A Product Line of Diodes Incorporated PAM2303 3A LOW NOISE STEP-DOWN DC-DC CONVERTER Description Pin Assignments The PAM2303 is a 3A step-down DC-DC converter. It operates in two different modes: PSM and PWM modes. At light load, it automactically enters into the PSM mode to improve efficiency. At heavy load, the constant frequency PWM control performs excellent stability and transient response. No external compensation components are required. The PAM2303 supports a range of input voltages from 2.7V to 5.5V. The output voltage is adjustable from 0.6V to the input voltage. The PAM2303 employs internal power switch and synchronous rectifier to minimize external part count and realize high efficiency. During shutdown, the input is disconnected from the output and the shutdown current is less than 1A. Other key features include over- temperature and short circuit protection, and under-voltage lockout to prevent deep battery discharge. The PAM2303 delivers 3A maximum output current while consuming only 42A of no-load quiescent current. Ultra-Low R integrated DS(ON) MOSFETs and 100% duty cycle operation make the PAM2303 an ideal choice for high-output voltage, high-current applications which require a low dropout threshold. The PAM2303 is available in SOP-8(EP), DFN3X3-10 and QFN3X3- 16 package. Features Output Current: Up to 3A Output Voltage: 0.6V to V IN Input Voltage: 2.7 to 5.5V Efficiency up to 95% 42A (typ) No Load Quiescent Current Shutdown Current: <1A 100% Duty Cycle Operation Applications 1.5MHz Switching Frequency 5V or 3.3V Point of Load Conversion Analog Soft Start Telecom/Networking Equipment No external Compensation Required Set Top Boxes Current Limit Protection Storage Equipment Thermal Shutdown Video Cards SOP-8(EP), DFN3X3-10 and QFN3X3-16 Package DDR Power Supply 1 of 14 November 2012 PAM2303 Diodes Incorporated www.diodes.com Document number: DSxxxxx Rev. 1 - 2 A Product Line of Diodes Incorporated PAM2303 Typical Applications Circuit R1 = 0.6 1 + VO R2 Pin Descriptions Package Name Pin Function Name QFN3x3-16 SOP-8EP DFN3x3-10 PGND 1, 2, 3 2 Main power ground pin. FB 4 3 6 Feedback voltage to internal error amplifier, the threshold voltage is 0.6V. GND 5 4 4 Signal ground for small signal components. NC 6, 16 7 Not connected. Enable control input. Force this pin voltage above 1.5V, enables the chip, and below EN 7 5 5 0.3V shuts down the device. Test 8 6 Test mode. Lowconnection is recommended. VIN 9 7 8, 9, 10 Bias supply. Chip main power supply pin. PVIN 10, 11, 12 8 Input supply for power stage. Must be closely decoupled to PGND. SW 13, 14, 15 1 1, 2, 3 The drains of the internalmain and synchronous power MOSFET. Functional Block Diagram 2 of 14 November 2012 PAM2303 Diodes Incorporated www.diodes.com Document number: DSxxxxx Rev. 1 - 2