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LTC3676.cpp File Reference

LTC3676: Power management solution for application processors. More...

Detailed Description

LTC3676: Power management solution for application processors.

The LTC3676 is a complete power management solution for advanced portable
application processor-based systems. The device contains four synchronous
step-down DC/DC converters for core, memory, I/O, and system on-chip (SoC)
rails and three 300mA LDO regulators for low noise analog supplies. The
LTC3676-1 has a 1.5A buck regulator configured to support DDR termination
plus a VTTR reference output. An I2C serial port is used to control regulator
enables, power-down sequencing, output voltage levels, dynamic voltage
scaling, operating modes and status reporting.
Regulator start-up is sequenced by connecting outputs to enable pins in the
desired order or via the I2C port. System power-on, power-off and reset
functions are controlled by pushbutton interface, pin inputs, or I2C.
The LTC3676 supports i.MX, PXA and OMAP processors with eight independent
rails at appropriate power levels. Other features include interface signals
such as the VSTB pin that toggles between programmed run and standby output
voltages on up to four rails simultaneously. The device is available in a
40-lead 6mm x 6mm QFN package.

I2C DATA FORMAT (MSB FIRST);

http://www.linear.com/product/LTC3676

http://www.linear.com/product/LTC3676#demoboards

Copyright 2018(c) Analog Devices, Inc.

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  • Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
  • Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
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  • The use of this software may or may not infringe the patent rights of one or more patent holders. This license does not release you from the requirement that you obtain separate licenses from these patent holders to use this software.
  • Use of the software either in source or binary form, must be run on or directly connected to an Analog Devices Inc. component.

THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Library for LTC3676: Power management solution for application processors

Definition in file LTC3676.cpp.

Go to the source code of this file.

Functions

int8_t LTC3676_register_read (uint8_t i2c_address, uint8_t register_address, uint8_t *register_data)
 Reads an 8-bit register from the LTC3676 using the standard repeated start format. More...
 
int8_t LTC3676_register_write (uint8_t i2c_address, uint8_t register_address, uint8_t register_data)
 Writes to an 8-bit register inside the LTC3676 using the standard I2C repeated start format. More...
 
int8_t LTC3676_bit_set (uint8_t i2c_address, uint8_t register_address, uint8_t bit_number)
 Sets any bit inside the LTC3676 using the standard I2C repeated start format. More...
 
int8_t LTC3676_bit_clear (uint8_t i2c_address, uint8_t register_address, uint8_t bit_number)
 Clears any bit inside the LTC3676 using the standard I2C repeated start format. More...
 
int8_t LTC3676_bit_write (uint8_t i2c_address, uint8_t register_address, uint8_t bit_number, uint8_t bit_data)
 Writes any bit inside the LTC3676 using the standard I2C repeated start format. More...
 
uint8_t LTC3676_bit_is_set (uint8_t i2c_address, uint8_t register_address, uint8_t bit_number)
 Reads the value of any bit in any register or the LTC3676. More...
 
float LTC3676_set_buck_output_voltage (uint8_t i2c_address, uint8_t register_address, float output_voltage)
 Sets the output voltage of any buck. More...
 
float LTC3676_set_buck_fb_ref (uint8_t i2c_address, uint8_t register_address, float fb_ref_voltage)
 Writes the Feedback Reference Voltage of any buck. More...
 
float LTC3676_buck_vout_max (uint8_t buck_number)
 Calculates the maximum output voltage of any buck in mV based on the feedback resistors. More...
 
float LTC3676_buck_vout_min (uint8_t buck_number)
 Calculates the minimum output voltage of any buck in mV based on the feedback resistors. More...
 
int8_t LTC3676_select_buck_reference (uint8_t i2c_address, uint8_t buck_number, int8_t ref_char)
 Selects the reference for the specified buck regulator(s). More...
 
int8_t LTC3676_set_buck_mode (uint8_t i2c_address, uint8_t buck_number, uint8_t mode)
 Sets the switching mode for the specified Buck regulator. More...
 
int8_t LTC3676_set_startup_mode (uint8_t i2c_address, uint8_t buck_number, uint8_t startup_bit)
 Sets the start-up mode for all bucks. More...
 
int8_t LTC3676_set_buck_pgood_mask (uint8_t i2c_address, uint8_t buck_number, uint8_t pgood_bit)
 Sets the PGOOD mask bit in the DVBxB register for all bucks. More...
 
int8_t LTC3676_set_uv_warning_threshold (uint8_t i2c_address, float uv_warning_threshold)
 Writes a new UV warning threshold voltage in the CTRL register. More...
 
int8_t LTC3676_set_overtemp_warning_level (uint8_t i2c_address, uint8_t ot_warning_level)
 Writes the UV warning threshold of any buck. More...
 
int8_t LTC3676_1_set_ldo4_voltage (uint8_t i2c_address, uint8_t ldo4_output_voltage_code)
 Sets LDO4 output voltage on the LTC3676-1. More...
 
int8_t LTC3676_set_buck_sequence_down (uint8_t i2c_address, uint8_t buck_number, uint8_t sequence_phase)
 Sets the Sequence Down bits for any buck in the SQD1 register. More...
 
int8_t LTC3676_set_ldo_sequence_down (uint8_t i2c_address, uint8_t ldo_number, uint8_t sequence_phase)
 Sets the Sequence Down bits for any buck in the SQD1 register. More...
 

