DatasheeDatasheett 3.6V to 35V Input 1ch Buck Controller BD9845FV General Description Key Specifications BD9845FV is a switching regulator controller that uses Supply Voltage Range: 3.6V to 35V pulse width modulation. This IC can be used for Error Amplifier Reference Voltage: 1.0V1% step-down DC/DC converter applications. BD9845FV is Oscillation Frequency: 100kHz to 1500kHz available in a compact package that is optimum for Standby Current: 0A(Typ) compact power supplies of many kinds of equipment. Operating Temperature Range: -40C to +85C Features Package W(Typ) x D(Typ) x H(Max) Operates up to (V =35V) CC Contains FET Driver Circuit (Step-Down Circuit 1 output). REG Output Circuit (2.5V) are contained. Built-In Over Current Protect Adjustable Soft Start and Pause Period. Three modes of Standby, Master, and Slave can be Switched. (ICCS = 0 A typ during standby) ON/OFF control is enabled independently for each channel. (DT terminal) Applications SSOP-B14 LCD, PDP, PC, AV, Printer, DVD, Projector TV, Fax, 5.00mm x 6.40mm x 1.35mm Copy Machine, Measuring Instrument, etc Typical Application Circuit V IN STB VC C VC C V R EF VC C VR EF VR EF VC C - 5VR EG 5V C 5V CT O SC U VLO TSD IN V VC C V R EF - V O SS - O U T + +PW M DRV ER R (Step-dow n) + + VC C VC C -5V O C P 2 - FB O C P + DT VC C - 5V O C P + O C P- G N D Figure 1. Typical Application Circuit Product structureSilicon monolithic integrated circuit This product has no designed protection against radioactive rays www.rohm.com TSZ02201-0Q3Q0AJ00470-1-2 2015 ROHM Co., Ltd. All rights reserved. 1/25 TSZ2211114001 06.Nov.2015 Rev.001 BD9845FV Pin Configuration (TOP VIEW) VREF DT 1 14 CT SS 2 13 INV 3 GND 12 FB 11 4 STB SEL 5 10 C5V 6 OCP- 9 OUT OCP+ 7 VCC 8 Pin Description Pin Pin Pin Pin Function Function Number Name Number Name Reference voltage (2.5V) Output over-current detector 1 VREF 8 OCP output terminal + input terminal Output over-current detector 2 CT Timing capacity external terminal 9 OCP - input terminal 3 GND Ground 10 SEL Master/Slave mode setting terminal 4 STB Standby mode setting terminal 11 FB Output error amplifier output terminal 5 C5V Output L side voltage (VCC-5V) 12 INV Output error amplifier - input terminal 6 OUT Output 13 SS Output soft start time setting terminal 7 VCC Power terminal 14 DT Output dead time setting terminal Block Diagram SEL VCC STB OCP+ OCP- VCC VCC VREF + VCC MASTER STB - OCP REG REG + /SLAVE VREF OCP (2.5V) C5V (VCC-5V) - 50mV10mV C5V C5V DT DTLow - DTOFF DT + FB 1.25V VREF VCC 1V10mV 2 A + + SS LS + ERR + PWM DRV OUT - SSOFF - C5V INV PROTECTION LOGIC DTLow SSOFF OSC 200 A TSD OCP TSD + DTOFF Hold time - 2.0V - (1.6msec) 1.5V 200 A UVLO TSD VCC Hold time 3.2V (0.2msec) MASTER UVLO VREF 2.2V /SLAVE 2V UVLO 3V 1.5V C5V CT GND www.rohm.com TSZ02201-0Q3Q0AJ00470-1-2 2015 ROHM Co., Ltd. All rights reserved. 2/25 TSZ2211115001 06.Nov.2015 Rev.001