MAX1999EEI+T Maxim Integrated Products, MAX1999EEI+T Datasheet - Page 12

• Manufacturer Part Number: MAX1999EEI+T
• Description: IC CNTRLR PS QUAD HI EFF 28QSOP
• Manufacturer: Maxim Integrated Products
• Type: Step-Down (Buck)r

Specifications of MAX1999EEI+T

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 4
• Voltage - Output: 3.3V, 5V, 2 ~ 5.5 V
• Current - Output: 10A
• Frequency - Switching: 200kHz, 300kHz, 400kHz, 550kHz
• Voltage - Input: 6 ~ 24 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-QSOP
• Power - Output: 860mW
• Output Voltage: 3.3 V, 2 V to 5.5 V
• Input Voltage: 6 V to 24 V
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

High-Efficiency, Quad Output, Main Power-
Supply Controllers for Notebook Computers
12
MAX1777
MAX1977
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PIN
MAX1999
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5
6
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PGOOD
NAME
SHDN
ILIM3
ILIM5
SKIP
N.C.
ON3
ON5
PRO
CS3
FB3
REF
FB5
3.3V SMPS Current-Sense Input. Connect CS3 to a current-sensing resistor from the source of
the synchronous rectifier to GND. The voltage at ILIM3 determines the current-limit threshold
(see the Current-Limit (ILIM) Circuit section).
No Connection. Not internally connected.
Power-Good Output. PGOOD is an open-drain output that is pulled low if either output is
disabled or is more than 10% below its nominal value.
3.3V SMPS Enable Input. The 3.3V SMPS is enabled if ON3 is greater than the SMPS on level
and disabled if ON3 is less than the SMPS off level. If ON3 is connected to REF, the 3.3V
SMPS starts after the 5V SMPS reaches regulation (delay start). Drive ON3 below the clear
fault level to reset the fault latches.
5V SMPS Enable Input. The 5V SMPS is enabled if ON5 is greater than the SMPS on level and
disabled if ON5 is less than the SMPS off level. If ON5 is connected to REF, the 5V SMPS
starts after the 3.3V SMPS reaches regulation (delay start). Drive ON5 below the clear fault
level to reset the fault latches.
3.3V SMPS Current-Limit Adjustment. The GND-LX current-limit threshold defaults to 100mV if
ILIM3 is tied to V
at ILIM3 over a 0.5V to 3V range. The logic threshold for switchover to the 100mV default value
is approximately V
Shutdown Control Input. The device enters its 6µA supply current shutdown mode if
V
greater than the SHDN input rising edge trip level. Connect SHDN to V+ for automatic startup.
SHDN can be connected to V+ through a resistive voltage-divider to implement a
programmable undervoltage lockout.
3.3V SMPS Feedback Input. Connect FB3 to GND for fixed 3.3V operation. Connect FB3 to a
resistive voltage-divider from OUT3 to GND to adjust the output from 2V to 5.5V.
2V Reference Output. Bypass to GND with a 0.22µF (min) capacitor. REF can source up to
100µA for external loads. Loading REF degrades FB_ and output accuracy according to the
REF load-regulation error.
5V SMPS Feedback Input. Connect FB5 to GND for fixed 5V operation. Connect FB5 to a
resistive voltage-divider from OUT5 to GND to adjust the output from 2V to 5.5V.
Overvoltage and Undervoltage Fault Protection Enable/Disable. Connect PRO to V
disable undervoltage and overvoltage protection. Connect PRO to GND to enable
undervoltage and overvoltage protection (see the Fault Protection section).
5V SMPS Current-Limit Adjustment. The GND-LX current-limit threshold defaults to 100mV if
ILIM5 is tied to V
at ILIM5 over a 0.5V to 3V range. The logic threshold for switchover to the 100mV default value
is approximately V
Low-Noise Mode Control. Connect SKIP to GND for normal idle-mode (pulse-skipping)
operation or to V
ultrasonic mode (pulse skipping, 25kHz minimum).
SHDN
is less than the SHDN input falling edge trip level and does not restart until V
CC
CC
CC
CC
CC
. In adjustable mode, the current-limit threshold is 1/10th the voltage seen
. In adjustable mode, the current-limit threshold is 1/10th the voltage seen
for PWM mode (fixed frequency). Connect to REF or leave floating for
- 1V. Connect ILIM3 to REF for a fixed 200mV threshold.
- 1V. Connect ILIM5 to REF for a fixed 200mV threshold.
FUNCTION
Pin Description
CC
SHDN
to
is