Function Documentation

◆ LTC3676_1_set_ldo4_voltage()

int8_t LTC3676_1_set_ldo4_voltage ( uint8_t  i2c_address,
uint8_t  ldo4_output_voltage_code 
)

Sets LDO4 output voltage on the LTC3676-1.

Returns
Returns the state of the acknowledge bit after the I2C addresss write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676-1.
ldo4_output_voltage_codeVoltage code for new LDO4 output voltage: 0=1.2V, 1=2.5V, 2=2.8V, 3=3.0V

Definition at line 341 of file LTC3676.cpp.

◆ LTC3676_bit_clear()

int8_t LTC3676_bit_clear ( uint8_t  i2c_address,
uint8_t  register_address,
uint8_t  bit_number 
)

Clears any bit inside the LTC3676 using the standard I2C repeated start format.

Returns
Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
register_addressAddress of the LTC3676 register to be overwritten. This is also known as the "command byte".
bit_numberAddress of the bit to set within the register.

Definition at line 108 of file LTC3676.cpp.

◆ LTC3676_bit_is_set()

uint8_t LTC3676_bit_is_set ( uint8_t  i2c_address,
uint8_t  register_address,
uint8_t  bit_number 
)

Reads the value of any bit in any register or the LTC3676.

Returns
Returns the bit value at the passed register subaddress and bit location.
Parameters
i2c_addressI2C address of the LTC3676.
register_addressAddress of the LTC3676 register to be read. This is also known as the "command byte".
bit_numberBit location (0-7) to be read.

Definition at line 137 of file LTC3676.cpp.

◆ LTC3676_bit_set()

int8_t LTC3676_bit_set ( uint8_t  i2c_address,
uint8_t  register_address,
uint8_t  bit_number 
)

Sets any bit inside the LTC3676 using the standard I2C repeated start format.

Returns
Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
register_addressAddress of the LTC3676 register to be overwritten. This is also known as the "command byte".
bit_numberBit location (0-7) to be written.

Definition at line 95 of file LTC3676.cpp.

◆ LTC3676_bit_write()

int8_t LTC3676_bit_write ( uint8_t  i2c_address,
uint8_t  register_address,
uint8_t  bit_number,
uint8_t  bit_data 
)

Writes any bit inside the LTC3676 using the standard I2C repeated start format.

Returns
Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
register_addressAddress of the LTC3676 register to be written.
bit_numberBit location (0-7) to be written.
bit_dataBit data (0 or 1) to be written.

Definition at line 122 of file LTC3676.cpp.

◆ LTC3676_buck_vout_max()

float LTC3676_buck_vout_max ( uint8_t  buck_number)

Calculates the maximum output voltage of any buck in mV based on the feedback resistors.

Returns
Returns the maximum possible output voltage for the selected buck.
Parameters
buck_numberNumber (1-4) of buck.

Definition at line 191 of file LTC3676.cpp.

◆ LTC3676_buck_vout_min()

float LTC3676_buck_vout_min ( uint8_t  buck_number)

Calculates the minimum output voltage of any buck in mV based on the feedback resistors.

Returns
Returns the minimum possible output voltage for the selected buck.
Parameters
buck_numberNumber (1-4) of buck.

Definition at line 212 of file LTC3676.cpp.

◆ LTC3676_register_read()

int8_t LTC3676_register_read ( uint8_t  i2c_address,
uint8_t  register_address,
uint8_t *  register_data 
)

Reads an 8-bit register from the LTC3676 using the standard repeated start format.

Returns
Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
register_addressAddress of the LTC3676 register to be read. This is also known as the "command byte".
register_datareturns 8-bit value read from the LTC3676 register.

Definition at line 78 of file LTC3676.cpp.

◆ LTC3676_register_write()

int8_t LTC3676_register_write ( uint8_t  i2c_address,
uint8_t  register_address,
uint8_t  register_data 
)

Writes to an 8-bit register inside the LTC3676 using the standard I2C repeated start format.

Returns
Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
register_addressAddress of the LTC3676 register to be overwritten. This is also known as the "command byte".
register_dataValue that will be written to the register.

Definition at line 86 of file LTC3676.cpp.

◆ LTC3676_select_buck_reference()

int8_t LTC3676_select_buck_reference ( uint8_t  i2c_address,
uint8_t  buck_number,
int8_t  ref_char 
)

Selects the reference for the specified buck regulator(s).

Returns
Returns the state of the acknowledge bit after the I2C addresss write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
buck_numberNumber (1-4) of the buck whose reference will be selected. Enter 0xFF for all bucks.
ref_charReference to select (A or B).

Definition at line 233 of file LTC3676.cpp.

