Linear Technology LTC2977 Demo Board: Octal Power Supply Manager [Requires DC1613] DC2028A DC2028A Data Sheet
Product codes
DC2028A
LTC2977
37
2977fa
TEMPERATURE RELATED COMMANDS
OT_FAULT_LIMIT, OT_WARN_LIMIT, UT_WARN_LIMIT and UT_FAULT_LIMIT
These commands provide supervising limits for temperature.
These commands provide supervising limits for temperature.
Data Contents
BIT(S) SYMBOL
OPERATION
b[15:0] Ot_fault_limit[15:0],
Ot_warn_limit[15:0],
Ut_warn_limit[15:0],
Ut_fault_limit[15:0]
Ut_warn_limit[15:0],
Ut_fault_limit[15:0]
The data uses the L11 format.
Units: °C.
Units: °C.
TIMER LIMITS
TON_DELAY, TON_RISE, TON_MAX_FAULT_LIMIT and TOFF_DELAY
These commands share the same format and provide sequencing and timer fault and warning delays in ms.
TON_DELAY sets the amount of time in milliseconds that a channel waits following the start of an ON sequence before
These commands share the same format and provide sequencing and timer fault and warning delays in ms.
TON_DELAY sets the amount of time in milliseconds that a channel waits following the start of an ON sequence before
its V
OUT_EN
pin enables a DC/DC converter. This delay is counted using SHARE_CLK only.
TON_RISE sets the amount of time in ms that elapses after the power supply has been enabled until the LTC2977’s
DAC soft-connects and servos the output voltage to the desired level if Mfr_config_dac_mode = 00b. This delay is
counted using SHARE_CLK if available, otherwise the internal oscillator is used.
TON_MAX_FAULT_LIMIT is the maximum amount of time that the power supply being controlled by the LTC2977
TON_MAX_FAULT_LIMIT is the maximum amount of time that the power supply being controlled by the LTC2977
can attempt to power up the output without reaching the VOUT_UV_FAULT_LIMIT. If the output reaches VOUT_UV_
FAULT_LIMIT prior to TON_MAX_FAULT_LIMIT, the LTC2977 unmasks the VOUT_UV_FAULT_LIMIT threshold. If it
does not, then a TON_MAX_FAULT is declared. (Note that a value of zero means there is no limit to how long the power
supply can attempt to bring up its output voltage.) This delay is counted using SHARE_CLK if available, otherwise the
internal oscillator is used.
TOFF_DELAY is the amount of time that elapses after the CONTROLn pin and/or OPERATION command is deasserted
TOFF_DELAY is the amount of time that elapses after the CONTROLn pin and/or OPERATION command is deasserted
until the channel is disabled (soft-off). This delay is counted using SHARE_CLK if available, otherwise the internal
oscillator is used.
TON_DELAY and TOFF_DELAY are internally limited to 13.1 seconds, and rounded to the nearest 10µs when smaller
TON_DELAY and TOFF_DELAY are internally limited to 13.1 seconds, and rounded to the nearest 10µs when smaller
than 655ms, or rounded to the nearest 200µs when larger than 655ms. TON_RISE and TON_MAX_FAULT_LIMIT are
internally limited to 655ms, and rounded to the nearest 10µs. The read value of these commands always returns what
was last written and does not reflect internal limiting.
Data Contents
BIT(S) SYMBOL
OPERATION
b[15:0] Ton_delay[15:0],
Ton_rise[15:0],
Ton_max_fault[15:0],
Toff_delay[15:0]
Ton_max_fault[15:0],
Toff_delay[15:0]
The data uses the L11 format.
Units: ms.
Units: ms.
pMbus coMManD DescripTion