NXP Semiconductors Document Number: MC34845 Rev. 8.0, 8/2016 Data Sheet: Technical Data Low cost six channel led backlight 34845 driver with integrated power supply LED DRIVER The 34845 series represents high efficiency LED drivers for use in backlighting LCD displays from 10 to 17. Operating from supplies of 5.0 V to 21 V, the 34845 series is capable of driving up to 16 LEDs in series in six separate strings. The LED current tolerance in the six strings is within 2% maximum and is set using a resistor to GND. 98ASA00602D PWM dimming is performed by applying a PWM input signal to the PWM pin 24-PIN QFN-EP which modulates the LED channels directly. An Enable Pin (EN) provides for low Applications power standby. Alternatively, a single wire scheme selects power down when PWM is connected to the Wake pin and held low. PC notebooks The integrated boost converter uses dynamic headroom control to automatically Netbooks set the output voltage. There are three device versions for boost frequency GPS screens 34845C is 600 kHz, and the 34845D is 300 kHz. External compensation allows Portable DVD players the use of different inductor/ capacitor combinations. Picture frames The 34845 includes fault protection modes for LED short and open, Smaller screen televisions overtemperature, overcurrent and overvoltage errors. It features an internally Industrial/instrumentation displays fixed OVP value of 60 V (typical) which protects the device in the event of a failure Health care device displays in the externally programmed OVP. The OVP level can be set by using an external resistor divider. This device is powered using SMARTMOS technology. Features Input voltage of 5.0 V to 21 V Boost output voltage up to 60 V 2.0 A integrated boost FET Fixed boost frequency - 300 kHz or 600 kHz OTP, OCP, UVLO fault detection LED short/open protection Programmable LED current between 3.0 mA and 30 mA 34845 12V VIN SWA VDC1 SWB VDC2 VOUT PGNDB COMP PGNDA OVP 5V EN ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ FAIL PWM CONTROL CH1 UNIT WAKE CH2 CH3 CH4 ISET CH5 CH6 GND EP GND Figure 1. 34845 simplified application diagram 2016 NXP B.V.1 Orderable parts Table 1. Device variations Boost switch current limit Switching frequency Slope compensation V SLOPE Temperature (1) I (A) f (kHz) (V/s) BOOST LIMIT S Part number Package (T ) A Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. MC34845CEP 1.9 2.1 2.3 540 600 660 0.52 -40 to 85 C 24 QFN-EP - - MC34845DEP 2.1 2.35 2.6 270 300 330 0.22 Notes 1. To order parts in Tape and Reel, add the R2 suffix to the part number. 34845 2 NXP Semiconductors