◆ LTC3676_set_buck_fb_ref()

float LTC3676_set_buck_fb_ref ( uint8_t  i2c_address,
uint8_t  register_address,
float  fb_ref_voltage 
)

Writes the Feedback Reference Voltage of any buck.

Returns
Returns the new Feedback Reference Input Voltage, the closest allowable voltage to the user's chosen voltage.
Parameters
i2c_addressI2C address of the LTC3676.
register_addressAddress of the LTC3676 Buck FB reference register to be written.
fb_ref_voltageNew Feedback Reference voltage to set in mV. Values between 412.5 and 800 are allowed.

Definition at line 176 of file LTC3676.cpp.

◆ LTC3676_set_buck_mode()

int8_t LTC3676_set_buck_mode ( uint8_t  i2c_address,
uint8_t  buck_number,
uint8_t  mode 
)

Sets the switching mode for the specified Buck regulator.

Returns
Returns the state of the acknowledge bit after the I2C addresss write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
buck_numberNumber (1-4) of the buck to set. Enter 0xFF for all bucks.
modeSwitching mode to be set (0=pulse skipping, 1=burst, 2=forced continuous)

Definition at line 255 of file LTC3676.cpp.

◆ LTC3676_set_buck_output_voltage()

float LTC3676_set_buck_output_voltage ( uint8_t  i2c_address,
uint8_t  register_address,
float  output_voltage 
)

Sets the output voltage of any buck.

Returns
Returns the new buck output voltage, the closest allowable voltage to the user's chosen voltage.
Parameters
i2c_addressI2C address of the LTC3676.
register_addressAddress of the LTC3676 Buck FB reference register to be written.
output_voltageNew output voltage to set, in mV. Assumes a valid voltage for the feedback resistors.

Definition at line 147 of file LTC3676.cpp.

◆ LTC3676_set_buck_pgood_mask()

int8_t LTC3676_set_buck_pgood_mask ( uint8_t  i2c_address,
uint8_t  buck_number,
uint8_t  pgood_bit 
)

Sets the PGOOD mask bit in the DVBxB register for all bucks.

Returns
Returns the state of the acknowledge bit after the I2C addresss write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
buck_numberNumber (1-4) of the buck to set.
pgood_bitData to write to PGOOD bit (0=PGOOD low when slewing, 1=PGOOD not forced low when slewing)

Definition at line 293 of file LTC3676.cpp.

◆ LTC3676_set_buck_sequence_down()

int8_t LTC3676_set_buck_sequence_down ( uint8_t  i2c_address,
uint8_t  buck_number,
uint8_t  sequence_phase 
)

Sets the Sequence Down bits for any buck in the SQD1 register.

Returns
Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
buck_numberNumber (1-4) of the buck to sequence.
sequence_phaseSequence down phase: 0=with WAKE, 1=WAKE+100ms, 2=WAKE+200ms, 3=WAKE+300ms.

Definition at line 354 of file LTC3676.cpp.

◆ LTC3676_set_ldo_sequence_down()

int8_t LTC3676_set_ldo_sequence_down ( uint8_t  i2c_address,
uint8_t  ldo_number,
uint8_t  sequence_phase 
)

Sets the Sequence Down bits for any buck in the SQD1 register.

Returns
Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
ldo_numberNumber (2-4) of the LDO to sequence.
sequence_phaseSequence down phase: 0=with WAKE, 1=WAKE+100ms, 2=WAKE+200ms, 3=WAKE+300ms.

Definition at line 368 of file LTC3676.cpp.

◆ LTC3676_set_overtemp_warning_level()

int8_t LTC3676_set_overtemp_warning_level ( uint8_t  i2c_address,
uint8_t  ot_warning_level 
)

Writes the UV warning threshold of any buck.

Returns
Returns the state of the acknowledge bit after the I2C addresss write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
ot_warning_levelNew overtemp warning level to set, degrees C below Overtemperature fault level. Values 10, 20, 30, and 40 are allowed.

Definition at line 326 of file LTC3676.cpp.

◆ LTC3676_set_startup_mode()

int8_t LTC3676_set_startup_mode ( uint8_t  i2c_address,
uint8_t  buck_number,
uint8_t  startup_bit 
)

Sets the start-up mode for all bucks.

Returns
Returns the state of the acknowledge bit after the I2C addresss write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
buck_numberNumber (1-4) of the buck to set. Enter 0xFF for all bucks.
startup_bitData to write to start-up bit (0=enable at any output, 1=enable only if output <300mV)

Definition at line 276 of file LTC3676.cpp.

◆ LTC3676_set_uv_warning_threshold()

int8_t LTC3676_set_uv_warning_threshold ( uint8_t  i2c_address,
float  uv_warning_threshold 
)

Writes a new UV warning threshold voltage in the CTRL register.

Returns
Returns the state of the acknowledge bit after the I2C addresss write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC3676.
uv_warning_thresholdNew UV warning threshold to set, in volts. Values between 2.7 and 3.4 are allowed.

Definition at line 311 of file LTC3676.cpp.