RT5035A/B
RTC time read/write method :
When reading RTC time via I2C interface, suggest read 6 bytes (address A11 to A16) together and finish reading
within 0.5 second to avoid the second carry issue. A16.RTCT_SEC[0] can be used for checking whether second is
carried during reading time. When writing RTC time via I2C interface, suggest to write 6 bytes (address A11 to A16)
together. A11 is first and then A12, A13, A14, A15, A16. Suggest finishing writing within 0.5 second to avoid second
carry issue during writing.
Output Voltage Ramp Rate
For instance, CH3 VCORE output voltage ramp up rate = 1.5 x 0.8V / 4ms = 0.3V/ms. The ramp up/down rate is kept
the same for enabling soft-start or dynamic output voltage adjustment.
Each channel has different ramp rate as listed below.
1.3V
Ramp rate =
1.5 x 0.8V/4ms
1.1V
Ramp rate = 1.5 x
0.8V/4ms
0V
0.7ms
3.7ms
Note :
About Dynamic Voltage Scaling, CH1, CH3, CH4, CH8, CH10 output voltage can be changed without inrush and
Vout ramping control when they have been turned on (said, dynamically change Vout). CH2, CH5, CH6 are not.
Synchronization and Spread Spectrum
If SYNC remains logic high or low, the spread spectrum clock will act the main clock for PWM. And, spread spectrum
function can be turned off by register A15.SS.
If the toggling clock of SYNC is detected, the PLL clock will act the main clock for PWM and the clock of PLL will
track its frequency. And the division ratio is decided by A15.SYN_DIV.
Furthermore, according to the logic high and low level threshold voltage, both 1.8V and 3V logic are compatible. If it
isn't used, the SYNC pin must be connected to GND.
VDDM
SYNC
ASIC
CLK
Spread Spectrum
Clock Generator
Detection
0
1
Clock for PWM
synchronization
A15.SS
The output interface
of ASIC : Push-Pull
is preferred.
DIV
A15.SYN_DIV
PLL
If the clock of SYNC is 12MHz, VDDM is not recommended as pull-up power voltage. Other power domains can be
used if they fit the logic high and logic low threshold voltage.
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is a registered trademark of Richtek Technology Corporation.
DS5035A/B-03 February 2020
www.richtek.com
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