® LY1152 Inverting DC/DC Controller (SOP) Rev. 1.2 FEATURES GENERAL DESCRIPTION 2.4V ~ 7.0V Power supply. Low shutdown current at 0.1uA (Typical). Low quiescent current at 90.0uA (Typical). Adjustable Output Voltage to -40V. 60KHz ~ 160KHz Switching Frequency. High Efficiency with Low Cost External PNP Bipolar Transistor. Pulse Frequency Modulation Maintains High Efficiency (80%). Lead free and green package available. (RoHS Compliant) Space Saving Package： - 8-pin SOP package. The LY1152 is a high performance inverting DC/DC controller, and the LY1152 designed to drive an external power switch to generate adjustable negative voltages. Output voltage can be scaled to -40V. The LY1152 quiescent current is about 90.0uA and shutdown mode current can be reduced to 0.1uA. In the LCD bias contrast application, efficiency of 80% can be achieved with low cost PNP bipolar transistor drivers. The LY1152 switching frequency can be around 60KHz to 160KHz range, and small size package is ideally suited for powered portable equipments. APPLICATION Negative Voltage Supply. Negative LCD Contrast Bias for - Portable Data Collection Terminals. - Notebook Computers. PIN CONFIGURATION LY1152 SOP8 (Top View) Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 FAX: 886-3-6668836 1 ® LY1152 Inverting DC/DC Controller (SOP) Rev. 1.2 PIN DESCRIPTION SYMBOL PIN NO DESCRIPTION VIN 1 Power supply input VREF 2 Reference output (1.22V).(*1) SHUTDOWN 3 Shutdown the device.(when low level is enable)(*2) FB 4 Feedback signal input to sense ground.(*3) GND 5 Ground. DLOW 6 Driver sinking output.(*4) DHI 7 Driver sourcing output.(*5) CL 8 Current-limit input.(*6) (*1)：Bypass with 0.047uF capacitor to GND, Sourcing capability is guaranteed to be greater than 250uA. (*2)：>1.5V = operation mode, GND = shutdown, In shutdown mode DLOW and DHI pins are at high level. (*3)：Connecting a resistor R2 to VOUT and a resistor R1 to VREF pin yields the output voltage: VOUT = -(R2/R1 ) x VREF (*4)：When using an external PNP bipolar transistor, connect a resistor R3 from this pin to DHI. R3 value depends on VIN, inductor and PNP bipolar transistor. By adjusting the R3 value, efficiency can be optimized. (*5)：Connect to base of the PNP bipolar transistor. (*6)：This pin clamps the switch peak current to prevent over-current damage to the external switch. The RCL resistor equation: R = V / I = 100mV(CL Threshold) / 100mA(the current(100mA) depend on user) R= 1Ω, (so the RCL resistor use 1Ω). APPLICATION CIRCUIT Figure 1. Application schematic for negative LCD contrast BIOS power supply Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 FAX: 886-3-6668836 2 ® LY1152 Inverting DC/DC Controller (SOP) Rev. 1.2 ORDERING INFORMATION LY 1 152 VV VV : PACKAGE TYPE SL : 8-PIN SOP PRODUCT NAME A : PRODUCT LINE LY : LYONTEK PRODUCT NUMBER PREFIX ABSOLUTE MAXIMUM RATINGS* PARAMETER Supply Voltage Operating Temperature Storage Temperature Junction Temperature Soldering Temperature (under 10 sec) SYMBOL VDD TA TSTG TJMAX TSOLDER RATING 7.0 -40 to 85 (I grade) -65 to 150 125 260 UNIT V ℃ ℃ ℃ ℃ ELECTRICAL CHARACTERISTICS (VIN=5.0V, TA = 25℃) Refer to Typical Application Circuit. PARAMETER Input voltage Quiescent Current Shutdown Current Shutdown Threshold CL Threshold VREF Voltage VREF Source Current TEST CONDITION VFB = -50mV VSHUTDOWN = 0V - MIN. 2.4 250 TYP. 90 0.1 1.5 100 1.22 - Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 FAX: 886-3-6668836 3 MAX. 7.0 1.0 - UNIT V uA µA V mV V uA ® LY1152 Inverting DC/DC Controller (SOP) Rev. 1.2 TYPICAL PERFORMANCE CHARACTERISTICS Fig.1 Shutdown Current vs Vin Fig.2 Efficiency vs Vin Fig.3 Frequency vs Vin Fig.4 Duty Cycle vs Vin Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 FAX: 886-3-6668836 4 ® LY1152 Inverting DC/DC Controller (SOP) Rev. 1.2 PACKAGE OUTLINE DIMENSION 8-PIN SOP (150 mil) PACKAGE OUTLINE DIMENSION： Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 FAX: 886-3-6668836 5