RAA230221 查看數據表（PDF） - Renesas Electronics

零件编号

产品描述 (功能)

生产厂家

RAA230221

16V Input, 3A, Dual Step-Down DC/DC Converter / BatteryBackup

Renesas Electronics 

RAA23022x RAA23023x

Battery Backup (RAA23022x)

RAA23022x has a battery backup circuit which is used to operate some devices at system power-off.

The circuit can be easily designed by RAA23022x without two diodes.

When CH1 operates, VBB_OUT = VOUT1. When CH1 stops and VOUT1 pin voltage is higher than

VBB_IN pin, VBB_OUT = VOUT1 pin. When CH1 stops and VOUT1 pin voltage is lower than

VBB_IN pin, VBB_OUT = VBB_IN pin.

VBB_OUT voltage value is dependent on on-resistance between VBB_IN and VBB_OUT,

On-resistance between VOUT1 and VBB_OUT and VBB_OUT output current. VBB_OUT can be

calculated by equations below.

1. Normal operation mode (VBB_OUT = VOUT1)

2. Battery backup mode (VBB_OUT = VBB_IN)

VBB_OUT : VBB_OUT voltage (V)

VOUT1 : VOUT1 voltage = CH1 output voltage (V)

VBB_IN : VBB_IN voltage = Battery voltage (V)

IBB_OUT : VBB_OUT output current (A)

Ron_vout1 : On resistance between VOUT1 and VBB_OUT

Ron_vbat : On resistance between VBB_IN and VBB_OUT

100Ω (Typ.)

400Ω (Typ.)

Note : 2.7V ≤ VBB_OUT ≤ 3.7V

Connect over 0.47uF capacitor to VBB_OUT pin.

Note : POK1 is an IC internal signal which identifies CH1 operating status.

It cannot be seen from IC outside.

VBB_OUT pin output status

CH1

Operation

(POK1 = H)

Stop

(POK1 = L)

Note : L: Low level, H: High level

VOUT1, VBB_IN

VOUT1 ≥ VBB_IN

or

VOUT1 < VBB_IN

VOUT1 ≥ VBB_IN

VOUT1 < VBB_IN

VBB_OUT

VOUT1

VOUT1

VBB_IN

R18DS0017EJ0100 REV.1.00

Apr.21.2015

Page 20 of 30

Share Link: