www.fairchildsemi.com
FAN1589
2.7A, 1.2V Low Dropout Linear Regulator for VRM8.5
Features
•
•
•
•
•
•
Fast transient response
Low dropout voltage at up to 2.7A
Load regulation: 0.05% typical
Trimmed current limit
On-chip thermal limiting
Standard TO-220, TO-263, TO-263 center cut and
TO-252 (DPAK) packages
Description
The FAN1589 is a low dropout three-terminal regulator with
2.7A output current capability. This device has been optimized
for V
TT
bus termination, where transient response and mini-
mum input voltage are critical. The FAN1589 offers fixed
1.2V with 2.7A current capability for a GTL+ bus V
TT
termination.
Current limit is trimmed to ensure specified output current and
controlled short-circuit current. On-chip thermal limiting pro-
vides protection against any combination of overload and
ambient temperature that would create excessive junction
temperatures.
The FAN1589 is available in the industry-standard TO-220,
TO-263, TO-263 center cut and TO-252 (DPAK) power
packages.
Applications
• A GTL+ bus supply for VRM 8.5
• Low voltage logic supply
• Post regulator for switching supply
Typical Application
FAN1589
V
OUT
V
IN
+
10µF
GND
+
V
IN
= 3.3V
1.2V at 2.7A
22µF
REV. 1.0.5 11/10/03
FAN1589
PRODUCT SPECIFICATION
Pin Assignments
FAN1589T
FRONT VIEW
FAN1589M
FRONT VIEW
Tab is OUT
Tab is OUT
1
2
3
1
2
3
GND OUT IN
3-Lead Plastic TO-263
θ
JC = 3°C/W*
GND OUT IN
3-Lead Plastic TO-220
θ
JC = 3°C/W
FAN1589MC
FRONT VIEW
FAN1589D
Tab is OUT
1
2
3
1 2 3
FRONT VIEW
Tab is OUT
GND
IN
GND OUT IN
3-Lead Plastic TO-252
θ
JC = 3°C/W*
3-Lead Plastic TO-263 Center Cut
θ
JC = 3°C/W*
*With package soldered to 0.5 square inch copper area over backside ground plane or internal power plane,
Θ
JA
can vary from
30°C/W to more than 40°C/W. Other mounting techniques can provide a thermal resistance lower than 30°C/W.
Absolute Maximum Ratings
Parameter
V
IN
Operating Junction Temperature Range
Storage Temperature Range
Lead Temperature (Soldering, 10 sec.)
0
-65
Min.
Max.
7
125
150
300
Unit
V
°
C
°
C
°
C
2
REV. 1.0.5 11/10/03
PRODUCT SPECIFICATION
FAN1589
Electrical Characteristics
Tj = 25°C unless otherwise specified.
The
•
denotes specifications which apply over the specified operating temperature range.
Parameter
Output Voltage
Line Regulation
1, 2
Load Regulation
1, 2
Dropout Voltage
Current Limit
Minimum Load Current
Quiescent Current
Ripple Rejection
Thermal Regulation
Temperature Stability
Long-Term Stability
RMS Output Noise
(% of V
OUT
)
Thermal Resistance,
Junction to Case
Thermal Shutdown
T
A
= 125
°
C, 1000 hrs.
T
A
= 25
°
C, 10Hz
≤
f
≤
10kHz
TO-220
TO-263, TO-252
Conditions
3.3V
≤
V
IN
≤
7V
10mA
≤
I
OUT
≤
2.7A
(V
OUT
+ 1.5V)
≤
V
IN
≤
7V,
I
OUT
=
10mA
(V
IN
– V
OUT
) = 3V
10mA
≤
I
OUT
≤
2.7A
∆
V
REF
= 1%, I
OUT
= 2.7A
(V
IN
– V
OUT
) = 2V
1.5V
≤
(V
IN
– V
OUT
)
≤
5.75V
V
IN
= 5V
f = 120Hz, C
OUT
= 22
µ
F Tantalum,
(V
IN
– V
OUT
) = 3V, I
OUT
= 2.7A
T
A
= 25
°
C, 30ms pulse
•
•
•
•
•
•
•
•
60
3.1
10
4
72
0.004
0.5
0.03
0.003
3
3
150
1.0
0.02
13
Min.
1.176
Typ.
1.200
0.005
0.15
1.150
4
Max
1.224
0.2
1.5
1.300
Units
V
%
%
V
A
mA
mA
dB
%/W
%
%
%
°
C/W
°
C/W
°
C
Notes:
1. See thermal regulation specifications for changes in output voltage due to heating effects. Load and line regulation are
measured at a constant junction temperature by low duty cycle pulse testing.
2. Line and load regulation are guaranteed up to the maximum power dissipation (18W). Power dissipation is determined by
input/output differential and the output currrent. Guaranteed maximum output power will not be available over the full input/
output voltage range.
REV. 1.0.5 11/10/03
3
FAN1589
PRODUCT SPECIFICATION
Typical Performance Characteristics
1.5
0.10
OUTPUT VOLTAGE DEVIATION (%)
∆I
= 2.7A
1.4
DROPOUT VOLTAGE (V)
1.3
1.2
1.1
1.0
0.9
T=25°C
0.8
0.7
0.6
0.5
0
0.5
1
1.5
2
2.5
3.0
OUTPUT CURRENT (A)
T=0°C
T=125°C
0.05
0
-0.05
-0.10
-0.15
-0.20
-75 -50 -25
0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 1. Dropout Voltage vs. Output Current
Figure 2. Load Regulation vs. Temperature
1.30
V
OUT
SET WITH 1% RESISTORS
MINIMUM LOAD CURRENT (mA)
REFERENCE VOLTAGE (V)
1.20
5
4
1.10
3
1.00
2
0.90
1
0.80
-75 -50 -25
0
25 50 75 100 125 150 175
0
-75 -50 -25
0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
JUNCTION TEMPERATURE (°C)
Figure 3. Output Voltage vs. Temperature
Figure 4. Minimum Load Current vs. Temperature
5.0
SHORT-CIRCUIT CURRENT (A)
90
80
RIPPLE REJECTIONS (dB)
4.5
70
60
50
40
30
20
10
(V
IN
– V
OUT
)
≤
3V
0.5V
≤
V
RIPPLE
≤
2V
I
OUT
= 2.7A
100
1K
FREQUENCY (Hz)
10K
100K
4.0
3.5
3.0
-75 -50 -25
0
25 50 75 100 125 150 175
0
10
JUNCTION TEMPERATURE (°C)
Figure 5. Short-Circuit Current vs. Temperature
Figure 6. Ripple Rejection vs. Frequency
4
REV. 1.0.5 11/10/03
PRODUCT SPECIFICATION
FAN1589
Typical Performance Characteristics
(continued)
20
15
10
OUTPUT CAPACITANCE ESR, (Ω)
2.5
POWER (W)
2
1.5
Area of Instability
1
5
0
50 60 70 80 90 100 110 120 130 140 150
CASE TEMPERATURE (°C)
0.5
Stable Area
0
0
1000
2000
2700
LOAD CURRENT (mA)
Figure 7. Maximum Power Dissipation
Figure 9. Stability Region
REV. 1.0.5 11/10/03
5
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