Source and Sink, 2A, Fast Transient Response Linear Regulator
Features
General Description
• Provide Bi-direction Current
Sourcing or Sinking Current Up to 2A
• Built-in Soft-Start
• Power-On-Reset Monitoring on VCNTL Pins
• Fast Transient Response
• Stable with Ceramic Output Capacitors
• ±10mV High System Output Accuracy Over Load
and Temperature Ranges
• Adjustable Output Voltage by External Resistors
• Current-Limit Protection
• On-Chip Thermal Shutdown
• Shutdown for Standby or Suspend Mode
• Simple SOP-8 and SOP-8 with Exposed Pad
(SOP-8P) Packages
• Lead Free and Green Devices Available
(RoHS Compliant)
Applications
• DDRII/III SDRAM Termination Voltage
• Motherboard and VGA Card Power Supplies
• Setop Box
• Low Power DDR3
The APL5337 linear regulator is designed to provide a
regulated voltage with bi-direction output current for DDR-
SDRAM termination voltage. The APL5337 integrates two
power transistors to source or sink load current up to 2A.
It also features internal soft-start, current-limit, thermal
shutdown and enable control functions into a single chip.
The internal soft-start controls the rising rate of the output
voltage to prevent inrush current during start-up. The
current-limit circuit detects the output current and limits
the current during short-circuit or current overload
conditions. The on-chip thermal shutdown provides ther-
mal protection against any combination of overload that
would create excessive junction temperatures.
The output voltage of APL5337 is regulated to track the
voltage on VREF pin. A proper resistor divider connected
to VIN, GND, and VREF pins is used to provide a half
voltage of VIN to VREF pin. In addition, connect an exter-
nal ceramic capacitor and an open-drain transistor to VREF
pin for external soft-start and shutdown control.
Pulling and holding the voltage on VREF below the en-
able voltage threshold shuts down the output. The output
of APL5337 will be high impedance after being shut down