BU90104GWZ-E2 ROHM

Datasheet Single-chip Type with Built-in FET Switching Regulator Series 1.0A, Step-down Switching regulators with Built-in Power MOSFET BU90104GWZ General Description Applications The BU90104GWZ are a high efficiency 6MHz Smart phones, Cell phones, Portable applications and synchronous step-down switching regulator with ultra Micro DC/DC modules, USB accessories low current PFM mode. It provides up to 1.0A load current and an input voltage Package(s) W(Typ.) x D(Typ.) x H(Max.) range from 3.0V to 5.5V, optimized for battery powered UCSP35L1 1.30mm x 0.90mm x 0.40mm portable applications. BU90104GWZ has a mode control pin that allows the user to select Forced PWM(Pulse Width Modulation) mode or PFM(Pulse Frequency Modulation) and PWM auto change mode utilized power save operation at light Typical Application Circuit(s) load current. Features Fast transient response Automatic PFM/PWM operation Forced PWM operation Internal Soft Start Under voltage lockout Over current protection Thermal shutdown Figure 1. Typical Application Circuit(s) Lineup Operating mode Output Part No. Input voltage Switching frequency voltage MODE=L MODE=H Automatic BU90104GWZ 1.80V 2.3V to 5.5V 4.8MHz to 6.0MHz Forced PWM PFM/PWM Pin Configuration(s) Pin Description(s) (BOTTOM VIEW) Pin No. Symbol Function A1 VIN Power supply input pin A2 EN Enable pin A3 GND GND pin B1 MODE Forced PWM mode pin B2 LX Inductor connection pin B3 FB Feedback voltage input pin Figure 2. Pin Configuration(s) Product structureSilicon monolithic integrated circuit This product is not designed protection against radioactive rays www.rohm.com TSZ02201-0F1F0AG00080-1-2 2015 ROHM Co., Ltd. All rights reserved. 1/14 TSZ2211114001 22.Jul.2015 Rev.001DatasheetDatasheet BU90104GWZ Block Diagram(s) Figure 3. Block Diagram(s) Description of Block(s) The BU90104GWZ are a synchronous step-down DC/DC converter that achieves fast transient response from light load to heavy load by hysteretic PWM control system and current constant PFM control system. PWM control BU90104GWZ operates by hysteretic PWM control. This scheme ensures fast switching, high efficiency, and fast transient response. When the output voltage is below the VREF voltage, the error comparator output is low to high and turning on P-channel MOSFET until above the VREF voltage and minimum on time. PFM control At light load the regulator and MODE=low, the regulator operates with reduced switching frequency and improves the efficiency. During PFM operation, the output voltage slightly higher than typical output voltage. Figure 4. Operation of PFM mode and PWM mode www.rohm.com TSZ02201-0F1F0AG00080-1-2 2015 ROHM Co., Ltd. All rights reserved. 2/14 TSZ2211115001 22.Jul.2015 Rev.001