3A Bus Termination Regulator
Copyright ANPEC Electronics Corp.
Rev. A.8 - Oct., 2003
APL5331
www.anpec.com.tw1
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise
customers to obtain the latest version of relevant information to verify before placing orders.
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••
• Provide Bi-direction Current
- Sourcing or Sinking Current up to 3A
••
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• 1.25V/0.9V Output for DDR I/II Applications
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••
• Fast Transient Response
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••
• High Output Accuracy
- ±20mV over Load, VOUT Offset and
Temperature
••
••
• Adjustable Output Voltage by External Resistors
••
••
• Current-Limit Protection
••
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• On-Chip Thermal Shutdown
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••
• Shutdown for Standby or Suspend Mode
••
••
• Simple SOP-8, SOP-8-P with thermal pad,
TO-252- 5 and TO-263-5 Packages
Features General Description (Cont.)
On-chip thermal shutdown provides protection against
any combination of overload that would create excessive junction temperature. The output voltage of
APL5331 track the voltage at VREF pin. A resistor
divider connected to VIN, GND and VREF pins is
used to provide a half voltage of VIN to VREF pin. In
addition, an external ceramic capacitor and an opendrain transistor connected to VREF pin provides softstart and shutdown control respectively. Pulling and
holding the VREF to GND shuts off the output. The
output of APL5331 will be high impedance after being shut down by VREF or thermal shutdown function.
Applications
• DDR I/II SDRAM Termination
• SSTL-2/3 Termination Voltage
• Applications Requiring the Regulator with
Bi-direction 3A Current Capability
Pin Configuration
TO-252-5 (Top View)
VOUT
VREF
VCNTL
GND
VIN
12345
TAB is VCNTL
TO-263-5 (Top View)
VIN
GND
VCNTL
VREF
VOUT
1
2
3
4
5
TAB is VCNTL
SOP-8 (Top View)
1
2
3
45
6
7
8
VIN
GND
VREF
VOUT VCNTL
VCNTL
VCNTL
VCNTL
General Description
The APL5331 linear regulator is designed to provide
a regulated voltage with bi-directional output current
for DDR-SDRAM termination. The APL5331 integrates
two power transistors to source or sink current up to
3A. It also incorporate current-limit, thermal shutdown and shutdown control functions into a single
chip. Current-limit circuit limits the short-circuit
current.
1
2
3
45
6
7
8
VIN
GND
VREF
VOUT
NC
VCNTL
NC
NC
SOP-8-P (Top View)
= Thermal Pad
NC = No internal connection
(connected to GND plane for better heat
dissipation)