3A Bus Terminator Regulator
AP1127
Anachip Corp.
www.anachip.com.tw Rev.1.1 Jan 17, 2005
3/4
Electrical Characteristics
Unless otherwise stated, these specifications apply TA=25oC; VIN=+2.5V and VCCA=+3.3V, VREFEN=1.25V) maximum ratings are stress
ratings only and functional device operating is not implied. (Note 1)
Symbol Parameter Conditions Min. Typ. Max. Unit
VOS Output Offset Voltage IOUT=0A (Note 2) -20 - 20 mV
IOP Operating Current at VIN No load, COUT=200uF - - 1 mA
IL: 0A~3A - 0.8/1.2 2/3
∣∆VLOAD∣ Load Regulation (DDR I/II) IL: 0A~3A - 0.8/1.2 2/3 %
ICCQ Quiescent Current at VCCA At room temp. - 190 230 µA
ISHDN Current in Shutdown Mode REFEN < 0.2V,
RL=10Ω - 90 110 µA
VIN Input Voltage Range (Note 3) No load 1.35/1 2.5/1.8 6 V
VCCA Input Voltage Range (Note 3) R
L=10Ω 3.75 - 6 V
Short Circuit Protection
ILIMIT Current Limit - 5 - A
ISC, VIN Short Current Sinking 2 - - A
ISC, GND Short Current Sourcing 3 - - A
Over Thermal Protection
THSD Thermal Shutdown Temperature 3.75V ≤ VCCA ≤ 6V 125 150 - oC
Thermal Shutdown Hysteresis 25 30 35
oC
REFEN Function
REFEN Threshold VREFEN < VIN
VREFEN < VCCA-2.5V 0.4 0.5 0.6 V
Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions.
Note 2: VOS=VREFEN-VOUT
Note 3: Keep VCCA ≥ VIN and VCCA ≥ VREFEN + 2.5V on operation power on and power off sequences.
Note 4: Guaranteed by design, not 100% test.
Function Description
The AP1127 is a linear regulator that is capable of
sinking and sourcing 3A of current without an
external heat sink.
The AP1127 integrates power MOSFETs that are
capable of source and sink 3A of current while
maintaining excellent voltage regulation. The output
voltage can be regulated within 3% or less by using
the external feedback. Separate voltage supply
inputs have been added to fit applications with
various power supplies for the data bus and power
buses.
Outputs
The output voltage pins (VOUT) are tied to the data
bus, address, or clock lines via an external inductor.
Output voltage is determined by the VIN.
Inputs
The input voltage pins (VIN) determine the output
voltages (VOUT). At AP1127, the desired output
voltage could be programmable by two external
voltage divider resistors. VIN is suggested to connect
to VDDQ of memory module for better tracking with
memory VDDQ.
Other Supply Voltages
VCCA provide the voltage supply to the logic section
and internal error amplifiers of AP1127.