MP6546

– 22V, 3A PEAK, 3-PHASE BLDC DRIVER WITH 1MHZ I2C INTERFACE

MP6546 Rev. 1.0

MonolithicPower.com

13

3/20/2023

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the corresponding channel. All these changes

only take effect after register 09h is written to a

certain value.

I2C Input Interface

To access the internal register and angle data,

the MP6546 has fast-mode plus I2C mode, which

can support a clock frequency up to 1MHz.

The slave address can be configured via two

methods. The first method is to set ADDR[1:0] in

register 00h to 0. In this scenario, the address is

set by the ADDR pin. The low level represents

0x07h, the middle level represents 0x08h, and

the high value represents 0x09h.

The second method is to set the address using

the register. See the Register Description

section on page 16 for more details.

The

MP6546

supports

multi-slave

bus

connections to support up to three slaves (see

Figure 7). All slaves can monitor the SDA input

data and receive data at the same time with the

broadcasting address. With the mapped address,

only one slave can transmit data through the

SDA data pin, while the other two slaves release

the bus.

System

MCU

Controller

MP6546

#1

MP6546

#2

MP6546

#3

Write UD/Q[9:0],

Read ANGLE[14:0]

I

2C Bus

Gyro

Angle

Sensor

Angle

Sensor

Angle

Sensor

Figure 7: Multi-Slave Bus Connection

D/Q Reference Frame Voltage Control

The MP6546 provides D/Q reference frame rotor

FOC voltage control. The voltage command for

the D/Q reference comes from the main system

MCU via the I2C interface. Then the UA/UB/UC

output is modulated with the SVPWM output.

This controls the three-axis motors via the

system MCU.

Enable and Standby Operation

To reduce the operating current, the IC works in

two modes for flexibility. These modes are

described below.

1. By pulling the EN pin high: Set the

STDBY_EN bit in register 00h then write to

register 10h. Then the IC works in standby

mode to reduce the quiescent current. A

3.3V low-dropout (LDO) regulator can be

shut down or activated via the trimming bit

TRIM_ENP in register 03h.

Write to register 0Fh to force the IC to return

to normal operation. The IC also resumes

normal operation if a negative edge is

detected on the SCL/SCK pin.

2. By pulling the EN pin low: The IC completely

shuts down.

Over-Current Protection (OCP)

The MP6546 has a cycle-by-cycle current limit to

clamp the peak current near a certain threshold.

When the current flowing through the MOSFETs

exceeds this threshold, all low-side MOSFETs

(LS-FETs) turn on to reduce the phase current.

This trigger threshold is selectable. The default

threshold is a 3A peak current, and it scales

down to 75% if the OCP_SEL bit in register 00h

is set to high. The current-limit function can be

disabled by setting OCP_EN in register 00h to 0.

Short-Circuit Protection (SCP)

The MP6546 provides short-circuit protection

(SCP) to prevent IC damage caused by an over-

current condition. When the current through the

MOSFETs exceeds the threshold after the 1µs

blanking time, all MOSFETs turn off. After about

150ms, the IC resumes normal operation. The

default threshold is a 4.5A peak current, and it

scales down to 75% if the OCP_SEL bit in

register 00h is set to high. SCP can be disabled

by setting SCP_EN in register 00h to 0.

Thermal Shutdown (TSD)

The

MP6546

’s die also features thermal

monitoring. If the die temperature exceeds

155°C, all MOSFETs turn off. Once the die

temperature drops below 105°C, operation

automatically resumes.

Over-Voltage Protection (OVP)

VIN is detected to prevent MOSFET breakdown.

If VIN exceeds 18V, all MOSFETs turn off. Once

VIN drops below 16V, operation automatically

resumes. Over-voltage protection (OVP) is