MP8847 – 6A, 2.7V-6V, HIGH-EFFICIENCY, SYNCHRONOUS

STEP-DOWN SWITCHER WITH I

MP8847 Rev. 1.02

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18

12/28/2017

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The MP8847 can communicate with the core

control interface (see Figure 3). The installation

process and usage can be found in the MP884x

Family Software Guide.

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/ 0xC1H internally (see Table 2). If other slave

addresses are needed, please contact the

factory.

Table 2: I

Hex

A7 A6 A5 A4 A3 A2 A1

A0

W 0xC0

R 0xC1

1

1

0

0

0

0

0

R/W

Address

0x60

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The MP8847’s EN pin can start up and

can control the converter as well. The Reg01

writing D7=0, the converter is off. When writing

D7=1, the converter is on. Both the external EN

converter works only when both EN pins are

high.

Output Voltage Selection

The

MP8847

output

voltage

is

programmable. There is no need to set

feedback resistors to achieve different output

voltages. The default output voltage is 0.95V

but can be set from 0.6V to 1.235V in 5mV

write the Go bit (Reg03 Syscntlreg2 [D5]) to 1.

This action means that the output voltage can

be set to another value that is not the default Vo

voltage. Then write the Output reference bit

(Reg01 VSEL [D6:D0]). The output voltage can

be changed according to Table 1.

To guarantee a normal output voltage, the input

voltage is suggested to be 1.5V higher than the

pre-set output voltage.

Switching Frequency

The default switching frequency of the MP8847

is 1.25MHz. However, the frequency can be

changed based on the application. By writing

the

switching

frequency

bits

(Reg02

SysCntlreg1 [D7:D5], the switching frequency

can be programmed to one of six possible

values. Their corresponding data can be found

in Reg02 SysCntlreg1.