Nisshinbo Micro Devices Inc. RP509Z161B-E2-F

The RP509x is a low supply current PWM/VFM step-down DC/DC converter with synchronous rectifier featuring 0.5 A/1 A output current. Internally, a single converter consists of a reference voltage unit, an error amplifier, a switching control circuit, a mode control circuit, a soft-start circuit, an undervoltage lockout (UVLO) circuit, a thermal shutdown circuit, and switching transistors. The RP509x is employing synchronous rectification for improving the efficiency of rectification by replacing diodes with built-in switching transistors. Using synchronous rectification not only increases circuit performance but also allows a design to reduce parts count. Output voltage controlling method is selectable between a PWM/VFM auto-switching control type and a forced PWM control type, which further reduces noise than a normal PWM control under a light load, and these types can be set by the MODE pin. Output voltage type is selectable between an internally fixed output voltage type and an externally adjustable output voltage type. Protection circuits in the RP509x is current limit circuit and thermal shutdown circuit. LX current limit value (Typ.) is selectable between 1.6 A and 1.0 A. The RP509Z is available in WLCSP-6-P6 which achieves high-density mounting on boards. Using capacitor of 0402-/1005-size (inch/mm) and inductor of 0603-/1608-size (inch/mm) as external parts help to save space for devices. The RP509N is available in SOT-23-6.

• Input Voltage Range (Maximum Rating): 2.3 V to 5.5 V (6.5 V)
• Output Voltage Range (Fixed Output Voltage Type): 0.6 V to 3.3 V settable in 0.1 V steps (Adjustable Output Voltage Type): 0.6 V to 5.5 V
• Output Voltage Accuracy (Fixed Output Voltage Type): ±1.5% (VSET ≥ 1.2 V), ±18 mV (VSET < 1.2 V)
• Feedback Voltage Accuracy (Adjustable Output Voltage Type): ±9 mV (VFB = 0.6 V)
• Output Voltage/Feedback Voltage Temperature Coefficient: ±100 ppm/℃
• Selectable Oscillator Frequency: Typ. 6.0 MHz
• Oscillator Maximum Duty: Min. 100%
• Built-in Driver ON Resistance (VIN = 3.6 V): Typ. Pch. 0.175 Ω, Nch. 0.155 Ω (RP509Z) Typ. Pch. 0.195 Ω, Nch. 0.175 Ω (RP509N)
• Standby Current: Typ. 0 μA
• UVLO Detector Threshold: Typ. 2.0 V
• Soft-start Time: Typ. 0.15 ms
• Inductor Current Limit Circuit: Typ. 1.6 A/1.0 A, selectable Current Limit
• Package: WLCSP-6-P6 (1.28 mm × 0.88 mm × 0.69 mm) SOT-23-6 (2.9 mm × 2.8 mm × 1.1 mm)

• Portable Communication Equipment: Mobiles/Smartphones, Digital Cameras and Note-PCs
• Li-ion Battery-used Equipment