RT5112A
HWEN
LDOX_DELAY
SEQ_CTRL = 10
BUCK1_EN
LDO1_EN
SEQ_CTRL = 01
SEQ_CTRL = 11
SLOT1
SLOT2
SLOT3
SLOT4
SLOT5
SLOT6
SLOT7
SLOT7
SLOT6
SLOT5
SLOT4
SLOT3
SLOT2
SLOT1
BUCK1
LDO1
LDO2
LDO3
LDO4
Figure 8.
Example for sequence control SEQ_CTRL change from 01 to 11. All channels are turned off immediately.
Output Voltage Setting
The RT5112Aoutput voltage can be programmed via I2C
with dedicated registers.
Bucks
Auto PFM (Pulse Frequency Modulation) Mode
In order to save power and improve efficiency at low
loads, the Buck operates in PFM mode as the inductor
drops into DCM (Discontinuous Current Mode). The
switching frequency is proportional to loading to reach
output voltage regulation. When load increases and
inductor current becomes continuous again, the Buck
automatically goes back to PWM fixed frequency
mode. Additionally, the RT5112A will enters DSLP
(Deep Sleep) to reach input low quiescent current at
no load.
Bucks
Registers 0x0C[7:0]/0x12[7:0] are used to control
Bucks output voltage.
Register 0x14[7:6] is used to control Bucks voltage
scaling slew rate.
LDOs
Registers 0x0D[7:1], 0x0E[7:1], 0x0F[7:1], 0x10[7:1]
are used to control LDO1, LDO2, LDO3 and LDO4
output voltage.
Register 0x14[5:4] is used to control LDOs voltage
scaling slew rate.
FPWM (Forced Pulse Width Modulation) Mode
The switching frequency is forced into PWM mode
2.5MHz (typ.) operation. In this mode, the inductor
current is in CCM (Continuous Current Mode) and
the voltage is regulated by PWM.
Operating Mode
The RT5112Aprovides different operating modes for Bucks
and LDOs for flexible application. Registers 0x00[1:0],
0x01[1:0], 0x02[1:0], 0x03[1:0], 0x04[1:0] and 0x06[1:0]
are used to control the operating mode.
Normal Mode
The operation is same as Auto PFM mode. The only
one difference is that there is no DSLP in this mode.
Copyright 2019 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS5112A-02 August 2019
www.richtek.com
27
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