JP14 3.3nF/50V 100pF/50V LX JP19 JP15 JP17 TP2 LED3 LED27 D1 F1 L1 P1 VOUT 15H PVIN 2A Fuse PMEG6030 XAL6060-153MEB C1 C5 C6 C8 LED2 C7 LED26 4.7F/ 4.7F/ NC 10F/50V NC 50V 50V 2-layer board. Connect top layer PGND and bottom JP7 JP9 layer AGND LED1 LED25 When SW1 = SW2 = 3: Fsw = 600kHz, WITH phase shift SW1 = 1, SW2 = 3: Fsw = 1.2MHz, WITHOUT phase shift JP3 JP5 JP2 SW1 = 3, SW2 = 1: Fsw = 600kHz, WITHOUT phase shift SW1 = SW2 = 1: Fsw = 1.2MHz, WITH phase shift I OUT EN can be connected in the following ways to enable/disable JP2: For measuring total output current the device: JP3-JP6: For measuring current on CH1-CH4 respectively (1) Connected it to VIN directly on JP1 to enable JP7-JP10, JP13-JP16: For easy configuration of 8x LED or 10x LED per string (2) Connected it to GND directly on JP1 to disable (3) Directly apply external voltage on P3(EN) to enable/disable the device without putting shunt on JP1. 2 2 2 3 1 9 4 FSW LX 10 3 PGND RSET VDC 11 2 COMP VDC 12 1 OVP AGND