AP1184 ANACHIP [Anachip Corp], AP1184 Datasheet - Page 4

• Manufacturer Part Number: AP1184
• Description: 4A Ultra Low Dropout Positive Adjustable or Fixed-mode Regulator
• Manufacturer: ANACHIP [Anachip Corp]

4A Ultra Low Dropout Positive Adjustable or Fixed-mode Regulator
Unless otherwise specified, these specifications apply over, Cin=1uF, Cout=10uF, and Tj=0 to 150
Vout=Vsense.
NOTE:
AP1184-ADJ incorporates an internal thermal shutdown that protects the device when the junction temperature exceeds the allowable
maximum junction temperature.
TO263/TO220
SOP7
Introduction
The AP1184 regulator is 5 terminal device designed
specifically to provide extremely low dropout
voltages comparable to the PNP type without the
disadvantage of the extra power dissipation due to
the base current associated with PNP regulators.
This is done by bringing out the control pin of the
regulator that provides the base current to the
power NPN and connecting it to a voltage that is
greater than the voltage present at the Vin pin. This
flexibility makes the AP1184 ideal for applications
where dual inputs are available such as a computer
motherboard with an ATX style power supply that
provides 5V and 3.3V to the board. One such
application is the new graphic chip sets that require
anywhere from 2.4V to 2.7V supply. The AP1184
can easily be programmed with the addition of two
external resistors to any voltages within the range
of 1.25V to 15.5V. Another major requirement of
these graphic chips is the need to switch the load
Anachip Corp.
www.anachip.com.tw
Sym.
θ
Iadj
JC
Package
Functional Descriptions
Electrical Characteristics(Continued)
Thermal Regulation 30mS Pulse
Ripple Rejection
Control Pin Current
Adjust Pin Current
Thermal Resistance
Junction-to-Case
Parameter
2.4W~4.4W
1W~2W
Max Pd.
V
120Hz
Vadj=0V for all conditions below.
V
V
Vctrl=2.75V, Vin=2.05V, Io=4A
Vctrl=2.75V, Vin=2.05,Vadj=0
TO-263: Control Circuitry/Power Transistor
TO-220: Control Circuitry/Power Transistor
SOP-7: Control Circuitry/Power Transistor
ctrl
ctrl
ctrl
=5V, Vin=5V, Io=4A, Vadj=0V, Tj=25, Vripple=1Vpp at
=2.75V, Vin=2.05V, Io=1.5A
=2.75V, Vin=2.05V, Io=3A
With heat sink or amount of copper board needed.
With heat sink or amount of copper board needed.
Test Condition
4/11
current from zero to several amps in tens of
nanoseconds
translates to an approximately 300 to 500ns of
current step at the regulator. In addition, the output
voltage tolerances are also extremely tight and they
include the transient response as part of the
specification.
The AP1184 is specifically designed to meet the
fast current transient needs as well as providing an
accurate initial voltage, reducing the overall system
cost with the need for fewer number of output
capacitors. Another feature of the device is its true
remote sensing capability that allows accurate
voltage setting at the load rather than at the device.
Output Voltage Setting
The AP1184-ADJ can be programmed to any
voltages in the range of 1.25V to 15.5V with the
addition of R1 and R2 external resistors according
to the following formula:
Remarks
at
the
o
C. Typical value refer to Tj=25
processor
Min. Typ.
60
0.01
3.5
2.5
70
30
33
50
20
Rev.1.1 Sep 7, 2004
AP1184
6
pins,
Max. Unit
0.02
150
25
60
70
which
O
O
O
%/W
mA
C/W
C/W
C/W
dB
µA
o
C.