Nisshinbo RP604 Buck-Boost DC-DC Converters
Nisshinbo RP604 Buck-Boost DC-DC Converters feature a minimum supply current and high efficiency at low loads. The series operates at a low operating quiescent current (0.3µA), making it ideal for wearable devices, applications for the Internet of Things (IoT), and wireless communications modules requiring a low level of current consumption to extend battery life. The converters provide up to 300mA in buck mode. In boost mode, the output current is less and related to the input voltage level. In order to reduce valuable circuit board space, the RP604 converters require only three external components. These devices are offered in compact WLCSP-20-P2 and DFN(PLP)2730-12 packages for design flexibility.
Protection Circuits
Nisshinbo RP604 Buck-Boost DC-DC Converters include safety functions to protect the IC and other parts of the application against possible damage and defects. Protections include:
- Undervoltage lockout - converter is switched off in case input voltage falls below minimum threshold
- Soft-start - regulates output voltage to smoothly rise and prevents output overshoot and undershoot during start-up period
- Lx current limit - prevents peak current through inductor from exceeding specific maximum current threshold
- Output overvoltage - turns off both P channel and N channel MOSFETs
- Thermal shutdown - switches off IC in case junction temperature rises above +140°C
Li-ion Battery Discharge Curve
The RP604 converters are ideal for use in battery-powered devices like wearables, IoT applications, and wireless sensor modules, as well as in circuits for energy harvesting. The RP604 series is particularly well suited when a supply voltage is required and located somewhere in between the voltage level of a fully charged and fully discharged battery. At the correct moment, the DC-DC converter automatically switches over from buck mode to boost mode to maintain the output voltage setting.
Active & Sleep Modes
These converters are designed for applications that are mainly in sleep mode and wake up periodically to perform a measurement, transmit data, and then return to sleep mode. For these types of applications, the current consumption in sleep mode should remain as low as possible. The RP604 series features a low quiescent current and consumes only 300nA to prolong battery life, resulting in the use of a smaller-sized battery for applications.
Features
- 1.8V to 5.5V (6.5V) maximum input voltage range
- 0.3µA operating quiescent current
- 0.01µA standby current
- 1.6V to 5.2V (0.1V step) output voltage range
- ±1.5% output voltage accuracy
- 92% peak efficiency
- 300mA (at buck) maximum output current
- Optional auto-discharge mode
- -40°C to +125°C junction temperature range
- -40°C to +85°C operating temperature range
- Built-in driver ON-resistance (RP604Z, VIN = 3.6V):
- PMOS = Typ. 0.12Ω
- NMOS = Typ. 0.12Ω
- Undervoltage lockout, soft-start, overvoltage protection, Lx peak current, and thermal shutdown
- Packages
- WLCSP-20-P2 (1.71mm x 2.315mm)
- DFN(PLP)2730-12 (3.0mm x 2.7mm
- Halogen free
- RoHS compliant
Applications
- Wearable devices
- Smart watches
- Smart bands
- Healthcare
- Fitness
- Li-ion/coin battery-powered devices
- Low-power devices for CPU and memory
- Low-power wireless communication equipment
- BLUETOOTH® Low Energy (BLE)
- Zigbee®
- Wi-SUN®
- ANT
- Sensor devices
- Energy harvesting
Videos
Block Diagram
Typical Application Circuit
Development Tools
Nisshinbo RP604Z331B-EV Evaluation Board
Demonstration and evaluation platform based on the RP604 Buck-Boost DC-DC Converter.
Related Products
Nisshinbo RP605 Buck-Boost DC-DC Converters
300mA ultra-low-power buck-boost DC-DC converter with an integrated battery monitor.