Datasheet 5.0V to 14V, 3.0A 1ch Buck Converter with Integrated FET BD9859EFJ General Description Key Specifications The BD9859EFJ is a high-efficiency step-down switching Input Voltage Range: 5.0V to 14V regulator with built-in power MOSFET switch. This device Output Voltage Range: 1.0V to 0.7xVCC can operate over a wide range of input voltages and is Output Current: 3.0A (Max) flexible enough to produce output voltages from 1.0V up to Switching Frequency: 750kHz(Typ) 70% of the supply voltage, depending on the external High Side Nch FET ON-Resistance 100m(Typ) resistor values. The built-in N-Channel FET switch has a Nch FET ON-Resistance for Pew-Charge: 5(Typ) very high absolute maximum rating of 15V and is capable Standby Current: 0A (Typ) of handling current of up to 3.0 A. The implementation of Operating Temperature Range: -40C to +85C current-mode control for this switching regulator gives the advantage of a high-speed load response. The device has Package W (Typ) x D (Typ) x H (Max) a fixed switching frequency of 750kHz, allowing the use of smaller output inductors and capacitors. Also, its phase compensation network, although external to the device, is very simple and requires a minimal number of components, making the construction of a compact power supply really easy. Features 1.0V1.0% Feedback Voltage Built-In Soft Start Function Built-In Over Current Protect, Under Voltage Lockout, HTSOP-J8 and Thermal Shutdown Circuits ON/OFF Control through EN Pin 4.90mm x 6.00mm x 1.00mm Applications Generally for Household Equipment with 9V/12V Lines Typical Application Circuit (Input 12V, Output 5.0V/ 2.5A) C BST CBST RENR 0 0.022 uF J EN JENEN V VBBAATT V SW ENEN 0 CBAT C CENC open BAT EN 22 uF/ 16V GRM31CB31C226KE15 VCC VCC BST EN (murata) 4.7 uH LXLx GND VC FB (FDV0630 - 4R7M) 10 uF/ 6.3V GRM219B30J106KE18 (murata) L V VOOUTUT CC1 1000 pF C C1 COCUT D OUT RRC 7.5 k C CCC2 open C2 0 RFRA RSX301-LA30 (ROHM) 120 k RINV1 RINV2 30 k Figure 1. Typical Application Circuit Product structure : Silicon monolithic integrated circuit This product has no designed protection against radioactive rays . www.rohm.com TSZ02201-0Q3Q0AJ00420-1-2 2014 ROHM Co., Ltd. All rights reserved. 1/20 TSZ22111 14 001 22.Jan.2016 Rev.002 BD9859EFJ Pin Configuration (TOP VIEW) VCC VCC EN BST 8 7 6 5 Thermal Pad 1 2 3 4 VC LX GND FB Figure 2. Pin Configuration Pin Description Pin No. Pin Name Function 1 LX Power switch node 2 GND Ground pin 3 VC Error amplifier output pin 4 FB Feedback pin 5 EN Stand-by ON/OFF pin 6 BST High-side gate driver pin 7 VCC Voltage input pin 8 VCC Voltage input pin Block Diagram ON/OFF EN VCC TSD Reference UVLO REG VREF ICOMP shutdown BST ERROR FB AMP - 1.0V R Q + 100m + S LX V OUT Soft Start 5 GND OSC 750kHz VC Figure 3. Block Diagram www.rohm.com TSZ02201-0Q3Q0AJ00420-1-2 2014 ROHM Co., Ltd. All rights reserved. 2/20 TSZ22111 15 001 22.Jan.2016 Rev.002