RT9025 2A, Ultra Low Dropout LDO General Description Features l Ultra Low Dropout Voltage 230mV at 2A The RT9025 is a high performance positive voltage regulator l Output Current up to 2A designed for use in applications requiring very low Input l High Accuracy Output Voltage 2% voltage and extremely low dropout voltage at up to l Power Good Output 2A(Peak). It operates with a VIN as low as 1V and VDD l Output Voltage Pull Low Resistor when Disable voltage 3V with programmable output voltage as low as l Over Current Protection 0.8V. The RT9025 features ultra low dropout that is ideal l Thermal Shutdown Protection for applications where VOUT is very close to VIN. l RoHS Compliant and 100% Lead (Pb)-Free Additionally, it has an enable pin to further reduce power dissipation while shutdown and provides excellent Applications regulation over variations in line, load and temperature. The RT9025 provides a power good signal to indicate if l Note Book PC Applications the voltage level of Vo reaches 90% of its rating value. l Motherboard Applications The RT9025 is available in the SOP-8 and SOP-8 (Exposed Pad) package with 1.05V, 1.2V, 1.5V, 1.8V and 2.5V Pin Configurations internally preset outputs that are also adjustable by using external resistors. (TOP VIEW) PGOOD GND 8 Ordering Information EN 2 ADJ 7 RT9025- VIN 3 6 VOUT VDD 4 5 NC Package Type S : SOP-8 SOP-8 SP : SOP-8 (Exposed Pad-Option 1) Lead Plating System PGOOD GND 8 P : Pb Free EN 2 7 ADJ G : Green (Halogen Free and Pb Free) GND VIN 3 VOUT 6 Z : ECO (Ecological Element with 9 VDD 4 5 NC Halogen Free and Pb free) Output Voltage SOP-8 (Exposed Pad) 1K : 1.05V/Adj 12 : 1.2V/Adj 15 : 1.5V/Adj 18 : 1.8V/Adj 25 : 2.5V/Adj Note : Richtek products are : RoHS compliant and compatible with the current require- ments of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. DS9025-05 March 2011 www.richtek.com 1RT9025 Typical Application Circuit R1+ R2 V = 0.8 OUT R2 V V IN VIN V IN VIN V VOUT OUT VOUT OUT C IN C IN C F C C R1 OUT OUT 10F 10F RT9025 RT9025 10F 10F Chip Enable Chip Enable ADJ ADJ EN EN R2 PGOOD PGOOD V V VDD VDD DD DD GND GND 100k 100k 1F 1F V V OUT OUT Figure 1. Fixed Voltage Regulator Figure 2. Adjustable Voltage Regulator Functional Pin Description Pin No. Pin Name Pin Function 1 PGOOD Power Good Open Drain Output. 2 EN Chip Enable (Active High). 3 VIN Supply Input Voltage. 4 VDD Supply Voltage of Control Circuit. 5 NC No Internal Connection. 6 VOUT Output Voltage. Set the output voltage by the internal feedback resistors when ADJ is grounded. 7 ADJ If external feedback resistors is used, V = 0.8V x (R2 + R1) / R2. OUT 8, Ground. The exposed pad must be soldered to a large PCB and connected to GND 9 (Exposed Pad) GND for maximum power dissipation. Function Block Diagram VIN VOUT SD OCP Error Amplifier EN OTP VDD POR 0.8V Mode ADJ PGOOD - + 0.72V GND www.richtek.com DS9025-05 March 2011 2 + -