MAX15569 Datasheet, PDF (26/41 Pages) Maxim Integrated Products – 2-Phase/1-Phase QuickTune-PWM Controller with Serial I2C Interface

MAX15569
2-Phase/1-Phase QuickTune-PWM Controller with
Serial I²C Interface
tEN ≥ = 0ns
VBIAS
VTT
ENABLE
INT
VOUT
tCAL
tSS
tSTRT
tSS
Figure 7. Startup Sequence
Alarms
Temperature Comparator (VRHOT)
The device features an independent comparator with
input at THERM. This comparator has an accurate thresh-
old of 0.5 x V_BIAS. Use a 100kΩ NTC with a β of 4250K.
The NTC resistance drops to 5.68kΩ when the tempera-
ture reaches +100°C. The NTC forms a divider with the
internal 5.35kΩ pullup resistance, so the voltage drops
below the 0.5 x V_BIAS threshold. VRHOT is then asserted.
The internal 5.35kΩ resistor is disconnected in shutdown,
saving power.
Overcurrent Warning (OC)
The device includes an overcurrent-warning threshold
that samples the phase 1 current-sense signal before
each phase 1 on-time. When the CSP1 - CSN1 voltage
exceeds the 23mV (typ) threshold, the status bit (D2) in
register 0x04h) is asserted. If the warning is not masked,
the controller asserts the INT output to alert the system to
the overcurrent condition.
The fixed 23mV OC_ALARM threshold is 15mV
lower than the valley current-limit threshold to provide
sufficient design margin before the regulator limits the output
current. Additionally, the controller includes a IMON
register that can be monitored by the system.
Output-Code Violation (VOUTMAX)
The controller includes a maximum output register
(VOUTMAX register 0x02h) to protect against target
output voltage codes that could violate the absolute maxi-
mum rating of the load. The value of this configuration
register limits the output range. If a target output voltage
is loaded into register 0x07h, the regulator sets the appro-
priate status bit. If the warning is not masked, the control-
ler asserts the INT output to alert the system to the over-
current condition. The output voltage attempts to ramp to
the new target, but the regulator effectively clamps the
output to the VOUTMAX voltage to avoid an overvoltage
condition. See the I²C Commands and Registers section
for additional details.
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