Preliminary Datasheet LP3164 4-Channel Current Source White LED Driver General Description Features The LP3164 is a low-dropout bias supply for white LEDs is a high-performance alternative to the simple ballast resistors used in conventional white LED designs. It supports 4 white LEDs with regulated constant current for uniform intensity. The LP3164 maintains low dropout current regulators. The LP3164 requires a 50mV dropout at a 20mA load on each output to match the LED brightness. The brightness of LEDs can be tuned through a pulse width modulated signal at the PWM pin. The LP3164 is available in a QFN-16 package. 2.7V to 6V Input Voltage 20mA maxim sink current PWM tuned LED brightness through PWM pin(2KHz) Soft Start Function Built-in Thermal Protection IQ<1uA in Shutdown QFN-16 Package RoHS Compliant and 100% Lead (Pb)-Free Typical Application Circuit VBATT PWM 1 2 3 4 9 14 15 16 Order Information LP3164 - 8 EN LP3164 NC NC NC NC NC NC NC NC VIN 7 1uF LED1 LED2 LED3 LED4 PGND GND 13 12 11 10 6 5 □ □ □ F: Pb-Free Package Type QV: QFN-16 Marking Information Please see website. Applications LCD Panel Cellular and Smart mobile phone PDA/DSC PMP LP3164 – Ver. 1.0 Datasheet Feb.-2008 Page 1 of 5 Preliminary Datasheet LP3164 Functional Pin Description Part No. LED1 13 NC 14 LED2 LED3 LED4 NC 11 10 9 Pin Configurations 12 P a c k a g e Ty p e PIN EN 7 VIN PGND QFN-16 NAME AGND 4 5 NC 16 3 NC NC PGND 2 6 NC 15 1 NC NC LP3164 8 DESCRIPTION QFN-16 1,2,3,4,9,14,15,16 5/6 7 NC No Internal Connection. AGND/PGND Ground. VIN Power Supply. Chip Enable(active High).and connects to a GPIO of MCU,the GPIO supply a PWM singal dimming method to control the brightness(0-20mA) of white LEDs and the PWM frequency from 200Hz to 10KHz,the duty from 0% to 100%.the typical frequency is 2KHz. 8 EN/PWM 10 LED4 LED4 cathode terminal. 11 LED3 LED3 cathode terminal. 12 LED2 LED2 cathode terminal. 13 LED1 LED1 cathode terminal Function Block Diagram LP3164 – Ver. 1.0 Datasheet Feb.-2008 Page 2 of 5 Preliminary Datasheet LP3164 Absolute Maximum Ratings Input Voltage to GND (VINA, VINB) ---------------------------------------------------------------------------- 6V EN/LED to GND Voltage (Ven/LED) ---------------------------------------------------------- 0.3V to Vin+0.3V Maximum DC Output Current(Iout) ----------------------------------------------------------------------- 150mA Operating Junction Temperature Range (TJ) ----------------------------------------------------40℃ to 150℃ Maximum Soldering Temperature (at leads, 10sec) ------------------------------------------------------ 300℃ Thermal Information Maximum Power Dissipation (PD) QFN-16 ---------------------------------------------------------------- 1.5W Thermal Resistance (JA) ------------------------------------------------------------------------------------50℃/W Electrical Characteristics (Over recommended operating conditions unless specified otherwise) VINA =3.6V,EN=High, TA=25℃ ) Parameter Symbol Conditions Min. 3 0.6 VOUT Input Voltage Output Voltage Range IQ Quiescent Current No Load,1X mode ISHDN ILED-ERR Shutdown Current ENB = GND LED Current Accuracy 3mA< ILED<30mA 19 ILED-LED-ERR LED Channel Matching Any two channel mismatch -3 VEN(L) Enable Threshold Low VEN(H) Enable Threshold High VIN LP3164 – Ver. 1.0 Datasheet Feb.-2008 LP3164 Typ. Max. 5.5 Unit V V VINB 250 uA 0.1 1 µA 20 21 mA 3 % 0.5 V 100 2 V Page 3 of 5 Preliminary Datasheet LP3164 Typical Operating Characteristics LP3164 – Ver. 1.0 Datasheet Feb.-2008 Page 4 of 5 Preliminary Datasheet LP3164 Packaging Information LP3164 – Ver. 1.0 Datasheet Feb.-2008 Page 5 of 5